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Advances in Oil and Gas Exploration & Production
Troyee DasguptaSoumyajit Mukherjee
Sediment Compaction and Applications in Petroleum Geoscience
Advances in Oil and Gas Exploration &Production
Series Editor
Rudy Swennen, Department of Earth and Environmental Sciences,K.U. Leuven, Heverlee, Belgium
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Troyee Dasgupta • Soumyajit Mukherjee
Sediment Compactionand Applicationsin PetroleumGeoscience
123
Troyee DasguptaDepartment of Earth SciencesIndian Institute of Technology BombayMumbai, Maharashtra, India
Soumyajit MukherjeeDepartment of Earth SciencesIndian Institute of Technology BombayMumbai, Maharashtra, India
ISSN 2509-372X ISSN 2509-3738 (electronic)Advances in Oil and Gas Exploration & ProductionISBN 978-3-030-13441-9 ISBN 978-3-030-13442-6 (eBook)https://doi.org/10.1007/978-3-030-13442-6
Library of Congress Control Number: 2019935486
© Springer Nature Switzerland AG 2020This work is subject to copyright. All rights are reserved by the Publisher, whether the whole orpart of the material is concerned, specifically the rights of translation, reprinting, reuse ofillustrations, recitation, broadcasting, reproduction on microfilms or in any other physical way,and transmission or information storage and retrieval, electronic adaptation, computer software,or by similar or dissimilar methodology now known or hereafter developed.The use of general descriptive names, registered names, trademarks, service marks, etc. in thispublication does not imply, even in the absence of a specific statement, that such names areexempt from the relevant protective laws and regulations and therefore free for general use.The publisher, the authors and the editors are safe to assume that the advice and information inthis book are believed to be true and accurate at the date of publication. Neither the publisher northe authors or the editors give a warranty, express or implied, with respect to the materialcontained herein or for any errors or omissions that may have been made. The publisher remainsneutral with regard to jurisdictional claims in published maps and institutional affiliations.
This Springer imprint is published by the registered company Springer Nature Switzerland AGThe registered company address is: Gewerbestrasse 11, 6330 Cham, Switzerland
Troyee Dasgupta dedicates this book to her daughter “RahiniDasgupta, born on 31-Jan-2017”.
Soumyajit Mukherjee dedicates this book to Profs. JoydipMukhopadhyay and Prabir Dasgupta for teachingsedimentology and stratigraphy in great detail during his B.Sc.studies in the then Presidency College (Kolkata) during1996–1999.
Acknowledgements
TDG wrote this book while in maternity leave (February to August 2017).SM co-authored while in research sabbatical in IIT Bombay in 2017. Weacknowledge our spouses, Swagato Dasgupta and Payel Mukherjee,respectively, for their support. TDG is thankful to Dr. Lalaji Yadav for hisfruitful mentorship in Petrophysics. Sandeep Gaikwad (IIT Bombay) drewfew diagrams. Thanks to Helen Ranchner, Annett Beuttner and the proof-reading team (Springer).
