This paper was prepared for presentation at the SPE Latin American & Caribbean Petroleum Engineering Conference held in Buenos Aires, Argentina, 15–18 April 2007. This paper was selected for presentation by an SPE Program Committee following review of information contained in a proposal submitted by the author(s). Contents of the paper, as presented, have not been reviewed by the Society of Petroleum Engineers and are subject to correction by the author(s). The material, as presented, does not necessarily reflect any position of the Society of Petroleum Engineers, its officers, or members. Papers presented at SPE meetings are subject to publication review by Editorial Committees of the Society of Petroleum Engineers. Electronic reproduction, distribution, or storage of any part of this paper for commercial purposes without the written consent of the Society of Petroleum Engineers is prohibited. Permission to reproduce in print is restricted to a proposal of not more than 300 words; illustrations may not be copied. The proposal must contain conspicuous acknowledgment of where and by whom the paper was presented. Write Librarian, SPE, P.O. Box 833836, Richardson, TX 75083-3836, U.S.A., fax 01-972-952-9435.

Proposal Cerro Dragon is a mature Area located in the Argentine Republic, 90 km to the West of Comodoro Rivadavia and 1,900 km to the South of Buenos Aires, with a surface of 3,480 km² and with 3,738 perforated wells. Since its discovery in1958, and after a long history of production, a change of strategy on 1999 resulted in an important increase in Production and Reserves Decision making at every level, such as people health, environment care, and strategic, organizational, structural, operative and technological planning, was key for the rebirth of this field. The work is centered in how we handle the information, the entailment of the data bases and the use of systems we have built to contribute to maintain the production growth of the Cerro Dragón Asset. Based on the field complexity we recognized that it was necessary to implement new tools that would allow us to make production and investments prognoses, integrating information from different sources, as well as to detect improvement opportunities. The selected software tools allowed us to perform simulations and dynamically survey the projects. The information used came from geological, geophysical, physical production, interventions, measurements, and automation databases, among others. Some of them were developed during the 2

The selected software tools additionally let us integrate the projects into the Long Term Plan, and Budget, taking advantage of the virtuous Circle of Plan-Do-Control-Learn. A project simulation is solved in a period substantially shorter than the one it demands a conventional simulator, which is of great advantage at the time of analyzing different scenarios in an area where the structural complexity and the meager petrophysical information are important barriers at the time of making a study. The control and daily pursuit of the Projects through these systems have favored substantially the fast decision making, the correct lease of resources and a better operative answer. To complete the description of our Optimization options other tools and practices are described. Introduction Cerro Dragon fields are located at the Northern flank of the San Jorge Gulf Basin, in the province of Chubut and Santa Cruz, Argentina. Figure 1 Cerro Dragon Areas Location Plat

SPE 107918

Design and Surveillance of Development Projects Through Specific Software Tools: Importance of Data Management in Mature and Complex Fields in the Golfo San Jorge Basin, Argentina Ricardo Mazzola, Isabel Cano Frers, and Dario R. Baldassa, Pan American Energy LLC; Jorge Valle and AlejandroLacivita, Interfaces SA; and Carlos A. Ponce, Alfredo F. Viola, and Miguel A. Laffitte, Pan American Energy LLC

