Edinburgh Anisotropy Project: British Geological Survey

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Edinburgh Anisotropy Project: British Geological Survey
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The Edinburgh Anisotropy Project at the British Geological Survey[1] has made many significant advances in seismic anisotropy research over the past 24 years. The main technical achievements of EAP include: fracture identification and characterization based on shear-wave splitting and azimuthal characteristics of P-wave attributes; improving the industry’s awareness of the effects of seismic anisotropy and the processing of anisotropic seismic data; advancing the use of multicomponent seismic data in the industry; and enhancing seismic imaging techniques for both PP and converted waves in the presence of anisotropy. EAP has also contributed many highly qualified scientists to the geophysical community. Today EAP continues its pioneering research in relating seismic anisotropy to petroleum reservoir characterization. Through a large cohort of graduate students from the University of Edinburgh, EAP has authored over 100 SEG abstracts, and a plethora of papers in Geophysics, The Leading Edge, and many other journals.

Citation for the SEG Distinguished Achievement Award

Contributed by Gary Hampson, Rodney Johnston, and Wenjie Dong

It is our pleasure to provide a citation in support of a Distinguished Achievement Award for the Edinburgh Anisotropy Project (EAP), a sustained research effort over the last 24 years which has substantially advanced the science of exploration geophysics by demonstrating the presence, analysis and value of seismic anisotropy.

EAP began as a result of Stuart Crampin’s lifetime quest to predict earthquakes. During the 1970s and 1980s, Stuart and his colleagues at the British Geological Survey (BGS) set up the Turkish Dilatancy Project (TDP) which comprised a series of 3C seismology networks in Turkey to investigate shear-wave splitting over small earthquake swarms. TDP confirmed the observation of shear-wave splitting in rocks with stress-aligned cracks, with a fast (slow) wave polarized parallel (normal) to the fracture planes with the time-delay between them an indication of fracture density. This gained the attention of the oil industry in the 1980s. Through the enlightened management of Chris Browitt and academic charm of Stuart Crampin, 12 major oil companies agreed to support a program of research called the Edinburgh Anisotropy Project with additional support from the UK’s Natural Environmental Research Council (NERC). This was the first sponsorship of its kind in the venerable 150-year history of the British Geological Survey.

Under Stuart’s leadership, EAP initially focused on whether the shear-wave splitting observed in earthquake data could also be found in exploration data. Today, substantially through the contributions of EAP, anisotropy is widely accepted as present in most seismic data sets and techniques pioneered by EAP are used for its analysis. After seven years, Stuart passed the baton to Colin Macbeth who led EAP for five years. Colin worked on many fundamental aspects of anisotropic wave propagation, data acquisition, wavefield analysis and VSPs, much of which is summarized in a book.

In 1999, leadership passed to Xiang-Yang Li. The focus grew to include the use of wide-azimuth P-wave and converted-wave data for fracture characterization, while continuing to understand the response of shearwave splitting. Xiang-Yang’s leadership was characterized by pragmatic approaches supported by scientific rigor that the sponsors could employ in their analysis of seismic anisotropy (having been developed and tested on sponsor data sets). The familiar company mergers of the late 1990s precipitated strong funding challenges for EAP. Xiang-Yang and colleagues worked tirelessly to ensure the necessary industrial sponsorship and at the same time succeeded in doubling the NERC funding in 1999. During this period, Enru Liu and Mark Chapman joined the project and enhanced EAP’s fundamental research into anisotropic rock physics principles and models. Hengchang Dai and Alexander Druzhinin focused on converted-wave data processing in the presence of anisotropy and anisotropic depth imaging.

Over the last several years, EAP has developed a new research focus on frequency-dependent anisotropy for characterization of fracture scale length and fluid content, supported by rock physics model-based inverse schemes. In 2012, leadership of EAP passed to Mark Chapman, who undoubtedly will continue its tradition in linking science and research to practical applications.

During its 24 years, EAP’s research interests and contributions have spanned fracture characterization and anisotropic imaging through techniques such as data processing, interpretation, modeling and acquisition design; all rest on the fundamentals of anisotropic wave propagation and rock physics. In 1988, few people in our industry were aware that seismic anisotropy existed. Today, largely because of EAP, its presence is universally accepted, not only by academic and industry researchers but also by seismic processing and interpretation practitioners. Considerable progress has been made to accommodate its effects in workflows and it is now widely exploited as a source of useful information in seismic data sets. EAP remains the major contributor to this paradigm shift.