PETROLEUM GEOCHEMISTRY Dr. D. Satyanarayana Visiting Professor, Delta Studies Institute & Former Professor of Marine Chemistry Andhra University, Visakhapatnam 2011 DAYA PUBLISHING HOUSE Delhi - 110 035
iv 2011, D. SATYANARAYANA ISBN 81-7035-675-X ISBN 978-81-7035-675-2 All rights reserved. Including the right to translate or to reproduce this book or parts thereof except for brief quotations in critical reviews. Published by : Daya Publishing House 1123/74, Deva Ram Park Tri Nagar, Delhi - 110 035 Phone: 27383999 Fax: (011) 23260116 e-mail : dayabooks@vsnl.com website : www.dayabooks.com Showroom : 4760-61/23, Ansari Road, Darya Ganj, New Delhi - 110 002 Phone: 23245578, 23244987 Laser Typesetting : Classic Computer Services Delhi - 110 035 Printed at : Chawla Offset Printers Delhi - 110 052 PRINTED IN INDIA
Acknowledgements I am grateful to the following publishers, Authors/Editors of books for according permission to use their published illustrations. P M/S Academic Press, R.C. Selley. Elements of Petroleum Geology (1998); J. Brooks (Ed). Organic Maturation Studies and Fossil Fuel Exploration (1981). P M/S Applied Science Publishers, G.D. Hobson (Ed). Developments in Petroleum Geology, Vol. I (1977) and Vol. II (1980). P M/S Burgess Publishing Company, Douglas Waples. Organic Geochemistry for exploration Geologists (1981). P M/S Chapman & Hall, Steven A Tedesco. Surface Geochemistry in Petroleum Exploration (1995). P M/S Directorate General of Hydrocarbons (DGH). India Petroleum Exploration and production Activities 2005-2006. P M/S Elsevier Publishers, E.C Donaldson (Ed). Enhanced oil Recovery I : Fundamentals and analysis (1985). P M/S Indian Petroleum Publishers, S.K. Biswas et al., (Eds). Proceedings of 2 nd Seminar on Petroliferous Basins of India. Vol. I and Vol. II (1993); Lakshman Singh. Oil and Gas Fields in India (2000).
vi P M/S International Human Resource Development Corporation (IHRD), Douglas, W. Waples. Geochemistry in Petroleum Exploration (1985). P M/S Kluwer Academic Publishers, M.D. Max (Ed). Natural Gas Hydrates (2000). P M/S Springer Verlag, B.P Tissot and D.H. Welte. Petroleum Formation and Occurrence (1984). P M/S. Unwin Hyman Publishers, F.K. North. Petroleum Geology, 2 nd edition (1990). P M/S Freeman and Company, J.M. Hunt. Petroleum Geochemistry and Geology, 2 nd edition (1996); A.I. Levorsen. Geology of Petroleum, 2 nd edition (1967). D. Satyanarayana
Foreword Petroleum Geochemistry is a branch of Organic Geochemistry that deals with the study of distribution, composition and constitution of petroleum, its constituents and its precursors in sedimentosphere at gross and molecular levels to define principles of occurrence and origin of petroleum in sedimentary basins, the ubiquitous natural habitats of economically attractive accumulations. The vicissitudes of basin evolutionary history of each sedimentary basin are complex and no two points along dip or strike theoretically have identical depositional conditions. No technique of petroleum exploration is, therefore, equally sensitive and accurate in space and time. Petroleum exploration and exploitation is thus both knowledge and technology intensive and is essentially a multidisciplinary task where an inadequacy of one discipline or technique is covered by strengths of one or other discipline or technique or set of disciplines or techniques. While geology and geophysics are excellent in unraveling the types of rocks, their physical attributes, structural attitudes and their distribution and superposition in space and time in a basin, they are unable to deal directly with aspects of origin, migration and accumulation of petroleum.