R í o S e n g u e r

R ío D e s e a d o

Rí o

Ch

ico

Lago Musters

Lago

Colhué

Huapi

PIEDRACLAVADA

KOLUEL KA IKEEL VALL E

ANT.GRANDE

C.DRAGÓN

ANT.FUNES

El Cordón

L.Perales

L.Mesetas

El Tordillo

Escalante

Manantiales

Behr

C.Vasco

M.Magallanes

M.Espinosa

C.León

P.Truncado

El Huemul

Cerro Drag ón

Zorro

Las Flores

Escorial

Ant.Grande

CañadonGrande

Oriental

Buenos Aires

C.Minerales

PicoTruncad o

Las Heras

Sarmiento

26

3

43

ValleHermoso

C.Perdido

40

Perito More no

0 100 km

OIL FIELDS

CERRODRAGON

CERRODRAGON

CaletaOlivia

S A N J O R G E

Comodoro

G O L F O Rivadavia

ATLA

NTI

C O

CEA

NAT

LAN

TIC

OC

EAN

PIEDRA CLAVADAKOLUEL KAIKE

PIEDRA CLAVADAKOLUEL KAIKE

Lago

R í o S e n g u e r

R ío D e s e a d o

Rí o

Ch

ico

Lago Musters

Lago

Colhué

Huapi

PIEDRACLAVADA

KOLUEL KA IKEEL VALL E

ANT.GRANDE

C.DRAGÓN

ANT.FUNES

El Cordón

L.Perales

L.Mesetas

El Tordillo

Escalante

Manantiales

Behr

C.Vasco

M.Magallanes

M.Espinosa

C.León

P.Truncado

El Huemul

Cerro Drag ón

Zorro

Las Flores

Escorial

Ant.Grande

CañadonGrande

Oriental

Buenos Aires

C.Minerales

PicoTruncad o

Las Heras

Sarmiento

26

3

43

ValleHermoso

C.Perdido

40

Perito More no

0 100 km

OIL FIELDSOIL FIELDS

CERRODRAGON

CERRODRAGON

CaletaOlivia

S A N J O R G E

Comodoro

G O L F O Rivadavia

ATLA

NTI

C O

CEA

NAT

LAN

TIC

OC

EAN

PIEDRA CLAVADAKOLUEL KAIKE

PIEDRA CLAVADAKOLUEL KAIKE

Lago

Copyright 2007, Society of Petroleum Engineers

initial years (1999 – 2000).

2 SPE 107918

The Cerro Dragón Contract Area, consists of approximately 50 fields. The area has been operated by Amoco since 1959. In 1997, Pan American Energy, become the operator following the formation of a joint venture between Amoco (now BP Amoco) and Bridas. Cerro Dragon has been under development as an oil producing area since 1959 through a combination of infill and extension drilling for additional primary oil production and Waterflooding Projects in some selected fields. Approximately 60% of the area is now under water flood. Cumulative oil recovery to date from both primary and secondary development exceeds 760 million barrels. There are currently 2410 Oil producing wells and 405 water injection wells in the area.

General Geologic Setting & Reservoir Description The Cerro Dragon asset comprises 800,000 acres in a roughly rectangular block located on the north flank of the Golfo San Jorge Basin, a Mesozoic extensional basin filled with Jurassic lacustrian and Cretaceous fluvial deposit with Tertiary compression and wrenching superimposed on earlier extensional features. The main reservoir consists of sandstones of the Comodoro Rivadavia Formation and altered tuffaceous sandstones and siltstones in the Mina Del Carmen Formation. Hidrocarbons Traps consist of tilted horst blocks, faulted anticlines and structurally enhanced stratigraphic pinch outs. Wells are produced commingled from stacked individual reservoirs 1 to 8 meters thick, each one with different initial reservoir pressure and fluid properties and contacts.

Figure 3. A schematic cross-section show the Field complexity Some keys of the Cerro Dragon rebirth

A Development Master Plan 3D Record and Processing

An electrification plan

Facilities expansion

DATA MANAGEMENT AND SOFT

INTEGRATION In 1999 more than 90 % of the fields and wells information was available only in hard copies, the challenge was integrate it into Databases. First step:

Digitalization of old logs Develop and copy Wells File

INFOPROD and BDIEP data entry (3500 wells)

Detailed geological studies in the waterflooding

blocks Second step:

A virtuous circle “Planning , Doing, Control, Learn” was a very useful tool, associated with more friendly and empowered softwares. Sotware tools objectives goals: 1. Adjust the Production Forecast 2. Improve CAPEX and OPEX 3. Identify and Qualify the information required to

share in the new Databases.

