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[email protected] 4/2013 The effectiveness of modern technologies of secondary opening of productive horizons and the ways of its improvement Hoshovskyi S.V., Voitenko Yu.I., Sorokin P.O. About the concept of underground gas storage in Ukraine Storchak S.O., Zayets V.O., Savkiv B.P.

Gas turbine exhaust-gas heat utilization of main gas pipeline gas-compressor units Redko A.O., Redko O.F., Kompan A.I.

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XI International Forum Fuel and Energy Sector of Ukraine: Today and Tomorrow

XI International Forum Fuel and Energy Sector of Ukraine: Today and Tomorrow was held from 24 to 26 of September 2013 at the International Exhibition Center (Kyiv) under the auspices of the Cabinet of Ministers of Ukraine and the Committee of Fuel and Energy Sector, Nuclear Policy and Nuclear Safety of Verkhovna Rada of Ukraine. It was organized by the Ministry of Energy and Coal Industry of Ukraine, and by the administration of the International Exhibition Centre.

This Forum is the unique opportunity to communicate with the heads of the relevant ministries and institutions, top managers of state energy companies , directors of different enterprises active in the energy and power industry, leading experts, professional experts and analysts, strategic investors and financiers, directors of industrial enterprises of different branches,

and experts of engineering, design, research and construction companies.

The main purpose of the event:

facilitation of the implementation of the Energy Strategy of Ukraine till 2030 to ensure the safe and efficient operation of the power system of the country , as well as energy independence and security of the country;

demonstration of achievements in the fuel and energy sector , aimed at modernization of the energy infrastructure and its technological , organizational, legal and scientific development;

creating an effective platform for the annual meeting of the Energy Community , the implementation of new projects, learning about global trends and prospects of energy sector, and fruitful dialogue between business and government.

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Oil and Gas Industry of Ukraine

Scientific and production magazine. Published once in 2 months

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Ivano-Frankivsk National Technical University of Oil and Gas

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E. M. Bakulin

4/2013

(4) July – September

Index 74332

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Recommended for publishing by the Scientific and Technical Board of Naftogaz of Ukraine National joint-stock company



CONTENTS OIL AND GAS GEOLOGY PROKOPIV V.Y., PITONIA V.A., PRYDACHYNA O.M.

Express method for determining of residual oil zones at a late stage of field development............................................................................ 3 WELL DRILLING KUSTUROVA O.V., SHEVCHENKO R.O., ZHUHAN O.A., LIAMENKOV S.V.

Lubricating additives in drilling and methods of their research..................................................................................................................................7 KUNTSIAK Ya.V., LUBAN Yu.V., LUBAN S.V., KULYK Ya.I. Concerning the issue of mudding permeable beds when using clayless drilling fluids ............................................................................................. 10

OIL AND GAS PRODUCTION MYSLIUK M.A., PETRUNIAK V.Ya. Concerning the use of statistical estimates of productive bed parameters using pressure recovery curves...............................................................15 RUDYI S.M., KACHMAR Yu.D., RUDYI M.I. Interaction of silicate rocks with acid-cut clay muds under pt conditions in the reservoir. Part 2. The mechanism of formation component dissolution ................................................................................................................................................ 19 HOSHOVSKYI S.V., VOITENKO Yu.I., SOROKIN P.O. Ef ectiveness of the state-of-the-art technologies of secondary penetration of productive horizons and ways to improve it ....................................25 OIL AND GAS TRANSPORTATION AND STORAGE STORCHAK S.O., ZAYETS V.O., SAVKIV B.P. About the concept of underground gas storage in Ukraine ....................................................................................................................................... 28 BILOBRAN B.S., DZIUBYK A.R., YANOVSKYI S.R. Inf uence of the installation elastic bending on the stress-strain state of the pipeline aboveground passages in the mountains ................................................................................................................................................................... 30 PRYTULA N.M., HRYNIV O.D., VECHERIK R.L., BOIKO R.V. Replacement of buf er gas by nitrogen in gas storage reservoirs (models, methods, numerical experiments) ..........................................................34 DATSIUK A.V., OSINCHUK Z.P. Underground gas storage facilities as an important factor of providing consumers in Ukraine with gas in emergency situations .........................42 UNCONVENTIONAL TECHNOLOGIES AND ENERGY EFFICIENCY REDKO A.O., REDKO O.F., KOMPAN A.I. Gas turbine exhaust-gas heat utilization of main gas pipeline gas-compressor units .............................................................................................. 45 AT THE BRANCH ENTERPRISES SHVYDKYI O.A., DOVZHOK T.Ye., HRYSHANENKO V.P., KHOMYK P.M. SE «Naukanaftogaz»: 10 years path from regional research to discovery of oil and gas f elds................................................................................49

INDUSTRY EXPERTS Skliar V.T. . ................................................................................................................................................................................................................ 41 Information .................................................................................................................................................... ....................................................... 9, 24

ISSN 0548–1414. Oil & Gas Industry of Ukraine. 2013. No. 4

Oil & Gas Industry of Ukraine Editor-in-chief

Ievhen Mykolayovych Bakulin - Chairman of the National Joint Stock Company "Naftogaz of Ukraine"

Deputy chief editors

Vadim Prokopovych Chuprun - Deputy Chairman of the National Joint Stock Company "Naftogaz of Ukraine"

Ievstakhiy Ivanovych Kryzhanivskyy - Doctor of Engineering Sciences, professor, corresponding member of The National Academy of Sciences of Ukraine, the Rector of Ivano-Frankivsk National Technical University of Oil and Gas

Editorial board

Oleg Maksimovych Adamenko - Doctor of Geologo-Mineralogical Sciences

Yurii Volodymyrovych Banakhevych - Doctor of Engineering Sciences

Serhii Valeriyovych Bojchenko - Doctor of Engineering Sciences

Mykhailo Mykhailovych Bratychak - Doctor of Chemical Sciences

Frants Frantsovych Butynets - Doctor of Economic Sciences

Hennadiy Borysovych Varlamov - Doctor of Engineering Sciences

Volodymyr Mykhailovych Vasyliuk - Candidate of Engineering Sciences

Yurii Oleksandrovych Venhertsev - Doctor of Philosophical Sciences, Candidate of Engineering Sciences

Serhiy Andriiovych Vyzhva - Doctor of Geological Sciences

Yaroslav Stepanovych Vytvytskyi - Doctor of Economic Sciences

Mykhailo Davydovych Hinzburh - Doctor of Engineering Sciences

Vasyl Vasylovych Hladun - Doctor of Geological Sciences

Petro Fedosiiovych Hozhyk - Doctor of Geological Sciences, member of The National Academy of Sciences of Ukraine

Liliana Tarasivna Horal - Doctor of Economic Sciences

Oleksandr Ivanovych Hrytsenko - Doctor of Engineering Sciences, corresponding member of Russian Academy of Sciences

Volodymyr Yaroslavovych Hrudz - Doctor of Engineering Sciences, professor

Mykola Oleksiiovych Danyliuk - Doctor of Economic Sciences

Tetiana Yevhenivna Dovzhok - Candidate of Geological Sciences

Volodymyr Mykhailovych Doroshenko - Doctor of Engineering Sciences

Oksana Teodorivna Drahanchuk - Doctor of Engineering Sciences

Dmytro Oleksandrovych Yeher - Doctor of Engineering Sciences, corresponding member of The National Academy of Sciences of Ukraine

Yurii Oleksandrovych Zarubin - Doctor of Engineering Sciences

Oleksandr Yuriiovych Zeikan - Candidate of Geological Sciences

Ihor Mykolaiovych Karp - Doctor of Engineering Sciences, member of The National Academy of Sciences of Ukraine

Oleh Mykhailovych Karpash - Doctor of Engineering Sciences

Oleksii Mykolaiovych Karpenko - Doctor of Geological Sciences

Ihor Stepanovych Kisil - Doctor of Engineering Sciences

Volodymyr Pavlovych Kobolev - Doctor of Geological Sciences

Yurii Petrovych Kolbushkin - Doctor of Economic Sciences

Roman Mykhailovych Kondrat - Doctor of Engineering Sciences

Mykhailo Dmytrovych Krasnozhon - Doctor of Geological Sciences

Ihor Mykolaiovych Kurovets - Candidate of Geologo-Mineralogical Sciences

Mykola Volodymyrovych Lihotskyi - Candidate of Engineering Sciences

Oleksandr Yukhymovych Lukin - Doctor of Geologo-Mineralogical Sciences, member of The National Academy of Sciences of Ukraine

Borys Yosypovych Maievskyi - Doctor of Geologo-Mineralogical Sciences

Yurii Fedorovych Makohon - Doctor of Engineering Sciences (University of Texas, USA)

Mykhailo Ivanovych Machuzhak - Candidate of Geologo-Mineralogical Sciences

Oleksandr Oleksandrovych Orlov - Doctor of Geologo-Mineralogical Sciences

Zynovii Petrovych Osinchuk - Candidate of Engineering Sciences

Myroslav Ivanovych Pavliuk - Doctor of Geologo-Mineralogical Sciences, corresponding member of The National Academy of Sciences of Ukraine

Viktor Pavlovych Petrenko - Doctor of Economic Sciences

Oleksandr Pavlovych Petrovskyi - Doctor of Geological Sciences

Viktor Mykhailovych Svitlytskyi - Doctor of Engineering Sciences

Mariia Dmytrivna Serediuk - Doctor of Engineering Sciences

Orest Yevhenovych Serediuk - Doctor of Engineering Sciences

Vitalii Ivanovych Starostenko - Doctor of Physico-mathematical Sciences,member of The National Academy of Sciences of Ukraine

Serhii Oleksandrovych Storchak - Doctor of Engineering Sciences

Leonid Mykhailovych Unihovskyi - Doctor of Engineering Sciences

Dmytro Dmytrovych Fedoryshyn - Doctor of Geological Sciences

Illia Mykhailovych Fyk - Doctor of Engineering Sciences

Pavlo Mykolaiovych Khomyk

Ihor Ivanovych Chudyk - Doctor of Engineering Sciences

Anatolii Petrovych Chukhlib - Candidate of Economic Sciences

Eduard Anatoliiovych Shvydkyi - Candidate of Economic Sciences

Oleh Anatoliiovych Shvydkyi - Director of "Naukanaftogaz"

Anatolii Stepanovych Shevchuk - Candidate of Engineering Sciences

Contributors to this issue

Management of Science and Technology Policy

National Joint Stock Company "Naftogaz of Ukraine" Department of the publication organization of scientific and practical journal

Head of Department

T.P. Umuschenko

Editor N.H. Vorona

Delivered on 13.10.2013. Published: 21/11/2013 Format 205 × 285. Paper coated. Offset printing.

OIL AND GAS GEOLOGY Express method for determining of residual oil zones at a late stage of field development UDC 622.276.344

V.Y. Prokopiv Candidate of Geological Sciences

V.A. Pitonia O.M. Prydachyna PJSC «UKRNAFTA»

Presents the method of rapid analysis to identify wild (or little produced) zones of oil deposits at a late stage of development. The method was tested on the example of horizon P-1+2 Gnidyntsi field.

The most of oil fields of PJSC "Ukrnafta" are at the late or final development stage. The deposits are characterized by high water product content. The average water content in most of them is 83-88%.

The main effective method of oil field development of PJSC "Ukrnafta" is the process of maintaining reservoir pressure (MRP) by flooding, which is widely used for a long time in order to provide for high levels of oil production. In the process of oil displacement by stratal and injection water field zones are left that are not covered by drainage. It is important to identify these areas to maximize the production of inventories.

Methods for hydrodynamic modeling of field development are widely used in the world. They allow creation of a detailed hydrodynamic model based on the majority of the factors affecting the development process. This makes it possible to use all source material that accumulates in the oil field as a result of docume8nting the development state of wells and deposits in general.

For most of the fields of "Ukrnafta" PJSC, which are at the late stage and have a long history of development, hydrodynamic modeling leads to great time and labor costs and complicates the process of making operational decisions.

It is necessary to create more simplified methods, the so-called "express methods", in order to perform operational tasks. For example, quick clarification of the the location of the project wells or determination of the appropriateness of the well transfer from other horizons. The availability of objective but integral well indicators complicates to complete the task quickly.

So. in order to address the above challenges the authors proposed an express method for the determination of residual oil zones in late or final stages of development based on limited initial data of integral type.

Initial data for the express method is accumulated samples of oil, water and fluid from the extraction wells, and (with availability of MRP) accumulated water pumping from injection wells. Equally important is the availability of information about the contour performance of the horizon, its effective oil-saturated and total thickness.

The method involves the developmen2t of a base map according to data of accumulated oil, water, liquid and water pumping from wells.

Subsequently, the input data are adjusted to the thickness of the reservoir by mathematical transformations to exclude the impact of oil-saturated thickness variable of the oil reservoir and resulted in values of bulk planar characteristics.

Fig. 1. Maps of accumulated selections: a - oil, - a liquid

Fig. 2. Maps of planar distribution: a - water injection on the horizon; b - water content horizon

When you create maps of the detailed distribution of geological information in the hydrocarbon field, there is a challenge in spreading of horizon research parameters that are identified in wells throughout the area. Accordingly, the amount of output data is limited, that is why one of the key factors in the process of distribution on the development object is an evaluation of the data distribution uniformity and the choice of this method for data processing in which the visualization accuracy of the initial information would be the best. The task is to examine the homogeneity and density of parameter distribution and logical connection between them. The most reliable results are obtained in the course of solving complex tasks [1, 2].

At the first stage a map of the primary parameter distribution by area is developed. At the second stage math operations are used both for base maps and maps with data from wells..

A wide range of algorithms of data interpolation and extrapolation can be used for developing regular grids, but not everyone is suitable for solving the problem. For example, developing a grid by an algorithm of thin membrane makes it possible to simulate the curvature of the reservoir and to detect in the areas of greatest curvature fracture zones and (with achieving the critical values of geomechanical stresses) tectonic faults. These developments are much more

accurately reproduce the spatial configuration of thin layers of a geological model than statistically deterministic algorithms of Kriging method that are usually used.

One of the key factors in the process of developing the model is geologically meaningful and differentiated distribution of parameters for the area.

A modified Shepard's method [3, 4] was used for a base grid development, which is similar to the method of inverse distance to a power. It also uses inverse distance for the calculation of weighting coefficients, by which the weighted value of the experimental data points of disclosure wells are solved. The difference is that during the developing of the interpolation function in the local area the method of least squares is used. This eliminates the appearance of the generated artifacts on the surface such as "bull's eye".

Radius of influence should be large enough to combine wells in the area with mode of sustainable extraction, but also small enough, so that one zone does not affect the other zones. Therefore, the Shepard's method allows during mapping to specify both a radial and local radii of influence.

For example, horizon P-1+2 of Hnidyntsivskuy field is selected for conducting of express method to assess the distribution of residual oil.

Horizon P-1+2 is a lithologic and stratigraphic trap , which is stretched at the plan in the form of a crescent from north to south. Its total thickness varies from zero in the western part of the accumulation up to 70 meters in the east. Horizon is represented by the sandstones, which are intercalated with clay layer and aleurolites.

The peculiarity of the geological structure of the object is to have a lithologic blowout of reservoirs in the western of the vault structure, which greatly complicates the inventory extraction in these areas as a result of deterioration of reservoir properties and significantly reduce its oil-saturated thickness (2-6 m).

The productive part of the horizon P-1+2 is limited by initial oil-bearing contour line and the line of lithologic blowout of reservoirs. Oil-water area is very wide and covers almost one third of deposit.

The development of horizon occurs during the displacement of oil by water from oil-bearing contour line to the line of blowout of productive layers. This pattern of displacement of oil by water creates favorable conditions for the formation of deadlock poorly drained areas between the lines of blowout and the first row of extraction wells. In these areas considerable residual oil are concentrated.

Fig. 3. Maps of planar distribution: a - moving fluid volumes, b - accumulated oil, displaced by water

Fig. 4. Maps of planar distribution: a - compensation of selections by blowing; b - residual oil saturation

MRP was performed on the horizon by water injection (1974-2001). In total the horizon P-1+2 developed 57 extraction and 10 injection wells. Reservoir is located at the final stages of development.

The maps of accumulated samples of oil, water and fluids in wells are developed by the initial information. The basic map of accumulated pumping water in wells is developed by the data of water injection.

The same radial radius was chosen for all basic maps - 3,000 m, and the local radii were chosen depending on the goal in front of us. For example, for the map of accumulated oil and liquids it is 100 m (Fig.1, a and b).

The map of pumping water and water content of the horizon (Fig. 2 a and b) was developed with radii of 80 m. The ellipse of anisotropy should be oriented by the fall of the reservoir or from a group of injection wells up to the extraction group.

Screening dislocations were digitalized to create borders of regions on the maps of the zone of lithologic blowout and parameter values on the border are taken equal to 0. An external contour of performance was similarly digitalized, which depending on the tasks that were solved, was given a value of 0 or 100 %.

All further maps were developed as a combination of the above mentioned basic maps and adjusted to the effective thickness:

a map of motive fluid (Fig. 3a) was calculated as the sum of the values of the map of accumulated water injection and maps of accumulated fluid selections;

a map of accumulated oil which is displaced by water (Fig. 3b) was calculated as the product of two grids of the accumulated oil and water content;

a map of selection compensation by water injection was defined as the proportion of values of accumulated injection maps to the values of map of accumulated fluid selections specified in percentage (Fig. 4a);

a map of residual oil saturation was defined as the unit difference and part of the oil amount that is displaced by water, accumulated selections of oil and is specified in percentage (Fig. 4b).

Two seals of grid were carried out by drilling new wells and well transfer from other horizons on the horizon P-1+2. In the period 2011-2012 wells No.216, 217, 218, 222 were put into drilling, and well No.206 was transferred from other horizons. The withdrawal values of oil, water and liquids in new wells were not taken into account during developing of the primary maps of the parameter distribution.

The location and operation of new wells were analyzed in relation to certain areas of residual oil by express methods.

The well No.206 began to operate with an initial flow of oil 55.3 tons per day, watering products was 11.4 %. Current oil flow was 17.6 tons per day, water content is 77 %. At the map of residual oil saturation (Fig. 4b) the well is located in the zone with saturation of 38% in the area of washed zone (wells No. 58, 98, 86, 47), indicating that in the short term work (several months) production watering increases significantly.

The well No.216 was kicked off at the horizon with initial flow of 18 tons per day of oil and water content production 1.2%. At end of the year oil production was up to 15.6 tons per day, water content was 0.7 %. On the Figure 2b the well is located in the zone of low water content, at the map of accumulated extraction oil which was superseded by water (see Fig. 3b), in the area of small water displacement. At the map of motion fluid volumes (see Fig. 3a) the well is located on the border of intensive fluid flows and fluid that remains in a static state. Perhaps, it still drains a fixed fluid. On the Fig. 4b the well is located in the area of residual oil saturation 63%. More than half of the oil in the drained area remains in the reservoir.

The well No.217 began to develop horizon with the initial oil flow rate of 4.7 tons per day, and water content products of 1.6%. On the map of residual oil saturation the well is located in the zone with saturation of 32% (Fig. 4b) and can drain the area at the side lines of blowout, where the oil reserves with an initial saturation are concentrated.

The well No.218 was kicked off with an initial oil flow of 8.2 tons of oil per day, and water content of 94.3 %. According to the Fig. 2b, the well is located in the zone of high water content (80%), as evidenced by its actual value. At the map of accumulated oil withdrawal that is displaced by water (see Fig. 3b), the well is located in the flooded area, and well No.185 is located near well No.218, which is on the path of the Water motion of well No.185 (Fig. 2b).

On the Fig. 4b the well is located in an zone of low oil saturation (10%), which corresponds to the well with water content products.

The well No.222 was kicked off with an initial flow of oil of 17.3 tons per day, and watering products of 0.8%. Considering the small thickness of the reservoir (2 meters), the well is successful among the control group. The actual water content corresponds to the zone of minimum water content (Fig. 2b).

On the Fig. 4 it is seen that the well is in the zone outside the area of increased water motion (near wells No.60-58), where the paths of water breakthrough are predicted. On the map of residual oil saturation (see Fig. 4b) the well is located in the zone with the value of 78 %, where from the line of the blowout oil reserves with initial saturation are concentrated.

On the maps of horizon water content, volumes of motive fluid and residual oil saturation the areas of increased of high water content are detected that are connected to the outer contour area and an area of intense pumping water and evaluated as a possible paths of water migration.

It may be concluded on the carried out analysis based on the developed method of construction and calculation of the above maps that the most permeable horizon areas are concentrated in the vaults of the structure. The deterioration of reservoir properties were observed in the north and south terminal structures. Areas of increased water motion correlate to the zones of fracturing in the area of distribution by geomorphological data of possible tectonic disturbances. The residual oil reserves are concentrated near the zone of lithologic blowout of reservoirs (through wells No.29-222-21) and the north-western part of the deposit (near wells No.17-90-49). In this triangle there are is minimum volume of motive fluid.

According to the developed maps of water content of the horizon it can be assumed that wells No.17, 211, 49, 8, 36 are located at the north of screening faults along the south side of which formed the "tongue" of water contour breakthrough.

Developed predictive maps are well supported by the work of new wells. The maps of residual oil saturation that are based on the integral parameters are enable to make a decision when choosing and justifying the project wells location and transfer to the object wells from other horizons.

Based on the express method for selecting a location of wells in order to seal the grid and the residual oil withdrawal of the horizon P-1+2 points 1-4 are offered (see Fig. 4b).

Thus, the approbation of express method for determining the residual oil zones in the example of horizon P-1+2 of Hnidyntsivskyy field confirmed the possibility of its use in the oil reservoirs.

References 1. Придачина О.М. Екстраполяція даних при створенні геологічних моделей // Геодинамика, сейсмичность и нефтегазоносность Черно-морско-Каспийского региона. – Сімферополь, 2005. – С. 180–181.

2. Придачина О.М. Нові технології моделювання колекторів як основа гідродинамічної моделі / О.М. Придачина, В.Ю. Філатов // Проблеми нафтогазової промисловості. Зб. наук праць. – К.: ДП «Науканафтогаз» НАК «Нафтогаз України», 2006. – Вип. 3. – С. 78–83.

3. Shepard D. A two-dimensional interpolation function for irregularly-spaced data // Proc. of the 23 ACM National Conference. – ACM Press, New York, 1968. – Pp. 517–524.

4. R. Caira. Shepard-Bernoulli operator / R. Caira, F. Dell’Accio // Matematics of computation. – 2007. – V. 76. – N. 257. – Pp. 229–321.

The authors of the article

Prokopiv Volodymyr Yosypovych

The director of geology and drilling department of PJSC "UkrNafta", Candidate of Geological Sciences, corresponding member of the Ukrainian Oil and Gas Academy, a member of the International Geophysical organization "Association of Scientific and technical and business cooperation in geophysical study and work in wells (AIS)". He is graduated from Ivano-Frankivsk National Technical University of Oil and Gas, specialization is geophysical methods for prospecting and exploration. Range of interests - advanced technologis of search, exploration and development of oil and gas.