viii One of the imperatives of the industry is to have knowledge on aspects of origin and occurrence of petroleum specific to each basin or part thereof. This is essential to ensure reduction of risk in petroleum exploration. Petroleum Geochemistry helps exploration and development effort in each phase, right from reconnaissance and stage of general assessment to the final stage of extraction of the last producible content of hydrocarbons in a locale of accumulation, by providing geochemical concepts and data sets on various aspects of origin, migration and accumulation of petroleum specific to each basin under exploration and development. Tremendous developments have taken place in acquisition of petroleum geochemical data since the nineteen sixties through availability of robust equipments and methods of chemical analysis. It is now possible to have practically real time geochemical data to be integrated timely for making an exploration or development decision. Synergy amongst Petroleum Geology, Petroleum Geochemistry and Geophysics has become an accepted practice for laying down risk based priorities in a portfolio of exploration and development opportunities. The synergy also leads to working out manageable investments to initialize an E&P activity with cash flows that can be deployed for further exploration and development efforts while assuring market competitive returns during the entire cycle of any given exploration and development activity. Dr. D. Satyanarayana of the Delta Studies Institute of Andhra University has done yeoman s service to Indian academia to bring out a maiden Indian text book on Petroleum Geochemistry. This book will be found useful to graduate and postgraduate students taking courses in petroleum geology, petroleum exploration and petroleum engineering. The book touches upon authentically all aspects of petroleum geochemistry that are relevant to exploration and development effort. In India, Oil and Natural Gas Corporation commenced undertaking petroleum geochemical studies in 1957 and established formal laboratories in 1960. ONGC Limited has since 1963 best in class research facilities in Petroleum Geochemistry at Keshav Dev Malviya Institute of Petroleum Exploration (KDMIPE) along with a strong Basin Studies Group at Dehradun. ONGC Limited also has, since 1985, standard data acquisition laboratories in all operational areas. Oil India has modern Petroleum Geochemistry laboratories
ix since 1990. National Geophysical Research Institute has a National Centre of Excellence in Surface Geochemical Prospecting backed by Oil Industries Development Board and Director General Hydrocarbons since 2001-02 which caters to the requirements of geochemical data acquisition of various private sector oil companies and DGH to help evaluate prospectively of various acreages and exploration blocks. All private sector and joint venture major upstream oil companies profusely integrate geochemical data in exploration decision making. This book of Dr. Satyanarayana is therefore has great practical value for the upstream petroleum industry in general and especially for India where large acreages still remain explored, where deep and ultra deep water exploration has just begun and where the ageing oil fields are being operated for maximizing recovery factors. To students with enquiring and creative minds and aptitude for innovation, the book surely would inspire to undertake basic and applied research. Dr. Satyanarayana joins the illustrious eminent academicians of the world, who brought out books born of lecture notes meant to disseminate in depth knowledge of Petroleum Geochemistry for geoscientists actively engaged in upstream activities. The book is going to be a prized possession of academia in geosciences and of all the scientists and engineers of the upstream petroleum industry who are desirous to contribute their mite towards sustaining and augmenting global energy security through long time availability of petroleum. Dehradun Kuldeep Chandra Former Executive Director R&D ONGC Limited, and Chairman, Afro-Asian Association of Petroleum Geochemists