30 JUL 200630 JUL 2006

Cuenca San Jorge – Area Cerro DragónHistoria de Producción y Actividad

CAN

TID

AD D

E PO

ZOS

PRO

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RES

510

200

1400

1000

600

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2200

510

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1000

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2200

1960 197519701965 1980 1985 1990 20001995 2005

TOTAL DE POZOS EN PRODUCCION

TOTAL POZOSINYECTORES

WI

NUMERO DE EQUIPOS DE PERFORACION

WP

1960 197519701965 1980 1985 1990 20001995 20051960 197519701965 1980 1985 1990 20001995 2005

TOTAL DE POZOS EN PRODUCCION

TOTAL POZOSINYECTORES

WI

NUMERO DE EQUIPOS DE PERFORACION

WP

400

1960 197519701965 1980 1985 1990 20001995 20051960 197519701965 1980 1985 1990 20001995 20051960 197519701965 1980 1985 1990 20001995 2005

PRO

DU

CCIO

N (B

OPD

)

12500

25000

50000

62500

75000

37500

87500

100000

200

VEN

TAS

DE

GAS

(MM

ft3/d

)

100

PRODUCCION TOTAL DE PETROLEO

VENTAS DE GAS

RECUPERACION SECUNDARIA

300

OILOIL

IWIW

GasGas

PRO

DU

CCIO

N (B

OPD

)

12500

25000

50000

62500

75000

37500

87500

100000

200

VEN

TAS

DE

GAS

(MM

ft3/d

)

100

PRODUCCION TOTAL DE PETROLEO

VENTAS DE GAS

RECUPERACION SECUNDARIA

300

OILOIL

IWIW

GasGas

SPE 107918 3

Figure 4. A virtuous circle The core of the new way for our work was SAHARA a friendly software to history matching the production wells and forecasting. Along the years this software was empowered with new options of connectivity with our data bases and new options of calculations and simulation became available. Waterflooding Projects, Workovers and Drillings Plan were simulated block by block in each field of Cerro Dragon. Figure 5. Inputs and outputs from SAHARA The source of the Geological models was Landmark Software, the production and operation information source was INFOPROD , the completion and work over information including test was BDIEP SLPOS, the beam pumping information source was Dynapack . For each one of these sources data loading processes were added to SAHARA. The simulation time in Sahara was reduced dramatically compared with conventional simulators, less information or simplification of it to simulate is very important when you have around a hundred layers in each well, with different fluid properties, only a SFT pressure by layer and completion or workover test for each one by swabbing.

Figure 6. History Match and forecast Figure 7. Some case of design Figure 8. How you see each layer and the injection pattern

WF MANGEMENT TOOLS

INFOPROD(PAE Production DB)

DYNA PACK(Artificial Lift DB)

LANDMARK(geological & geophysical)

BDIEP(Drlg, WO & Completion DB)

SAHARAReservoir Simulation

Reservoir Management

New Projects Simulation

Current Project Management

Forecasts & Reserves Estimation

i-Choke

Cuenca del Golfo de San Jorge (C.G.S.J)

Control

DoingPlannig

Learning Control

DoingPlannig

Learning

New Tools

TOTAL FIELD HISTORY MATCH

qlP [m³/d] qo P [m³/d] qlAlP [m³/d] qo AlP [m³/d]

10

100

1000

10000P CD-80/P CD-81/P CD-149/P CD-153/...