Pitonia Viktor Anatoliiovych

Head of process optimization of mining management of hydrodynamic modeling of hydrocarbon deposits PJSC "UkrNafta." Graduated from Ivano-Frankivsk National Technical University of Oil and Gas, specialization is development of oil and gas fields. The key research areas are process optimization design of oil and gas, the study of factors that affect the value of oil extraction in the final stages of development.

Prydachyna Olena Mykhailivna

Deputy head of the geological and hydrodynamic modeling of the hydrodynamic modeling of hydrocarbon deposits. Graduated from Ivano-Frankivsk National Technical University of Oil and Gas, specialization is geophysical methods for prospecting and exploration. The key research areas are prediction of geological section, modeling reservoirs, construction of three-dimensional geological models of hydrocarbon deposits

WELL DRILLING Lubricating additives in drilling and methods of their research UDC 622.24.084.34

O.V. Kusturova Candidate of Engineering Sciences

R.O. Shevchenko Candidate of Engineering Sciences

O.A. Zhuhan UkrNDIgas

S.V. Liamenkov DB «Ukrburgas»

The paper presents an analysis of the properties of various lubricating additives, which are used for treatment of drilling fluids to reduce the consumption of crude oil and methods of research.

A supply shortfall of high quality chemicals including lubricants became an actual problem of drilling companies in 2010-2012. During the past 10 years in the market of lubricants for drilling fluids and process liquids, in addition to traditional chemicals, oil and graphite, lubricant additives are distributed based on the modifying oil and fat production processing waste (phosphatide concentrate, hydrofuse): labrykol, wells of small diameter (WSD), SMZh, burol and others in Ukraine and FC-2000 in Russia. The use of such additives for drilling made it possible to reduce the cost of oil for reduction of the coefficient of coating friction (CCF).

It is known that oil as a component of drilling additives has the following functional properties: inhibition of clay swelling, inhibition of thermal degradation, hydrophobizated, anti-foam, anti-oxidant and anti-friction properties. In addition, oil is a quality lubricating component and kolmatant during productive horizons exposure. The use of oil as a part of the liquid for the development of productive horizons reduces interfacial tension and facilitate the inflows of fluid from the reservoir [1]. During drilling of wells with depth of 2000 m the hydrophobizated particles of formation cuttings facilitates solution cleaning and increases drilling speed.

Useful properties of oil are determined by its chemical composition: asphaltenes (0.2-0.7 %), resinous substances (0.4 - 25.5 %), naphthenic acids (0,6-2,4 %), bituminous substances (up to 10 %) [2]. We know that foreign companies use pure asphaltic reagents under various brand names (Soltex, Sulphoneted Asphalt, etc.).

The versatility of oil makes it possible to build wells, even in the absence of reagents of special purpose. The recommended concentration of oil in drilling fluids is traditionally up to 10 %, but there are some restrictions on the use of oil while drilling. According to [3], the use of oil as part of the drilling fluid in the range of drilling from 0 to 2000 m is prohibited, requiring the use of lubricating additives of other origin.

An important factor affecting the occurrence of friction during well drilling, is the degree of lubrication properties of the drilling fluid [4]. So, the timely determination of the quality of lubricating additives in the composition of drilling fluids is important. The authors of the article compared the current available methods for determining of lubrication (anti-friction) properties of drilling fluids.

It is generally accepted a method of determining the lubricating properties by measuring CCF using the CCF-1 device. The use of CCF-1 allows measuring of the displacement angle of

the objects (indenter) with clay coating in degrees. Note that this parameter as the CCF considered to be less informative because it does not allow to express the coefficient of friction in conventional terms, namely in H and Pa.

It is also known a method by the standard of the American Petroleum Institute (API), in which the lubricating properties of drilling fluids are determined by measuring the friction coefficient of the pair "metal- metal" when metal ring is rotating towards relatively fixed metal block. It allows you to simulate the rotation of the drill pipe in the well. The result of research is to establish the coefficient of the lubricating properties of the drilling fluid. The use of techniques and devices proposed by API helps to determine the degree of lubrication properties of the drilling fluid, but does not allow simulation of the real conditions encountered in the well during friction of drilling pipes.

Fig. 1. The dependence of static stress of indenter shift: from a clay coating of their contact time: 1 - clay model solution Т = 20-25 s, F = 15 cm3, 2 - model solution+1 % of graphite, 3 - model solution+3 % of labrykol, 4 - model solution+3 % SMZh, 5 - model solution+3 % WSD, 6 - model solution+10 % of oil

Fig. 2. The dependence of the coefficient of coating friction from lubricating additives

In order to study the anti-friction properties of the drilling fluid the authors used the method for determining the shift stress in the clay coating by pressure changes at the mount NK-1, developed by the Instrument Engineering Plant of Baku. The setting enables to measure the shift stress of indenter with clay coating formed by the differential pressure of 5 MPa, which makes it possible to simulate the conditions that occur during differential friction. The use of NK-1 enables to measure the static filtration of drilling solution and fluids that can be used in the form of "baths" in case of frictions, under pressure up to 50 atm. In addition, the thickness of the clay coating formed within a specified time can be measured with NK-1, and be varied with the

pressure and time at which indenter sticks to the clay coating. Thus, the use of mount NK-1 allows to approach the conditions of experiment to the real conditions of well drilling.

It should be noted that the mount NK-1 has drawbacks: low performance of filter working solution, due to the lack of perforations in the filter node. This deficiency prevents the formation of clay coating to be thick enough for indenter sticking. The drawback was removed by cutting auxiliary cylindrical grooves (for example BM-6) on the filter node, which doubled filtration rate and helped to form a coating.

The work technique with the mount of NK-1 goes as follows: 1) a model solution with volume of 550-600 cm3 is prepared, and lubricant additive is added there in a predetermined ratio 2) the mount casing is filled with work solution and working pressure up to 5 MPa is applied to form clay coating and 3) clay coating and indenter are brought into the contact 4) after a fixed period of time the indenter is displaced from the clay coating.

The use of the mount NK-1 made it possible to vary the filtration pressure, pressure and time at which the indenter is sticked and pressure at which the displosal of the indenter with clay coating is performed. Ultimately, the breakdown point of indenter is fixed by the counter the readings of which are multiplied by a spring factor (in this case the actual value of the spring constant K = 0.009 MPa/h), which enables you to get the value of a static shift stress (Pss) in MPa. During the research the pressure in the working chamber of the mount (Pw) was maintained between 0.5 and 4 MPa for 30 min to form a clay cover, time of indenter and the clay coating being in contact (Tcont) ranged from 5 to 30 minutes, the pressure at which there was a shift of indenter (Pshift) ranged from 0 to 4 MPa.

Conducted research at the mount NK- 1 helped to identify the main criteria that affect the static shift stress of indenter of clay coating, namely the composition of the solution and contact time of indenter and clay coating. The received dependences are shown on the Fig. 1.

Analyzing the above dependencies it can be concluded that the adhesive interaction between the metal surface and indenter and clay coating occurs most actively during the first five minutes of contact, subsequently strengthening of the connection of the metal surface and the cover is not going so fast that appears as a flat section of described dependencies.

Thus, a flat interval is observed in the case of lubricating additives on the fat base or oil due to their specific adsorption on the metal surface as well as on the active surface area of the clay phase. In contrast to the above additives, the presence of graphite in the model solution does not allow to get dependency with low static shift stress, indicating the inability to form graphite adsorption bonds with the metal surface. Thus, graphite is an inert lubricating additive, lubricity of which explains the decrease of the friction force due to sliding metal surface on the edges of the crystal lattice of graphite. A wide range of oil chemical composition is shown in the best performance of anti-freezing properties with relation to all of the above lubricating additives. Thus, the specific absorption which is inherent to lubricant additives on the fat base and oil makes it possible to increase the lubricity of drilling fluid for a long time compared with inert lubricants additives like graphite.

If these circumstances apply to the drilling conditions, it is fair to conclude on the need of quick overcoming of frictions because sometimes it is necessary to put more shift stress to displace drill pipes.

In parallel with the measurement of static shift stress of indenter from the clay coating the measuring of the coefficient of coating friction was performed. The base liquid was a model clay solution with the following parameters: T = 30 s, F = 11-12 cm3.

The received results are shown in the histogram on the Fig. 2.

The comparison of the results obtained for the installation NK-1 and CCF-1 device, allows them to detect a clear correlation. Thus, the test lubricants and anti-freezing additives for gear

CCF can be recommended as an express method in an industrial environment with a high reliability of the results.

References

1. Гиматудинов Ш.К. Физика нефтяного и газового пласта / Ш.К. Гиматудинов. - М.: Недра,1971. - 312 с.

2. Потапов В.М. Органическая химия / В.М. Потапов, С.Н. Татаринчик. - М.: Химия, 1972. - 512 с.

3. ГСТУ 41-00032626-00-007-97 Охорона довкілля. Спорудження розвідувальних і експлуатаційних свердловин на нафту і газ на суші. Правила проведення. - К.: ДНВП «Геоінформ України», 1997.

4. Дж.Р. Грей. Состав и свойства буровых агентов (промывочных жидкостей): пер. с англ. / Дж.Р. Грей, Г.С.Г. Дарли. – М.: Недра, 1985. – 509 с.

Authors of the article

Kusturova Olena Valeriivna

Leading research scientist of the engineering and drilling technology department of UkrNDIgas, Candidate of Engineering Sciences, specialization of well drilling, corresponding member of Ukrainian Oil and Gas Academy. She graduated from V. N. Karazin Kharkiv National University. She is engaged in the research of the properties and improvement of drilling fluids for well drilling in difficult geological conditions of ERS.

Shevchenko Roman Oleksandrovych

Candidate of Engineering Sciences, leading engineer in the engineering and drilling technology department of UkrNDIgas. Specialization - technical fluids for well drilling in oil and gas.

Zhuhan Oskar Anatoliiovych

Leading engineer of drilling solution laboratory of UkrNDIgas. He graduated from the Kharkov National University "KPI", specialization - technology fats. The main activity is development, implementation and physico-chemical studies of new drilling fluids, jamming liquids and polyfunctional reagents.

Liamenkov Serhii Volodymyrovych

Graduated from the Gubkin Russian State University of Oil and Gas, a leading engineer of drilling management of "Ukrburhaz". A leading expert in drilling fluids.

NEWS Perspectives of gas imports from Israel to Jordan

Since Israel plans to export 40 % of its energy from the Mediterranean Sea, Jordan is considering a draft agreement for the procurement of natural gas. Though, because of geopolitical considerations the final decision is not taken, several variants of gas supplies from Israel to Jordan are studied. Among them are the extension of gas pipeline from gas-chemical complex of Israel which is on the shore of the Dead Sea, to the Soda Factory in Jordan, the construction of a new pipeline from the Mediterranean Sea through Jezzerel Valley to Beit Shean and on to Jordan and so on.

Pipeline & Gas Journal/August 2013, p. 16 ISSN 0548-1414.

WELL DRILLING Concerning the issue of mudding permeable beds when using clayless drilling fluids UDC 622.24.06.32

Ya. V. Kuntsiak Candidate of technical sciences

Yu. V. Luban Candidate of technical sciences “NDIKB BI” PJSC

Luban S. V. Geosintez Engineering Ltd.

Ya. I. Kulyk “NDIKB BI” PJSC

In conditions of multi-zone hydrocarbons deposits non-uniform in depth and strike the use of carbonate blockers of the same type is ineffective due to the low reliability of the data on the size of collector pores. The problem can be solved by using composite blockers containing both rigid and elastic materials. The paper shows the results of laboratory studies and examples of practical application of the composite blockers in Biokar clayless mud system.

According to modern concepts [1, 2], among drilling fluid water-based, only clayless biopolymer systems provide top quality disclosure of productive horizons. Unlike clay or polymer clay drilling fluid, which filtration is accompanied by deep penetration of colloidal particles into the porous medium and the formation of the inner zone mudding, biopolymer fluids with negligibly low content of colloidal phase, form a crust on the surface of the filtration layer, which plays role of the impermeable occluding screen (Fig. 1). This is achieved through the use of special reagents blockers, particle size of which is adjusted according to the pore size of the collector.

During formation of interior mudding, cleaning of the natural reservoir is extremely difficult, which leads to a partial or a complete loss of well productivity. When clayless fluids are used, the thin surface crust can be easily destroyed by the flow of reservoir fluid during the flood and operating of wells. The natural permeability of the reservoir is almost completely restored in this case.

To create an insulating layer on the surface of the productive, fractionated, finely ground carbonate fillers are used, such as limestone, dolomite and marble, more often belonging to the class of so-called hard colmatants [3]. These substances seem almost ideal blockers because they are characterized by high degree of homogeneity, acid-solubility, resistance to dispersion, low abrasiveness and inertia to the reservoir fluids. In case of the proper selection, colmatants are split in the openings of pores between grains of rock, creating unique arched bridges, which act as the foundation for future filtration surface crust. The strength of the blocking layer is comparable to the strength of reservoir bed. This allows avoiding acquisitions and providing high quality disclosure of permeable horizons by excessive repressions, which, in particular, occur during drilling in areas of abnormally low reservoir pressure.

However, the effective blocking of filtration channels of the collectors occurs only in a narrow range of size relations with the size of colmatant particles. Even in case of minor deviations, as in one or the other side, arched lintels formation does not occur, and the permeability of the occluding layer and the amount of filtered fluid increase dramatically [4]. The result is a deep penetration of the components of the drilling fluid and increase in the

thickness of the contaminated zone. There are real examples where the quality of disclosure of productive horizons was worse than in case of use of obsolete clay systems, because of a bad selection of the fractional composition of the solid phase of drilling fluids.

Therefore, the application of rigid blockers requires complete and accurate information about the pore structure of the reservoir, since wrong choice of a colmatant can negate all the benefits of the use clayless drilling fluids. The situation is further complicated by the presence of cracks in the reservoir, which can change their size depending on the pressure in the borehole. In addition, the rate of formation of occluding layer and its permeability is affected by dispersion of blocker particles during drilling, inflow of sludge formed by drilled rock into the solution, presence and concentration of dense media solids and more. Thus, as most of fields in Ukraine are multihorizon fields, which are characterized by heterogeneity in the depth and strike, determining of the optimal particle size of a hard blocker reagent for each particular hole is an extremely complex technological challenge. There is an opinion, which is gaining more and more popularity in Ukraine, that the much advertised approach aiming to bring mathematical analysis methods and computer simulation process to solve the problem of mudding [5] is "inefficient and unreasonable from either an economic or a technological point of view". [6]

In our view, a necessary condition for the solution of this problem is a complete rejection from false practice of the use of hard colmatants of the same type and transition to composite blockers, containing as tough and elastic material.

The class of elastic colmatants includes organic materials that are prone to elastic deformation under pressure within the pore space of the reservoir. Due to it, elastic colmatants are characterized by better splitting and formation bond. The inconsistency of their size with the size of collector pores affects the formation of the insulating layer, which is also characterized by greater resistance to pressure fluctuations, to a lesser extent. But its strength is significantly inferior to the layer of hard colmatants [3].

In case of combined use of elastic and rigid colmatants they complement each other, which makes it possible to get a blocker, largely devoid of these shortcomings.

Composite blockers help create a flexible insulating layer of high strength. During its formation elastic material fills the voids between the hard colmatant particles and grains of hard rocks which are formed as a result of discrepancies between their dimensions. In this case, due to elastic deformation under pressure, elastic materials are able to act as an elastic sealant, regardless of the size of the voids and their configuration (Fig. 2). Thus, there is no need for a detailed study of the characteristics of the collector for the effective application of composite blockers.

Clayless biopolymer solution Polymeric mud drilling fluid

Fig. 1. Formation of zones of lowered permeability in the reservoir pore environment during opening with different solution types: 1 - outer polymer layer, 2 - outer colmatage layer 3 - internal colmatage layer (zone of penetration), 4 - clay coating, 5 – colmatage zone, 6 - penetration zone

Fig. 2. Colmatage of a reservoir pore space by a composite blocker: a - hard blocker particles; b - elastic blocker particles; c – rock grains

Table 1 Use of Biokar flushing fluid for the opening of production horizons

Well No., field Customer Operation particulars

Well No. 545, Bugruvativske Ukrnafta PJSC horizontal well Well No. 97, Yablunovske Karpatigaz PJSC horizontal well

Well No. 301, 303, 304, 306, 307, Lelyakivska

SP Kashtan Petroleum Ltd. inclined controlled and horizontal wells, abnormally low

formational pressure, carbonate reservoir with cracks

Well No. 10, Olhivske Kub-gaz Ltd. abnormally low formational pressure Well No. 22, 23, 24, 62, Ostroverkhivske

Ukrgazovydobutok PJSC inclined controlled wells

Well No. 10, Krasnozayarske Ukristgaz Ltd. hydrostatic pressures Well No. 53, Sviridivske Regal Petroleum Corporation Ltd. abnormally high formational pressure Well No. 2, Roganske Esko-Pivnitch Ltd. abnormally low formational pressure Well No. 20, 21, Ostroverkhivske Ukrgazovydobutok PJSC for perforation, damping and repairs Well No. 14, Sakhalinske DK Ukrnaftoburinna CJSC for perforation, damping and repairs

Theoretical notions were confirmed during laboratory tests of clayless filtering liquids containing colmatants of different types, with the use of the sand filter model [1]. Granulometric composition of filters was selected according to the size of the particles, typical for large- , medium- and fine-grained sand and coarse aleurite. [7] For mudding filters carbonate reagent blockers were used, that are applied for well drilling in Ukraine. Efficacy was assessed by an insulating layer of fluid that was filtered for 30 min. through the sand filter under pressure of 0.7 MPa.

As is evident from the research results (Fig. 3), hard colmatants show selective efficacy in all cases. That is to say, that there is no carbonate or any other hard blocker with equal efficiency in the entire range of pore sizes of collectors. For optimal size ratio of pores and blocker particles, solution filtration level is low, but the change in pore size leads to its increase, and therefore an adjustment of the blocker fractional structure is required. Determination of the need for such adjustment is only possible in case of additional introduction of elastic organic filler into the drilling fluid. In this case, the formation of an impermeable insulating barrier is independent of the reservoir porosity, and filtration remains minimal in all experiments.

Fig. 3. Insulating properties of different colmatants after pumping of biopolymer solution through sand filters of different granulometric composition.

Fig. 4. Samples after the pumping of the flushing fluid (а) and final permeability detection (б)

Past studies have helped to define the types and optimal concentrations of organic materials that can be used as fillers for clayless drilling fluids. It was established that the optimal content of hard colmatants in clayless drilling fluid is about 10%, and its relation with the content of elastic colmatant must be maintained at 10:1-1,5. The obtained results formed the basis for the development of composite reagents-blockers for Biokar biopolymer clayless drilling fluid, which is successfully used to disclose productive horizons in the fields of Ukraine (Table 1).

The high insulating properties of Biokar drilling fluid and its positive influence on quality of disclosure of productive horizons is demonstrated by research results obtained in the Oil and Gas Institute in Cracow. During the research with the methodology of the American Petroleum Institute the following items were used:

Filter press for determining filtration in static and dynamic conditions and temperatures (High Pressure High Temperatur Filter Press: OFI, USA);

Permeability meter to determine corn permeability in situ (Universal Permeability Meter – Core flooding System: Temco, USA);

unit for determine the thickness of the inner and outer filter cake (RVG Kodak 2000).

Fig. 5. Radiographs of samples after pumping of drilling fluid (a) and the final determination of permeability (б)

Experiments were performed in the cores productive layers of Starosambirskyi field using oil of Polish Carpathians collectors at the temperature 80 °С (Table 2).

Table 2

The measurement results of the Institute of Oil and Gas (Cracow)

Filtration rate,

cm3/30 min Sample permeability, mD

Oil Sample porosity, %

dynamical static oil-field water model start End

Permeability recovery

rate, %

11.3 0.9 0.5 3.40 1.47 1.36 92.5 9.4 1.1 0.4 0.48 0.33 0.31 93.9

As shown in Fig. 4, after pumping of the drilling fluid a dense filtration cake is formed on the surface of samples, which is a layer of colmatant particles that block the pore space, forming arched bridges between grains of rock. Filtration cake is easily destroyed during reverse oil flow because of minimal penetration depth of colmatant particles into the rock. Lack of internal colmatage of the samples is also confirmed by their X-ray examination (Fig. 5). The results of determining of the thickness of the inner and outer filter cake are shown in Table . 3.

Table 3 Filter cake thickness after mudding and cleaning of corn samples

Filter cake thickness after mudding of the sample (drilling fluid pumping), mm

Filter cake thickness after cleaning of the sample (reverse oil pumping), mm

External Internal External Internal 1.4 0 0.7 0 1.2 0 0.5 0

Thus, studies have confirmed that Biokar drilling fluid ensures efficient maintenance of filtration properties of reservoir with permeability recovery rate amounting to 92.5 - 93.9%. Two or more times decrease in the thickness of the outer filter cake upon cleaning of samples and almost complete lack of interior colmatage zone indicate a high insulating capacity of composite blockers, which guarantees high quality of disclosure of productive horizons.

References

1. Лубан Ю.В. «БІОКАР» – безглиниста промивальна рідина для буріння похило-скерованих і горизонтальних свердловин та розкриття продуктивних горизонтів / Ю.В. Лубан, Я.В. Кун-цяк, С.В. Лубан [та ін.] // Нафт. і газова пром-сть. – 2008. – № 4. – С. 18–21.

2. Куксов В.А. Новые технологии промывочных жидкостей для первичного вскрытия / В.А. Куксов // Нефть и газ. – 2004. – № 9. – С. 16–18.

3. Использование наполнителей при бурении скважин // Нефтяная промышленность. Обз. инф. – М.: ВНИИОЭНГ, 1985. – Вып. 8 (91). – 48 с. (Сер. «Бурение»).

4. Михайлов Н.Н. Изменение физических свойств горных пород в околоскважинных зонах / Н.Н. Михайлов. – М.: Недра, 1987. – 152 с.

5. Крылов В.И. Применение кольматантов в жидкостях для первичного вскрытия продуктивных пластов с целью сохранения их коллекторских свойств / В.И. Крылов, В.В. Крецул // Строительство нефтяных и газовых скважин на суше и на море. – 2005. – № 4. – С. 36–41.

6. Васильченко А.О. Методологія оцінки впливу окремих реагентів та їх сумішей на відновлення проникності порід-колекторів / А.О. Васильченко // Нафт. і газова пром-сть. – 2007. – № 4. – С. 18–19.

7. Ханин А.А. Породы-коллекторы нефти и газа и их изучение / А.А. Ханин. – М.: Недра, 1969. – 368 с.

The authors of this article

Kuntsyak Yaroslav Vasylyovich

Dr. of technical Sciences, Director General of NDIKB Drilling Tools JSC. Graduated from the Ivano-Frankivsk Oil and Gas Institute. Fields of research: technology of drilling of inclined and horizontal wells, recovery of wells by sidetracks drilling, development of rock destruction tools and equipment for coring.