Preface During the last three decades there has been a rapid progress in petroleum geochemistry. The aim of this book is to cover the advances in a comprehensive way providing a background for understanding the basic concepts and principles. It is designed to develop principles of petroleum geochemistry and emphasise its applications to hydrocarbon exploration. Several geochemical and analytical techniques are described along with their relative merits and limitations so that an appropriate technique can be selected in a particular exploration programme. Application of principles of petroleum geochemistry to common exploration programmes are lucidly brought out by introducing worked out examples and case studies. The book is written primarily for postgraduate students of earth sciences and graduate students of engineering taking courses in petroleum science or engineering. It is also useful for those working in oil industry dealing with exploration and related fields. Each geochemical concept is explained in detail prior to its application. Adequate references are cited in the text. Exhaustive list of books, memoirs, papers published in journals and proceeding of World Congress, International Seminars and Symposia are included in the bibliography for further reading. The contents are arranged in the following sequence so as to interpret geochemical data of varied
xii reliability and to unravel complex geochemical processes involved in petroleum exploration and production. P Role of petroleum geochemistry in prospect identification, prioritisation and risk reduction in hydrocarbon exploration and production. Composition, properties and genetic classification of crude oil and natural gas. P Occurrence of petroleum in sedimentary basins Basin type, classification and hydrocarbon richness. Resource estimation and production potential of typical Indian petroliferous basins of proven commercial production. P The origin of Petroleum-Inorganic (abiogenic) and organic (biogenic) theories and their relative merits and limitations. Polymerisation theory of petroleum formation and its implications. P Geochemical processes involved in generation, migration and accumulation of hydrocarbons in sedimentary basins. Factors effecting them and optimum conditions for commercial production of petroleum. P Application of geochemical methods for the study of organic maturation, evaluation of stratigraphic units and distribution of organo facies for delineation of hydrocarbon kitchens. Principles of source rock evaluation. Typical examples and case studies. P Geochemical surface prospecting of hydrocarbons to identify anomalous areas that prioritise targets for future exploration. Relative merits and limitations of surface geochemical methods. P Application of hydrogeochemical surveys in exploration. Genetic indicators for delineation of oil wells. Role of oil field waters in enhanced oil recovery operations, and in situ oil degradation in reservoirs. Implications of scale formation and corrosion in petroleum exploration and production operations. P Role of biomarkers for characterization and evaluation of source organo facies and depositional environments. Application of high resolution geochemical techniques such as GC-MS, CF-IRMS, MRM-GC-MS for molecular level studies involving thermal cracking of light oil and
xiii condensates; oil-oil, oil-source rock correlations to understand migration pathways; petroleum system and paleodepositional environments at micro level. P Geochemical modeling of hydrocarbon generation based on kinetics of kerogen degradation. Integration of the model with geological history of the basin to delineate prospective areas. Validity of the model and its application for evaluation of petroleum potential and determination of timing of its formation for comparison with the age of traps. P Application of geochemical techniques to unconventional petroleum resources such as shale gas and oil shale; bituminous sands; basin centered (tight) gas sands; coal bed methane (CBM); gas hydrates. Study of their characteristics, depositional environments, resource potential, exploration and production strategies, and environmental concerns. Global and Indian unconventional petroleum resources. I acknowledge with thanks the authorities of Andhra University for offering an honorary professorship in Delta Studies Institute (DSI) which prompted me to write this book. It evolved from a series of lectures delivered on petroleum geochemistry to the students of M.Tech. Petroleum Exploration and discussions with several distinguished visiting faculty members. I take this opportunity to thank Prof. D. Rajasekhara Reddy, Director (DSI) for offering facilities, and to Sri T. Karunakarudu and V. Jayasundar Reddy (Teaching Assistants) for their assistance in the institute. My thanks are also due to several visiting faculty of DSI and former scientists of ONGC Sri P.V. Ramana Rao, GGM; Sri S.S. Yalamarty, GGM & Basin Manager; Sri P.V. Ramana, G.G.M & Director, IRS; Sri G.S. Chari, D.G.M; Sri B.V. Rao, D.G.M; Dr. P.V.L.P. Babu, D.G.M for their encouragement. I am particularly grateful to Dr. Kuldeep Chandra, Former Executive Director, ONGC and President of Afro-Asian Association of Petroleum Geochemists, for offering several constructive suggestions and improving the quality of the text. I am very much thankful and obliged for his kind gesture of writing the Foreword.