vii
Contents
1 Compaction of Sediments and DifferentCompaction Models . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11.2 Porosity Models . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
1.2.1 Athy’s Model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21.2.2 Hedberg’s Model. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21.2.3 Weller’s Model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31.2.4 Power’s Model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31.2.5 Teodorovich and Chernov’s Model . . . . . . . . . . . . . . . 41.2.6 Burst’s Model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41.2.7 Beall’s Model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41.2.8 Overton and Zanier’s Model . . . . . . . . . . . . . . . . . . . . 4
1.3 Normal Porosity Profiles for Clastics . . . . . . . . . . . . . . . . . . . 41.3.1 General Points . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41.3.2 Shales . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51.3.3 Shaly Sandstones. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61.3.4 Sandstones. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
1.4 Carbonates . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6References. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
2 Porosity in Carbonates . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92.2 Origin of Carbonate Rocks . . . . . . . . . . . . . . . . . . . . . . . . . . . 102.3 Carbonate Classification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 112.4 Carbonate Factories . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 112.5 Porosity and Its Classification. . . . . . . . . . . . . . . . . . . . . . . . . 142.6 Porosity Classification. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
2.6.1 Archie’s Scheme . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 152.6.2 Choquette-Pray Classification . . . . . . . . . . . . . . . . . . . 152.6.3 Lucia Classification . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
2.7 Permeability Classification . . . . . . . . . . . . . . . . . . . . . . . . . . . 162.8 Diagenetic Processes and Porosity Development . . . . . . . . . . 16References. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
3 Pore Pressure Determination Methods. . . . . . . . . . . . . . . . . . . . . 193.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 193.2 Normal Pressure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
ix
3.3 Overpressure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 203.4 Underpressure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 213.5 Pore Pressure Estimation Methods . . . . . . . . . . . . . . . . . . . . . 23References. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
4 Detection of Abnormal Pressures from Well Logs . . . . . . . . . . . 314.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 314.2 Wireline Log Responses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32References. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48
5 Global Overpressure Scenario . . . . . . . . . . . . . . . . . . . . . . . . . . . 515.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 515.2 Global Scenario in Overpressure Zones . . . . . . . . . . . . . . . . . 515.3 Specific Cases (Table 5.1) . . . . . . . . . . . . . . . . . . . . . . . . . . . 54
5.3.1 Abnormal Pressure Occurrences in Middle East . . . . . 545.3.2 Abnormal Pressure Occurrences in Europe . . . . . . . . . 545.3.3 Abnormal Pressure Occurrences in Africa . . . . . . . . . . 575.3.4 Abnormal Pressure Occurrences in China . . . . . . . . . . 585.3.5 Abnormal Pressure Occurrences in and Around
SE Asia, Australia and New Zealand . . . . . . . . . . . . . 605.3.6 Abnormal Pressure Occurrences in Some Parts of
Asia. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62References. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79
6 Investigation of Erosion Using Compaction TrendAnalysis on Sonic Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 836.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 836.2 Exhumation Estimation from Porosity Logs . . . . . . . . . . . . . . 846.3 Transit Time and Shale Compaction . . . . . . . . . . . . . . . . . . . . 846.4 Methodology. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85References. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89
