Seismic Data Interpretation and Evaluation for Hydrocarbon Exploration and Production A Practitioner's Guide PDF

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Niranjan C. Nanda Seismic Data Interpretation and Evaluation for Hydrocarbon Exploration and Production A Practitioner’s Guide Seismic Data Interpretation and Evaluation for Hydrocarbon Exploration and Production Niranjan C. Nanda Seismic Data Interpretation and Evaluation for Hydrocarbon Exploratio...

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Niranjan C. Nanda

Seismic Data Interpretation and Evaluation for Hydrocarbon Exploration and Production A Practitioner’s Guide

Seismic Data Interpretation and Evaluation for Hydrocarbon Exploration and Production

Niranjan C. Nanda

Seismic Data Interpretation and Evaluation for Hydrocarbon Exploration and Production A Practitioner’s Guide

Niranjan C. Nanda Petroleum Geophysicist Cuttack, Odisha, India

ISBN 978-3-319-26489-9 ISBN 978-3-319-26491-2 DOI 10.1007/978-3-319-26491-2

(eBook)

Library of Congress Control Number: 2015957432 Springer Cham Heidelberg New York Dordrecht London © Springer International Publishing Switzerland 2016 This work is subject to copyright. All rights are reserved by the Publisher, whether the whole or part of the material is concerned, specifically the rights of translation, reprinting, reuse of illustrations, 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 this publication does not imply, even in the absence of a specific statement, that such names are exempt 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 in this book are believed to be true and accurate at the date of publication. Neither the publisher nor the authors or the editors give a warranty, express or implied, with respect to the material contained herein or for any errors or omissions that may have been made. Cover illustration: A composite display of multiattributes showing a cutaway seismic cube intersected with two strata cubes, the lower one from the most-positive curvature attribute, and the upper one from coherence attribute overlaid with the time horizon in semi-transparent colour (image courtesy: Arcis Seismic Solutions, TGS, Calgary). Printed on acid-free paper Springer International Publishing AG Switzerland is part of Springer Science+Business Media (www.springer.com)

Preface

Young students in universities and freshers in oil companies have asked me on many occasions after my lectures, if I could suggest a reference book on interpretation and evaluation of seismic data. I could not do so because, honestly, I was not aware of any such book. Interpretation, being an aspective art, depends to a large extent on an individual’s perception and, perhaps due to this reason, it becomes difficult for one to express abstract things in writing. Interpretation of any data, especially seismic data in petroleum exploration, needs to be conclusive and logically extended to its geological implications, in evaluating the prospects for techno-economical risk analysis, and consequently in strategizing field development plans for exploration and production of hydrocarbons. There is a difference between interpretation of data and its evaluation, which needs emphasis. For example, detecting and mapping a fault is not an end of an interpretation in itself. It is essential for the interpreter to evaluate its significance in terms of its role in source and reservoir potentials, in trapping and migration mechanisms, and ultimately for accumulation and production of hydrocarbons. This guide is for practioners, students as well as geoscientists and engineers in the industry in the field of seismic data interpretation and more significantly for data evaluation. It is assumed that the young professionals are well acquainted with the elementary theory, principles and the equations in their respective disciplines of geology and geophysics taught in schools, and as such these preliminaries are mostly kept to the bare minimal. However, as it is essential for a seismic analyst to be familiar with certain relevant geophysical, geological and reservoir engineering principles for a holistic interpretation and evaluation of multidisciplinary data, some of the basics are restated very briefly and in a simple way in the book for expediency. This guide is principally an expanded and enlarged version of my lecture and training notes to post-graduate students of Petroleum Geology and Geophysics and young professionals in oil companies. A caveat that may appropriately be stated here is that the handbook reflects a flavor of many of my personal perceptions and idealistic thoughts, sieved out of many decades of my practicing experiences in v

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Preface

petroleum exploration and development. It is an attempt to encourage and steer young analysts to become more imaginative, logical, and practical in application of their knowledge to achieve the goals. Ultimately, it aims to motivate and facilitate the practitioners in the art of seismic data interpretation and evaluation and to gain proficiency in a shorter span of time, an objective often sought by E&P companies in the industry. It is hoped that this handbook provides enough stimuli to the inquisitive and sharp minds of the young geoscientists and engineers, compelling them to continue thinking and questioning followed by offering rejoinders, and in the process excel in their profession. Cuttack, India