xiv My special thanks are due to Prof. V.R.R.M. Babu, Former Professor of Geology and Geoengineering; Prof. U. Muralikrishna, Former Professor of Chemistry of Andhra University; Sri K. Ananta Krishna, Former DGM, ONGC for critically going through the text and offering valuable suggestions. I am thankful to Prof. G.S.Roonwal, Former Professor of Geology, Delhi University; Dr. V.V. Sarma, Scientist G, Regional Centre of NIO, Visakhapatnam; Dr. I. Nageswara Rao, Research Scientist, School of Chemistry; Dr. P. Prabhakar, Chief Chemist, ONGC for their assistance. My special appreciation goes to Sri V. Hari Prasad and Sri M. Santhosh Kumar, Technical Assistants of DSI, for diligently bringing out the text including Tables and Figures. D. Satyanarayana Visiting Professor, Delta Studies Institute & Former Professor of Marine Chemistry Andhra University, Visakhapatnam
Contents Acknowledgements Foreword Preface 1. Introduction 1 2. Composition and Properties of Petroleum 5 2.1. Saturated Hydrocarbons 7 2.2. Unsaturated Hydrocarbons 14 2.3. Compounds with Hetero (NSO) Atoms 18 2.4. Natural Gases 20 2.5. Physical Properties of Crude Oils 23 2.6. Thermal Alteration of Oil in the Reservoir 28 2.7. Classification of Crude Oils 28 3. Occurrence of Petroleum in Sedimentary Basins 34 3.1. Definition of a Sedimentary Basin 34 3.2. Classification of Indian Petroliferous Sedimentary Basins 40 3.3. Cambay Basin 48 v vii xi
xvi 3.4. Mumbai Offshore Basin 55 3.5. Krishna Godavari (K G) Basin 64 3.6. Cauvery Basin 70 3.7. Assam-Arakan Basin 74 3.8. Rajasthan Basin 85 4. Origin of Petroleum 90 4.1. Inorganic (abiogenic) Theory 90 4.2. Organic (biogenic) Theory 95 4.3. Conclusion 97 5. Hydrocarbon Generation, Migration and Accumulation in Sedimentary Basins 98 5.1. The Carbon Cycle 98 5.2. Genesis of Petroleum 102 5.3. Migration and Accumulation of Hydrocarbons 113 5.4. Mechanism of Primary Migration 115 5.5. Secondary Migration 122 5.6. Accumulation and its Efficiency 125 6. Geochemical Methods in Petroleum Exploration 128 6.1. Isolation of Kerogen and Bitumen 128 6.2. Petrographic Methods 129 6.3. Geochemical Methods 135 6.4. Stable Isotope Analysis 138 6.5. Rock-Eval Pyrolysis Method 141 6.6. Time Temperature Index (TTI) 148 6.7. Level of Organic Metamorphism (LOM) 166 6.8. Correlation Between Geochemical and Petrographic Techniques 172 7 Source Rock Evaluation and Correlations 176 7.1. Principles of Source Rock Evaluation 176 7.2. Interpretation of Source Rock Data 181
xvii 7.3. Quantitative Volumetric Estimation of Source Rock Hydrocarbons in a Basin 189 7.4. Oil-oil and Oil-Source Rock Correlations 193 7.5. Alteration Processes of Crude Oil Composition 197 7.6. Oil-oil Correlations 200 7.7. Oil-Source Rock Correlations 202 7.8. Correlation Parameters for Gases 207 7.9. Case Studies 208 8. Surface Geochemical Prospecting of Hydrocarbons 220 8.1. Seepages 220 8.2. Surface Geochemical Prospecting 223 8.3. Categories of Surface Geochemical Methods 224 9. Hydro Geochemistry of Oil Field Waters 234 9.1. Types and Definitions of Oil Field Waters 235 9.2. Classification of Oilfield Waters 236 9.3. Physical Properties of Oil Field Waters 238 9.4. Chemical Composition of Oil Field Waters 239 9.5. Origin and Evolution 242 9.6. Genetic Relation to Evaporites 243 9.7. Patterns and Significance of Salinity Distribution 244 9.8. Role of Oil Field Waters in Enhanced Oil Recovery (EOR) Operations 246 9.9. Oil Degradation in the Reservoir 249 10. Organic Geochemistry and Analytical Techniques 257 10.1. Biomarkers 257 10.2. Specific Biomarkers 259 10.3. Use of Biomarkers 271 10.4. Analytical Techniques in Petroleum Exploration 273 10.5. Column Chromatography 276 10.6. Gas Chromatography (GC) 277 10.7. Mass Spectrometry 281
xviii 10.8. Spectroscopic Methods 284 10.9. Thermogravimetry (TG) and Differential Thermal Analysis (DTA) 291 11. Geochemical Basin Modeling: Application to Petroleum Exploration 294 11.1. Integrated Models of Hydrocarbon System 294 11.2. Qualitative Models of Hydrocarbon System 295 11.3. Quantitative Geochemical Models 296 11.4. Mathematical Model of Kerogen Degradation and Hydrocarbon Generation 297 11.5. Application of the Model to Petroleum Exploration 308 12. Unconventional Petroleum Resources 314 12.1. Typical Unconventional Petroleum Systems 314 12.2. Basinal (Deep) Gas (Tight Gas) Sands 315 12.3. Shale Gas 316 12.4. Oil Shale 317 12.5. Bituminous (Tar) Sands 318 12.6. Coal Bed Methane (CBM) 320 12.7. Gas Hydrates 342 12.8. Stability of Gas Hydrates 348 12.9. Detection of Gas Hydrates 352 12.10. Distribution of Gas Hydrates 357 Appendices 363 References 371 Bibliography 405 Author Index 417 Subject Index 425