7 Pore Pressure in Different Settings. . . . . . . . . . . . . . . . . . . . . . . . 917.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 917.2 Plate Margins . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92
7.2.1 Convergent Margins . . . . . . . . . . . . . . . . . . . . . . . . . . 927.2.2 Extensional Margins . . . . . . . . . . . . . . . . . . . . . . . . . . 95
References. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 98
x Contents
Symbols
U PorosityU0 Average surface porosity of the surface claysc A constantz Burial depthqh Hydrostatic pressureɣw Specific weight of waterh Height of column of waterGh Hydrostatic pressure gradientP Pore pressurerv Overburden stressre Effective stressa Biot’s effective stress coefficientRn Resistivity normal trendR Resistivity logX Normal compaction trendDt Interval transit timeDtn Interval transit time normal trendY Pore pressure gradientPf Formation fluid pressureav Normal overburden stress gradientb Normal fluid pressure gradientZ DepthDt Sonic transit timeA, B ParametersPB Pore pressurerA Effective stress at APNA Hydrostatic normal pore pressure at point AOBB Overburden pressure at point BOBA Overburden pressure at point ArM Mean effective stressr Vertical effective stress
xi
rh Minimum horizontal stressrH Maximum horizontal effective stressV Sonic velocityVmin Minimum sonic velocity of the rock matrixVmax Maximum sonic velocity of the rock matrixR Vertical effective stressP Pore pressureqmax Maximum matrix densityqf Fluid densityDtf Interval transit time of fluidDtn Interval transit time for the normal pressure in shalesDt Transit time of shaleVp Compressional wave velocityVml Mudline velocityU Parameter representing uplift of the sedimentsrmax Effective stressv VelocityVm Sonic interval velocity with the shale matrixam Ratio of the loading and unloading velocities in the effective stress
curvesVmax Velocity at the start of unloadingPulo Pore pressure due to unloadingØRHOB Porosity from density logqma Matrix densityqb Bulk density measured by logqfl Fluid densityΔtma Interval transit time of the matrixΔtfl Fluid transit timeΔt Average interval transit time from logØDT Porosity from sonic logØRILD Porosity from resistivity logRw Formation water resistivityn Saturation exponentm Cementation exponentRt True resistivity of the formationtma Sonic transit time of the rock matrix/z Porosity at depth z/0 Porosity at the surfaceb A constantDt Transit time measured by the sonic log
xii Symbols
Dto Transit time at the present sedimentary surfacec Compaction coefficientz Burial depthDto Transit time near to the transit time of water
Symbols xiii
List of Figures
Fig. 1.1 Compaction models shown by porosity versus depth ofburial. Inter-relationship for shales and argillaceoussediments: 1–9: Different curves. Modified afterFig. 17 of Rieke and Chilingarian (1974) . . . . . . . . . . . . . 2
Fig. 1.2 a Bulk density versus depth relationship for shalesfrom Oklahoma (U.S.A). b Porosity versus depthrelationship for shales from Oklahoma (U.S.A)(Modified after Fig. 14 of Riekeand Chilingarian 1974) . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
Fig. 1.3 Comparison between Athy’s and Hedberg’scompaction curves. Modified after Chapman (1994) . . . . . 3
Fig. 1.4 Different stages of compaction effect on claydiagenesis. a Clays consist of bound water at the timeof deposition. b Free water increases with burial withthe consequent release of boundwater. c Free water issqueezed out and the original volume reduces(Fig. 57 in Rieke and Chilingarian 1974) . . . . . . . . . . . . . 3
Fig. 1.5 Comparison of normal depth profile curve. Athy’soriginal curve, shale compaction profile curve fromNagaoka basin, Gulf coast, and Beaufort Mackenziedelta. Porosity data derived from density log(Burrus 1998) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Fig. 1.6 Mechanical compaction in sands. Fine grainedsands compact easily than core grained sand(Chuhan et al. 2002) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Fig. 1.7 Changes in sand compaction with burial(Bjørlykke et al. 2004) . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Fig. 2.1 Latitude-wise distribution of organisms(Moore 2001) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