Luban Yuriy Volodimirovich

Candidate of technical sciences, Head of Laboratory of drilling fluids at NDIKB Drilling Tools JSC. Graduated from the Moscow I. M. Gubkin Institute of Oil and Gas. Fields of research: development of drilling fluids formations for drilling of oil and gas wells in different geological conditions and drilling horizontal and parallel sidetracks, special fluids for disclosure productive horizons, finishing and recovery of wells, introduction and personal support of drilling fluids use in wells.

Luban Serhiy Volodimirovich

Deputy Director of Heosyntez Engineering Ltd. Graduated from the State I.M. Gubkin Academy of Oil and Gas (Moscow). Areas of industrial activity: development of formulations of drilling fluid for drilling of oil and gas wells in different geological conditions, drilling of horizontal and parallel sidetracks, development of special fluids for disclosure productive horizons, introduction and personal support of drilling fluids use in wells.

Kulyk Yaroslav Ihorevych

Leading engineer of NDIKB Drilling Tools JSC. Graduated from the Ivano-Frankivsk Oil and Gas Institute. Areas of industrial activity: study of colmatage properties of clayless washing fluids; introduction of drilling fluids at wells.

OIL AND GAS PRODUCTION Concerning the use of statistical estimates of productive

bed parameters using pressure recovery curves MYSLIUK M.A., Doctor of technical Science IFNTUOG PETRUNIAK V.Ya. JV “Poltava Oil and Gas Company”

Nowadays hydrodynamic monitoring of productive beds is mostly conducted with the help of pressure recovery curves (PRC). Common methods of interpretation of hydrodynamic research on the PRC [1-6] are based on deterministic productive bed evaluation that does not correspond to information provision and limits their practical use.

Some authors [7, 8] proposed a method of processing of data of productive bed PRC hydrodynamic monitoring, which lays in selection of the most adequate model of a class of possible hydrodynamic modeling of the reservoir. Model and parameters of a productive bed are estimated with the use of maximum likelihood function. Note that in this case the evaluation of bed parameters satisfies the condition of effectiveness.

In the applied aspect of data interpretation of hydrodynamic data for productive bed lays in building statistical estimates of the bed parameters, formulation and verification of relevant statistical hypotheses, simulation of hydrodynamic processes which take place during implementation of active impact on the productive bed. The aforementioned elements of application of statistical information are considered below:

Data processing of PRC hydrodynamic study lays in estimation of a0 and a1 parameters of the following linear model

where – results of time and pressure measurement; – approximating functions

that depend on interpretation method and fluid type (oil, gas).

For example, for D.K. Horner method and oil reservoir [2–4]

for the modified D.K. Horner method and oil reservoir [2–4] for a fiery seam at

for a fiery seam at

etc. Where: – duration of well operation with the flow rate or till its stop and

pressure recovery; – reservoir pressure and temperature; – permeability and piezoconductivity of the bed; – fluid viscosity; – bed thickness; – equivalent well radius; – gas flow rate in normal conditions –

gas-compressibility factor in bed conditions.

Note, that there is a statistical dependence between the evaluation of the parameters of the model (1) according to the results of the PRC measuring and covariance matrix [7, 8]

Fig. 1. PRC of well No. 206 of Movchanivsky oil-gas condensate field before (study date 27.03.2009 ) and after (1-5.04.2009) intensification: 1, 3 – measurement data; 2, 4 – results of processing acc. to D.K. Horner method

where dispersion evaluation of a0 and a1, respectively;

– correlation coefficient evaluation between these parameters; – derivative matrix according to estimated bed parameters and its transposed matrix; C – covariance matrix for a random component in the task of processing of hydrodynamic research data [7, 8].

With the confidence probability α, ellipsoid of estimated model parameters (1) is defined by an inequality [9]

(7)

where – quantile of F-distribution of with degrees of freedom q

and n-q; q – vector length for model parameters (1).

Statistical evaluation of a0 and a1 composite bed parameters (water permeability permeability k etc.) is made with the use of such dependencies as (2)–(5) and others

with regard to information on laws and parameters of distribution of input values.

In general, for different laws of distribution of known values methods of statistical modeling or Monte Carlo simulation [10] are used for statistical evaluation of composite parameters . Let the vector of composite of the parameters of the reservoir be given with (2) - (5), etc. as

where [9]– exactly known values; - inaccurately known statistically independent values,

inaccurately known statistically dependent variables. In this case, the algorithm for constructing of statistical estimates of is reduced to simulation of random variables forming the sample of layer component parameters and for their statistical evaluation.

In terms of applied sciences, the availability of statistical information requires the formulation and testing of statistical hypotheses, and in some cases - building of statistical models of decision making [7, 9, 11, 12]. Of the highest priority are statistical hypotheses on vector estimated parameters like and , where a and b are vectors of bed parameters, - a fixed vector of bed parameters. The first of these hypotheses is tested using statistics [9]

which corresponds to F-distribution. To check the H0: a = b hypothesis we can use a correlation criteria of the likelihood function [11]

where – are likelihood functions

This parameter is assumed according to confidence probability α of the criterion of verifiability of the hypothesis [11]:

General data on studied objects Gas properties Well Horizon

index Perforation interval (top/bottom),m

Effective thickness, m

Study date Bed temperature, °С

Well operation time before stop

Study duration, h

206 Т-1-2-3 2439 2478

48.9 27.03.09 85 1,3727 0,0206

0,637 0,025

0,011 0,0008

0,858 0,043

47 97

206 Т-1-2-3 2439 2478

48.9 01–05.04.09 84 2,9502 0,0443

0,637 0,025

0,011 0,0008

0,858 0,043

9 10

167 Т-1-2 2577 2998

46.2 20–25.02.10 89 0,0463 0,0007

0,626 0,025

0,011 0,0008

0,874 0,044

48 114

167 Т-1-2 2577 2998

46.2 05–08.03.10 89 1, 3704 0,0206

0,626 0,025

0,011 0,0008

0,874 0,044

20 63 рг – relative gas density by air, standard deviation

Table 1

Table 2

Results of PRC interpretations for Movchanivsky oil-gas condensate field before and after intensification works

Before intensification After intensification Well

206 562,628

0,7956 -70,915 0,8574

-0,973 2,540 504,779 1, 3756

-99,167 3,0088

-0,994 0,882

167 356,811 0,5870

-66,333 1,6170

- 0,9 99 13,613 333,647 0,0554

-278,4 41 0,1947

-0,999 591,928

where Р0 - distribution of sample (10) for parameter.

Testing of statistical hypotheses (9) and (10) with a given confidence probability α provides justification for judgments about effective influence of various methods of action on the bottomhole formation zone. More important is the use of statistical information in decision-making, which generalizes the estimation of parameters and their ranges of reliability, formulation and testing of statistical hypotheses, and so on.

In problems of decision making in an explicit form (monetary or conditional) a numerical function (loss function) is introduced, that represents effects resulting from each step in the given conditions [12]. Availability of information on statistical estimated parameters allows for the construction of probability space for possible states of bed properties, which provides reliability of modeling of hydrodynamic processes and building of loss function during implementation of the technology at bottomhole formation zone. The loss function reflects a situation that goes beyond estimation and testing of a hypothesis.

Let us consider statistical evaluation of productive bed parameters using data obtained as the result of hydrodynamic studies of some wells of Movchanivsky oil-gas condensate field (GOCF) before and after their treatment with hydrochloric acid.

Gas flow rate of the well No. 206 amounted to 254.88 thousand m3 gas a day and 79.5 tonnes condensate a day. After formation treatment (35 m3 of 15% hydrochloric acid solution) the gas flow rate reached 91.05 thousand m3 gas a day and 8 tonnes condensate a day

The well No. 167 was put into operation with the gas flow rate of 4 thousand m3 a day. After formation treatment (200 m3 of 15% hydrochloric acid solution) the gas flow rate reached 118.37 thousand m3 gas a day and 1 tonne condensate a day.

General information about the objects of study is given in Table. 1. Taking into consideration the recommendations [1], the PRC processing for wells was performed by (1) and (4) according to the method [7, 8]. Class of possible hydrodynamic models of productive bed (2) was generated parametrically depending on the number of points of the linear plot of the diagnostic chart. The most appropriate hydrodynamic model of the reservoir was selected with the use of the minimum variance adequacy criterion. The main results of PRC interpretation before and after intensification are given in Table. 2.

Table З Results of productive bed parameters estimation at the wells of Movchanivsky GOCF

Well No. 206 Well No. 167 Statistical estimate of the

bed parameters BEFORE intensification After

intensification

BEFORE intensification

After intensification

23.718 23.720

22.469 22.467

18.890 18.889

18.266 18.266

328.7 327.2

502.9 501.4

12.15 12.15

85.88 85.68

0.0742 0.0736

0.1136 0.1128

0.0029 0.0029

0.021 0.020

0.016 0.029 0.015 0.001 17.99 29.48 0.693 4.39

0.0069 0.0108 0.00028 0.0019 -0.210 -0.466 -0.412 -0.007 -0.127 -0.290 -0.246 -0.007

Гск 0.556 0.581 0.597 0.546

Fig. 2. PRC of well No. 167 of Movchanivsky oil-gas condensate field before (study dare 20 - 25.02.2010) and after (5 - 8.03.2010) intensification: 1, 3 – measurement data; 2, 4 – results of processing acc. to D.K. Horner method

Fig. 1 and 2 show the productive bed PRC measurements before and after the intensification at the well No. 206 and 167 at Movchanivsky GOCF and the results of their treatment. The analysis shows compliance with the terms diagnostic measurement data (1) with due consideration of (4). Fig. 3 demonstrates ellipsoids of parameter estimates of the model (1) [confidence probability α = 0.05] for the PRC of the well No. 167. Table. 2 shows the evaluation of the maximum likelihood function values for the parameters of the bed according to the results

of PRC processing, the conditions (10) of testing of the statistical hypotheses with confidence probability α = 0,05 are not fulfilled for the wells in question. This indicates a statistically significant difference of estimates of the model parameters of the bed (1) before and after intensification, which is also clearly illustrated in Fig. 1-3.

Table 3 shows the results of the PRC estimation of productive bed parameters before and after hydrochloric acid treatment at the wells 206 and 167 of Movchanivsky GOCF. Statistical estimation of the bed parameters was prepared for models (1) and (4) and (8) with the help of Monte-Carlo simulation. Simulation of and ах parameters was performed for a normal two-dimensional distribution with the covariance matrix (6), in case of - for normal case of probability distribution. Initial data for is given in Table 1. The sample volume for statistical modelling amounts to 400.

Bed parameters estimates (see Table 3) which include data on mathematical expectation of bed pressure , water conductivity G, permeability coefficient к, their standard deviations

and correlation coefficients are complete according to D. Horner method for a fiery seam. With the purpose of comparison the denominator (see Table 3) shows estimates of the mean value of bed parameters excluding information on data accuracy. Analysis of these data indicates that they differ slightly. In some cases (for different distribution laws of probability with greater volatility of output values, etc.) the differences between the estimated parameters of the bed may be more significant.

Fig. 3. Ellipsoids of PRC estimation of model parameters (1) of for the well No. 167 before and after the intensification

Table 4 Estimated parameters for the productive bed of well No. 167 at Movchanivsky GOCF

Number n of statistical experiments Statistical evaluation

of bed parameters 50 100 200 300 500 1000 18,26 18,266 18,266 18,266 18,266 18,26685,09 86,54 85,64 85,86 85,65 85,57 0,020 0,021 0,020 0,021 0,020 0,020 0,001 0,0015 0,0013 0,0016 0,0014 0,00155,431 4,496 4,173 4,303 4,415 4,519 0,001 0,0021 0,0017 0,0018 0,0018 0,0019-0,068 -0,136 -0,038 -0,090 -0,031 -0,024-0,028 0,012 -0,070 -0,083 0,024 -0,0220,650 0,658 0,581 0,573 0,621 0,566

Table. 4 shows the results of the estimation of the reservoir parameters (mathematical expectation and matrix covariance elements) of the well No. 167 (study date 05 - 08.03.2010) depending on the number of statistical experiments, analysis of which indicates the stability of the statistical estimates of the bed parameters at n> 200.

Data given in the Table 3 indicate, in particular, the impact of hydrochloric acid treatment on the productive bed properties. The results of hydrodynamic studies of the well No. 206 show

a 1.5 times increase of water conductivity that occurred during processing of the T-1-2-3 horizon, but its gas flow rate decreased. The probable reason for the latter is mudding with terrigenous acid sediments of productive horizon, where the main gas and condensate extraction was made before intensification. Increasing in water conductivity of the T-1-2-3 horizon is associated with its carbonate sediments. Hydrodynamic studies of the well No. 167 indicate significant increase in water conductivity (7.1 times) and gas flow rate (29.6 times) and improvement of work progress.

Thus, the use of information on the accuracy of estimation of the productive bed parameters is an important generalization of the PRC processing method. This allows considering the statistical estimates of the productive bed parameters during modeling of tasks of oil and gas fields development, in condition of information uncertainty it permits the use of statistical models for decision making for the purpose of selection of sound projects.

References

1. Гриценко А.И. Руководство по исследованию скважин / А.И. Гриценко, З.С. Алиев, О.М. Ермилов, В.В. Ремизов, Г.А. Зотов. – М.: Наука, 1995. – 523 с.

2. Шагиев Р.Г. Исследование скважин по КВД / Р.Г. Шагиев. – М.: Наука, 1998. – 304 с.

3. Хисамов Р.С. Гидродинамические исследования скважин и методы обработки результатов измерений / Р.С. Хисамов, Э.И. Сулейманов, Р.Г. Фархуллин, О.А. Никашев, А.А. Губайдуллин, Р.К. Ишкаев, В.М. Хусаинов. – М.: ОАО «ВНИИОЭНГ», 2000. – 228 с.

4. Иктисанов В.А. Определение фильтрационных параметров пластов и реологических свойств дисперсных систем при разработке нефтяных месторождений / В.А. Иктисанов. – М.: ОАО «ВНИИОЭНГ», 2001. – 212 с.

5. Bourdet D. Use of Pressure Derivative in Well-Test Interpretation / D. Bourdet, J.A. Ayoub, Y.M. Pirard // SPE Formation Evaluation. – 1989. – June. – Pp. 293–302.

6. Чодри А. Гидродинамические исследования нефтяных скважин / А. Чодри. – М.: ООО «Премиум Инжиниринг», 2011. – 687 с.

7. Мыслюк М.А. Методика обработки кривых восстановления давления / М.А. Мыслюк // НТВ «Каротажник». – 2009. – Вып. 7. – С. 112–120.

8. Мислюк М.А. До оцінки параметрів продуктивних газових пластів за кривими відновлювання тиску / М.А. Мислюк, В.Я. Петруняк // Нафт. і газова пром-сть. – 2012. – № 2. – С. 38–40.

9. Ермаков С.М. Математическая теория планирования эксперимента / С.М. Ермаков, В.З. Бродский, А.А. Жиглявский [и др.]. – М.: Наука, 1983. – 392 с.

10. Ермаков С.М. Статистическое моделирование / С.М. Ермаков, Г.А. Михайлов. – М.: Наука, 1982. – 296 с.

11. Боровиков А.А. Математическая статистика. – М.: Наука, 1984. – 472 с.

12. Мислюк М.А. Моделювання явищ і процесів у нафтогазопромисловій справі / М.А. Мислюк, Ю.О. Зарубін. – Івано-Франківськ: Екор, 1999. – 426 с.

The authors of this article

Mysliuk Mikhailo Andriyovich

Dr. of technical sciences, professor of the Faculty of Drilling of Oil and Gas Wells at Ivano-Frankivsk National Technical University of Oil and Gas. Research fields - the choice and decision-making during process of drilling and drilling process simulation.

Petruniak Volodymir Yaroslavovich

Oil and gas engineer at "Poltava Petroleum Company", research student at of the Faculty of Drilling of Oil and Gas Wells at Ivano-Frankivsk National Technical University of Oil and Gas. Graduated from the Yu.Kondratyuk Poltava National Technical University, specialty: “Oil and gas”. Research fields - Hydrodynamic study of productive beds.

OIL AND GAS PRODUCTION Interaction of silicate rocks with acid-cut clay muds under pt conditions in the reservoir. Part 2. The mechanism of formation component dissolution UDC 622.276

S.M. Rudyi Candidate of technical sciences

Yu.D. Kachmar Candidate of technical sciences

M.I. Rudyi Candidate of technical sciences, “Ukrnafta” PJSC

It was established that in case of excess rock to acid-cut clay mud at increase of interaction pressure the selectiveness of dissolution of oxides within Bentonite Clay disappears. In case of excess rock the mechanism of dissolution of these oxides at high pressures is unchanged. Increasing pressure from 0.1 to 15 MPa leads to decreasing Horodyshche gel powder dissolution at higher specific consumption of acid for its dissolution, which is associated with the occurrence of secondary reactions of newly produced neutralizing products.

The proposed article is a continuation of a series of works [1, 2] that study the mechanism of interaction of clay-acid solutions (CAS) based on the mixture of 10% HCl and 1% HF with silicate rocks (clay-carbonate sandstone of Precarpathians and Gorodyshchenske clay Bentonite powders ) at different pressures (0.1 – 15 MPa) and temperatures (40 – 80°C). The previous studies have established that moderating or accelerating capacity of the pressure on the dissolution of terrigenous rocks is determined by the mineralogical composition of a particular rock, i.e. the content of carbonate and silicate rocks, and by the composition of the acid solution as silicon and aluminum oxides have different dissolution dependence compared with iron oxides and oxides of monovalent and divalent metals [2].

It also has been established that dissolution of the silicate rocks models at atmospheric pressure and a temperature greater than critical can vary depending on the rock excess or acidity [1]. If case of excess of acid, the dissolution of CAS clay powder oxide at temperature of interaction amounting to 40°C is as follows:

which corresponds to their initial content in the rock, and at a temperature of 80°C the given

sequence is broken – removal of aluminum oxide predominates over the removal of silicon oxide. Relative removal of silicon oxide amounts to only 12.9 – 27% of the initial content in the sample; for aluminum oxide this value amounts to 20 – 60%, while the oxides of iron, calcium and magnesium are dissolved much more - from 65 to 100%. During the interaction of CAS with sandstone relative removal of silicon oxide is reduced to 10%; the removal rate for oxides of iron, aluminum, calcium and magnesium is 80 – 100%. Therefore, sandstone is most soluble in clay-carbonate cement while matrix solid material remains comparatively poorly soluble. In the event of rock excess, CAS acts selectively: interlayer cations and isomorphic impurities in powders and cement in sandstone are primarily dissolved. The oxides dissolution takes plase in the following sequence:

The work is dedicated to studying of the dissolution mechanism of components of silicate minerals in the clay-acid solution based on a mixture of 10% HCl and 1% HF in thermobaric

conditions that are close to those of the bed (with the bed temperature of 40 to 80°C and pressures ranging from 0.1 to 15 MPa, contact time of the acid solution and the rock is 6 hours). The results of studies of the solubility of the clay powder in CAS over a short contact time (15 min) in the thermobaric conditions similar to those of the bed are given in [2].

Fig. 1. The dependence of the solubility of the Gorodischensky clay powder on pressure and temperature: 40 °C - curves 2 and 4; at 80 ° C - curves 1 and 3, with exposure time 6 h and excess: 1, 2 - acid, 3, 4 - rock

Fig. 2. The dependence of the solubility of the Gorodischensky silicon on pressure and temperature: 40 °C - curves 2 and 3; at 80 ° C - curves 1 and 4, with exposure time 6 h and excess: 1, 2 - acid, 3, 4 – rock

Maximum time of the stay of the acid solution in the bed can be up to 6 hours (2 - 3 hours - injection into the layer 2-3 hours – exposure for interaction of the latter portions of the acid solution with rock components and beginning of well development). Therefore, further research of the solubility of Bentonite clay in CAS was conducted with the use of 6h exposure value that is optimal for maximum dissolution of rock. The results are shown in Fig. 1-6.

The laboratory studies have demonstrated that prolonged exposure (6 hours) of Gorodischensky Bentonite clay to the acid-clay solution of 10% HCl and 1% HF leads to changes in dependency of clay dissolution on the pressure: in all cases, a decrease in total solubility of Bentonite is observed with increasing interaction pressure. The decrease rate of the solubility of powders is usually less than 30% (see Fig. 1). This interaction mechanism significantly differs from dependence observed in the case of short-term exposure of clay to the acid mixture [2]. If there is a significant dissolution of Bentonite powder, which is achieved during its prolonged exposure to the acid solution, the effect of the solubility of the oxides of iron, magnesium and calcium dominates over the solubility of silicon and aluminum oxides. The result is a decrease in the Bentonite solubility with increase in pressure because this factor primarily affects the solubility of the above-mentioned oxides so that it decreases.

It has been also shown that overpressure leads to a change in the mechanism of dissolution of basic oxides of the Bentonite Clay. Thus, under conditions of acid excess with the increase in pressure from 0.1 to 15 MPa, the mechanism of removal of metal oxides from the clay power is maintained in accordance with the following sequence (1). The amount of removed silicon oxide is always larger compared with other oxides:

The obtained order of removal of oxides expressed in absolute values in conditions of acid

excess corresponds to their natural distribution in the clay powder.

In case of excess of the rock during the pressure increase from 0.1 to 15 MPa, the mechanism of the metal oxide removal from the clay powder changes. Consequently, a number

of metal oxides, which are removed from the clay powder, can be displayed as follows in decreasing order:

Fig. 3. The dependence of the solubility of the aluminum oxide from Gorodischensky powder on pressure and temperature: 40 °C - curves 2 and 4; at 80 ° C - curves 1 and 3, with exposure time 6 h and excess: 1, 2 - acid, 3, 4 – rock.

Fig. 4. The dependence of the solubility of the ferric oxide from Gorodischensky powder on pressure and temperature: 40 °C - curves 2 and 4; at 80 ° C - curves 1 and 3, with exposure time 6 h and excess: 1, 2 - acid, 3, 4 – rock

A significant difference, at pressures high compared with atmospheric, is the increase of solubility of alumina and silica. The greatest effect of pressure is observed during the interaction of acid and silica, because it is practically insoluble with clay acid at atmospheric pressure. However, even low pressure (5 MPa) leads to partial dissolution of silica in the range of 2 to 3 % of its amount (see Fig. 2). Further increase in the pressure up to 15 MPa does not cause the increase in dissolution of silica. These results suggest that the increase in pressure enhances the movement of acid to the structure-forming silicon cations, ensuring their partial dissolution at the same time. After a slow dissolution speed of such oxides, their share in the total amount of dissolved oxides is negligible. These results support the earlier conclusion that with increase in pressure during interaction of the clay powder with CAS, with all other conditions being equal, an increase of loss of hydrofluoric acid for dissolution of the silicon oxide is observed, since it is the only acid capable of dissolution of the said oxide [2]. The greatest effect of pressure on the mechanism of dissolution of powders occurs when an insufficient amount of clay-acid solution in circumstances where the dissolution of oxides is determined primarily by the speed and area of contact with nitric acid (i.e. in case of the rock excess over the acid, which is characteristic for injection of the first portion of clay-acid solution into the pore space of the bed).

