Hydrocarbon exploration has many phases: from the heavy engineering aspects of the rig building and drilling industries, to the geological interpretation and attribute analysis of oil company geologists and rock physicists. However, underpinning all this activity is geophysical signal processing, which produces, as a final product, a 3D image of the subsurface of the Earth and related attribute volumes. This image is then used by rock physicists and engineers to infer what fluids are present in the rock formations, and by geologists to decide where to drill exploration wells.
Since the late 1970s, geophysicists have constructed images of the Earth's subsurface by estimating the speed of sound in the different rock layers, and using this information to reposition seismic data recorded on the Earth's surface, back to the subsurface reflecting surfaces to form a seismic image. This latter process is called migration.
In writing a migration algorithm, it is possible to make many simplifying approximations, so that forming an image becomes a tractable problem for the available computer power. However, to form the image, the migration algorithm needs a good estimate of the velocity of sound in the various subsurface rock layers, and there are many techniques for estimating these velocities.
In this talk, I'll review these aspects of contemporary imaging, and introduce some emerging ideas which perhaps seem to promise circumvention of the current two-step imaging procedure of velocity model building followed by migration, so as to estimate subsurface reflectivity, velocity, density and absorption parameter fields directly from the recorded data. This emerging technology is known as full waveform inversion.
Ian Jones received a joint honours BSc in Physics with Geology from the University of Manchester, UK, in 1977, an MSc in Seismology from the University of Western Ontario, Canada, and a PhD in Geophysical Signal Processing from the University of British Columbia, Canada, in 1985.
After working for Inverse Theory & Applications Inc. in Canada for two years, he joined CGG, where for 15 years he was involved in R&D in the London and Paris offices. Since 2000 he has been with ION GX Technology, as a Senior Geophysical Advisor in their London office.
He has published various articles on imaging related topics, and was co-organizer of: the 1998 SEG-EAEG summer research workshop entitled Depth Imaging of Reservoir Attributes, the 2002 EAGE workshops on Kirchhoff versus Wave Equation Imaging and High Resolution Velocity Estimation, and 2010 SEG summer research workshop on Subsalt Imaging. He was the instructor of the 2004 and 2008 SPG one-day workshops on Depth Imaging, and also for the EAGE and SEG continuing education courses on Velocity Model Building.
His current interests include velocity model building and migration, and his most current activity includes writing the text book ‘An introduction to velocity model building' published by the EAGE in 2010; and co-editing the SEG Geophysics Reprints series volumes Classics of Elastic Wave Theory and Pre-Stack Depth Migration and Velocity Model Building.
He is a member of the SEG, EAGE and the PESGB; serves on the SEG editorial committee and the EAGE OGGD and technical program committees, is an associate editor for Geophysics and also Geophysical Prospecting, and was awarded the EAGE's Anstey Medal in 2003 for "contributions to the depth imaging literature", and made the SEG 2012 Honorary Lecturer for Europe, for "contributions to advancing the science and technology of geophysics".
Please tell us a little bit about yourself (e.g., your educational and work experience, why you became geophysicist, etc.)
I grew up in Liverpool, started my undergrad studies in physics in Manchester, and then went to Canada, where I gravitated toward geophysics due to my interest in things geological – how the Earth formed and why it is the way it is. My initial fascination was with heat flow, but I soon became engrossed in signal processing and image enhancement. My first geophysics-related job was with IT&A Inc., in Vancouver, then with CGG in London and Paris for 15 years, and since 2000 with GXT (now part of ION) in the UK.
What work opportunities facilitated your career development, what motivates you, and how did you end up doing what you do today?
I've always been curious about finding the answers to particular questions. I've had some outstanding teachers, and also been fortunate in that various managers gave me opportunities to work on topics that interested me. As you know, commercial imperatives being what they are, there are often opportunities to present what one is working on, as from a contractor's point of view, presenting R&D is a form of technical marketing. I found that I enjoyed explaining things, and fortunately, there's a place for that in our industry, since describing complex concepts and applications is important.
Why did you choose this lecture topic? Why is it important?
For the past 20 years, I've been working on migration and velocity model building -- originally writing algorithms, then building and managing groups deploying the technology, and in more recent years promoting this technology. Seismic imaging is the only way of obtaining a relatively high-resolution view of the subsurface (and involves an interesting balance of maths, physics, and computer science). For finding hydrocarbons, we need these images and derived attributes to both see what the geological structures are like, and also to determine the rock and fluid properties needed to help exploit hydrocarbon reserves.
Could you tell us in a few sentences what your presentation objectives are?
The SEG Honorary Lecture program is different from most other lecture series, in that it targets two distinct audiences. First, those already working in the field of geoscience (members of local SEG affiliate societies), and second, university students studying diverse science and engineering topics. Much of the lecture tour seeks to interest students in the hope of recruiting potential candidates - the next generation of geoscientists.
For these potential newcomers, I'd like to give an overview of the importance of energy supply, how we find hydrocarbons, the role that imaging plays in this endeavor, and the rapid evolution of the technology we employ to provide subsurface images and attributes.
What do you hope people will have learned after they attend your lecture?
The wide and diverse aspects of geoscience in the oil and gas industry offer a home for a very broad range of interests and abilities. I hope that after this tour, some – who would not otherwise have thought of employment in our industry – may have been encouraged to consider using their talents in it.
You have quite a busy year ahead. Do you enjoy traveling? Will it be difficult to balance the tour with your work?
I enjoy travelling, but unfortunately, it's never in moderation: I'm sure that after this lecture tour I'll glad not to see an airport for a while! As for work – I should be able to combine some of the lectures with client visits, and thereby continue to "justify my existence." And, "tongue in cheek," I could also observe whether, being permitted to undertake this tour by my employers, really indicates that I am somewhat superfluous to requirements, and won't be missed for the next six months either!
Would you share with us one or two of your most exciting successes?
In the 1990s, it was seeing that the depth-migration research that I had worked on came to fruition and became a commercial service that has become an industrial norm. And since moving on from an R&D role, I've found that besides speaking, I also enjoy writing, and this, to some extent, is appreciated by the geoscience community.
How about a couple of disappointments?
Hmmm.. that's a tricky one to answer politely. I guess my biggest disappointments have been when internal politics interfere with the advancement and promotion of good science. Fortunately, I've not seen that too often, and not in recent years.
What advice would you give to geophysics students and professionals just starting out in the industry?
My advice would be to try to take a long-term and broad view of your career. Learning a complex topic and developing the competencies to do specific things well, are not isolated or short-term activities. Once you've become a competent geoscientist, there are plenty of specialist niche areas – offering interesting and exciting opportunities to be creative, that are both stimulating and rewarding.