Fig. 2.2 The dashed line represents the predicted growthand the open circles represent the actual growthof the corals (Moore 2001) . . . . . . . . . . . . . . . . . . . . . . . . 10
xv
Fig. 2.3 Three carbonate factories with different mineralogicalcontents (Schlager 2005) . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Fig. 2.4 Different modes of precipitation of carbonate factories(Schlager 2005) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Fig. 2.5 Depth of occurrence of carbonate factories alongwith production rate (Schlager 2005) . . . . . . . . . . . . . . . . . 13
Fig. 2.6 Porosity classification incorporating the details aboutthe depositional as well as the diagenetic changes andare as categorised as fabric selective, not fabricselective and fabric selective or not category(Scholle 1978) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Fig. 3.1 Typical hydrostatic pressure, pore pressure,overburden stress in a borehole well (Zhang 2011) . . . . . . 20
Fig. 3.2 Pressure versus depth plot showing “overpressure”zones when the pressure is more than hydrostatic.“Underpressure zones” develops when the pressureis less than the hydrostatic pressure (Swarbrick andOsborne 1998; Swarbrick et al. 2002) . . . . . . . . . . . . . . . . 21
Fig. 3.3 Maximum pressure generation due to hydrocarbonbuoyancy in North Sea (Swarbrick and Osborne 1998) . . . 23
Fig. 3.4 Vertical and horizontal methods of pore pressureestimation. Pore pressure indicator is used as the samevalue as the normal trend (point A) in vertical methodof pore pressure estimation. Whereas, in horizontalmethod, the effective stress data is estimated from thenormal trend (point B) (Bowers 2001) . . . . . . . . . . . . . . . 24
Fig. 3.5 Pore pressure versus resistivity crossplot(Owolabi et al. 1990) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
Fig. 3.6 Published pore pressure crossplots for sonic transit time(Owolabi et al. 1990) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
Fig. 3.7 Vertical effective stress methods (Bowers 2001) . . . . . . . . 27Fig. 3.8 Scenario where vertical effective stress method fails . . . . . 27Fig. 4.1 Log pattern of Not formation along with helium
calculated porosities. Some parts of the Not formationare affected by poor hole conditions (3968–3993 m).Modified after Hermanrud et al. (1998) . . . . . . . . . . . . . . . 33
Fig. 4.2 Log pattern of Ror formation along with heliumcalculated porosities. Some average porositieswere calculated for all the shaly formations in theUpper and lower Ror formations. Modified afterHermanrud et al. (1998). . . . . . . . . . . . . . . . . . . . . . . . . . . 34
Fig. 4.3 Average porosities calculated in Not formation froma Sonic (DT) log, b Density (Rhob), c Resistivity(Rt) and d neutron log. Each of the pressure regimesare indicated by different symbols. Modified afterHermanrud et al. (1998) . . . . . . . . . . . . . . . . . . . . . . . . . . 35
xvi List of Figures
Fig. 4.4 Average porosities calculated in Ror Formation froma Sonic (DT) log, b Density (Rhob), c Resistivity(Rt) and d neutron log. Each of the pressure regimes areindicated by different symbols. Modified afterHermanrud et al. (1998) . . . . . . . . . . . . . . . . . . . . . . . . . . 35
Fig. 4.5 Pore structure model of a rock, constitutingstorage pores with high aspect ratio and connectingpores with low aspect ratio. Modified afterBowers and Katsube (2002) . . . . . . . . . . . . . . . . . . . . . . . 36
Fig. 4.6 Cartoon depicting the wireline responses ina overpressure generated due to compactiondisequilibrium process, b overpressure generateddue to unloading process (Ramdhan et al. 2011) . . . . . . . . 37
Fig. 4.7 Well from Gulf of Mexico showing the typicalresponse due to unloading. At the onset of overpressurezone the extent of response shown by sonic velocityand resistivity log is more than that of the densitylog. Modified after Bowers and Katsube (2002) . . . . . . . . 38
Fig. 4.8 Velocity versus density crossplot for identifyingunloading behaviour. Modified after Bowers (2001) . . . . . 38
Fig. 4.9 Detection of unloading behaviour a Velocity versuseffective stress, velocity reversal along with reductionin effective stress. b Density versus effective stress,effective stress reduction but density remains constant(Bowers 2001) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
