European Association of Geoscientists & Engineers

This book sets out to give the reader a non-mathematical understanding of the basic principles of migration and of building a velocity model of the earth’s subsurface. The intended readership includes anyone who has to work with, or to understand, how contemporary seismic images are created: what are the underlying principles and pitfalls? How is a velocity model typically built and what are the consequences of not getting it right?

Concepts such as uncertainty and non-uniqueness are discussed as are the ways in which these topics translate to risk-reduction and reliability in the final image. The different ways of representing a velocity model are reviewed as are the techniques used for picking velocity and anisotropy related information. A review of the principles of tomography is presented, to familiarize the reader with the techniques that underpin all contemporary velocity model update. Also, the physics behind anisotropy and its consequences for obtaining images in ?true? geological depth are discussed.

An historical overview of velocity model building techniques over the past 30 years is presented to give the reader a feel for how the black art of model building has evolved in tandem with the increase in computer power and the emergence of powerful interactive graphics, covering the evolution from a purely linear compartmentalized industrial process towards a fully interactive multidisciplinary approach to iteratively building a reliable subsurface velocity model.

The book concludes with a look at emerging and future trends: the promise of velocity-independent imaging and the potential of full waveform inversion.

This book explains how geophysicists in the energy industry measure, interpret, and use seismic anisotropy.
The book is designed for geophysicists who want to enhance their understanding of the subsurface and learn about modern techniques for extracting more information from seismic data.

Basin Research is an international journal which aims to publish original, high impact research papers on sedimentary basin systems. We view integrated, interdisciplinary research as being essential for the advancement of the subject area; therefore, we do not seek manuscripts focused purely on sedimentology, structural geology, or geophysics that have a natural home in specialist journals. Rather, we seek manuscripts that treat sedimentary basins as multi-component systems that require a multi-faceted approach to advance our understanding of their development. During deposition and subsidence we are concerned with large-scale geodynamic processes, heat flow, fluid flow, strain distribution, seismic and sequence stratigraphy, modelling, burial and inversion histories.
In addition, we view the development of the source area, in terms of drainage networks, climate, erosion, denudation and sediment routing systems as vital to sedimentary basin systems. The underpinning requirement is that a contribution should be of interest to earth scientists of more than one discipline.

Basin Research is published in association with the International Association of Sedimentologists and the European Association of Geoscientists and Engineers.

Editorial Board
Editor in Chief: Atle Rotevatn
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Velocities, Imaging, and Waveform Inversion - The evolution of characterizing the Earth’s subsurface is part of Ian Jones' EAGE Education Tour and will be a fusion of practical industrial elements, concentrating on the origin and nature of the geological complexities that give rise to imaging problems, as well as a physical (rather than mathematical) understanding of subsurface parameter estimation, and will also look at some possible future directions. The course is designed for: practising geoscientists who desire to better understand the principles and limitations of both current and emerging technologies involved in subsurface parameter estimation and imaging and geoscience students. Following this course, participants should ideally understand how contemporary velocity estimation methods work, and what approximations are involved in obtaining computationally tractable solutions.
In using sound waves to characterise the Earth’s subsurface, we can employ ray theory and/or wave theory, and both migration algorithms and parameter estimation schemes employ one or other of these theoretical descriptions. In this course, we will review the evolution of the industry’s approaches to building earth models via velocity estimation and imaging, outlining the evolution from ray tomography to full waveform inversion, and look towards the emerging possibilities for replacing imaging techniques with direct subsurface parameter inversion methods.
The approach will be mostly non-mathematical, concentrating on an intuitive understanding of the principles, demonstrating them via case histories, and will be divided into the following sections:
- Dealing with the near surface
- The effects of strong vertical velocity contrasts
- The effects of strong lateral velocity contrasts
- Waves versus rays - Model building using ray methods (tomography)
- Model building using wavefield extrapolation methods (FWI)
- Data examples and comparisons
- Future developments
The first three sections outline the nature of the problems we face when building images representing subsurface impedance contrasts, and the next three deal with the technology we deploy to address the problems. In addition, I have included three appendices to outline: the historical development of model building, anisotropy and pre-processing considerations for complex imaging. Several of the individual chapters build on a series of recent tutorial papers which I published in First Break. However, only the key points from these tutorial papers are included, so I refer readers to the original papers for more detail and/or a range of real data examples for each of their topics.
However, due to space and time constraints in the EET format, I have had to omit or limit coverage of various topics, including migration of multiples, Marchenko and inverse scattering series migration, joint migration-inversion, least-squares migration and uncertainty estimation.

