Dr. Carl Sondergeld is Professor and Mewbourne Chair in the Mewbourne School of Petroleum and Geological Engineering, Oklahoma University (OU), Norman, Oklahoma, USA. After working at the Tulsa Research Center of Amoco Production Company for 19 years, Carl joined OU 11 years ago. His current research focuses on petrophysical and seismic rock physics, properties of gas shales and identifying ways of exploiting natural gas from them.
Together with Dr. Chandra Rai, his colleague of 30 plus years, Carl has been operating an industry sponsored research consortium on ‘Experimental Rock Physics’, and more recently they have initiated a similar consortium for gas shales called ‘Unconventional Shale Gas Consortium’.
Carl Sondergeld was the Fall 2010 SEG/AAPG Distinguished Lecturer and he delivered his talk at the CSEG luncheon on December 13, 2010, entitled ‘Rumblings from the laboratory – Past, Present and Future’. It was a pleasure engaging Carl in a chat and following are excerpts from that meeting.
(Photos courtesy: Mo Al Ibrahim, Geoph. I.T.)
Carl, for the benefit of our members, could I ask you to speak a little about your educational background and work experience?
I have a BA and MA from Queens College of CUNY in Geology and a Ph.D. from Cornell University in Geophysics. I did a Master’s thesis under Prof. Ed Schreiber in equation of state work on oxide candidates for the mantle. I worked part time and used the laboratory facilities at Lamont Doherty Geological Observatory. At Cornell I worked in seismology with Dr. Muawia Barazangi but eventually did my thesis work with Prof. Donald Turcotte. I studied two phase convection in porous media. I accepted a Postdoctoral position at the Cooperative Institute for Research in Earth Sciences, CIRES, at the University of Colorado. I worked with Drs. Hartmut Spetzler and Randy Martin studying rock mechanics and earthquake prediction.
How did you switch over from geology (B.A. & M.A.) to geophysics (doctorate)?
Queens College only offered degrees in geology even though I was technically doing geophysical research. The switch was natural as I was seeking more definitive and quantitative answers than one typically got in geology at that time. I was encouraged to take more math and physics as an undergraduate; I still had a lot more to learn when I got to graduate school.
After finishing your doctorate, you took up consultancy work with Occidental Oil Shale Company and Integrated Sciences Inc. first, before taking up teaching assignments at University of Colorado and Los Alamos National Laboratory. Were jobs difficult to come by at the time or was it because of your specialization?
At that time I had no intention of joining the industry. I never even seriously considered it. I was never exposed to what went on in the industry until I went to graduate school and then it was very peripheral. Our faculty was pretty much focused on academics and it was at the height of one of the most exciting times in geophysics; plate tectonics was happening and I was studying with people who started and embraced the revolution. This was followed by an emphasis on trying to “predict” earthquakes. And there were recently returned lunar samples from the Apollo mission. There were lunar samples in safes and we were doing measurements on them. How could industry compete with this level of excitement? They were finding oil and gas but the gas was being shut-in!
Thereafter you started your long stretch of 18 years with Amoco Production Company. I have interviewed many people like Sven Treitel, Larry Lines, Kurt Marfurt and others who have spoken very highly of Amoco Research. How did the Amoco BP merger go off? How did their technology and expertise compare?
Amoco Research was a wonderful place to be. It was lead by a remarkable individual, Mr. Mike Waller, and was populated with extraordinary scientists with industrial support. We had pockets of extreme excellence and competencies. We did not have the spectrum of strength of an Exxon, for example. First, it was not a merger, it was a take-over. There was never any sense at the scientific level of merging. It was the same when BP bought ARCO. What was astonishing to me was how little BP knew of the AMOCO technologies, but nevertheless made unilateral decisions before any meaningful evaluations. They fundamentally killed internal and sponsored research efforts.
I have been asked to find out from you, what was the background on having the Amoco research core testing gurus test ‘cold fusion’, just in case it worked?