Fig. 4.10 Cartoon showing the overpressure trends possiblydue to unloading. a Fluid pressure versus depth trend;b shale porosity versus depth trend; c shale porosityversus effective stress, and d bulk density versusvelocity trend . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39
Fig. 4.11 Map of Malay basin with well locations (Hoesni 2004) . . . 40Fig. 4.12 Sonic velocity-effective stress plot showing the
normally pressured data fallowing loading curvewhereas Mildly overpressured (11.5–14 MPa km−1),Moderately Overpressured (14–17 MPa km−1) &Highly Overpressured (>17 MPa km−1) data fallingoff the loading curve. Overpressure in the formationfollowing the unloading curve is because of the fluidexpansion, load transfer or vertical transfer mechanism.Most of the data representing unloading curve(Tingay et al. 2013) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
Fig. 4.13 Sonic velocity-effective stress plot of the threeformations 2A, 2b and 2C. Dark grey dots with pressure>11.5 MPa km−1 (0.51 psi ft−1) represent the unloadingcurve and the normally pressured (hydrostatic pressure)
List of Figures xvii
wireline formation tester data represent the loadingcurve (Tingay et al. 2013) . . . . . . . . . . . . . . . . . . . . . . . . . 43
Fig. 4.14 Sonic velocity-effective stress plot of 49 data withexcellent mobility (>10 mD/cp). Low mobilityformation show inaccurate measurements(Tingay et al. 2013) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44
Fig. 4.15 Sonic velocity versus density to distinguishoverpressure generated by fluid expansion mechanism(Adapted from Hoesni 2004; O’Conner et al. 2011;Tingay et al. 2013). Data of the formation in whichoverpressure is generated by compaction disequilibriumfollow the loading curve. Mechanisms related to claydiagenesis and load transfer shows drastic increase inthe density and little change in the sonic velocity.Overpressure generation due to gas generation showssevere drop in sonic velocity with little or no increase indensity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44
Fig. 4.16 Cross plot between Sonic velocity versus density forfour wells in Malay basin. The normally pressuredsediments are represented by white squares and theyfollow the loading curve. The loading curve are the dataof normally pressured formations and are shown bywhite squares. As discussed in the text, the part of thesequences within the overpressure transition zone isrepresented by gray squares, the center of theoverpressured zone is represented by black squares(After Tingay et al. 2013) . . . . . . . . . . . . . . . . . . . . . . . . . 45
Fig. 4.17 Porosity (sonic velocity) versus effective stress plotdistinguishing the overpressure due to compactiondisequilibrium (black dots) and fluid expansionmechanism (ash colored squares). The normalpressured data following the loading curve is definedby small grey colored dots (after Tingay et al. 2009) . . . . 46
Fig. 4.18 Velocity versus density crossplot from the onshore wellsof Niger delt. Adapted after Nwozor et al. (2013) . . . . . . . . . 46
Fig. 4.19 Velocity versus vertical effective stress crossplot fromthe onshore wells of Niger delt (Nwozor et al. 2013) . . . . 46
Fig. 4.20 a Sonic velocity versus effective stress crossplot for thewells in the northern part. 170 Wireline formation testerdata were used to calculate the vertical effective stress.Pore pressure data >11.5 MPa km−1 fall off the loadingcurve and delineate the unloading zones, b Pore pressurefrom 140 wireline formation tester data were plotted insonic velocity versus effective stress plot for southernNEC block, all the pore pressure >11.5 MPa km−1
follow the loading curve and signifies overpressure dueto undercompaction (John et al. 2014) . . . . . . . . . . . . . . . . . 47
xviii List of Figures
Fig. 4.21 a Sonic velocity versus density crossplot for the wellsin the northern part. 170 Wireline formation tester datawere used for the study. Pore pressure data >11.5 MPakm−1 fall off the loading curve and delineate theunloading zones representing sharp reduction in sonicvelocity and constant density. b Pore pressure from 140wireline formation tester data were plotted in sonicvelocity versus density plot for southern NEC block, allthe pore pressure >11.5 MPa km−1 follow the loadingcurve and signifies overpressure due toundercompaction (John et al. 2014) . . . . . . . . . . . . . . . . . . 47