Another proof of increase in removal of the both acids from the clay-acid solution is the increase in the specific consumption of the acid for powder dissolution. It has been demonstrated that with increase in pressure from 0.1 to 15 MPa, the specific consumption of the acid for the dissolution of the metal oxides (amount of clay powders dissolved in 1 mg of the equivalent acid) dramatically increases 5-8 times (Fig. 7). These results indicate that with increase in pressure, maintenance of the gas products (SiF4, CO2) in the liquid state leads to better rock dissolution with the same amount number of acid. In combination with improved permeation ability of acid into the structure of clay minerals it provides intensification of clay powder dissolution with the acid mixture. The maximum growth rate of the specific acid consumption is observed at the pressure amounting to 10 MPa. This dependence is related to the proportion of the contribution of each individual oxide into the overall result of dissolution of the clay model.

At pressures less than 10 MPa, an increase in the specific consumption of the acid is related to the solubility of silica and alumina. Further increase in pressure stabilizes the process of dissolution at a certain level. The removal of the remaining oxides tends to decrease with increasing pressure. Therefore, at pressures higher than 10 MPa a partial decrease of this value is observed.

Fig. 5. The dependence of the solubility of the calcium oxide from Gorodischensky powder on pressure and temperature: 40 °C - curves 2 and 4; at 80 ° C - curves 1 and 3, with exposure time 6 h and excess: 1, 2 - acid, 3, 4 – rock

Fig. 6. The dependence of the solubility of the magnesium oxide from Gorodischensky powder on pressure and temperature: 40 °C - curves 2 and 4; at 80 ° C - curves 1 and 3, with exposure time 6 h and excess: 1, 2 - acid, 3, 4 – rock

However, during the dissolution of some Bentonite Clay oxides deviations from the general trends are observed. This is especially true for silica (see Fig. 2). In case of rock excess and at 40° C the process of dissolution of silica is intensified with the increase in exposure time, and at pressures higher than 5 MPa it stabilizes at a certain level. The increase in the interaction temperature to 80° C leads to a decrease in the solubility of silica. The increase in the exposure time from 0.25 to 6 hours only worsens the process of dissolution of the said oxide. Deviations from the general trends of acid dissolution of oxides for silicon oxide are also observed in the case of an excess of the acid over the rock. The general downward trend in solubility with increasing pressure for silicon oxide is observed only with prolonged exposure to CAS at 40ºC. In all other cases (higher temperature, short-term exposure at 40ºC) there is an increase of solubility of silica with increasing pressure. Other deviations from the general trends of the process is reduce in the solubility of silica with the temperature increase from 40 to 80°C at atmospheric pressure; and increase in exposure time and of the temperature to 80°C. If Bentonite Clay is dissolved with the solution of 10% HCl and 1% HF, the maximum solubility of silica is achieved under the following conditions: excess of the acid over the rock at 80ºC and short-term (15 min) exposure.

In our opinion, the deviation of the solubility of silica in the event of the rock or acid excess or from the general trend, especially with the increase in temperature and exposure time, associated with the occurrence of secondary reactions during contact of the acids with neutralization products. This results is a partial return of the dissolved silica in an insoluble form (according to the formulas 1.5-1.9), which understates the actual values of dissolution of silicon oxide. The formation of the silicon hydrofluoric acid provides even further dissolution of carbonate and silicate components, but this may lead to the formation of water-insoluble products and blocking of the pore channels:

Fig. 7. Dependence of the specific consumption of the acid for solution of 1 mg equivalent of Gorodischensky clay powder from pressure and temperature (at 40 °С - curves 3, 5, 6, and 7; at 80 °С – curves 1, 2, 4, and 8), acid excess (curves 1, 3, 4, and 5) or rock excess (curves 2, 6, 7, and 8) and exposure time: 1, 2, 5, and 7 - 15 min; 3, 4, 6, and 8 - 6 hours

Besides that, hydrofluoric acid is capable of interaction with silica and aluminum fluorides that are formed during the reaction:

The formation of complex aluminum salts in the present of excess of hydrofluoric acid is

possible because the solubility of such salts is much higher than that of the initial salt (from 0.41 to 7.6% for the ammonium salt). The presence of hydrochloric acid in the clay acid solution mostly provides dissolution of oxides of calcium, magnesium and iron and converting of soluble fluoride salts of aluminum and iron into more soluble chloride salts.

Since the duration of secondary reactions increases with increasing temperature and exposure time, the amount of silica that is returned from the solution to the surface also increases thus leading to decrease in the observed rate of silicon oxide dissolution. Therefore, the increase in pressure, temperature and exposure time to such extent when the interaction between clay acid solution and silica takes place, does not slow down the dissolution, but rather accelerates it, resulting in the occurrence of secondary reactions and return of silicon dioxide into the surface of rocks in a modified form (water and anhydrous compounds of SiO2).

If there is an excess of the acid compared with rocks increase of the interaction pressure does not change the basic mechanism of dissolution of the clay powder oxides: it reaches its maximum and is associated mainly with the quantitative content of oxides in the rock. If there is an excess of the rock over the acid increase of the interaction pressure leads to the disappearance

of the selectivity of dissolution of the oxides, which occurs due to the acceleration of the penetration of the active acid into clay minerals and with increasing solubility of silica and alumina, which are a structure-forming cations of siliceous tetrahedral of the clay powder. However, the obtained figures for the solubility of the silicon, aluminum and iron oxides in these conditions are less than the values obtained in the conditions of the acid excess. The established mechanism of interaction suggests that during filtering of clay acid solution based on hydrochloric and hydrofluoric acids through a given volume of porous reservoir during the passage of the first portion of the solution (subject to an excess of acid rocks) only partial dissolution of basic rock oxides is observed, which is determined by the speed their dissolution. Indicative in this process is silica. At atmospheric pressure, it is not dissolved by clay acid solution. Increase in pressure causes the start of its dissolution (2-3% of the total). Only the excess of acid over rock while filtering of the bulk CAS volume provides intensive dissolution of silicon oxide, which is part of the silicate minerals.

The conducted studies show that strong hydrofluoric acid at high temperatures (80º C and above) and long exposure time is impractical for the use in the clay acid solution due to the high dissolution rate of silicate and clay minerals and the occurrence of secondary reactions that result in both inefficient use of hydrofluoric acid for reaction with fluorides of silicon, aluminum and iron, as well as in secondary formation of hydrous and anhydrous silicon oxides (which can result in blocking of the pores of the pore collector). It is reasonable to use slow acting forms of acid-clay solutions (a mixture of hydrochloric and hydrofluoric acids with a reduced concentration or the relevant additives, or a mixture of a weak acid, HF or its salts or acids of silicon hydrofluoric acid or boron hydrofluoric acid [3]). In the case of low concentration of clay acid solutions for HF it leads to reduction of the depth of acidic action, especially for silicate and clay components. Since the use of silicon hydrofluoric acid is optimal only in layers of clay cement alone, the boron hydrofluoric acid is a promising acid base, because it can be used in the layers of carbonate, clay carbonate or clay-cement [4].

References

1. Качмар Ю.Д. Исследование процесса разложения силикатных пород глинокислотой / Ю.Д. Качмар, Н.М. Ватаманюк, М.М. Па-два // Нефтепромысловое дело. – 1971. – № 8. – С. 11–13.

2. Рудий С.М. Взаємодія силікатних порід із глинокислотними розчинами в термобаричних умовах пласта. Ч.І. Вплив тиску на розчинність породи / С.М. Рудий, Ю.Д. Качмар, М.І. Рудий // Нафтогазова галузь України. – 2013. - № 1 . – С. 22–27.

3. Економидис М.Д. Воздействие на нефтяные и газовые пласты / М.Д. Економидис, К.Г. Нольте. – Краснодар: ВНИИКРнефть, 1992. – Т. 2. – 431 с.

4. Рудий М.І. Кислотне діяння на нафтогазовий пласт. Т. 1. Кислоти / М.І. Рудий, С.М. Рудий, С.В. Наслєдніков – Івано-Франківськ: ПП «Галицька друкарня Плюс», 2011. – 482 с.

The authors of the article

Rudyi Serhii Myroslavovych

Candidate of Engineering Sciences. He works in the Research and Design Institute of PJSC "UkrNafta". He graduated from the Institute of Natural Sciences of V. Stefanik Carpathian National University. His scientific interests are related to the research and development of new formulations of active solutions for oil recovery intensification of oil fluids..

Kachmar Yurii Dmytrovych

Lead engineer of Research and Design Institute PJSC "UkrNafta", mining engineer, Candidate of Engineering Sciences, senior scientist, academician of the Ukrainian Oil and Gas Academy. Among the scientific interests is the research of acid treatment of low permeable weak carbonate reservoirs.

Rudyi Myroslav Ivanovych

Candidate of Engineering Sciences, corresponding member of the Ukrainian Oil and Gas Academy. Works in the Research and Design Institute of PJSC "UkrNafta". The range of scientific and industrial interests: development of new and improvement of traditional technologies of intensification based on new chemicals and application of methods developed in the fields of PJSC "Ukrnafta" in order to stabilize oil and gas at the late stage of development of hydrocarbon deposits.

NEW BOOKS

On the occasion of the 20th anniversary of Ukrainian Oil and Gas Academy (UOGA) a

publishing center "Logos", with Candidate of Engineering Sciences Z.P. Osinchuk being the chief editor, issued a large format book called "Oil and gas industry of Ukraine: progress and personality". The book has 322 pages, its preparation and printing was possible because of the participation of 22 members of the UOGA and five Ukrainian companies that sponsored the publishing. It is unique in its content and scope of information. It consists of two sections. The first deals with historical aspects of seven areas of oil and gas complex of Ukraine: geology of oil and gas, well drilling, oil and gas extraction, transportation, refining, gas supply and gasification and providing field personnel. The descriptions of all directions represent the concentrated chronological summary of production activities with numbers, personalities, and results of scientific research, current issues and directions for further work. The direction of well drilling and refining of oil and gas are distinguished by completeness and highly outlining exposition.

The second section includes brief biographies and employment up to 515 persons, among them twelve women. The section covers stories about experts within age range from 1854 to 1984. The vast majority of them were born, studied and worked in Ukraine, 15% came to Ukraine mainly from Russia and Azerbaijan. 8% of professionals were born and educated in Ukraine, worked outside the country (mainly in Russia) and achieved considerable manufacturing success.

The insistence and desire to self-development are the distinguished character traits and manners of many oil and gas industry workers. This was the key to the industry flourishing in the second half of the twentieth century. During the period of the oil and gas sector establishing family dynasties of professionals rose, like Kysel, Mikhalevich, Mrozek, Rudko, etc.

Unfortunately, the book does not includ the biographies of S.P. Vitryk, V.Yu. Zaichenko, V.P. Kozak, V.I. Miasnikov, V.M. Stefanyshyn, S.Ye. Cherpak, M.V. Chervinska who have made outstanding contributions to develop the base of oil and gas and their output in eastern Ukraine.

The book will be useful not only for professionals and students of the oil and gas industry, but also for the local historians, economists and ethnographers.

I. Leskiv

Candidate of Geologo-Mineralogical Sciences

OIL AND GAS EXTRACTION The effectiveness of modern technologies of secondary opening of productive horizons and the ways of its improvement UDC 622.245.142

S.V. Hoshovskui Doctor of Engineering Sciences

Yu.I. Voitenko Doctor of Engineering Sciences

Ukrainian State Geological Institute

P.O. Sorokin Taras Shevchenko National University of Kyiv

The technologies of secondary penetration of productive formations are considered. Main factors affecting the efficiency of technologies in well completion and operation are shown.

The success of geological exploration (GE) of oil and gas is defined from the technology that is used at the main stages of exploration: seismic exploration, drilling and wells completion. In the field of drilling technology and well completion the most important factors that influence the ultimate effectiveness of the opening of the productive horizons and evaluation of the reliability are the values of repression in the reservoir during the primary and secondary opening, physicochemical properties of process fluids that are used during drilling and secondary opening layers, as well as some technological parameters: perforation depth, quantity, phasing angle holes, hole diameter [1-5].

The purpose of the work is to assess the effectiveness of modern methods of secondary opening of oil and gas reservoirs and to determine ways of its improvement.

The analysis of professional literature [2] shows that secondary opening of productive layers with repression in brine solution (CaCl2, KCl) leads to lower productivity of wells by 40-50 %, oil by 20-40 %.

According to data [1-3] of assessment of the initial opening of drilling productive horizons in the fields of Ukraine following features can be identified:

unacceptably high values of repression during the initial opening of productive horizons, especially in the intervals of abnormally low reservoir pressure (ALRP) at the depths exceeding 2,500 m, this leads to the need to use special activities to trigger off the influx of reservoir fluid [1];

drilling solutions and water-based fluids of well jamming (FWJ), including salt solutions, lead to deterioration of reservoir properties of reservoir granular rocks and permeability reduction by 20-50 % depending on the initial permeability; according to the date, particularly [2], the use of emulsions "water in oil" or petroleum based drilling solutions (or FWJ) enables to obtain specific well efficiency 4-20 times greater than the flushing of bottom hole with water or water-based drilling solution;

special drilling solutions are used outside Ukraine (in some cases in Ukraine) that pollute the area around the hole less; foreign drilling and service companies are using technology to balance the initial opening and pressure drawdown.

International experience [2-5 ], as well as author studies conducted for several dozen fields of Dnieper-Donetsk Basin (DDB), Carpathian and Transcarpathian basins showed that it's very

important for ultimate effectiveness of the opening of productive horizons the technologies of secondary opening: in case of drawdown, on the equal balance or overburden on formation. For drilling technologies with the use of clay, polymer-salt, polymer-humate solutions [1], or even petroleum-based solutions [2], which is used in Ukraine and neighboring countries, the general rule is a completion of the hole with cumulative perforation for drawdown, on the equal balance or minimal overburden on formation, rarely with hydroperforation or filter. According to our research in the fields of DDB and Sarmatian deposits of Prikarpatsky basin and due to the perforation technology for pressure drawdown with small perforators on the cable the increase of well flow rate in gas and condensate reaches up to 1.2-1.5, sometimes twice or thrice in comparison with perforation the same objects in the overburden with more powerful charges. According to [2], perforation of drawdown with perforators PR-43, PR-54 causes the increase of well flow rate twice or thrice in comparison with perforation charges PCB-80 even after additional intensifying pressure inflow of generator of type PHD.BK-100/150.

Under the conditions of deep drawdown during perforation in a gaseous medium the effect is enhanced so that the performance of the well is increased a lot [6, 7]. In the Russian Federation, the technology of opening of massive gas fields are used in two stages:

Under the conditions of deep drawdown the first few meters of productive horizon are opened with following purification on the torch of open area for a few days;

The opening of the reservoir main body is carried out in a gaseous medium that provides the increased depth of perforation hole of well performance a lot and reduces the cost of development and maintenance, as well as the impact on the environment [6, 7].

Hollow-carrier perforators on the cable and charges of extremely deep invasion, that are creating channels in the rock reservoir in 1.5-1.6 times deeper than their counterparts, are well established in the fields of oil wells in Western Siberia, where they are used for reperforation and overperforation of order to level the profile inflow, the intensification of fluid reservoir influx into active, including in low-wells [8].

Positive results in the case of perforation on overburden on formation of gas condensate wells even with charges of super deep invasion can be achieved only if the following conditions are met:

opening of a minimum of overburden;

injection of a special liquid into project material that does not pollute the rock-collector;

carrying out perforation in the shortest time;

carrying out work on the well development immediately after perforation.

It should be noted that during the overburden on the formation a rock-collector is in a state close to the compression, but in terms of drawdown, especially deep, with perforation in a gaseous medium rock-collector which increases porosity, opening cracks, that means deconsolidation of the rock and the increase of the channel depth. Some formations are deconsolidated by the known mechanism of zonal disintegration of concentric circular cracks around the unloaded well.

During the design work on the secondary openings often the real depth of the channel in the rock reservoir in situ is not considered, which should be commensurate with radius of clogging zone or exceed it for successful object opening. On the Fig. 1 the dependence of the coefficient of hydrodynamic perfection of well from length [2] of the perforation channel is shown. Hence the following result: if the area around the hole is reduced by 10 times of the permeability with the size (radially) of 100 mm, then a channel length = 90 mm gives = 0.4, and = 150 mm – about 0.9, more than twice. For most of the wells drilled in clay mud with overburden of formation, an area of contamination is 0.4-0.6 m, and in some cases up to several meters [2]. So for quality opening it is necessary to have charge of the depth channel exceeding the size of the filtrate invaded zone, that should be no less than 600-700 mm. The majority of Ukrainian and

foreign perforations of mass application have just the same channel parameters or even more, obtained by the method of target shooting of API RP-19B. However, they usually do not provide the well connection with unpolluted area of the reservoir.

Fig. 2. The dependence: a - channel depth from strength [2]: concrete (20 MPa); soft sandstone Berea (41 MPa), solid sandstone Berea (63 MPa), hard rock Nugget (104 MPa), Granite (140 MPa) Blue Thor (154 MPa), b - relative channel depth from the density of the target material (1 - steel, 2 - aluminum alloy, 3 - granite, 4 - concrete, 5 - foam)

The perforation depth in the rock reservoir is usually different from the depth obtained in the channel depth lc from the resistance of rocks [2], in Fig. 2b - from the density of the target material. The curve in Fig. 2b the authors obtained in the tests of the cumulative airtight charge ZKM-38D on aerocrete, concrete, granite, aluminum and steel targets (dc – diameter of charge cartridge). The porosity of aerocrete, concrete and granite in the experiments was respectively 80-82, 20-22 and 1.7-1.9 %. Considering that with increasing of rock density usually increases strength [9], we can predict that the solid rocks of the sedimentary cover and rock foundation the channel depth will be lower, and in the rocks of medium and high porosity, fractured rocks will be more. But it will always be less than the channel depth obtained on the targets of artificial geomaterials or a core material which are promoted by manufacturing and service companies. The graph on the Fig. 2b illustrates the known experimental result of a sharp decrease in the channel depth in brittle materials and rocks (granite channel depth is lower than steel). This means that for dense sedimentary rocks and foundation rocks it is necessary to use a more powerful system perforation.

The analysis of the work results from the secondary opening of productive horizons with increasing depth indicates that at depths more than 4-4.5 km the efficiency of all perforation is reduced because of the decrease in porosity and increase the rock resistance. So often the well did not reach the design productivity [10]. With depth increasing it is necessary to increase the depth and a number of holes, i.e. the power of perforation charges and to accompany the opening operation with the intensification of the reservoir inflow [2].

In reservoirs with low porosity, particularly at the border rate (kп ≤ 5–8 %), the perforation efficiency also falls down sharply. For this type of collector a technology of well completion is required with the inflow intensification or construction of aimed and inclined horizontal wells with completion of their deep invasion perforation, and in some cases the inflow intensification, as it is done during the extraction of shale gas and gas of central basin type type. An alternative may be a special technology of initial opening with limitation of mud filtrate invasion into the reservoir [11].

The reducing of the channel depth in dense hard rock reservoir to some extent is compensated by the crack formation around the hole, which can found in experiments [2]. During overperforation of before perforated intervals these cracks increase in size under the influence of shock waves and hydraulic flows, especially from the charges of cumulative perforators without casing and torpedoes. In the interaction areas of the blast waves from the neighboring charges dilatancy areas can be formed [2, 9]. Cumulative ray penetrates the rock, saturated with filtrate of drilling solution that enhances the intensity of the shock and cracking process.

These physical and mechanical effects explain the positive intensification impact of reperforation at the wells performance, which is further enhanced in the case of perforation in physically and chemically active fluids. It should be noted that there is a class of collectors who have held the opposite: the walls seal of the perforation hole. These are mainly clay and highly porous sedimentary rocks.

It is known that a non-zero angle of charge phasing in the perforator (60°, 90°) increases the well productivity by 10-15% [4]. This fact is explained by the spatial diversity of the holes, which are located in a spiral rather than along the generatrix at zero phasing angle. This arrangement allows the holes to prevent a further thickening of the plastic reservoir in case of high density perforation and increases the volume of drainage area in brittle rocks and quasi-brittle reservoir, reduces hydraulic resistance of fluid movement near the well.

Due to the examples of Yuliyivskyy, Skvortsivskyy and some other fields it was found that the high reservoir pressure in the gas fields and moderate values of overburdern on the foundation during the initial opening reservoir of average porosity, good results are obtained even in the case of perforation during overburden and drawdown in older systems perforation PKSUL-80, DFP-89 , PR-43 and more.

If there is no result after the second opening of low porosity reservoirs, in reservoirs with ALRP, represented with pure quartz sandstones, and in collectors represented by foundation rock (granite, granodiorite), it is recommended to use explosive-pulse method of intensification (section torpedoes , oil-oxidizing mixture etc.), and for rocks with small impurities of the plastic component (clay sandstones, siltstones, including calcareous cement) use pulse-chemical methods of intensification (small section torpedoes, powder generators pressure in combination with chemical and physical chemical reagents in the absence of nearby aquifers).

Finally, it should be noted the main ways to improve opening efficiency of productive horizons:

technology of filtering limitations of the liquid phase of drilling fluids in the reservoir;

technological improvements and technology of secondary opening of productive layers.

From all described above the following conclusions can be made.

Based on the professional literature and research of the authors on the effectiveness of second opening of productive horizons it was found that the conditions of successful opening of object search and extraction of traditional hydrocarbons are controlled moderate values of overburden on a foundation during the primary and secondary opening, the predominant use of secondary opening in deep drawdown layer or at equal balance, the increase of the number and depth of the holes with depth of the reservoir, the minimum period of work, the use of

intensification liquids during the second opening in terms of overburden on foundation. In case of non-compliance with specified conditions intensification treatment should be applied to the working space area of the reservoir, including overperforation and reperforation of perforated intervals in the first stage, the physical, chemical and integrated methods of intensification in the second stage.

In reservoirs with maximum porosity a well completion should include intensified inflow with formation of new drainage channels in the layer in vertical,inclined-aimed and horizontal wells. References

1. Мислюк М.А. До оцінки первинного розкриття продуктивних горизонтів на родовищах України / М.А. Мислюк, І.М. Ковбасюк, В.М. Стасенко, М.В. Гунда // Нафт. і газова пром-сть. – 2005. – № 6. – С. 17–19.

2. Гайворонский И.Н. Коллекторы нефти и газа Западной Сибири, их опробование и вскрытие / И.Н. Гайворонский, В.С. Замахаев, Г.Н. Леоненко. – М.: Геоинформцентр, 2003. – 364 с.

3. Світлицький В.М. Сучасні проблеми розкриття та збереження продуктивних характеристик пластів / В.М. Світлицький, О.О. Іванків, Є.В. Вішнікін // Нафт. і газова пром-сть. – 2006. – № 6. – С. 16–18.