Many advances in stochastic reservoir modelling have been introduced in the past decade. Novel method of data integration and more accurate representation of geology have been developed with the advances in spatial statistics. However, integrated approach for predictive reservoir modelling still attracts continuous effort to manage reservoir decisions under uncertainty and make better use of the increasing amounts of data and domain knowledge accumulated in the field.
Many solutions to these challenges lie in the cross-disciplinary vision, where modern rigour of computer science and statistics brought together with core geological and engineering domain expertise and basic physical conceptual thinking.
This book aims to bridge across different fields — geostatistics, machine learning, and Bayesian statistics — to demonstrate the common grounds in solving challenging problems of uncertainty quantification, geological realism, and data integration in reservoir prediction. It presents an overview of key concepts and some of the basic and more advanced algorithms for reservoir modelling and uncertainty quantification. This book includes several practical examples to reinforce the learning outcomes. A tutorial on decision making under uncertainty provides a practical way to apply integrated thinking to a real field dataset.

he work of geoscientists is generally addressed to solve practical problems, like for instance finding new hydrocarbon reservoirs or studying volcanoes. In these scientific fields, intuitions and qualitative analogies are equally important as the application of advanced technology and rigorous mathematical approaches.
The thesis of this book is that the activity of geoscientists can also contribute to illuminate fundamental aspects and open questions of epistemology and cognition. How do geologists and geophysicists think, manage information, develop knowledge and communicate their ideas? What is a good model, a valid theory, a useful methodology? What is the meaning of ‘true’ and ‘false’ in their field of study? What is creativity? Is it a property of exceptional individual minds or a dialectic relationship between entire communities and their ecosystem? Or is it the combination of both? Is it possible to promote individual and team creativity? How? Can we find an aesthetic value in the daily work of geoscientists?
All the above challenging questions are investigated in this book using a multidisciplinary approach. The discussion starts from the geosciences and continues with stimulating incursions in the field of ancient and modern philosophy, epistemology, cybernetics, Chaos theory, neurobiology, psychology and art. The objective is to highlight some unexplored links between cognition, philosophy of science and Earth disciplines, motivating the study and the application of all these fields observed from an unusual and inedited point of view.
Despite the intrinsic complexity of the subject, this book is addressed to a large audience. This includes students, researchers, professionals and all those who are interested in exploring the cognitive and epistemological fundamentals of the Earth sciences. It can be useful also for managers leading creative teams, dealing with complex information, developing innovative products, services and ideas. Finally philosophers of science and cognitive scientists can find practical examples in this book related to important aspects of epistemology and human cognition.

This volume documents part of the Shell Digital Geology project that has demonstrated how you can use digitalisation and its many flavours to your benefit for subsurface characterisation. Conveying complex geological concepts, business workflows used in Exploration, Development and Production and their links to decision-making has never been more transparent and easier to explain than via the Digital Geology exhibition and its associated learning nuggets. The novel set-up allows communicating to a wide range of audiences in an interactive and exciting way how geoscientists and engineers are dealing with developing an understanding of the subsurface and how such knowledge is used in the life cycle of subsurface projects. Therefore, the concepts behind Digital Geology can be applied in many ways, be it for hydrocarbon exploration and development, carbon capture and sequestration, geothermal energy or water resource management.

A deep knowledge of the subsurface geology is key for the success of our societies. To communicate this within them and within the geoscience and engineering communities will be equally important when it comes to providing future solutions for the energy transition. This transition will only work if we manage to translate workflows initially developed for hydrocarbons, and presented in this book, seamlessly into next-generation, decentralized energy solutions. Such will involve hydrogen storage, sequestration of green house gases as well as shallow and deep geothermal resources – our next challenge.

Eastern Mediterranean Workshop 2018

This is a substantially revised and enlarged version of the Russian-English Dictionary of Exploration Geophysics. It contains about 15,500 terms used in seismic, electrical, gravity, magnetic and radioetric prospecting, logging and remote sensing. Also included are terms from geology, mathematics and computer science frequently used by geophysicists.