Fig. 5.1 Global occurrence of overpressure zones takenfrom Bigelow (1994a, b) and physical world mapof geology.com . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
Fig. 5.2 Abnormal formation pressure environments in Iran(Fertl 1976) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54
Fig. 5.3 Location map of the central graben and the quadrantis the licensing structure in the United KingdomContinental of the area (Holm 1998) . . . . . . . . . . . . . . . . . 55
Fig. 5.4 The Forties Montrose High divides the graben intoeastern and western grabens. The oil and gas fieldsare from Devonian to early Eocene age and the majorformations are Upper Jurassic Fulmar Sandstone,Upper Cretaceous Chalk Groupand the PaleoceneForties Formation (Holm 1998) . . . . . . . . . . . . . . . . . . . . . 56
Fig. 5.5 Pressure versus depth plots. The measured pressure datafrom the permeable zones have been used and in theimpermeable zones the pressures have been estimatedby indirect methods of pressure estimation(mud-weights, D-exponents, connection gases, etc.).a Pressure versus depth plot in the Central graben areawhich shows the normally pressured Paleocenesandstones and beneath that there is normally pressuredchalk group. There is rapid change in the profile withincrease in the pore pressure from f to g and the highestat the pre-Cretaceous structure in the h. b Pressureprofile of Ekofisk Field. The chalk group (c, d) ismoderately overpressured (Holm 1998) . . . . . . . . . . . . . . . 57
Fig. 5.6 Pressure profiles of a Ekofisk area b North sea area’sZechstein evaporate section (Rehm 1972) . . . . . . . . . . . . . 58
Fig. 5.7 Comparison of predrill and actual pore pressureprediction in north sea area (Herring 1973) . . . . . . . . . . . . 59
Fig. 5.8 Schematic diagram depicts the formation ofoverpressure and underpressure zones as thehydrocarbon migration takes place (Holm 1998) . . . . . . . . 60
List of Figures xix
Fig. 5.9 a Tectonic map of the Italian Adriatic area. b Pressureprofile of a well in the Italian Adriatic area. In the zonesB & C the pressure values are far beyond the normalpressure values. c Plots showing overpressuredenvironments in Adriatic sea (Rizzi 1973) . . . . . . . . . . . . . 61
Fig. 5.10 Pore pressure plot of the North Sinai basin and the Niledelta. Abnormal increase in the pore pressure and leakoff test is there (Nashaat 1998) . . . . . . . . . . . . . . . . . . . . . 62
Fig. 5.11 Location of Yinggehai basin in the South China seaalong with the location of wells along with structuralfeatures such as faults, diapir like structures . . . . . . . . . . . 63
Fig. 5.12 Pressure and Pressure coefficient versus depth plotof the different stratigraphic units in the Dongyingdepression of the Bohai Bay basin where the Es3 andEs4 are overpressured. DST denotes drill stem testing . . . 64
Fig. 5.13 Depth versus sonic, resistivity, density, calliper profileof well log data of wells in Dongying depression . . . . . . . 65
Fig. 5.14 Shows the relationship of the fluid pressure versusdepth ratio with stratigraphic horizon. The stratigraphiczones in different wells are overpressured becauseof the presence of apparent low permeability zone . . . . . . 66
Fig. 5.15 Figures showing abnormal formation pressures inAustralia and Papua New Guinea area. a Locationof overpressured wells. b Pressure profile ofoverpressured wells of Australia. c Pressure profileof overpressured wells of Papua New Guinea.(Bigelow 1994a, b) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67
Fig. 5.16 Sedimentary basins of India showing overpressurearea (Sahay 1999) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68
Fig. 5.17 Details of well W-32. Courtesy: Journal GeologicalSociety of India, Volume 75 . . . . . . . . . . . . . . . . . . . . . . . 69
Fig. 5.18 Depth versus ΔT plot of the wells in Bengal basin,the deviation from the normal compaction trend is takenas the top of the overpressure and is also confirmedwith the RFT results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70
Fig. 5.19 Relationship between shale acoustic parameterdifference Δtob(sh) − Δtn(sh) from drilled wellsand reservoir fluid pressure gradient (modifiedHottmans curve of Bengal Basin) (Roy et al. 2010) . . . . . 71