4. Чарли Косад. Выбор стратегии перфорирования / Чарли Косад // Нефтегазовое обозрение. Шлюмберже. – 1998. – Вып. 3. – С. 34–52.

5. Гошовський С.В. Вторинне розкриття нафтогазових пластів та шляхи підвищення його ефективності // Нафт. і газова пром-сть. – 1999. – № 4. – С. 24–27.

6. Силкин Г.Е. Вторичное вскрытие продуктивных пластов на газоконденсатных и нефтяных месторождениях Томской области // Каротажник. – 2005. – № 1 (128). – С. 34–47.

7. Андреев О.П. Новая технология вторичного вскрытия пластов на Заполярном НГКМ / О.П. Андреев, С.И. Райкевич, Р.М. Минигу-лов// Актуальные проблемы и новые технологии освоения месторождения углеводородов Ямала в ХХI веке. – М., 2004. – С. 150–160.

8. Шпуров И.В. Эффективность применения перфорационных систем фирмы «Динамит нобель» на месторождениях Западной Сибири / Шпуров И.В., Абатуров С.В., Ротбергер А.В. [и др.] // Техника и технология добычи нефти. – 2001. – № 2. – С. 7–10.

9. Михалюк А.В. Горные породы при неравномерных динамических нагрузках / А.В. Михалюк. – К.: Наук. думка, 1980. – 154 с.

10. Лукин А.Е. Нефтегазоносные коллекторы глубокозалегающих нижнекаменноугольных комплексов центральной части Днепровско-Донецкой впадины / А.Е. Лукин, Н.В. Щукин, О.И. Лукина, Т.М. Пригарина // Геофизический журнал. – 2011. – Т. 33. – № 1. – С. 3–27.

11. Васильченко А.О. Завершення нафтогазових свердловин в Україні: сучасний стан і можливі напрями розвитку технології / А.О. Васильченко, М.А. Мислюк // Нафт. і газова пром-сть. – 2008. – № 5. – С. 13–15

OIL AND GAS TRANSPORTATION AND STORAGE About the conception of underground gas storage in Ukraine UDK 622.619.24-55

S.О. Storchak D. Sc. in Engineering

V.О Zaiets National Joint Stock Company “Naftogaz of Ukraine”

B.P. Savkiv

New conception of underground storage is proposed. It includes formation of gas hub on the base of West Ukrainian complex of underground gas storage facilities, situated in the centre of Europe.

The high-power underground gas storage (UGS) complex created in Ukraine mainly in 1965–1992 according to its active volume (31.95 bln m3) ranks the second one in Europe after the Russian one and one of the first ones according to the total daily capacity after full filling (250 mln m3). Although in the initial phases of development of underground gas storage facilities, formulation of conceptions of their creation as a normative or directive instrument was not practiced, the relevant conceptual approaches existed indeed. This is first of all an issue for creation of underground facilities for safe gas supply of Kyiv, gas delivery to main gas consumption centers of Ukraine, as well as for grand transit to the European countries [1].

Creation in the last century of underground gas storage facilities (UGSF) in the former USSR was performed on the basis of decrees of the government and orders of the Ministry of gas industry. Therewith, recently they took into account feasibility reports (FRs) on the gas industry development. At the turn of the century, planning of development of the underground gas storage system in Russia and Ukraine is performed on the basis of the approved conceptions.

The conception of creation of underground storage facilities is a primary instrument for creation or modernization of UGSFs and is based on the computer model of combined functioning of the integrated gas supply and underground gas storage system in the long run (for 10 and if necessary for more years) and is updated every five years. The task of the conception is evaluation of irregular gas consumption, prospects of change thereof and development of the strategy of regulation thereof at the expense of further development and optimization of UGSFs in the gas supply system. The conception of creation and improvement of underground gas storage facilities approved in accordance with the established procedure is the basis and, in fact, the first phase for designing of a new storage facility, expansion or modernization thereof.

Establishment of the procedure of systematic updating of the conception of underground gas storage in Russia on the basis of partial or radical change of export gas flows requires adequate improvement of the conception of functioning of the UGS system of Ukraine as the guarantee of reliability of transit gas supplies by the domestic gas transportation system. In 2007–2008, the subsidiary company “Naukanaftogaz” on request of National Joint Stock Company “Naftogaz of Ukraine” elaborated the Conception of functioning and development of the system of gas storage facilities of Ukraine. The structure of the natural gas consumption in Ukraine for the period of 2001–2005 was investigated in it, future prospects were evaluated, seasonal and daily gas demand changes were modeled, necessary gas storage volumes and the maximal capacity of storage facilities were determined, geological features for creation of new storage facilities were proposed, directions for the system development and improvement by 2030 were determined, issues of the technical progress and economic indicators of storage facilities in the market conditions were studied. It contemplates liquidation of shortage of the UGSF capacities in the central and eastern regions of the country by means of completion of expansion of the Proletarke

and Kehychivske UGSFs, expansion of the Solokhivske and Hlibovske UGSFs, modernization of the Chervonopartyzanske, Krasno-popivske and Verhunske UGSF, creation of an additional UGSF in water producing formations of geological structures located in the territory of the Kharkiv, Donetsk and Odesa regions.

The conception reflects the measures on increase of the gas withdrawal rate during the peak years and further study of the technology of substitution of a part of the buffer gas by alternative gases. But the proposed program was fulfilled incompletely. Only substitution of several engines on compressor stations for high-efficiency engines was performed, introduction of reliable sand filters on the sand-carry-over-prone wells was commenced, and preparatory works for introduction of the technology of partial substitution of the buffer natural gas for nitrogen in the Dashavske UGSF are performed.

For a long period of time, high potential of the domestic underground gas storage complex has been used not to full capacity. There is an urgent need for elaboration of an updated conception of underground gas storage with enhanced substation of its appeal both for gas importers and gas exporters. It must become the basis for usage to the fullest extent of transit capacities of the Ukrainian gas transportation system, as well as regulated capacities for parallel routes of the Russian gas. The system of underground gas storage of Ukraine, especially its western complex (the active capacity of about 25 bln m3) is the most advantageous place for creation of the western European gas hub for regulation and assurance of reliability of gas supply of Europe.

Despite creation of a significant gas component for reliability of export in the total active volume of UGSFs of Russia, by no means the coldest winter of 2011–2012 revealed unreadiness of OJSC “Gazprom” for reliable gas supply to the European consumers in the relatively extreme conditions. Only usage of the Ukrainian gas saved in UGSFs facilitated improvement of the situation.

The underground gas storage system built in Ukraine showed its high reliability during full stoppage of delivery of the Russian gas in January 2009, having assured in the relevant winter period gas supply of the country in the non-routine regime at the expense of the previously generated far from being full and significantly spent at the end of 2008 stocks.

In order to exclude economic uncertainty (from the tendency to minimize underground storage to the tendency to increase its potential by 1.5 times), several variants of functioning of the underground gas storage system must be economically substantiated in the new conception. Special attention must be paid to the unique Bilche-Volytsko-Uherske UGSF, taking into account the fact that for a long period of time only a half of its capacity was used.

In order to increase the total gas storage volume, in particular the potential total capacity of underground gas storage facilities, expediency and phasing of expansion of the Proletarske, Solokhivske, Oparske and Kehychivske UGSFs, modernization of the Verhunske and Krasnopopivske UGSFs must also be substantiated. Study of the possibility of expansion of the Hlibovske UGSF must be connected with usage of its capacity during increase of production of gas from the Black Sea shelf fields – Odeske and Bezimenne, its further delivery to the local gas transportation system of the Crimea and the whole gas supply system of Ukraine.

Usage of the international practice is of great importance for development of optimal ways to increase the peak performance of gas storage facilities of Ukraine by means of creation of UGSFs in saline deposits. High performance to ensure peak gas consumption in Germany and France is achieved through usage of UGSFs contructed in saline deposits.

The Institute of Geological Sciences of NAS of Ukraine and Ukrgazproekt [2] proposed the structures in the east and south of the country for creation of such UGSFs. Creation of UGSFs in combination with construction of a salt plant would be economically profitable [3].

Usage at an appropriate level of the proposed new variant of the conception would become for the Government of Ukraine and economic entities a reliable instrument in issues related to

planning of the prospects of functioning of domestic UGSFs for the purpose of usage of their unique possibilities in order to ensure reliability of gas supply to internal consumers and transit gas deliveries.

References 1. Савків Б.П. Підземне зберігання газу в Україні / Б.П. Савків. – К.: Кий, 2008. – 240 с.

2. Чабанович Л.Б. Научно-технические основы сооружения и эксплуатации подземных хранилищ в каменной соли / Л.Б. Чаба-нович, Д.П. Хрущев. – К.: Варта, 2008. – 304 с.

3. Заєць В.О. До питання створення підземних сховищ газу у пластах кам’яної солі / В.О. Заєць, Б.П. Савків, І.В. Ткачук // Нафт. і газова пром-сть. – 2011. – № 2. – С. 44–45.

Article Writers

Serhii Oleksandrovych Storchak

Doctor of Engineering Science, Professor, Laureate of the State Prize in the field of Science and Engineering, Honored Industry Worker. Director of the Labor Safety, Industrial Safety and Gas and Oil Transportation Reliability Department of National Joint Stock Company “Naftogaz of Ukraine”. Graduated from the Kryvyi Rih Ore Mining Institute by occupation of Mining Engineer and the Leningrad Mining Institute by occupation of Engineer-Economist. The principal direction of the scientific activities – reliability of gas supply of Ukraine.

Vitalii Oleksandrovych Zaiets

Associate Member of the UNGA. Head of the underground gas storage sector of National Joint Stock Company “Naftogaz of Ukraine”. Graduated from the Kharkiv State University with the specialization in geology and the Ivano-Frankivsk National Technical University of Oil and Gas with the specialization in oil and gas production.

The principal direction of the scientific activities – operation of underground gas storage facilities.

Bohdan Pavlovych Savkiv

Active Member of the UNGA. Graduated from the Lviv Polytechnic Institute in 1954. The focus of professional interest – underground gas storage, gas industry development history, operation of deep gas wells.

OIL AND GAS TRANSPORTATION AND STORAGE Influence of installation elastic bending on stress-strain state of pipeline aboveground passages in mountains UDK 622.692.4

B.S. Bilobran D. Sc. in Engineering

А.R. Dziubyk Cand. Sc. in Engineering. National University “Lviv Polytechnic”

S.R. Yanovskyi Cand. Sc. in Engineering. Branch “Oil-Trunk Pipelines “Druzhba” of PJSC “Ukrtransnafta”

The experiment-calculated methods of diagnosing stress-strain state of the pipeline aboveground beam passages are shown. By the example of pipeline aboveground passage in the Carpathians the influence of installation elastic bending on its stress-strain state was studied.

Aboveground passages because of various natural and artificial obstacles (rivers, ravines, irrigation channels etc.), as well as dug-up sections of underground pipelines for performance of repair works, belong to especially responsible sections of main oil and gas pipelines. Every such section consists of straight and curved elements (pipes).

In many cases on passages through obstacles of relatively small width they use beam passages without compensation of longitudinal strains and without special bearings on the edges. A characteristic feature of such passages is their hypersensitivity to daily and seasonal air temperature fluctuations, to changes in the pipeline operating mode, to subsidence of bearings and seismic motion effects on adjacent underground sections.

The stress-strain state (SSS) is one of the main parameters determining strength, tenacity and operation reliability of both open sections and the whole linear pipeline portion. The strain state must be determined and analyzed both at the pipeline design and construction phases and during pipeline operation.

It should be noted that determination of the pipe material SSS is an important element of diagnosing of the general technical condition of main pipelines [1], forecasting of strength and endurance of their linear portion [2], taking of a decision on the possibility to continue safe operation or the necessity to perform maintenance and repair works and constructive implementation thereof

The necessity to determine strains in the pipeline wall at the operational phase arises mostly on the so called “potentially dangerous sections” which are operated in difficult conditions and are affected by significant loads related to change in their estimated spatial arrangement.

Fig. 1. Overall view of aboveground passages of “Druzhba” oil pipelines through the Oriava river

The internal pressure is one of the main loads whose effect on pipelines is estimated at the design stage during determination of the wall width. Circular and longitudinal normal stresses arise under the effect of the internal pressure in the pipe wall material.

In accordance with the current standards [3], circular stresses are calculated on the basis of the membrane theory of cylindrical shells according to the well known from strength of materials (structural resistance) “boiler” formula. The value of longitudinal stresses stipulated by the internal pressure mostly depends on the structural layout of the section and its securing conditions and can make up from 30 to 50 % of circular stresses.

As distinct from stress components which depend on the internal pressure and to some extent can be regulated during operation by means of their variation, it’s sufficiently difficult to affect tress components resulted from other loading factors. It relates, first and foremost, to normal and tangent stresses arising in pipeline crosscuts, which are interconnected with internal efforts by longitudinal and lateral forces, bending and rotation moments and are resulted from operation of the pipeline section as the framework.

Occurrence of these stresses is mostly stipulated by deviations of the pipeline longitudinal axis from the designed location during construction or operation.

If the bent axis of the pipeline section is a plane curve, then in the general case such section is under the effect of plane bending, and two main internal force factors arise in the pipeline crosscuts: longitudinal force and bending moment. As to the lateral force, during its effect as the secondary internal force factor is mainly neglected g analysis of the pipeline stress-strain state. In case of a spatial section, the rotation moment arises in its crosscuts as well.

As regards strength calculation, the aboveground pipeline section constitutes in some cases a multiply statically indeterminate system. That’s why determination of internal force factors is related to evaluation of static indeterminacy of structure, which requires study of a geometrical side of the problem – strains of the pipeline axis as the framework. In addition, interaction of the

pipeline with the ground on the underground sections adjacent to the aboveground passage must also be taken into account.

The specificity of static analysis of aboveground pipelines is determined, first and foremost, by the peculiarities of the structural layouts and operation conditions and mostly depends on the availability of intermediate bearings, expansion bend and large-curve pipes (offsets).

The passages laid on the mountain slopes feature arising of high longitudinal stresses in the pipe walls, which are related to excessive elastic pipe bending as a result of grading during construction of oil pipelines.

In order to control the stress-strain state of potentially dangerous aboveground sections of “Druzhba” oil pipelines sections, they use experiment-calculated approaches taking into account the main requirements and recommendations of current normative documents [2, 3].

Fig. 2. Destruction of the mounting group of the second oil pipeline support D = 720 mm

Global stresses existing in the pipe metal are determined by the calculation method according to the linear elastic mathematical model taking into account the results of measurement during on-site surveys of actual lengths of bearings, deflection arrows of initially linear sections, pipe wall width and temperature, metal hardness, bearing loads. Therewith, it is accepted that the oil gravity is = 8 , 7 6 kN/m3, pipe steel elasticity module is E = 2,0·105 MPa, specific weight = 8,76 kN/m3, and the temperature-related linear expansion ratio is = 1,2·10–5 1/°C.

The value of the operating pressure on the controlled section is determined based on the results of measurement of the pressure on the neighboring pump stations taking into account the elevation differences and hydraulic friction losses.

As a temperature drop they take the difference between the measured pipe temperature and the pipe temperature during installation, which is established on the basis of the logs of the works performed on the pipeline route: closure of welded joints and laying of the sections adjacent to the aboveground passages into the trench.

The calculation model according to which an aboveground pipeline is considered a multiple covering stringer with unstrained edges of the cross section being under the effect of the internal pressure, lateral localized forces and distributed loading and longitudinal force is taken as the basis of the mathematical model. Interaction of a pipe with the ground on the sections adjacent to the aboveground passage is presented using the model of an ideal elastic-plastic body. The force method is used for disclosure of the system static indeterminacy. In order to determine displacements, an aboveground section is broken up into finite rectilinear elements. The longitudinal axis geometry is assumed discretely by the coordinates of junction points.

For the purpose of calculation using the personal computer of aboveground pipeline beam passages in relation to diagnosing of the stress state and strength evaluation during operation, the programs in the TURBOPASCAL language were developed. The results of measurements of the relevant aboveground passage parameters during on-site surveys and the information received during study of the engineering design documentation serve as the basis for formation of the output data.

Fig. 3. Overall view of of the first (along the oil flow) bearing after repair.

The abovementioned experiment-calculated method was used to investigate effect of the installation elastic bending on the stress-strain state of the structural elements of the aboveground passages of the “Druzhba” oil pipelines laid on the Carpathian slopes. Performance of these investigations is continuation of the works [4–6] which are carried out by the specialists of the Research Laboratory of the National University “Lviv Polytechnic” and the Branch “Oil-Trunk Pipelines “Druzhba” of PJSC “Ukrtransnafta” and which are intended for creation of methods to monitor the technical condition of aboveground passages of main oil pipelines.

As an example let’s study the results of analysis of the stress-strain state of the aboveground passages of the “Druzhba” oil pipelines through the Oriava river in the Carpathians which for a long time were operated subject to undersigned overloading of bearings.

The aboveground passages of both girders of oil pipelines were constructed according to the balk structure with two intermediate concrete supports located not far from the passage edges (Fig. 1). On the edges the pipelines lean directly against the ground.

The right side of the river is sufficiently rash, open, with the height of about 5 m. From this side the route crosses a mound coming to the river with the slope of about 5°. According to the design the trench bed slope relative to the horizontal aboveground section makes up 0.051. The left side is flat with the angle of elevation from the river of about 2°, and the trench bed slope 0.021. Covering of both slopes is designed by the elastic bending.

The aboveground passage of the “Druzhba-2” oil pipeline was constructed using weldless pipes 720 × 10 mm, steel grade “Ц” СР, operating pressure 2 MPa.

According to the certificates of these pipes, the least value of liquid limit equals 370 MPa, and the strength limits are 510 MPa. The total length of the aboveground pipeline is L = 34.4 m, and the girder lengths (along the oil flow) accordingly make up l1 = 4; l2 = 22.4; l3 = 8 m.

After long-term operation (33 years), destruction of the rear cap and mounting group was revealed up to the riser of the second (along the oil flow) U-shaped concrete support (Fig. 2) installed in 1961 during construction of the “Druzhba-2” oil pipeline. The aboveground section of the “Druzhba-2” oil pipeline was laid onto this support in August 1969.

As a result of this destruction a clearance between the rider and the bottom of oil pipeline with the diameter of 529 mm was formed, which brought to increase of the girder from 22.4 to 31.4 m (8 m from the support to the ground edge plus 1 m of the gap between the trench bed and the pipe bottom). Therewith, the pipeline with the diameter of 720 mm was partially supported by the destructed mounting group.

Analysis of the results of visual inspections and measurement of the elevation points of the top generatrix of both aboveground pipelines allows making of the following conclusions.

The main reason for destruction of bearing elements of the supports of the abovementioned objects is their overloading by the forces giving rise to elastic bending of the pipe in the vertical plane as a result of essential elevation of the support points over the designed height during construction of the “Druzhba-2” oil pipeline. It is evidenced by the downshift of the pipeline rider with the diameter of 720 mm connected with destruction of the mounting groups in relation to the initial position after the installation one of about 180 mm.

Destruction of the support as a result of gradual development of cracks occurred during a long period of time and began with breakage of welded joints made of the elbow of the cap sills to which the base plates of aboveground pipeline frames were welded. Growth of cracks can be explained first of all by seasonal changes of the pipe temperature with increase of the loading affecting the support at extreme temperatures, especially during stoppage of oil pumping.

The existing bending in the first support with upward crown in the aboveground pipeline with the diameter of 720 mm pointed at essential overloading of the first support which in two weeks brought to destruction of the console corbel of the right along the oil flow concrete riser of this support.

In order to renew the bearing capacity of the supports, the top part of the concrete risers was implanted by the metal with the width of 12 mm, the destructed concrete girders were replaced by the metal ones taken from the pipe and channel beam which were installed below the previous location of the concrete girders (Fig. 3), which allowed significantly decreasing of operating loads onto the supports. The result of measurements of the loading onto the girder of the first and the second supports of the pipeline with the diameter of 720 mm showed that they made up accordingly 90.5 and 99.0 kN.

Comparison of the main parameters of the aboveground passage of the “Druzhba-2” oil pipeline before destruction of the supports and after repair is given in the table, and the relevant curves of the bent axis of the second girder is shown in Fig. 4. The Table also shows the results of calculations for the rational variant corresponding to equality of the largest values of the bending stresses in bearing cross sections, in the middle of the second girder and absence of the pipe elastic bending in the adjacent underground sections.

Fig. 4. The curve of the bent axis in the vertical plane of the second girder of the aboveground passage of the pipeline with the D = 720 mm (points-experimental data, solid lines based on the calculation results: heavy line – before destruction, thin line – after repair)

Analyzing the obtained results (Table, Figure. 4), we see that the bending arrow of this girder is an essential influencing parameter of the stress state of the aboveground passage with two intermediate supports and absence of bent elements on the second girder. It should be noted that according to the design the second girder of the abovementioned passage is rectilinear.

Table

State Supporting forces, kN

Excessive elevation on the supports, mm

Bending arrow, mm

Stress, MPa

Position of

dangerous crosscut

estimated actual

Before destruction of the support

121.6 225.1 90 219 -72 — 194.4 ІІ support

After repair 90.5 99.0 11 9 6 -18 90.2 І support

Rational 93.1 89.9 -6 -8 26 — 43.6 І–ІІ

A relatively small downward bending arrow and sufficiently small values of maximal bending stresses is characteristic for rational technical condition of such aboveground passage. The crown of the bent axis of the initially rectilinear second girder is indicative of overloading of the supports and excessive stress of the pipeline in the supporting crosscuts. The maximal bending stresses before beginning of destruction of the mounting groups are 4.46 times larger than their values in comparison with the rational variant, after reconstruction they decreased by 2.15 times.

As it was mentioned, the excessive overloading of the second mounting group of the oil pipeline with the D = 720 mm resulted from excessive elevation of the supporting points in relation to the designed height became the main reason for its destruction. The Table gives the values of excessive elevation of the supporting points in the intermediate supports in relation to the straight line connecting the pipeline supporting points at the beginning of the adjacent underground sections.

The difference between the experimental and calculated values of the bends on the second girder after repair (Fig. 4) can be explained by initial deviations from the straight line related to performance of the erection welded joints, as well as to the creep resulted from the long-lasting effect of high level of bending stresses. The mountain-shaped pipes from which the oil pipeline is constructed have the valley depth of up to 2 mm.

Based on the survey results it was established that essential negative deflection arrows (100–200 mm) also exist on some aboveground passages of such type with two intermediate supports and initially designed rectilinear second girder, and the maximal estimated total longitudinal tension stresses determined taking them into account are close to the minimal liquid limit. Although despite long-term operation of the pipeline (42 years) no signs of destruction of the mounting groups were revealed here.

Fig. 5. Overall view of the mounting group of the oil pipeline with the D = 720 mm, whose frame is leaned onto the riser and girder.

It can be explained by location of the essential portion of the supporting frame immediately above the riser (Fig. 5), and, correspondingly, the girder mounting group undergoes considerably lesser stresses as compared to location of the frame only above the girder, as we can see it in the

case of the investigated aboveground passage (see Fig. 3). In addition, it should be noted that on this section of the route the oil pipeline is operated under relatively low pressures (< 1.5 MPa).