1965 1970 1975 1980 1985 1990 1995 2000 2005 2010 2015 2020 2025

Liquid rate

Oil rateOil rate forecast

Liquid rate forecast

Oil production wells

Injectors wells

Injection rate forecastInjection

rate

Sahara project expansionDesign & surveillance

CDIII: Expansion Horizontal

0.00 1.00 2.00 3.00 4.00 5.00 6.00 7.00 8.00

P CD-80

P CD-81

P CD-149

P CD-153P CD-159

P CD-160

P CD-164

P CD-173

P CD-179

P CD-180

P CD-183P CD-184

P CD-186

P CD-187

P CD-190

P CD-191

P CD-192

P CD-195

P CD-196

P CD-220

P CD-240 P CD-257

P CD-258

P CD-259

P CD-273

P CD-274P CD-804

P CD-832

P CD-845

P CD-847

P CD-848

P CG-26

P CG-86

P CG-109

P CG-113

P CG-153P CG-157

P CG-251

P CG-819

P CD-850

P CD-852

P CD-851

P CD-0A P CD-0B

P CD-0D

P CD-0F

P CD-0H

P CD-0IP CD-0J

P CD-0K

P CD-0L

P CD-0M

P CD-0P

P CD-0O

P CD-0R

P CD-0T

Arena J4E

The layer wf was improved with new injectors and infill well perforation

4 SPE 107918

The exploitation status, dynamic and statics parameters of the wells, dinamometer studies, artificial lift system conditions, monitoring, Pulling Frequence, Production Meeting comments, references, bottomhole installation, operating conditions, changes, formation water injection by injector well and by layer can be monitored very quickly. Early detection can be achieved for taking right decisions.

0

400

800

1200

1600

2000

2400

0.1

1

10

100

1000PCD-172

96 97 98 99 00 01 02 03 04 05 06 07 Figure 9. Well producing Chart For Injector Wells: In these charts it is possible to detect water distribution problems and injectivity reductions.

qw iP PC-49[m³/DC] qw iC PC-49 110[m³/DC] qw iC PC-49 113[m³/DC]qw iC PC-49 115[m³/DC] qw iC PC-49 150[m³/DC]

1

10

100

1000 PC-49

2000 2001 2002 2003 2004 2005 2006 2007

Figure 10. Well Injector Chart

Figure 11. How look a view of a typical well sketch Figure 12. Layers view in a 3D Screen The output of the SAHARA integrated data and simulation are :

1. Drilling Plans 2. Workover Plans 3. Conversion to injector Plans 4. Production and Injection forecast 5. Several Scenarios

All the SAHARA output is loaded into the P&CG system (Planeamiento & Control de Gestión system) where the analyst can manage the budget and CAPEX Expenditures to prepar the Long Term Plan.

Sahara surveillance - Well analysisWell sketch

Sahara surveillance3-D visualization

Wells

Sand J4

Sand M1

Sand M7

Sand O6

Sand S4

Workover- Puling Perforations Jobs

Liquid Production &Produciton tests

Oil Produciton & Production Tests

Sumergency

Artificial Lift System changes Decisions taken

Total Water injected

Layer 115

Layer 110

Layer 113 Layer 150

Workover Jobs

Waterfooding response

Artificial List system Change to ESP

Lifting Optimization

Water Injection Distribution per Mandrel and Layer

SPE 107918 5

Figure 13. Sumergency Map Figure 14. Quickly visualization of Drilling and WO Programs Figure 16. Underdeveloped status screen – Bubble map Figure 15. Underdeveloped status screen

Which tools are currently under development :

Facilities visualization WETS ™ module evaluation

Which are the challenges to addres in the future:

Export data to BDRC (Certified Reserves Data Base) Software utilities integration as:

o Well type design o Dynamic Pressure Calculation in pipes

o Gas material balance

Other systems and software developments support our daily work

Figure 16. Pump off and beam pumping data visualization Figure 17. Facilities Control Panel

Drilling & WO surveillance programm

0000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000

I-3

I-2I-1

PCG-949

PCG-948

PCG-924

PCG-939

PCG-938

PCG-937

PCG-935

PCG-936

PCG-934PCG-895

PCG-927

PCG-868

PCG-920

PCG-922

PCG-919 PCG-921

PCG-892

PCG-888

PCG-891

PCG-889

PCG-890

PCG-884PCG-882PCG-878

PCG-875

PCG-874

PCG-876

LOCPCG-94

LOCPCG-68

LOCPCG-64

LOCPCG-52

LOCPCG-208

LOCPCG-104

LOCPCG-102

PCG-872PCG-871

T-116

T-106

PCG-866

PCG-865

PCG-864

PCG-858

PCG-856

PCG-855

PCG-854

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PCG-841

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PCG-835PCG-828

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PCG-276PCG-275

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PCG-47PCG-46

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PCG-14PCG-12PCG-11

PCG-10

PCG-9 PCG-8 PCG-7

PCG-6PCG-5PCG-4PCG-3

PCG-2PCG-1

ICG-1

productor

Cañadón Grande II West

2005

2003

2006

2004

Drilling Productor

Adecuación

Conversión Inyector

Drilling Inyector

OILGASWATERINJECTORDRYLOCATIONOLD LOCATIONABANDONED-OILSHUT-IN-GASSHUT-IN-OILSHUT-IN-WATERDRILLING-OR-TESTINGSHUT-IN-INJECTOR