Fig. 5.20 Relation between effective stress from well data andreservoir fluid type in which below 7.9 MPa km−1 cutoff the chances of getting hydrocarbon is minimum(John et al. 2014). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71
Fig. 5.21 Tectonic map of Krishna–Godavari basin showinglocation of 10 wells (Chatterjee et al. 2015) . . . . . . . . . . . 72
xx List of Figures
Fig. 5.22 Gamma ray and resistivity log responses of wellsKD & KE. Location of wells and profile is shownin Fig. 5.21 (Singha and Chatterjee 2014) . . . . . . . . . . . . . 73
Fig. 5.23 a DT versus depth and density porosity sonic porosity(Øs) versus depth plot for onshore well #7. The top ofoverpressured zone is indicated at 1919.16 m bydeviation of sonic data from NCT and separationbetween (Ød) and (Øs). b DT versus depth and densityporosity sonic porosity (Øs) versus depth plot foroffshore well #13. The top of overpressured zone isindicated at 1600 m by deviation of sonic data fromNCT and separation between (Ød) and (Øs)(Chatterjee et al. 2015). . . . . . . . . . . . . . . . . . . . . . . . . . . . 74
Fig. 5.24 Pressure, salinity and Temperature data in the offshorewell Kutch basin, India (Sahay 1999) . . . . . . . . . . . . . . . . 75
Fig. 5.25 Bombay/Mumbai offshore basin with the location ofSaurashtra-Dahanu block (Nambiar et al. 2011) . . . . . . . . . 76
Fig. 5.26 Interval velocities of different wells plotted and thedifferent zones with lowering of interval velocities aremarked with circles and denote overpressure zones(after Nambiar et al. 2011). . . . . . . . . . . . . . . . . . . . . . . . . 76
Fig. 5.27 Location of overpressured zones in Pakistan: PotwarPlateau (a) and Makran basin (b) Modified after Lawet al. (1998) incorporating Google Earth imagery . . . . . . . 77
Fig. 5.28 Pressure and Temperature gradient in Gulf oil,FimKhassar well (Law et al. 1998) . . . . . . . . . . . . . . . . . . 78
Fig. 5.29 Interval transit time versus depth in the Gulf oil,FimKassar well (Law et al. 1998) . . . . . . . . . . . . . . . . . . . 79
Fig. 6.1 Erosion thickness calculation from compaction trendcurve derived from sonic transit time (Magara 1976).a No erosion and the surface transit time is equal to thatof water. b Upper surface is eroded and the thickness isthe vertical distance between the present surface and theoriginal surface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85
Fig. 6.2 Compaction trend and erosional thickness froma Emblem State1 and b Bridger Butte Unit 3 by Heaslerand Kharitonova (1996) . . . . . . . . . . . . . . . . . . . . . . . . . . . 86
Fig. 6.3 Porosity versus depth curve by Burns et al. (2005)for different lithology using volume of shale cut off.a Sand (vshale < 0.01), b Siltstone (0.49 vshale < 0.51)and c shale (vshale > 0.51) along with the curves byRowan et al. (2003) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 86
Fig. 6.4 Visual comparison of sonic porosity data and Rowanet al. (2003) curves for each lithology. The verticaloffset is the erosional thickness implied . . . . . . . . . . . . . . . 87
List of Figures xxi
Fig. 6.5 Sonic velocity data and porosity from sonic data.The porosity trend can be approximated as lineartrend (Li et al. 2007) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87
Fig. 6.6 Linear porosity trend of 26 wells from Xihu depressionarea (Li et al. 2007) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 88
Fig. 7.1 The occurrence of high overpressured zones iscorresponding to the fault zones. The fluid pressureestimates from consolidation tests are derived fromanalysis of individual samples and is in agreement withthe log derived fluid pressures (Moore et al. 1995) . . . . . . 92
Fig. 7.2 Spike at 505 and 515 m which shows increase inporosity and decrease in resistivity through decollementzone (Saffer 2003) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93
Fig. 7.3 Annular pressure while drilling for the sites. The sitesC0002, C0004, C0006 and the shallower part of theC0001 and C0003 follows the standard gradient. Thereis divergence in the annular pressure while drilling datain the deeper section of C0001 and C0003 section(Moore et al. 2012) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 94