So, the existing pipeline installation elastic bending in the vertical plane on some aboveground passages of the “Druzhba-2” oil pipeline related to essential elevation of the supporting points in excess of the designed height gives rise to significant overloading of the supports and overstress of pipes in the supporting crosscuts.

References

1. Правила технической эксплуатации магистральных нефтепроводов. – М.: Недра, 1979. – 159 с.

2. ДСТУ-НБВ.2.3.-21:2008. Визначення залишкової міцності магістральних трубопроводів з дефектами // Мінрегіонбуд України. – К., 2008. – 87 с.

3. СНиП 2.05.06-85. Магистральные трубопроводы // Минстрой России. – М.: ГУП ЦПП, 1997. – 60 с.

4. Білобран Б.С. Діагностика напруженого стану надземного переходу нафтопроводу в зоні зсуву / Б.С. Білобран, В.М. Василюк, О.Б. Кінаш// Механіка і фізика руйнування будівельних матеріалів і конструкцій. – Львів: Каменяр, 1998. – Вип. 3. – С. 580–584.

5. Bilobran B. Diagnostyka stanu naprezen odkrytych odcinkow ropociagow eksploatowanych w warunkach skomplikowanych / В. Bilobran, W. Wasyluk // Materialy ІI Krajowej Konferencji Technicznej «Zarzadzanie ryzykiem w eksploatacji rurociagow». – Plock. – 1999. – S. 129–132.

6. Білобран Б.С. Напружено-деформований стан надземного балкового переходу в кожусі магістрального нафтопроводу / Б.С. Білобран, А.Р. Дзюбик, С.Р. Яновський // Нафт. і газова пром-сть. – 2010. – № 1. – С. 50–52.

OIL AND GAS TRANSPORTATION AND STORAGE Replacement of buffer gas with nitrogen in gas storage formations (models, methods, numerical experiments) UDK 621.64.029

N.M. Prytula Cand. Sc. in Engineering

O.D. Hryniv LLC “Mathematical Center”

Mathematical Modeling Center of the Pistryhach Institute for Applied Problems of Mechanics and Mathematics of the National Academy of Sciences of Ukraine

R.L. Vecherik, R.V. Boiko Cand. Sc. in Engineering, PPJSC “Ukrtransgaz”

The paper gives description of the object of study - reservoir of the underground gas storage facility. A problem of replacement of buffer gas with nitrogen is raised and the problem formulations for its candidate solution are shown. A mathematical model of replacing buffer gas with nitrogen is proposed, which includes filtering model and convection model - diffusion of gases with concentrated sources. For the cases of unmixing gases the algorithm was developed for finding the propagation path of nitrogen. Numerical experiments were carried out.

Gas storage formations are porous media of different permeability. Filtration of two-component gas in them is accompanied by the convection and diffusion processes. The mathematical model of gas filtration in heterogeneous formations is quite complicated. It is related, in particular, to essential heterogeneity of formations. Another factor is that the diffusion and convection processes create flows of different intensity: convective processes in a porous medium are usually much more intensive than the diffusive ones. As a result, the mathematical models of filtration processes in gas storage formations contain transient nonlinear differential equations in partial derivatives with quick-changing and discontinuous ratios. Most of the parameter problems which can be formulated in the framework of such models cannot be solved analytically, so in order to solve them numerical methods must be applied.

The content of any gas storage can be conditionally divided into two parts – buffer and commercial gas. As distinct from the commercial one, the buffer gas as a rule does not go outside of the storage tank. In the filled gas storage the buffer gas is mostly located in the collector – formation parts with low permeability. Essential escalation in prices for the natural gas actualizes the problem of development of economic feasibility of the technology of replacement of a part of the buffer gas with the cheap gas subject to preservation of existing modes of extraction / injection of the commercial gas and environmental safety.

Development of such technology for each specific gas storage envisages performance of numeric and thus on-site experiments. For performance of numeric experiments the mathematical models describing the physical processes which accompany replacement of the natural buffer gas with another gas or liquid are required. In the framework of such models one can evaluate effect of various physical processes on the process of replacement of the buffer gas, make forecast calculations in considerable time intervals and work out the replacement technologies which would ensure controlled effect of replacement of the natural gas on the existing modes of extraction / injection of the gas in storage, as well as work out various replacement variants. All possible replacement variants developed on the basis of modeling and expert values may be classified according to economic and operating criteria, safety degree, feasibility etc.

One of the main problems which cannot be neglected during modeling of replacement of the natural gas with nitrogen is quantitative evaluation of their mixing taking into account effect of changes in directions of the commercial gas flow (extraction and injection modes) and filtration speed, as well as interdiffusion of the commercial and buffer gases. In case of high intensity of mixing, the commercial gas quality decreases, that’s why replacement of the buffer gas with the commercial one may become economically unjustified. The process of mixing of the buffer and commercial gases in heterogeneous formations will essentially depend on intensity of injection of the buffer gas, flows between heterogeneous gas storage formations which depend on the storage operating modes.

Construction of the mathematical model in order to describe the physical processes which accompany replacement of a part of the buffer gas with nitrogen and work out various replacement variants, economical advantageous volumes and paces of replacement requires solving of a range of tasks, in particular:

performance of comparative analysis of gasodynamic characteristics of nitrogen and the natural gas;

study of filtration, diffusion properties and solubility of nitrogen in the natural gas under the real conditions of interaction thereof with each other and the water;

study of dynamic parameters of interaction of gas with porous medium of the formation (study of factors of influence on the interaction dynamics);

study of the processes of mixing of the natural gas and nitrogen during their cofiltration;

performance of analysis of the processes of codiffusion of nitrogen, the natural gas and water;

study of the processes of combustion of the natural gas with various nitrogen concentration and effect of the nitrogen concentration in the natural gas on the mixture heating value;

modeling of the process of extraction / injection of the natural gas with concurrent injection of nitrogen;

planning of the UGSF operating modes with partial replacement of the buffer gas with nitrogen and evaluation of its efficiency for specific collector-layers.

Solving of these tasks is possible in the framework of adequate mathematical models which describe replacement of the buffer gas taking into account the volumes and paces of displacement of the buffer gas with the cheap substitute. Besides, in order to solve nonlinear dynamic problems formulated in the framework of such models, efficient numeric methods must be used.

The works [1–7] are devoted to the problem of modeling of the processes of gas filtration in underground storage facilities. But the filtration problems arising during investigation of replacement of the buffer gas with nitrogen in specific gas storage facilities has presently been studied insufficiently.

This work is intended to construct the mathematical model of two-component isothermal filtration of the gas mixture in the formations which are heterogeneous by permeability, porosity and capacity, formulation in the framework of the model of the problems of replacement of the buffer gas with nitrogen, development of numeric methods of solving thereof and quantitative study of the filtration processes.

Fig. 1. Structural map with division of the UGSF into activity blocks

Physical study subject – collector-layer

According to the data of the studies performed during operation of the Dashavske underground gas storage facility (UGSF), the gas saturation zone of the facility and the gas volumes accumulated in it can be divided into four blocks (Fig. 1), delimited by the low permeability areas. The first block contains the main operating deposits Г and Е which are directly operated in the gas injection and extraction modes. During cyclic operation, the gas outflows from these deposits to the deposit Д-Д1 and the next one and vice versa.

The second block is transient from the active zone of the first block to the dead zones. The deposit Д-Д1 belongs to it.

The third block is located to the south from the tectonic deformation. Arrangement of the deposit Ж+В corresponds to the forth block. Unessential inflow of the gas to it from the second block of the deposit Д-Д1 is possible.

Presently, interaction between the deposits became stable, which stipulates stable operation of the storage facility in general. The gas deposits Г, Е, Д and Ж+В in the aggregate make up a uniform gas-hydrodynamic system and are operated as one object of the gas facility.

Study subject parameters The total porous volume of the UGSF makes up 117.4 mln m3, including the deposits

Е+Г+Д – 108.5 mln m3, deposits Ж+В – 8.9 mln m3. The total area of the UGSF deposits (Е+Г+Д) makes up 62,790 thsd. m2, including the first block – 19,350 thsd. m2 (30.8 %), the second block – 23,600 thsd. m2 (37.6 %), the third and the forth blocks – 19,840 thsd. m2 (31.6 %).

Analyzing propagation of the gas among the blocks at the end of the extraction (as of 01.04.2002) and injection seasons (as of 01.10.2002), we make the conclusion that the third and the forth blocks are “replacement” zones with the gas reserves of about 460 mln m3, which practically did not change during the cycle. In the second block the “dead” area contains about 1,500 – 1,600 mln m3 of the natural gas. On this basis we can make the conclusion that in the dead areas about 1.9 blnд m3 of the natural gas which likely can be replaced with nitrogen was accumulated.

Mathematical model of filtration-diffusion processes

Nitrogen filtration in the porous medium filled with the natural gas is stipulated by the gas codiffusion and coconvection. As a result, on the edge of the media the gas mixing area appears with the gases which are close by viscosity. Convective diffusion depends on the structure of porous channels. The value of the convective diffusion is affected by pore dimensional variation. Molecular diffusion is determinative in case of low paces of the process of displacement of the natural gas by nitrogen. In case of the gas flow paces of about 3-4 m/sec the ratios of the molecular diffusion and convective diffusions are of the same magnitude. In case of high paces

of the gas filtration, the convective diffusion ratio is by 1-2 orders more than the molecular diffusion ratio. As the gas turbulence degree increases the molecular diffusion value decreases practically to nothing.

Formulating the mathematical model of replacement of the buffer natural gas with nitrogen we will proceed from the fact that according to gasodynamic characteristics the natural gas and nitrogen differ insignificantly. So, it should be expected that their permeability in porous media also differs insignificantly. It gives us the ground to combine the problems of filtration of both gases into one filtration problem. Such assumptions must not essentially affect the modeling results, since uncertainties as to the main physical and geometrical parameters of the formation are more essential.

In terms of such assumption, in case is the natural gas and the substitute are not mixed, the problem resolves itself to finding of the gas propagation limit at every moment of time of the replacement process. In other case one must determine the nitrogen (or the natural gas) concentration) in the gas mixture generated during the replacement process as the function of spatial coordinates and time.

We will calculate the gas-substitute volumes in the formation medium using the nitrogen state equation. The nitrogen compressibility factor under the real formation conditions will be close to 0.97.

Mathematical model of gas filtration. The gas storage facility formation is the geological formation which occupies a certain three-dimensional area and is characterized by a certain width and lateral dimensions. In order to describe the gas flows in the formation, let’s introduce the Cartesian coordinate system {x, y, z} with the directed vertically (conversely to the gravitation forces) axis Oz,. The width h(x, y) of the formation is much lesser than its other geometric dimensions. That’s why the vertical fluctuations of the values of gasodynamic parameters are insignificant, and, thus, we can neglect their dependence on the width coordinate and study the formation as a two-dimensional area limited by the line Г. The well bottom areas , i = 1, ..., n, whose sizes are small in comparison with the sizes of the area will not exclude the area . Then the line Г delimiting the formation consists of the line delimiting the bottom area and the line determining the external limit of the formation:

The gas propagation pressure p(x, y, t) during its filtration process in the porous medium is

determined using the equation [3]

where k = k(x, y, p) and m = m(x, y) – permeability and porosity factors, q(t) – source function; – compressibility factor; – dynamic viscosity ratio; – atmospheric pressure.

Since the value of the formation pressures in the bottoms of operating and supervised wells are known, then the pressures in the areas are assumed as given. That’s why on the portion of the line Г solution of the equation (1) must be subordinated to the Dirichlet’s boundary condition

where – components of the external normal vector up to the line .

Mathematical model of gas diffusion. The nitrogen concentration propagation C(x, y, t) in the porous medium filled with the natural gas is determined by the equation:

where D – molecular diffusion factor, – components of the gas filtration (convective transfer) pace vector, U(x, y, t) – known function of nitrogen concentrated sources. The molecular diffusion factor can be determined using the known formula [7]

where T – absolute temperature, P – gas pressure, vA, vG and MA, MG – mole volumes and mole weights of nitrogen and the natural gas correspondingly.

Solution of the equation (4) must be subordinated on the line to the boundary condition

which determines permeability for nitrogen of the formation limit .

The source function U determines intensity of the gas-substitute through the wells which are used for nitrogen injection into the formation. Since the bottom areas are small as compared to the formation sizes, then we will consider the function U as the totality of concentrated sources, presenting it in the form of

where NA – quantity of the wells through which nitrogen is injected into the formation, –

intensity of nitrogen injection through the i-th well – Dirac’s delta-function, – Heaviside’s function, – coordinates of the i-th well, – moments of commencement and ending of the process of gas injection through the i- th well.

Statement of problems. Identification problem [4]. Let’s consider the formation as the

combination of n various interconnected formations . The multitude of the formations is divided into the subset of the operating and buffer

formations: , where and – quantity of the operating and buffer formations correspondingly.

We will consider that in any formation there are the wells through which measurement of the formation pressure can be performed. The results of such measurement for the k-th well in the i-th formation can be given in the form of the time dependency , , where – period of time during which the pressure was measured in the k-th well of the i-th formation.

These empiric data can be used together with the mathematical model (1)–(3) in order to determine the pressure propagation in the formations and identification of filtration of the formation properties. In particular, based on the formation pressure measurement data in the framework of the mathematical model (1)–(3) the following tasks can be considered:

to find change in time of the average value of the formation pressure for each formation and determine dynamics of the gas flows between the formation and permeability

of the interformation areas;

assuming that the powers and porosity factors of the formations are known, to find factors of their permeability ;

subject to change of the middle formation pressures to determine the volumes of the gas accumulated in the formations and using the gas state equation

, where – surface area , average porosity, power and pressure in the formations correspondingly, to ascertain the average parameters of the formations та .

It should be noted that there are no universal algorithms of identification of the collector-layer model parameters. It is connected with the complex geological structure of the formations, their heterogeneous propagation, usage of the two-dimension model, impossibility to divide effct of the parameters on the pressure propagation, irregularity of arrangement of the wells both operation and supervised impossibility to perform measurement of losses concurrently in all wells etc.

Buffer gas replacement problems. Let’s assume that – multitude of the wells existing in the blocks 1–3, and – multitude of additional wells which, if necessary, can be installed at the gas storage facility. We will consider each of the multitudes as combination of two subsets

where

– multitude of existing wells which can be used for nitrogen injection into the formation during the replacement process, – multitude of existing wells which can be used for nitrogen extraction from the formation during the replacement process, – multitude of additional wells which must be installed for nitrogen injection азоту into the formation, – multitude of additional wells which must be installed for nitrogen extraction from the formation during the process of replacement of the natural gas with nitrogen. We will designate the multitudes of the well coordinates consisting of the multitudes and as and , ..., , where

– quantity of additional wells intended for gas injection, – coordinates of these wells, – quantity of additional wells intended for gas extraction, – coordinates of these wells. We will designate as , ( – quantity of existing wells intended for gas extraction) intensity of extraction (loss) of the natural gas through the i-th well, and as

, intensity of extraction (loss) through the j-th additional well which must be installed for the gas extraction. We will designate as та – losses of the fuel gas in the wells consisting of the multitudes

and correspondingly. Let’s assume that T – given period of time. Let’s introduce the gas extraction functional , nitrogen injection functional and fuel gas loss functional

during the process of replacement of the buffer gas in the formations with nitrogen

It comes out from the mathematical model (1)–(6) that under the given initial conditions in

all the formations , given gas extraction modes , and , as well as given nitrogen injection modes ..., and ,

functionals , and depend only on division of the multitude into the subsets and , as well as on the multitude of additional wells and

And coordinates of their arrangement in the formations, which are determined by the multitudes

and

Let’s formulate the problem of determination subject to the productive process of optimal extraction of the buffer gas with replacement thereof with nitrogen based on the given gas extraction modes , and and nitrogen injection modes

{1, ..., and {1, ..., determine the multitudes according to which the gas extraction functional , calculated using the mathematical model (1)–(6) achieves the maximal value

subject that the fuel gas loss functional does not exceed the given value :

and the nitrogen maximal concentrations in the working seam does not exceed the given value Ci*

let’s assume that the multitude of the well and its subsets and are given: In this case we can formulate the problems of optimal regulation of the buffer gas extraction and replacement modes.

Let’s designate as the set of the functions determined in the period of time Та, which determine the modes of nitrogen injection into the formation through the wells

- set of the functions determined in the period of time which determine the modes of extraction from the formation through the wells . As it comes out from the mathematical model (1)–(6) based on the given multitude , the functionals

and depend only on the initial conditions and modes of operation of the wells and :

Fig. 2. Formation pressure in the well 165 of the block 4 and in the operation area within six seasons of the gas extraction and injection

Fig. 3. Estimated formation pressure in the operation area (blue curve) during nitrogen injection into the top of the block 3 with the intensity of 2.9 m3/sec. within 4 years (1,460 days)

Let’s formulate now the problem of determination of the mode of optimal nitrogen injection based on the given multitude of the wells : for the given set of functions which determine the modes of operation of the wells to determine the set of the functions which determine the modes of operation of the wells subject to which the functional achieves the maximal value Q

where – multitude of all possible sets of functions which determine the modes of operation of the wells for which the maximal nitrogen concentrations in the operating formations calculated using the mathematical model (1)–(6) do not exceed the given values

Let’s assume that – set of functions given in the period of time TW which determine the modes of the gas extraction by the wells IW in the operating formations,

– set of functions given in the period of time which determine the modes of nitrogen injection through the wells in the buffer formations,

- set of functions given in the period of time which determine the modes of the buffer gas extraction from the wells in the buffer formations.

Let’s formulate now the problem of optimal control of the modes of replacement of the buffer gas with nitrogen in the operated formation: based on the given set of functions which determine the modes of operation of the wells in the operating formations to find the sets of functions and subject to which the functional calculated for the wells in the buffer formations achieves its maximal value Q

the least of all possible interval гof nitrogen injections and subject that the calculated using the model (1)–(6) maximal nitrogen concentrations in the operating formations do not exceed the given values.

Algorithm of calculation of the nitrogen propagation line coordinates. Calculation of the line of nitrogen propagation without mixing its with the natural gas.

Let’s consider a heterogeneous formation according to permeability, porosity and power. Let’s assume that the nitrogen propagation process happens without its mixing with the natural gas, i.e. separate filtration of two gases is considered. Nitrogen is injected through some wells, and through other ones extraction of the natural gas is possible. According to power (the difference of elevation points of the top and bottom surfaces of the formation) the collector-layer as compared to other sizes is insignificant. The geometric sizes of collector-layers achieve hundreds and thousands of meters, and the filtration processes are studied in significant time intervals (moths and years). In these assumptions the relation of the capillary pressure to the full

hydrodynamic loss of pressure is small. It allows neglecting the capillary forces. The gas flow is subordinated by the Darcy’s law. The gravitation forces are not taken into account.

The gas extraction (injection) in underground gas storage facilities is performed through n wells located in the points within a certain period of time . The density of extraction is determined using the formula

where – gas extraction from i-th well, – Dirac’s delta-function, – Heaviside’s unit function, – gas storage facility volume.

The multitude of all wells S is combination of two subsets of the wells S1 and S2. The multitude S1 consists of the operating wells, and S2 – wells through which nitrogen is injected. In this view, the collector-layer area is also divided into two multitudes of areas. In one of the area multitudes nitrogen is present. In the nitrogen propagation area the following nitrogen state equation is true

And in the external – the following natural gas state equation is true

where F – nitrogen arrangement area.

On the edge “nitrogen-natural gas” the pressure equality condition is true. The condition as to the gas volume in the internal area must also be taken into account.

In order to find the line point coordinates the following actions must be taken: at every moment of time the pace of movement of the points (x, y) of the line must be found

based on the pressure gradient along the normal up to the line delimiting the natural gas and the nitrogen and natural gas mixture, where – filtration pace vector in the direction of the normal in the point (x, y) on the line , k – permeability factor, – nitrogen dynamic viscosity,

– reduced pressure. In case of change of the line length, the density of points (x, y) on the line must be kept stable. In order to accelerate the time of calculation of the line parameters, the density of points on the line may be increased gradually.

One must continuously control the equation where – volume of the gas located in , and – total gas volume which

came into the collector-layer for the time t through n injection wells. In case if the estimated nitrogen volume according to the calculated line is not equal to the injected nitrogen volume (which is calculated based on the parameters of lumped wells), then adjustment of the pace of movement of points on the line is performed in such a way so that to achieve the equality (10) with the given accuracy.

If adjustment of the propagation rate on each time pace will be significant then it can be ascertained:

where the first summand is located in the internal area (nitrogen location area), and the seconf summand – in the external area. For the time the point (x, y) in the direction of the normal will pass the path

During nitrogen injection into several wells, the quantity of unconnected areas filled with nitrogen continuously changes.

Numeric Experiments Experiment 1. Performance of numeric experiments was preceded by adaptation of the mathematical model of calculation of the nitrogen propagation area to real gasodynamic and filtration processes which occur in heterogenic porous areas (collector-layers). The adaptation process consisted in finding of the parameters of permeability of formation of the gas storage facility, its separate blocks and low-permeable interlayers between separate formations. Experimenting on the program complex the adapted parameters were continuously ascertained. One of the important and sufficiently satisfactory arguments as to the model is high accuracy of the calculated parameters of the pressure change dynamics in the neutral period (between completion of the gas extraction and commencement of the gas injection).

Fig. 4. Nitrogen propagation line on the 600th day after injection of 260 mln m3 of nitrogen during 600 days (5 m3/sec.) (а); nitrogen propagation line on the 900th day after injection of 260 mln m3 of nitrogen during the first 600 days (5 m3/sec.) (б)

Calculation of the formation pressure in the operating area was performed within six seasons of the gas injection and extraction. You can evaluate the adaptation results based on the diagrams of the measured and calculated formation pressures in the operating area which are given in Fig. 3. Insignificant deviation of the calculated and measured formation pressures at the initial moment (the first season of injection) occurs based on insufficient balance of the model and real parameters, as well as as a result of different approaches to calculation of the formation pressures (the program allows calculating of the average pressure in the operating area for all operating wells).

It should be noted that the pressure change dynamics in the well 165 of the block 4 is close to real.

Experiment 2. Nitrogen injection was performed in the block 3. It is connected with the fact that the block 4 has sufficiently low permeability of the formation. Several variants were studied. Nitrogen injection was performed with different intensities. Fig. 3 shows the variant of nitrogen injection into the block 3 with the intensity of 2.9 m3/sec. Nitrogen injection effect was evaluated based on change of the formation pressure in the neutral period after the gas extraction.

Visually analyzing the diagram in Fig. 3, you can notice tangible changes of the formation pressure in the operating area (see pressures in the neutral periods).