There were famous credible chemists, Martin Fleischmann and Stanley Pons, who in 1989 made rich claims about excess heat associated with the process of ‘cold fusion’. They also reported measuring some nuclear byproducts, neutrons and tritium. Little was known about their actual experiments but their claims defied basic thermodynamics as we knew it. The potential was enormous and hence too important to ignore. So, a few people set out to duplicate their experiments and understand what was really going on. After a substantial investment and about a year of careful research we concluded there was a chemical explanation for the tritium and that the claims of neutrons were a consequence of a poor experiment.
Would it be fair to say that your accomplishments at Amoco were partly responsible for the recent SEG Award to Amoco Research for technology accomplishments?
I would like to think I contributed in a small way but there were numerous people making outstanding contributions on a weekly and yearly basis. It was the atmosphere created by management leaders like Mr. Waller and scientific leaders like Sven Treitel that allowed bright and creative people to succeed. We maintained a healthy dialog with our business units which kept us grounded and focused on delivering value. Active seminars, lunch meetings, research progress reviews and technology transfer meetings all promoted the free exchange of ideas and cooperation.
You have had a long association with Chandra Rai since the Amoco days. Please tell us about that.
Chandra and I go back a long time, some 30 years. I knew him when he was a graduate student doing research in mineral physics. I asked him in 1981 at an AGU meeting in Baltimore if he would be interested in working at AMOCO and he joined AMOCO shortly after that. We have worked together ever since. We have so many things in common as experimentalists and complement each other’s skill sets. I have developed an immense respect for his insight and talent that is strengthened and reinforced the more I continue to work with him. He is completely open and free in sharing ideas. We have developed an implicit trust which comes with years of friendship. Our collective success did not go unnoticed within AMOCO. We were the subject of study when AMOCO was trying to understand what made teams successful.
Please highlight for us the research work you performed at Amoco and now the work that you are pursuing at University of Oklahoma.
My work spanned a wide range of activities from lab measurements to writing software. Initially I was involved in developing a downhole logging tool for measuring shear waves reliably. I teamed with Martin Smith, Janice Norris and Paul Gutowski. We developed a real-time data logging and processing full waveform sonic tool which we licensed to a service company. It was the first system to do real-time processing for shear velocities in the field. This made the production engineers very happy and also recovered the coveted shear data the geophysicists needed. I started working with the velocity data we were collecting, focusing on lithology discrimination and rock physics relationships. I spent a few years automating the measurement of sonic velocities in the laboratory which lead to the development of a rather large and unique rock properties database.
Chandra and I were collaborating on this work as well as investigating shear waves and anisotropy. We were always interested in taking laboratory learnings and applying them in the field. At the time Rusty Alford had figured out the problem with shear waves and the need to rotate the recorded data. Chandra and I set about to study this from an experimental point of view and this lead to our birefringence work which was pivotal in convincing management of the reality of Rusty’s proposed rotation. I also was interested in anelastic reflections which lead to some interesting observations of reflections driven predominantly by Q contrasts. Some 30 years later these have captured the imagination of Larry Lines and Sven Treitel.
At the same time Chandra was working on P and S wave attenuation under partial saturation conditions. Our Rock Physics group was also teaching a week long “Rock Properties” course internally to AMOCO scientists. It became a required course in the AMOCO training program for geophysicists. As part of this course and as a result of the databasing of laboratory measurements, we wrote software integrating forward rock physics models including Q and anisotropy and their effects on AVO and full-offset synthetics with our database of rock properties. This was deployed throughout the company and became the preferred internal rock physics modeling software.
Around 1985-86, a progressive drilling engineer named Keith Millheim proposed SHADS, Stratigraphic High Speed Advanced Drilling System or Slim Hole Advanced Drilling System which married top-drive rigs and mining technology to continuous core from surface to TD. The byproduct was core. Chandra and I saw this as an opportunity to measure core in realtime at the wellsite and to integrate that data with the seismic while drilling a well. We built the GEM systems, Geophysical Evaluation Modules. These were helicopter portable core measurement laboratories complete with pressure vessels to measure compressional and shear velocities in the field. The rationale behind the project was that the first holes we drill in an exploration place were primarily for information; very few were put on production, why not maximize the information content? We sweated copper pipe, wired the electronics, designed the pressure systems, integrated instrumentation, and wrote a bar code driven data acquisition system.