Fig. 7.4 Annular pressure while drilling for the sites C0001Aand C0001D. In the site C0001A the standard APWD isthere up to 413 mbsf, beyond this depth up to 530 mbsfthere is shift in the pressure gradient and at placescrosses the lithostatic gradient and later follows thestable pressure gradient. In the hole C0001D theAPWD pressure is stable up to 400 mbsf but isfollowed by fluctuations in pressures while drillingdownhole and shoots above lithostatic above 522 mbsfand remains above till 690 mbsf and similar to holeC0001A the pressure falls back to normal gradient(Moore et al. 2012) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 94
Fig. 7.5 Fluid pressure gradient as a function of depth(Chilingarian and Wolf 1988) . . . . . . . . . . . . . . . . . . . . . . 95
Fig. 7.6 Pore pressure plot of KG basin offshore withthe example of well A (Chatterjee et al. 2012) . . . . . . . . . 96
Fig. 7.7 Pore pressure plot of KG basin offshore withthe example of well B (Chatterjee et al. 2012). . . . . . . . . . 97
xxii List of Figures
List of Tables
Table 3.1 Different overpressure generation mechanisms,tabulated in different categories. Modified after(Swarbrick and Osborne 1998) . . . . . . . . . . . . . . . . . . . . . 22
Table 4.1 Average porosities calculated in the Ror Formationfrom (a) Sonic (DT) log, (b) Density (Rhob),(c) Resistivity (Rt), and (d) neutron log(Hermanrud et al. 1998) . . . . . . . . . . . . . . . . . . . . . . . . . . 36
Table 4.2 Well list with dominant pressure mechanisms(denoted by symbols) on the basis of pore pressureprofile and velocity-density crossplot . . . . . . . . . . . . . . . . 41
Table 5.1 Categorization of overpressure zones(Roy et al. 2010). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
xxiii
1Compaction of Sedimentsand Different Compaction Models
AbstractVarious simple and advanced models exist formechanisms of uniform and non-uniform sed-iment compaction that increases density andreduces porosity. While the classical Athy’srelation on depth-wise exponential reductionof porosity is not divided into any distinctstages, the Hedberg’s model involves fourstages. Weller’s model utilized Athy’s andHedberg’s relations to deduce a sedimentcompaction model. Power’s compactionmodel additionally considers clay mineralogy.Several other porosity/compaction modelsexist, e.g., those by Teodorovich and Chernov,Burst, Beall, and Overton and Zanier. Thegeometry of the depth-wise porosity profiledepends on the sedimentation rate, compactionmechanism and pressure solution model. Thischapter reviews porosity variation with depthfor the following rock types: shales, shalysandstones, sandstones and carbonates.
1.1 Introduction
The chemical and the physical properties ofsediments and sedimentary rocks alter as theoverburden pressure increases. These changesrelate to burial depth, temperature and time.Experiments by Warner (1964) suggested that
acceleration of the rate of compaction of sedi-ments seem to be the only change at <200 °F.Compaction of sediments reduces porosity andincreases density (Bjørlykke et al. 2009). Thereduction of porosity is a convenient way ofmeasuring the amount of sediments compactedsince deposition took place, for practical pur-poses. Empirical compaction curves are the plotsof porosity versus depth up to *6 km.Mechanical compaction being the primarymechanism of compaction, clay minerals areoften utilized in many models to visualise howgrains rearrange with depth. The compositionvaries from proximal to distal part of the basinand the compaction pattern of each sediment typediffers (Bjørlykke et al. 2009). Compactionmodels explain the major processes for the sed-iment compaction. This helps the interpreters tovisualise the relationship of porosity loss withdepth and the probable reason for anomalouszones. The evolution of compaction models andporosity reduction with depth from different partsof the world are presented in Fig. 1.1.
1.2 Porosity Models
Sediment porosities undergo changes with burial.In the consecutive sections the different modelsare explained.
© Springer Nature Switzerland AG 2020T. Dasgupta and S. Mukherjee, Sediment Compaction and Applications in Petroleum Geoscience,Advances in Oil and Gas Exploration & Production, https://doi.org/10.1007/978-3-030-13442-6_1
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