Table 1 Pressure change (MPa) in the neutral period after injection of 182.9 mln m3 of nitrogen End of the і–th season of the natural gas extraction

After nitrogen injection

Without nitrogen injection

Pressure difference

i = 2 2.868 2.777 0.091 i = 3 2.265 2.116 0.149 i = 4 2.558 2.347 0.211

Table 2 Pressure change (MPa) in the neutral period after injection of 365.8 mln m3 of nitrogen

End of the і–th season of the natural gas extraction

After nitrogen injection

Without nitrogen injection

Pressure difference

i = 2 2.975 2.777 0.198 i = 3 2.397 2.116 0.281 i = 4 2.744 2.347 0.397

Experiment 3. Nitrogen injection into separate wells of the second area was performed during operation of the gas storage facility.

Experiment 4. Nitrogen injection into 4th area was performed within 5 years by four wells with the intensity of 0.7408 m/sec3 (the total nitrogen volume made up 467.237376 mln m3).

The pressure difference value in the neutral periods calculated within 5 years of operation of the Dashavske UGSF is given in Table 3.

Таблиця 3 Pressure change in the operating area during the nitrogen injection process (without extraction of the natural gas displaced from the low-permeable areas)

Year MPa Increase of the formation pressure in the operating area within the season

1 0.0662 0.0662 2 0.1619 0.0957 3 0.2651 0.1032 4 0.3829 0.1178 5 0.5375 0.1546

Concurrently with nitrogen injection into the 4th area which was performed within 5 years by four wells with the intensity of 0.7408 m/sec3 (the total nitrogen volume made up 467.237376 mln m3), the gas was additionally extracted from the UGSF operating area by three wells with the intensity of 0.75 m3/sec (the total nitrogen volume made up 354.78 mln m3).

If the pressures in the operating area at the end of the fifth season based on the found gas extraction in addition to the existing one coincided, then it confirms regularity of the found natural gas volumes displaced by nitrogen into the operating area.

Numeric experiment results 1. The gas volumes which will be displaced into the operating area for each season are

proportionate to change of the pressures in the operating area for the season (the pressure difference subject to absence of nitrogen injection and under the injection conditions), i.e. as of the end of: the first season – 0.0662, the second season – 0.0957, the third season – 0.1032, the fourth season – 0.1178, the fifth season – 0.1546 MPa.

As we see from the given table, the dynamics of flow of the gas displaced from low-permeability areas into the operating area increases over the years.

2. For five seasons of the natural gas extraction and injection as a result of injection of nitrogen with the volume of 467.237376 mln m3 (with the intensity of 256 thsd. m3 per day within five years), 354.78 mln m3 of the natural gas were displaced by nitrogen into the operating area from the low-permeable areas.

3. The buffer gas replacement process is possible. It will be connected more likely with the pressure growth and existing formation anisotropy rather than with the nitrogen line movement. It can be expected that during the line movement nitrogen propagation more than 30 % of the buffer natural gas will get into the internal nitrogen location area.

4. During the neutral period about 130 mln m3 of gas get into the operating area (operating well area), and about 200–250 mln m3 of gas – to the whole operating area depending on the gas injection and extraction volumes. Much more gas gets into the operating area during the gas extraction period. Stoppage of the gas flow from the operating into the third and forth areas can provide 92.08 mln m3 of nitrogen. For the gas extraction season amounting at average to 151 days, replenishment of the buffer gas allows saving 695.5 thsd m3 of the fuel gas.

References

1. Гімер Р.Ф. Підземне зберігання газу / Р.Ф. Гімер, П.Р. Гімер, М.П. Деркач. – Львів: Центр Європи, 2007. – 224 с.

2. Тетерев И.Г. Управление процессами добычи газа / И.Г. Тетерев, Н.Л. Шешуков, Е.М. Нанивский. – М.: Недра, 1981. – 248 с.

3. Вечерік Р.Л. Математичне моделювання процесу руху газу в системі пласт підземного сховища газу – магістральний газопровід / Р.Л. Вечерік, Я.Д. П’янило, М.Г. Притула, Ю.Б. Хаєцький // Нефть и газ. – 2004. – № 6. – С. 83–89.

4. Вечерік Р.Л. Математичний аналіз акумулюючої здатності газоносних пластів ПСГ / Р.Л. Вечерік, Я.Д. П’янило, М.Г. Притула, Ю.Б. Хаєцький // Нафт. і газова пром-сть. – 2005. – № 6. – С. 55–59.

5. П’янило Я.Д. Дослідження впливу параметрів пласта та приви-бійної області свердловини на розрахунок дебіту свердловини / Я.Д. П’янило, М.Г. Притула // Комп’ютерна інженерія та інформаційні технології. Вісник ДУ «Львівська політехніка». – 2002. – № 392. – С. 45–49.

6. Лопух Н.Б. Розрахунок початково-граничних умов в задачах фільтрації газу в пористих середовищах / Н.Б. Лопух, Я.Д. П’янило, М.Г. Притула, Н.М. Притула // Комп’ютерні науки та інформаційні технології. Вісник Національного університету «Львівська політехніка». – 2009. – № 638. – С. 239–243.

Ефимов А.В. Метод расчета коэффициентов диффузии при конденсации водяного пара из продуктов сгорания газообразного топлива / А.В. Ефимов, Л.В. Гончаренко, А.Л. Гончаренко // Теплова енергетика. – 2009. – № 3. – С. 18–21.

INDUSTRY PROFESSIONALS

Volodymyr Tykhonovych Skliar

In 2013 it would be 90 years after the day of birth of the distinguished scholar in the field of petrochemistry and petroleum refining, talented science organizer, honored worker of science and engineering of Ukraine, Doctor of Engineering Science, Professor, Member of the Ukrainian Oil and Gas Academy, Volodymyr Tykhonovych Skliar.

V.Т. Skliar belongs to the pleiad of the leading investigators, scholars and science organizers, whose efforts contributed to creation and development of the contemporary petroleum refining and petrochemical industry of Ukraine. The creative approach to work, strategic thinking, permanent desire for practical implementation of scientific results, extraordinary organizational skills peculiar of him rightly provided Volodymyr Tykhonovych with honor and glory among well-known oil processors and petrochemists not only in Ukraine, but also abroad.

V.Т. Skliar was born on July 14, 1923 in the Khomyntsi village of Romenskyi district of the Sumy region in the blacksmith’s family. After finishing of the secondary school in 1940, he entered the Novosibirsk Institute of Military Engineers of Railway Transport, worked as a lathe operator for some time at the defense factory. In 1942 he was delegated to the withdrawn Kyiv Infantry School where after graduation he trained future officers.

In 1945 V.Т. Skliar served at the Administration of Military Commandant of Ukraine, in 1946 demobilized and entered the second course of the oil department of the Lviv Polytechnic Institute. In 1951 he graduated from the institute with honors and stayed to work at the subdepartment “Oil and Gas Technology” as an assistant, later senior lecturer and vice-dean of the oil department.

In 1954 by the order of the Ministry of Higher Education of the USSR V.Т. Skliar was delegated to the Institute of Petroleum of the Academy of Science of the USSR where under supervision of the well-known scholar – Academician S.R. Serhiienko – in 1955 he successfully defended the doctoral thesis.

In 1956 he was elected as the head of the petroleum geochemistry of the Ukrainian Research and Geological Exploration Institute (UkrNDGRI), and in 1959 – as the petroleum chemistry laboratory chief, and later the acting deputy director for scientific work of the Ukrainian Research and Design Institute (UkrNDIproekt).

In 1963 on the basis of the laboratories and oil filed departments of the UkrNDIproekt V.Т. Skliar initiated and took active part in establishment of the All-Union Research and Design Engineering Institute (VNDPKnaftokhim), the current UkrNDINP “MASMA” and was appointed as its first director.

The scientific and organizational talent of Volodymyr Tykhonovych – the scholar, designer, manager – was especially vividly manifested in the position of the institute director. He founded

a complex research establishment which included the research institute in Kyiv, its branch in Lviv, design departments in Kyiv and Lviv, research plant in Drohobych.

For fruitful work of the institute V.Т. Skliar invited young scholars, talented researchers, designers and industrial workers from well-known scientific petroleum refining and petrochemistry centers of the Union (Hroznyi, Novokuibyshevsk, Omsk, Lviv, Drohobychi etc.).

In 1974 he was appointed as deputy director for scientific work of the Institute of Chemistry of High-Molecular Compounds of the Academy of Science of the USSR, and later – the head of the petrochemistry department of the institute of physical-organic chemistry and coal chemistry (INFOV) of the Academy of Science of the USSR.

In 1984 Volodymyr Tykhonovych defended the doctorate thesis and over the years headed the petrochemistry department of the INFOV of the Academy of Science of the USSR.

As from 1991 till the last days of his life Volodymyr Skliar worked as the general director of the international association “Highly Reliable Pipeline Transport” which functioned under the direct patronage of B.Y.Paton. And here V.T. Skliar manifested his organizer’s and scholar’s talent.

The focus of the scholastic interest of V.Т. Skliar includes a wide range of issues related to petroleum refining and petrochemistry: oil investigation, study of problems of synthesis and technology of alkysalicylate, succinamide and other additives to lubricants, high-viscosity materials which are used in road construction, greases, coke chemistry products, coolants and process means, ПАР for intensification of oil production. Production of over 50 names of oil products destined for assurance of production processes and operation of motor cars VAZ and KAMAZ were developed and promptly introduced under his direct supervision.

Volodymyr Skliar is one of the creators of the powerful petroleum refining industry of Ukraine. He made a significant contribution in elaboration of feasibility studies, designing, reconstruction and construction of the Lysychansk, Nadvirniansk, Kremenchuk, Drohobych, Odesa, Kherson petroleum refineries and Berdiansk distillery.

The results of investigations of Volodymyr Skliar are highlighted in six monographs and overviews, over 180 articles, registered in 136 author’s certificates and patents. He was the chief editor of a range of professional journals and member of various scientific societies. Work of the professor Skliar is awarded with prizes, medals, diplomas of merit.

Volodymyr Tykhonovych died on March 9, 1998, buried in Kyiv at the Baikove cemetery.

OIL AND GAS TRANSPORTATION AND STORAGE

Underground storage facilities as important factor of keeping Ukrainian consumers supplied with gas in the

extraordinary situation UDK 623.459.72

A.V. Datsiuk Ph.D

Public JSC «Ukrtransgaz»

Z.P. Osinchuk Ph.D

NJSC «Naftogaz of Ukraine»

Gas deliveries to Ukrainian consumers in the situation of full stopping of its importation by using Precarpathian underground gas storage facilities and gas transmission system reversing mode of work is described in the article.

Ukraine belongs to the countries with the developed gas industry. T e country gas consumption in 2012 totalled 54,7 bcm against 118,8 bcm in 1990 when Ukraine af er this index was third in the world af er the USA and Russia. During last two decades yearly gas consumption per capita decreased from 2.3 thousand cm to 1.2 thousand cm. More than double reduction of gas consumption for independence years is determined by falling of industrial production, restructuring of national economy, improvement of power sector structure and measures on the increase of energy ef ciency. If in 1990 natural gas was used mainly in industry and for power generation, and domestic users acted second-rate part (17,9 %), in 2012 the f rst place on the volumes of gas consumption belonged to the domestic sector (49,3 %). T e pattern of gas consumption became similar the countries of the European Union.

In 2011–2012 gas consumption totalled 55–59 bcm. Gas supply of the users is carried out both due to a domestic production (20–21 bcm per year) and to its import from the Russian Federation. T e powerful board far f ung network system of gas pipelines enables not only to supply with gas domestic consumers but also to carry out transit of Russian gas to the countries of Central and Western Europe and Tu r k e y [1].

Transit gas shipping from Russia reached the maximum in 2001–2010 totalling 110 bcm per year on the average.

Underground gas storage facilities Gas consumption in Ukraine, as well as in other countries with the developed gas industry,

is irregular during a year. If, for example, in January day's consumption is 150–160 % of average annual one, in July it makes only 40–45% (Fig. 1). It should be noted that the greater specif c gravity is in the gas consumption of domestic users, the greater irregular of season consumption. Taking into account that day’s gas production, as well as import, during a year f uctuate comparatively little, in a spring-summer season there is considerable surplus of gas which is injected into underground gas storage facilities (UGSF), and by the winter this gas is withdrawn from storages and comes to the market to meet the increased demand.

Fig. 1. Gas consumption in Ukraine during a year

For the reliable supply of gas users in the circumstances of irregular season gas consumption the complex of UGSF was created mainly in the depleted gas f elds of western (Precarpathian) region by total capacity on working gas of 31 bcm. T is complex was created in the period of increasing in 70-80th of the last century of volumes of internal consumption, and also most in the world of gas transit deliveries. T e for today existent capacity of the Ukrainian UGSF exceeds indigenous needs and they are mostly used for the regulation of transit Russian gas deliveries [2]. In a fall-winter period the Precarpathian UGSF are used for adjusting of transit deliveries on the western border of Ukraine not only through the irregularity of supplying with gas from Russia as a result of possible breakdown of transcontinental gas pipelines or sharp drop in a temperature but also for indemnif cation of part of transit gas, used in the east regions of Ukraine in this time of year.

Stopping Russian gas deliveries In such mode the gas transmission system (GTS) worked during a few decades. But a

situation sharply changed on January 1 in 2009, when Russian Gazprom on 8.27 January 1 warned about stopping the delivery of gas for the users of Ukraine by a volume 110 MMcm per day from 9.00. For other European countries gas continued to enter system (Fig. 2).

As such situations in a Ukrainian gas transmission company «Ukrtransgaz» were simulated, it was used preliminary envisaged measures on providing of maximally possible volumes of gas production from own f elds (increasing a gas withdrawal from wells, stopping of gas injection on f elds developed on technology of cycling-process etc.) and maximal gas extraction from underground storage facilities. Dispatcher's service in the real mode of time, coming from the technological information, conducted the calculations of the modes of exploitation, simulation of charts of switching compressor stations and valves in the case of change of directions and terms of transit gas deliveries, possible origin of emergencies, refusals of equipment and other situations.

Without regard to some diminishing of volumes of transit gas on inlet of GTS of Ukraine, it was enough of gas for providing both own users and transits deliveries to other European countries. Users of East and South Ukraine, wherever gas from own f elds and storage facilities of these regions was not enough, were provided in such a manner. Transit gas transmitted by mains «Soyuz» and partly «Urengoy - Novopskov», was consumed by users of these regions, and the volumes of the withdrawal gas were compensated by gas from the storage facilities of Western Ukraine, that provided the gas deliveries to Europe almost in the planned volumes. As a result of the accepted measures to January 5 the system worked practically in the regular mode.

From January 5 new substantial reduction of gas shipping into Ukrainian mains began, and on January 7 export deliveries of Russian gas through Ukraine were halted fully (Fig. 3). Possibility of such scenario of events development, when among the winter gas deliveries to the pipelines system are simultaneously halted in over 430 MMcm per day for the users of Ukraine and for other 20 European countries, was not foreseen and simulated never before. T e GTS of

Ukraine passed to work in autonomous behaviour. For avoidance of its misbalancing through hour-one and a half af er stopping of Gazprom gas shipping were closed valves on an exit from Ukraine in directions to Moldova and others European countries.

In a world history such occurrence took place only ones, but in incomparably less scales, when in 1976 af er arrival of new power in Iran the export of Iranian gas was halted to the former USSR by a volume about 30 MMcm per day, that made 3,5% of that time volume of its consumption in the country.

GTS reversing In Ukraine there was an extraordinary situation in providing users by gas, especially in its

south-east region, where f erce the winter stood with frosts to minus 27 C. Volumes of gas f elds produc t ion, as wel l as c apacit y of UGSF of t h is reg ion were to sm a l l to supply regional consumers. But there were suf cient resources of gas in the west storage facilities, the capacity of which makes an about 80% total capacity of Ukrainian UGS. T ey considerably exceeded the needs of region and not used in this moment for adjusting of transit deliveries. In this extraordinary situation the unprecedented reverse of the GTS was carried out for a day long, and gas from western gas storages was directed in the areas of south and east of Ukraine.

It should be underlined that GTS of Ukraine is very branched, transit mains have a few parallel lines with multishop compressor stations and are connected by pipeline crosspieces. It permits gas pipelines network to be high manoeuvrability and reliability for customers gas supply. Such mains pecularity and transit gas absence gave a possibility transmission system to turn to east and south gas f ows, though traditionally gas was delivered from east to west.

Fig. 2. Russian gas flow into Ukrainian gas transmition system on 01.01.2009

Fig. 3. Russian Gas flow into Ukrainian gas transmition system 01- 07.01.2009

Gas pipeline reversing chart was following (Fig. 4). Compressor stations (CS), located on Precarpathian UGSF, took of storing gas and delivered it to mains. Pipeline compressor stations (CS) worked in follow modes:

CS Dolyna, receiving gas from storages, delivered it in two directions: in «Soyuz», Urengoy–Pomary–Uzhhorod, «Progres» pipelines and in Kyiv-West Ukraine pipeline;

CS Bohorodchany, Husiatyn, Bar pumped over gas to the users of east and south by gas pipelines «Soyuz», Urengoy– Pomary–Uzhhorod and «Progres»;

CS Romny gave gas in a pipeline Kryvyi Rih to the south users;

CS Reshetylivka worked in the project mode, pumping over gas by pipeline Kryvyi Rih southward Ukraine;

CS Novopskov and Loskutivka gave gas in direction of Donetsk and Mariupol;

CS Radushne pumped over gas, which came from gas pipeline Yelets–Kursk–Kryvyi Rih, in two directions: one workshop gave gas in the side of Mykolaiv and Odesa, second, – to Dnipropetrovsk [3].

In the mentioned mode GTS of Ukraine worked to Januar y 20, when gas deliveries were fully restored from Russian Federation. During one day 160 compressor units on pipelines were put into operation, all pipeline establishments were switched and the GTS was carried out on regular mode.

It should be noted that the executed chart of gas deliveries from west to east was carried out in the hand mode, as existent programs of simulation of dif erent situations on gas pipelines such extraordinary situation was not foreseen. Due to high qualif cation of dispatch's personnel a chart was successfully realized, and residential users even in the remotest corners of Ukraine did not feel problems with the supply of gas or heat. Certainly, in this extraordinary situation the industrial users of gas were something limited and they mainly passed to the reserve type of fuel.

Fig. 4. Ukrainian gas transmission system It should be underlined that in this extraordinary situation the several of gas from Ukrainian

storages was delivered to Moldova, which did not have other sources of gas supply. A question was studied also in relation to possible delivery of gas from Ukrainian UGSF to Bulgaria.

At a reverse the GTS survived serious examination on its integrity and reliability. In fact some sections of gas pipelines on the entrance of the compressors stations, which by decades worked at reduced pressures through its falling on the route of gas pipeline, found oneself on the output of the stations, where pressure was substantially higher. And if there were some defects on pipelines, which did not prove during of long duration work in the conditions of lower

pressure, at its increase could prove, that would result in serious failures. As failures of gas pipelines were not in this period, it af rms their suf cient margin of safety and operating reliability.

Summary 1. Powerful underground gas storage complex as well as some level of indigenous

gas production can provide gas supply of residential and industrial consumers in the circumstances of full stopping gas deliveries from abroad.

2. High manoeuvring gas transmission system af rms the suf cient safety and operation reliability as well as capability to carry out the reliable gas deliveries to country consumers in the extraordinary situation.

3. T e experience of the maximal use of resources of UGSF and work of the GTS in the reversible mode in an extraordinary situation can be useful to other countries, which do not have the proper diversif cation of gas supply sources and for diverse reasons can appear in a similar situation.

4. Connected by pipelines with all neighbour countries West Ukrainian underground gas storage complex would became a reliable East European gas hub for gas transmission balancing of the region.

References

1. Rozhoniuk Vasyl. Ukrainian gas transit system expanding, modernizing to meet demand / Vasyl Rozhoniuk, Zinovii Osinchuk // Oil & Gas Journal, Feb. 19, 2001, pp. 46–49.

2. Datsiuk Andrii. Role of underground gas storage facilities of Ukraine to ensure reliable and efficient gas consumption / Andrii Datsiuk, Petro Galii // 25 World Gas Conference, 2012, Kuala-Lumpur.

3. Землянський В.В. Робота газотранспортної системи України в стані підвищеної готовності / В.В. Землянський, П.В. Афанасьєв // Трубопровідний транспорт. –2009. – № 1. – С. 7–12.

ALTERNATIVE TECHNOLOGIES AND ENERGY PERFORMANCE Exhaust gases heat recovery of GPU gas turbine compressor of gas-main pipelines А.О . Redko Doctor of Engineering Science

О.F.Redko

KhNUBA А.І. Kompan T.O.V. «Regional gas company»

The choice of the rational heating scheme of gas turbine exhaust-gas heat utilization of main gas pipeline gas-compressor units is one of the actual problems of increasing energy efficiency of gas transportations. A number of well-known publications state that problem solution can not be considered to be completed, some results of investigation being conflicting and requiring more precise definition, taking into consideration that the processes of converting low potential heat into electric power are considerably complex. The thermodynamic efficiency and various parameter influences are also analyzed. The choice of the plant working-medium at the temperature of exhaust gases of 350-380C is explained in detail.

Improvement of energy performance of gas main pipelines is ensured by energy saving during the transportation of natural gas. The power resources growing prices tendency impetuses to conduct energy-saving measures in the transportation of gas in the following areas: energy saving processes gas transportation, gas pumping energy saving appliances, use of waste energy [1–4].

At the compressor stations (CS) of gas mains pipelines is used centrifugal supercharger with turbine drive. Efficiency of gas turbine plant, is 23-28%. In modern gas turbine plant under operation the efficiency is higher. However, over 70% of heat is lost with exhaust gases. The temperature of the exhaust gas reaches 450-500°C, the gas losses is 60–120 kg/s.

Number of recovered heat for various types of gas turbine is based on the temperature: 20–32 МWtt for gas turbine complex is 10-4, 25–30 МWtt for GTC -16 and 28–46 МWtt for GTC -25 [5–9].

At the gas compressor stations are installed several gas turbines units. It depends on the performance and mode of operation of the pipeline, which determines the annual amount of recovered heat of the multi-workshops CS. Thus the indexes of CS gas efficiency (the ratio of the GTU CS gas-flow rate to the transport work) inferior to foreign at 7.12 m³/(mil m³• km) [3 , 4]. The use of combined cycle gas turbine (CCGT) with high-pressure steam generator and efficiency near to 40-44% will require significant capital expenditures, and the high-pressure mode of operation of pipeline reduces the effectiveness of their application. More effective is use of recycling steam turbine unit GTU with low temperature steam-generator unit organic working agent. Use of water vapor does not provide effective power generation due to low steam parameters : temperature 520–685К, pressure 2–3 Mpa.

Secondary energy sources (SES) of driving gas main pipelines can be used for heating, ventilation and warming of various objects, power production and additional quantity of mechanical energy, refrigeration [5-9]. Theretofore, these methods are not widely known. Share of SES usage for thermal needs of the CS is about 1-3% per year from the current amount of heat.