We first fielded and manned a unit in a well drilled in the Upper Peninsula in Michigan, St. Amour. This well penetrated an ancient rift. We predicted the TD, based on velocity measurements we made from cores, to be 200 feet shallower than the seismic interpretation and we drilled within 15 feet of our prediction. The system worked as designed and continued to be deployed on other wells throughout the US (Kansas, Texas and Wyoming), eventually processing over 54,000 feet of core. We also simultaneously processed core taken from other international exploration wells. The systems were modified and deployed in the former Soviet Union and used to evaluate a number of large Siberian field prospects. We immediately incorporated these system advances into our stationary laboratory which immensely improved our measurement throughput. Our work was recognized as integral to the respected AMOCO Petrophysics program and we became embedded instructors and advisors. About this time BP was knocking on the door.
In your SEG DL talk the other day, you emphasized that historically, laboratory measurements have been used to develop an understanding of the physical response of rock and fluid systems under various conditions (frequency, temperature, stress, sample size, etc.). In fact, rock physics has emerged as a separate discipline over the last 10-15 years, ever since Amos Nur started his group at Stanford. Somehow OU rock physics work has not seen as much exposure. Why do you think it is so important to study experimental rock physics? How is the work that you perform at your laboratory different from the work that is done at Stanford (Gary Mavko) and CSM (Mike Batzle)?
Unfortunately, once you do these things, you think it is obvious to everybody else. Stanford never really sustained an experimental emphasis beyond its early days. It drifted toward its strength in theoretical studies. However, noteworthy theoretical developments preceded their work, e.g. Biot, Gassmann, Toksoz and Kuster and O’Connell and Budianski. We continued to do work after arriving at OU but most of it was proprietary. Mike Batzle continues to do good experimental work and has pursued the properties of fluids and more recently heavy oil and tar sands. Mike does some novel experiments at extremely low frequency.
We have shifted our emphasis more toward petrophysics and the integration of all measurements. We appreciated this need as a result of our involvement with the AMOCO Petrophysics program. We have had a successful “Experimental Rock Physics” consortium with more than eight members for over ten years now. In the last six years, we have focused on gas shales and have been funded generously by Devon, Apache and Cimarex. We have been conducting proprietary research which is now just beginning to be published. This support has lead to the successful sponsorship of a second consortium “Unconventional Gas Shale.” This is a limited partnership dedicated to the comprehensive study of shales and shale gas/condensate exploitation. We are employing novel technologies such as Dual Beam FIB-SEM imaging, Scanning Acoustic Microscopy, and NanoIndentation to study the building blocks of shale. We are also conducting laboratory scale hydraulic fracture experiments while monitoring acoustic emissions in realtime. These are exciting and challenging experimental avenues.
Besides making simple measurements of compressional and shear velocities on rock specimens, or measuring attenuation on them, what other types of measurements do you carry out in the laboratory? What are the future directions in which measurements on rock samples are headed?
We routinely carry out a suite of measurements: mineralogy, porosity, density, permeability, mercury capillary pressure, NMR relaxation, resistivity, static moduli and failure strength. When sufficient material exists we conduct anisotropy measurements. We routinely do velocity measurements as a function of pore and confining pressures as well as common saturants. We conduct a variety of specialized measurements aimed at CO2 sequestration problems, source rock maturity, 4D calibration, wettability, etc. We look for rock property signatures that will help solve problems.
What personal qualities do you think enabled you to achieve the professional status that you enjoy today?
Creativity, determination, and being challenged.
What has been the most memorable moment in your professional life? Also, tell us about some of the successful landmarks in your geophysical career.
I live in the present, not the past. This questionnaire has made me think about the past and how fortunate I have been to be at so many great places and to meet and interact with so many good people. I have been a part of teams which have received awards for accomplishments such as the downhole logging tool development, the development of rock physics modeling software, the adoption of a rock properties courses, the development of the geophysical evaluation modules and most recently an unprecedented three Petrobowl championships!