Niranjan C. Nanda

Acknowledgments

Seismic interpretation is an art or a skill that is acquired with experience, which I happened to attain during my long stint with Oil and Natural Gas Corporation (ONGC), India. On my superannuation from ONGC after 37 years of service, my passion for seismic interpretation encouraged me to take up consulting projects and teaching assignments at Indian Universities, which I have enjoyed very much till the present. A few years ago, my good friend and erstwhile colleague at ONGC, Satinder Chopra of Arcis Seismic Solutions, TGS, Calgary, Canada, suggested that I should condense my long-standing experience in seismic interpretation in the form of a book. His persistent persuasion eventually compelled me to take up this task. From the beginning, Satinder has been extremely supportive and obliging in developing the project, both in mind and matter. His genial and meticulous review of the manuscript has finally brought the book to its present form. I gratefully and profoundly thank Satinder for these acts. I thankfully acknowledge ONGC, India; Arcis Seismic Solutions, TGS, Canada; Hardy Energy, India; Society of Exploration Geophysicists (SEG); American Association of Petroleum Geologists (AAPG); Earth Magazine; and the individual authors Rob Stewart, Frisco Brower, Paul Groot and Jon Downton who have accorded permission for publication of the many examples included in the book. I also thank my young friend Ravi Kumar of Saturn Energy Solutions, Hyderabad, India, for dispensation of the attractive images and the figures in the book. I thank Springer publishers for the dexterous handling of the manuscript for print. In particular, I would like to thank Hermine Vloemans and Petra van Steenbergen, who have been very cooperative and patient in ensuring that the book is published well and on time. And lastly, I owe an enormous gratitude to my wife not only for her ungrudging endurance of my reticence all these years, but also for her love and devotion that continued to encourage and push me to carry on with the endless task of writing this book until its completion. I also wish to place on record my appreciation and thanks

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to my two loving daughters who very thoughtfully presented me with a laptop to start the typescript and trained me in its intricate operations and eventually succeeded in making me a ‘sesquifingered’ computer ‘semi-literate’. Cuttack, India

Niranjan C. Nanda

Contents

Part I

Exploration Seismic

1

Seismic Wave Propagation and Rock-Fluid Properties . . . . . . . . . . . . Seismic Wave Propagation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Energy Losses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Absorption. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Scattering . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Transmission . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Spherical (Geometrical) Divergence . . . . . . . . . . . . . . . . . . . . . . . . . . . Geological Significance of Energy Attenuation . . . . . . . . . . . . . . . . . . . . Seismic Properties. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Rock-Fluid Properties (Rock Physics) . . . . . . . . . . . . . . . . . . . . . . . . . . . Rock Properties . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Elasticity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Bulk Density . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Porosity, Pore Size and Shape (Pore Geometry) . . . . . . . . . . . . . . . . . . Texture . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Fractures and Cracks, Geometry . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Fluid Properties . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Pore Fluid and Saturation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Viscosity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Pressure and Temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Seismic Rock Physics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

3 3 4 4 5 5 6 7 7 8 8 8 9 9 11 11 12 12 13 13 16 17

2

Seismic Reflection Principles: Basics . . . . . . . . . . . . . . . . . . . . . . . . . . Signal-to-Noise Ratio (S/N) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Seismic Resolution . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Vertical Resolution . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Lateral (Spatial) Resolution and Fresnel Zone . . . . . . . . . . . . . . . . . . .

19 20 21 22 23 ix

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Interference of Closely Spaced Reflections: Types of Reflectors . . . . . . . Discrete Reflectors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Transitional Reflectors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Complex Reflectors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Innate Attributes of a Reflection Signal . . . . . . . . . . . . . . . . . . . . . . . . . . Amplitude and Strength . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Phase . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Frequency (Bandwidth) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Polarity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Arrival Time . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Velocity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Seismic Display . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Plotting Scales (Vertical and Horizontal) . . . . . . . . . . . . . . . . . . . . . . . References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