Drilling Productor: 4/4Drilling Inyector: 7/8Conversión Inyector: 4/4

Adecuación Productor: 26/43Adecuación Inyector: 9/9

Locación P1 Locación P2 Locación P3

Sahara surveillanceUnderdeveloped status

SITU surveillance systemWell following up

SITU surveillance systemFacilities following up

6 SPE 107918

Figure 18. Beam pumping data visualization THE PRODUCTION CYCLE AND INJECTION COMPLEXITY IN TWO FIGURES Figure 19. Cerro Dragon production cycle

1,850 Beam pumped wells 30 PCP pumped wells

450 ESP pumped wells

2 Gas production wells

70 Oil and gas Stations

2 Oil treatment Plants

1 Gas Treatment Plant

Figure 20. Subsurface injection installation

405 water injection wells

19 injection plants

18 water treatment plants Conclusions

Integrated data management is one of the keys of the Cerro Dragon rebirth.

A flexible and friendly simulator with connection to

our data bases gives us a power tool to make good decisions.

Databases according the field complexity and needs

is the best way

The virtuous circle is the best tool of our teams to complete the targets.

Dynapack surveillanceWell analysis

Production Cycle

2 MAIN TREATING PLANTS AND ADITIONAL WATER SEPARATION PLANTS

TO CALETA CORDOVA TERMINAL (SALES)

WATER

WATERFLOOD PROJECTS

INJECTION PLANTS

OIL

WATERDISPOSALS

PROD. WELLS

SATELLITE STATIONS

FLUIDOIL+WATER+GAS

INJECTIONWELLS

FIELD GAS SYSTEM2 MAIN TREATING PLANTS AND ADITIONAL WATER SEPARATION PLANTS

TO CALETA CORDOVA TERMINAL (SALES)

WATER

WATERFLOOD PROJECTS

INJECTION PLANTS

OIL

WATERDISPOSALS

PROD. WELLS

SATELLITE STATIONS

FLUIDOIL+WATER+GAS

INJECTIONWELLS

FIELD GAS SYSTEM

Flooded sandFlooded sand

Flooded sandFlooded sand

Flooded sandFlooded sand

Tension PackerTension Packer Injection mandrel with flow Injection mandrel with flow regulator valveregulator valve

Tension PackerTension Packer

Anchor PackerAnchor Packer

Subsurface injection installationInjection histories analisys

SPE 107918 7

Acknowledgements Thanks are due to: PAE Cerro Dragon Development Reserves Teams because this paper reflect their hard daily work. The PAE facilities and automation team for improving the data loading and databases operation. The PAE IT Team for high quality systems and communications. INTERFACES Management and design Team because they’ve working along many years to improve and integrate into customized software for their and our ideas and needs. References

1. Ezequiel Massaglia, Dario Baldassa, Carlos Ponce,

Bernabé Zalazar. Injector-Well Completion Designs for Selectively Waterflooding up to 18 Zones in a Multilayered Reservoir: Experience in the Cerro Dragón Field. SPE paper 99997 presented at the 2006 SPE/DOE Symposium on Improved Oil Recovery held in Tulsa, Oklahoma, U.S.A., 20–26 April 2006.

2. J.P. Martins, SPE, J.M. MacDonald, C.G. Stewart, SPE,

and C.J. Phillips, SPE, BPExploration (Alaska) Inc. The Management and Optimization of a Major Wellwork Program at Prudhoe Bay. SPE paper 30649 , 1995.