Due to common usage and development of geothermal energy abroad are generalized power plants that implement Rankine cycle with organic working medium (i.e Organic Rankine Cycle – ORC) [10–16]. Known recycling power plants at CS of gas main pipelines GTU Rolls-Royce RB211 with waste-heat steam utilization plant firm Ormat-Energy Converter. Power circuits of plant operates on Rankine cycle with an organic coolant n-pentane (н-С5Н12) [13].

Fig. 1. Flowsheet of energy disposal power plant: 1 - turbine; 2 - generator; 3а and 3б - evaporators, regenerative heat exchanger; 4 - condenser; 5 – pump

GTU Rolls-Royce RB211 with a capacity of 28MW generation provides an additional generation of 6.5 MW electrical power. For personal use of unit (pumps, fans, etc.) the necessary capacity is 0.8 MW, remaining 5.7 kW can be transferred to an external network or consumed for compressor station. Similar studies are conducted in Ukraine [12–16].

For today, the OJSC "Gazprom" produce a water-steam turbine type K-6-1, 6 with capacity of 4–12 MW.

In the JSC "Sumy NPO n.a. MV Frunze" created gas turbine unit with capacity of 4 MW of close circuit and working fluid n-pentane [14].

However, efficiency data of cycles in professional literature either are not given or are contradictory [12–16].

Its known about the study, limited by working organic agent - n-pentane [10-16], some - n-hexane [13, 15] and benzene. Other substances are in the concrete unexplored. Payments are limited to water temperature (less than 200°C) plants cycle at higher temperatures are also more or less unexplored. Calculated data in professional literature is very scattered, its difficult to comparable them due to the lack of complete information.

In this regard, it is necessary to extend the theoretical and experimental researches on search and reasoning of rational thermal utilization schemes for waste treatment plants, selection of effective working agent and the optimal parameters of the power unit cycle.

Analysis of thermodynamic cycle parameters of energy disposal power plant and a choice of efficient working fluid is the purpose of this work.

Research results reported in this article relate to subcritical and supercritical cycle of power units. As working fluids were studied working agents R600, R600а, R601а, R602, R13в, R134а, R142в, R143а, R404а, R407а, R410а, R503в, R600а/R161, R600а/R141, R600а/R601, С7Н16, С8Н18, С10Н22, NH3/R170, other organic substances and their mixtures.

Thermodynamic efficiency of the cycle can be determined by the conversion factor (COF) and the coefficient of heat recovery. The thermal cycle efficiency (or COF) varies in the narrow range of 0,13-0,16 that is not adequately characterize the efficiency of cycles, and therefore more important selecting criterion of the working agent is a work that is carried out during steam expansion in the turbine.

In Fig.1 is shown the flowsheet of waste-heat utilization of the power unit. First circuit (I)

includes a heat exchanger, pump 5, working agent circulation system, connected to the evaporator and the regenerative heat exchanger 3, 3 a, the second circuit - turbine with generator, evaporator, pump, air condenser and regenerative heat exchanger. In the first and second circuits is circulating one and the same working agent.

Cycles of the power unit is shown in Figure. 2.

In Table 1 are shown characteristics of working agents.

Table 1 Physicochemical properties of working agents Flash limits Substance tкр, °С МПа tн.к., °С tвсп, °С

bottom upper Propane (С3Н8) 96,67 4,25 -42,07 466 2,1 9,5

n-butane (С4Н10) 152,93 3,60 -0,5 431 1,5 8,5 і- butane (С4Н10) 134,0 3,70 -12,55 431 1,8 8,4

n-pentane (С5Н12) 196,65 3,37 36,0 284 1,47 7,8 n-hexane (С6Н14) 234,15 3,05 69,0 261 1,24 7, 5 n-heptane (С7Н16) 267,15 2,68 98,43 240 1,07 6,7 n- octane (С8Н18) 296,0 2,49 126,0 210 0,94 3,2 n-decane (С10Н22) 344,65 2,096 174,1 208 0,60 5,5

ethane (С2Н6) 32,68 4,88 -89,63 472 3,07 15,0 ammonia (R717) 132,25 11,15 -33,35 650 15,0 28,0

water vapor (Н2О) 374,15 21,77 100 – – –

Calculations are performed under the same hypotheses: the temperature difference between the combustion products and the working agent, 10°C, the efficiency of the turbine - 0.7-0.8; pump efficiency - 0,75-0,80; steam expansion process in the turbine ends in the single-phase area, condensation of steam after the turbine takes place in the air-cooled condenser, the temperature of the air 15°С (288,15 К).

As a part of the study and optimization cycles with many working agents in both subcritical and supercritical cycles in the single stage power plant, it was found that the maximum power production is provided in the supercritical cycle [17]. It should be noted that the use of a mixture of working substances is more effectively than pure substances.

In the Table 2 are shown large body of results.

Table 2 Thermal parameters energy disposal power unit * Working agent tТ,

°С РТ, кПа

Рк, кПа

m, кг/с

N, кВт/(кг/с

Лц, %

і- pentane (і-С5Н12) 347 3200 80 0,3 60,8 n-butane (С4Н10) 347 3500 220 0,38 58,9 n-heptane (С7Н16) 347 4000 5,35 0,53 106,5 n- octane (С8Н18) 347 4000 1,6 0,54 109,6 n-decane (С10Н22) 347 4000 1,5 0,59 114,7

water vapor (Н2О) 347 4000 550 0,057 17,8 С7Н16(80 %) / Н2О(20 %) 347 4000 6,25 0,38 138,9

і- pentane (і-С5Н12) 347 6000 80 0,53 96,0 і- pentane (і-С5Н12) 297 6000 92 0,56 83,8 і- pentane (і-С5Н12) 247 6000 220 0,62 56,1

14,4 13,1 18,4 18,9 19,4 10,4 24,3 16,2 20,2 15,2

* РТ – steam pressure at the turbine; tТ – steam temperature at the turbine; N –available spec. gravity; generated by turbines – thermal efficiency of the cycle; m – working agent consumption.

It will be seen from results of calculations, the specific capacitance produced in supercritical cycles with organic agents several times higher than in the cycles with water vapor.

The electric power generated increases with increasing of temperature steam at the turbine. The dependence of the specific operation of steam expansion in the turbine , and generated specific capacitance (N) on pressure is more complicated: at subcritical temperatures, pressure increasing (up to critical) leads to increase of (and N); at the steam parameters close to critical

- to decrease of (N); at overcritical temperature increase of pressure leads to increase of (N). In addition to these parameters, to produced power level affects the vapor pressure in the

condenser. With pressure increasing in the condenser a capacity of turbine is reduced by 8-12 %.

Superheat working agent temperature limitation of relative critical temperature [15] is not needed because the main limitation is the temperature of the thermal decomposition of organic compounds - hydrocarbons, rather than ignition temperature, whose influence can be reduced by introducing into the working agents various phlegmatizing agents (nitrogen dioxide carbon, fluorine- and bromine-containing additives, water vapor, etc..) to prevent ignition of gas mixture.

Changes in vapor temperature of i -pentane (R601a) at the turbine from 350 to 250 ° C leads to decrease of specific capacity, which is generated from 96.0 to 56.1 kW / (kg/s), i.e. 32.2%.

The minimum temperature difference between the coolant and the working agent, which determines the efficiency of heat transfer in the power unit elements Atmin. is materially affected by generated power level. Thus, the increase of Atmin from 3 to 10 K leads to a power decrease produced by 15-20%. Also effected by the efficiency value of the turbine and the pump. Power increase produced by 12-20% is obvious with decrease of air temperature (seasonal effect) from 25 to 0°C and below by changing the coolant temperature in air condenser.

The results are compared with minor figures on n-pentane cycle, combined with the professional literature.

In Fig. 3 are shown calculated data of the specific enthalpy steam drop in turbine according to the temperature and steam pressure at the turbine.

In accordance with results of various researchers, the use of n-pentane and i-pentane as the working agent in vapor pressure of 6.5 MPa and temperatures up to 350°C provides the expansion in the turbine of about 170-180 kJ/kg. In case of heptane usage (С7Н12) = 208,6 kJ/kg; while the mixture is especially effective a noconstant boiling mixture (С7Н17 + Н2О) (80 % / 20 %), specific enthalpy vapor drop is = 375,7 kJ/kg at steam pressure of 4,0 MPа. A mixture of carbohydrate with water steam reduces their flammability.

Fig. 3. Dependence of working steam expansion in the turbine on pressure and temperature: - n- pentane, = 200 °С [12]; - n- pentane, = 300 °С [12]; - n- pentane, = 200 °С [15]; - n- pentane, = 220 °С [15]; - n- pentane, = 220 °С [14]; - n- pentane, = 300 °С [15]; - mixture of і- butane + R141в(60/40, = 200 °С (authors); +- n- butane, = 350 °С (authors); - і- pentane, = 350 °С (authors); - mixture of і- butane +і- pentane (40/60), = 350 °С (authors)

Thus, comparing various organic agents, we see that the generation of electric power in the turbine with decane reaches to 114.7 kW/ (kg/s). Herewith the mixture С7Н16(80 %) + Н2О(20 %) gives a possibility to increase a specific capacity up to 138,9 кW/(kg/s), i.e. in 17,2 %. Comparison results of specific steam drop enthalpy in turbines with different working agents at

= 347 °С show for the heptane turbine specific steam drop enthalpy is 208.6 kJ/kg, and for a mixture of n-heptane (80%) + Н2О(20% – 375,7 kJ/kg. Cycle on a mixture of n-heptane (С7Н16)+water steam (Н2) is characterized by low compression work (7,3 kJ/kg and 2,74 кW) due to small cost of working substance (m = 0,38 kg/s), pressure in the condenser – 6,25 kPа, cycle efficiency – 24,7%. The results of numerical studies show the possibility energy production in the amount of 6882-16670 kW in the case of heat recycling from exhaust gas mass flow rate of 60-120 kg/s gas turbine type ГТН-16, ГТН-25, ГТН-32. As the working agent of power unit can be used organic substances - heptane (С7Н16), octane (С8Н18) or decane (С10Н22) and noconstant boiling mixture with water vapor. Electricity generated can be used for personal needs of CS, drive АПОГ та and additional electric drive GPU that reduces power consumption of gas transportation.

Список літератури

1. Козаченко А.Н. Энергетика трубопроводного транспорта / А.Н. Козаченко, В.И. Никишин, Б.П. Поршаков. – М.: ГУП изд-во «Нефть и газ» РГУ нефти и газа им. И.М. Губкина, 2001. – 400 с.

2. Поршаков Б.П. Газотурбинные установки на газопроводах / Б.П. Поршаков, А.А. Апостолов, А.Н. Козаченко, В.И. Никишин. – М.: ФГУП изд-во «Нефть и газ» РГУ нефти и газа им. И.М. Губкина, 2004. – 216 с.

3. Сальников С.Ю. Энергоэффективные технико-технологические решения в транспорте газа / С.Ю. Сальников, В.А. Щуров-ский, З.Т. Галиуллин, В.В. Зюзьков // Наука и техника в газовой промышленности. – 2011. – № 1. – C.19–33.

4. Зюзьков В.В. Автономное электроснабжение модульных газотурбинных газоперекачивающих агрегатов / В.В. Зюзьков, В.А. Щу-ровский // Сб.тр. III Межд. научн.-техн. конф. «Газотранспортные системы: настоящее и будущее». – М.: ООО «Газпром ВНИИГАЗ», 2009. – C. 268–275.

5. Мужиливский П.М. Унификация теплоутилизационного оборудования газотурбинных установок компрессорных станций / П.М. Мужиливский, И.Л. Юращик // Использование газа в народном хозяйстве. – 1972. – Вып. 7. – C. 10–12.

6. Юращик И.Л. Утилизация теплоты приводных газотурбинных установок / И.Л. Юращик, Л.Ф. Глущенко, А.С. Маторин. – К.: Техника, 1991. – 152 с.

7. Ванюшин Ю.И. Утилизация тепла на компрессорных станциях магистральных газопроводов / Ю.И. Ванюшин, В.И. Глушков. – М.: Недра, 1978. – 160 с.

8. Редько А.Ф. Способы и устройства использования вторичных энергоресурсов на компрессорных станциях / А.Ф. Редько, М.М. Эшматов. – М.:ВНИИЭ ГАЗпром, 1983. – Вып. 2. – 43 с.

9. Воробьев О.Б. Оптимизация конструктивных параметров те-плоутилизаторов на термосифонах для ГПА-ГТК 10И / О.Б. Воробьев, А.Ф. Редько, Н.Г. Ланцберг // Сб. научн. ст. УКРНИИГаз. – 1991. – С. 103–114.

10. Білека Б.Д. Комплексне використання утилізаційних енерго установок на КС для підвищення ефективності ГПА / Б.Д. Білека, С.П. Васильєв, В.М. Клименко [та ін.]. // Нафт. і газова пром-сть. – 2000. – № 4. – C. 40–43.

11. Шварц Г.В. Утилизационные энергетические установки с органическими теплоносителями / Г.В. Шварц, С.В. Голубев, Б.П. Левыкин [и др.]. // Газовая промышленность. – 2000. – № 6. – C. 14–18.

12. Пятничко В.А. Утилизация низкопотенциального тепла для производства электроэнергии с использованием пентана в качестве рабочего тела / В.А. Пятничко, Т.К. Крушневич, А.Н. Пятничко // Экотехнологии и ресурсосбережение. – 2003. – № 4. – C. 3–8.

13. Гринман М.И. Перспективы применения энергетических установок с низкокипящими рабочими телами / М.И. Гринман, В.А. Фомин // Новости теплоснабжения. – 2010. – № 7. – C. 13–18.

14. Бухолдин Ю.С. Повышение эффективности и надежности компрессорных станций магистральных газопроводов/ Ю.С. Бу-холдин, А.С. Северин, В.М. Татаринов, С.В. Шахов // Технические газы. – 2010. – № 3. – C. 60–65.

15. Билека Б.Д. Особенности выбора начальных параметров безводного цикла Ренкина для энергетических установок, утилизирующих сбросную теплоту приводных газотурбинных установок компрессорных станций / Б.Д. Билека, В.Я. Кабков, Р.В. Сергиенко // Вестник двигателестроения. – 2011. – № 2. – C. 138–140.

16. Редько А.А. Методы повышения эффективности систем геотермального теплоснабжения. – Макеевка: ДонНАСА, 2010. – 302 с.

17. Редько А.А. Выбор рабочего вещества для когенерационного силового контура котельного агрегата / А.А. Редько, С.В. Павловский // Энергетика и электрификация. – 2012. – № 2. – С. 24–27.

Authors

Redko Andriy Oleksandrovych

Doctor of Engineering Science, Professor of the Department of gas supply, ventilation and secondary energy resources of the Kharkiv National University of Construction and Architecture (HNUCA). Research interests: low-grade energy, alternative energy, thermodynamics of energy conversion processes.

Redko Oleksandr Fedorovych

Doctor of Engineering Science, Professor, Senior Researcher, specialty construction and operation of main oil pipelines, oil plants and gas storage, Head of the Chair of gas supply, ventilation and secondary energy resources of the Kharkiv National University of Construction and Architecture (HNUCA). Research interests: usage of VER technologies, conversion processes of low-grade heat conversion of low heat in heat and cold supply systems, generation of electric power.

Kompan Artem Igorovych

Post-degree student of gas supply, ventilation and secondary energy resources of the Kharkiv National University of Construction and Architecture (HNUCA). Graduated from the Poltava National Technical University n.a.Yu Kontdratyuk, specialty - Oil and gas equipment. Research interests: accounting and rational use of natural gas, energy saving in industry.

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IN INDUSTRIES State enterprise «Naukanaftogaz»: 10-year way from regional studies to the oil and gas deposits О.А . Shvydkyi

Candidate of geological and mineralogical sciences

V.P. Hryshanenko

Candidate of Science

SE «Naukanaftogaz»

P.М. Khomik

National Joint Stock Company «Naftogaz of Ukraine»

This October the subsidiary enterprises "Research Institute of oil and gas Industry" the National Joint Stock Company "Naftogaz of Ukraine" (SE"Naukanaftogaz") will be 10 years. The main purpose of the SE "Naukanaftogaz" was and remains to ensure development and implementation of science and technology policy of the Company by the way of introduction of new technologies and exploration of oil and gas deposits, hydrocarbon production, their transportation, rational usage of hydrocarbons, energy saving, increase of workplace safety and labor protection.

The primary objectives of the Institute are conducting large-scale of geological, seismic regional researches and implementation of innovative approaches for increasing of technical-and-economic efficiency of hydrocarbon deposit development processes. This approach gave positive results. Thus, taking into account the recommendations of the SE "Naukanaftogaz" in parametric well 403- Subbotin of the government corporation "Chornomornaftogas" in 2006 was opened the first oil deposite in the Ukrainian sector of the Black Sea with considerable reserves (over 20 million tons of standard fuel). Following the recommendations of Institute specialists for 2006-2010 were opened 6 oil and gas fields in the Arab Republic of Egypt. Scientific researches of the Institute contributed to the discovery in 2012-2013 of three hydrocarbon deposits within Budishchansko - Chutovska license areas, namely Runovschynskoho, East Runovschynskoho and Academic Shpak.

In addition to the application tasks, related to exploration and appraisal and engineering support of oil and gas deposits in the SE "Naukanaftogaz" for 10 years of exploitation has been performed more than 200 research works, result of which are new scientific, technological, design, application and other results, including:

• Participation in the development of Ukrainian Energy Strategy till 2030;

• developed a refined state program of development of hydrocarbon resources of the Ukrainian sector of the Black Sea and Sea of Azov;

• prepared more than 100 recommendations of the ongoing exploration works and increase hydrocarbon resource base, ensuring gas reserve increment by 7.0 billion m³, oil – by 5.8 million tons;

• established Atlas of oil and gas facilities for oil-bearing regions of Ukraine;

• worked out a technology software of the processing and interpretation of the results of seismic surveys. *

SE "Naukanaftogaz" received the status of basic standardisation body of the National Joint Stock Company "Naftogaz of Ukraine". 57 regulations, including 3 of statutory instruments and

8 state standards of Ukraine.

In 2012, SE "Naukanaftogaz" passed the state attestation in the State Agency on Science, Innovations and Informatization of Ukraine and is classified as "B1" - organization with a high level of performance, may form prospective scientific and technical policy of a particular scientific field to be leading in the research, development, implementations of specific types of scientific, technical, design production and are active in integrating into the global information space.

For the time of operation of the SE "Naukanaftogaz" Institute staff published over 250 publications and monographs in Ukrainian and foreign publications. One expert of the institute awarded the State Prize in Science and Technology, two - the title of President of Ukraine Prize for Young Scientists laureate.

For today the SE "Naukanaftogaz " formed as a full-fledged research organization staffed by highly qualified scientists and engineers (6 doctors and 20 candidates of sciences), equipped with unique computer system for design and analysis information with the appropriate hardware and software equipment for integrated geological and industrial design and technical economic analysis, which is able to solve complex problems at the modern scientific and technical level facing oil and gas industry of the country, to provide scientific support to complete working cycle - from exploration to transportation.

Notwithstanding the foregoing, there are so-called "expert" publications that make in chase of false sensations unproved conclusions and incorrect statements about the quality and feasibility of studies conducted by the SE "Naukanaftogaz" (Diary “Terminal: Oil review” № 40 (678), 07.10.13, Article of G. Riabtsev "Destroy is easy. Create is difficult") A team of the SE "Naukanaftogaz" convinced that real experts in oil and gas industry of Ukraine highly appreciates its contribution to the development of sectoral science science focused on the formation and implementation of science and technology policy of the National Joint Stock Company "Naftogaz of Ukraine".

Editors of scientific and industrial journal "Oil and gas industry of Ukraine" congratulate the SE "Naukanaftogaz" team with the 10th anniversary of the establishment and sincerely wish the new scientific and professional achievements.

Publishing conditions of material in scientific and industrial journal "Oil and gas industry of Ukraine"

The journal "Oil and gas industry of Ukraine" publishes materials on current issues of the industry development: economics, geology of oil and gas, drilling, mining, extraction, transportation and storage of oil and gas, automation and information technologies, oil and gas refinery, environmental protection, and other materials related to the oil and gas complex.

• In accordance with the recommendations of the Higher Attestation Commission (HAC) of Ukraine scientific articles in Ukrainian , Russian (or other regional) and in English, submitted for publication must contain the following elements: problem in general and its connections with important scientific or practical tasks, analysis of recent researches that discuss this problems and on which based the author, selection of earlier not resolved parts of problems, which are dedicated to the article, the formulation of the objectives of Article (problem ), the main material of research with fully explanation of scientific results, the findings of this study and recommendations for further researches in the indicated direction. Number of authors - no more than four.

• Manuscript which index according to the UDK is obligate, must be submitted with all numbered pages. The volume of material, including tables, references, figure captions and

annotations in Ukrainian, Russian and preferably in English, should not exceed 6-8 pages.

• The author's manuscript is printed in text format in the program WinWord, one and half – spaced, font size 14 on one side of a white sheet of A4 paper (electronic version added).

• Physical and chemical characters in text as well as formulas should be marked by italicize with small and capital letters. Upper and lower indices, indicators of the degree should be allocated brackets up or down (P32, C18), Greek letters circle with red pencil. All symbols in the formulas is necessary to decipher. Number of formulas should be minimal, Latin letters in the formulas and explanations are submitted in italics.

• It is necessary to keep appropriate DSTU for terms and definitions, as well as international SI system.

• Tables must have titles of and serial numbers. Notes to tables printed underneath. On the margins of the manuscript it is necessary to number tables opposite to their location during typesetting and in text to make a reference to the table.

• Illustrations (maximum four) are added to the manuscript separately in duplicate on white (circuit drawings) or glossy (photos) paper, black and white or full color (illustrative graphics program Adobe Photoshop, Adobe Illustrator, Core Draw, formats AI,. EPS, CDR (preferably Adobe Illustrator - AI. EPS); image graphics TIFF. JPG,. EPS). Photographs should be clear. Different marks of photos are plotted only on the one copy. The back of both copies must be numbered in pencil in order of mention in the text, the author's name, the top and bottom of the illustrations. Positions on the figures must be numbered in Arabic numerals, beginning with 1, without gaps and repetitions clockwise. Location illustrations in the text should be noted in the margin of the manuscript.

Attention! It is vorbidden to get up illustrations in the paper, but shall be submitted in separate files.

• References should be made in order of references. These should include only the source, as referred to the article. It is possible to make a reference only to published works. It is necessary to strictly adhere to the order of the bibliographic description given in the "Bulletin of HAC of Ukraine" № 3, 2008.

• Both copies of the manuscript must be signed by all authors

• In the author cards must be noted names and surname of authors, institution where he received higher education, scientific positions and degrees, employment, sphere of industrial and scientific interests, office and home addresses and phone numbers, as well as specified the name of the author for correspondence in the process of work on the article. Together with the author cards must be added photo of the author.

• Improperly executed manuscripts will be returned to authors for revision without consideration.

Phone of the editors office 044-586-36-81 044-586-36-83

Phone/Fax 044-594-76-69

e-mail: [email protected]

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