26 27 27 28 28 29 30 30 31 32 32 33 34 35

3

Seismic Interpretation Methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Category I: Structural Interpretation (2D) . . . . . . . . . . . . . . . . . . . . . . . . Identification and Correlation of Horizons . . . . . . . . . . . . . . . . . . . . . . Contouring and Maps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Category II: Stratigraphic Interpretation (2D) . . . . . . . . . . . . . . . . . . . . . Seismic Calibration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Synthetic Seismogram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Vertical Seismic Profiling (VSP) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Continuous Velocity Logs (CVL) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Velocity Estimation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Seismic (Structure) Maps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Seismogeological Section . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Category III: Seismic Stratigraphy Interpretation. . . . . . . . . . . . . . . . . . . Seismic Sequence Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Seismic Facies Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Relative Sea Level Change (RSL) Analysis . . . . . . . . . . . . . . . . . . . . . Category IV: Seismic Sequence Stratigraphy Interpretation . . . . . . . . . . Low Stand Systems Tract (LST) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Transgressive Systems Tract (TST) . . . . . . . . . . . . . . . . . . . . . . . . . . . High Stand Systems Tract (HST) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Application of Seismic Sequence Stratigraphy. . . . . . . . . . . . . . . . . . . Seismic Stratigraphy and Stratigraphic Interpretation . . . . . . . . . . . . . . . References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

37 39 39 42 45 45 46 48 48 50 52 54 55 56 58 63 67 67 68 68 70 71 72

4

Tectonics and Seismic Interpretation . . . . . . . . . . . . . . . . . . . . . . . . . . Structures Associated with Extensional Stress Regimes . . . . . . . . . . . . . Compaction/Drape Folds . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Horsts and Grabens Accompanied by Normal Faults . . . . . . . . . . . . . . Compaction Faults and Gravity Faults . . . . . . . . . . . . . . . . . . . . . . . . .

73 74 74 74 74

Contents

5

6

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Listric Faults, Growth Faults and Roll-Over Structures . . . . . . . . . . . . Cylindrical Faults and Associated Toe Thrusts, Imbricates . . . . . . . . . Structures Associated with Compressional Stress Regimes . . . . . . . . . . . Folds/Duplexes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Reverse Faults, Thrusts and Overthrusts . . . . . . . . . . . . . . . . . . . . . . . . Structures Associated with Shear Stress (Wrench) Regime . . . . . . . . . . . En Echelon Conical Folds . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . High-Angle Faults and Half Grabens . . . . . . . . . . . . . . . . . . . . . . . . . . Flower Structures and Inversions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Strike-Slip Faults. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Salt/Shale Diapirs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Salt Diapirs - Types . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Synopsis of Significance of Seismo-Tectonics Studies in Seismic Data Evaluation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

76 78 79 79 79 81 81 82 83 83 85 86 87 89

Seismic Stratigraphy and Seismo-Tectonics in Petroleum Exploration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Basin Evaluation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Source and Generation Potential . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Reservoir Facies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Migration. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Entrapment and Preservation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Basin and Petroleum System Modeling . . . . . . . . . . . . . . . . . . . . . . . . Fault Attributes Analysis and Trap Integrity . . . . . . . . . . . . . . . . . . . . . . . Prospect Generation and Evaluation, Techno-Economics . . . . . . . . . . . . Type of Source . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Migration-Timing and Pathways. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Reservoir Lithology (Clastic/Carbonate) . . . . . . . . . . . . . . . . . . . . . . . Type of Traps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Estimate of Hydrocarbon Volume . . . . . . . . . . . . . . . . . . . . . . . . . . . . . References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

91 91 92 93 93 94 94 95 98 99 100 100 100 100 101

Direct Hydrocarbon Indicators (DHI) . . . . . . . . . . . . . . . . . . . . . . . . . DHI Amplitude Anomalies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Bright Spots . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Dim Spots . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Flat Spots . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Validation of DHI Amplitude Anomalies . . . . . . . . . . . . . . . . . . . . . . . . . Velocity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Polarity . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ‘Sag’ Effect . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Shadows . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Limitations of DHI . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

103 105 105 106 107 108 108 109 110 110 111 112

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Contents

Borehole Seismic Techniques . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Check-Shot Survey . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Vertical Seismic Profiling (VSP) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Types of VSP. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Check-shot and VSP Survey Comparison. . . . . . . . . . . . . . . . . . . . . . . . . Well (Seismic) Velocity and Sonic Velocity . . . . . . . . . . . . . . . . . . . . . . . Limitations of Well Velocity Surveys . . . . . . . . . . . . . . . . . . . . . . . . . . . . Cross-Well Seismic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Part II 8

9

115 115 116 120 121 122 124 12...