What are your aspirations for the future?
Build something at OU, e.g. creating a global center for shale research and having active participation by our undergraduates in research. Continuing to help develop the rich young talent we have at OU. Living up to the investment people have made in me.
You have a position of Associate Dean and Curtis Mewbourne Chair at the University of Oklahoma. Please tell us about your typical day and how many students you are supervising.
Days are unpredictable and hectic. I currently co-advise 22 students with Chandra. My door is always open, so students continuously drop in. I try to get into the lab and check on progress at least three times a day. I can occasionally sneak away and play with equipment for a few hours a week. The job of Associate Dean is not one that best uses my talents; so I have stepped down to focus on what I do best, teach and research.
How do you integrate rock physics into seismic interpretation? I believe you use experimental rock physics measurements and derive theoretical models for subsurface formations and then apply it into seismic data. Could you elaborate on that?
You fundamentally answered the question in your question but I might add that it is critical to keep in mind what the first order effects are and to focus on those. Very often there are second order effects of enormous academic interest but of no practical value. If you establish a sensitivity to a parameter, you next need to assess the ultimate resolution in the field or log before pursuing the idea. Forward modeling is an enormous help in this aspect of evaluation. That is why we built that forward modeling package at AMOCO.
What are the key sources of uncertainty in rock physics methods for reservoir characterization and how can we reduce them?
One is of course geological sampling and another is calibration. We reduce these the old fashion way, by properly sampling and making the right measurements. Another aspect is not overinterpreting the data and using ad hoc renormalized models because they explain the observations. There is a tendency to rely on solutions and not understandings to deal with reservoir characterization, e.g. such geostatistical techniques as cluster analysis. They provide answers but limit your understanding and hence your ability to extend knowledge.
What are the technical challenges facing experimental rock physics?
There are many challenges which include extending measurement capabilities to high temperatures and pressures at one extreme and to capturing and quantifying the nanoscale on the other. A fundamental limit in Q measurements, for example, is bandwidth.
Using sources such as lasers could open this area for new discoveries. I think you are starting to see the simultaneous measurement of multiple properties; this provides constraints on the interpretations. Researchers are making more comprehensive characterization studies of samples they are studying. A real challenge is to do more with less. How much information can be derived from cuttings?
What is the status on our challenge to estimate permeability from seismic data?
Permeability from seismic is more closely linked to attenuation measurements. We have several theories to relate permeability to energy loss but we lack good quality controlled experiments. The experiments I referred to above conducted by Chandra on attenuation of P and S with partial saturation took over a year to complete. The industry is reluctant to invest in such long term studies. While as indicated above these measurements are challenging in the lab, they are even more challenging in the field. So the emphasis here should be on preserving true amplitude data in our processing algorithms.
How does industry need to get core / oil contacts testing by labs standardized?
The industry has done an admirable job of standardizing the testing of conventional core and has established and published standards. Such standards don’t exist for shales. We hope to help in establishing testing standards and protocols for this new class of reservoir rocks. It will take some time to sort the current offerings.
How are you enjoying your Distinguished Lecturer tour? Where have you been and where do you still need to go?
This has been an incredible opportunity to meet many wonderful people. As you know I teach in petroleum engineering, so getting to meet people in “the other” department has been refreshing. I have been through Mexico, South America (Peru, Argentina, Colombia, Brazil, and Venezuela), Europe (England, France and Norway), Ukraine, Bulgaria, Canada (Calgary, Edmonton, Toronto, Regina) and US (Boise, Austin, Houston, Norman, Tulsa, Kansas City). I have endured the hot and cold, the rain, the snow and sunshine. I have lectured through translators and not known what they actually said but I trust them! The largest reception was no doubt my last visit to Calgary. I enjoyed after lecture beverages with students and faculty and even with a professor whose text books I read while in college. I enjoyed learning from students what they see as opportunities and challenges. I have seen the conditions and instrumentation available to students at other universities and now know how fortunate my students are. I try to share that appreciation with my students. This is difficult for our students to realize unless they experience this first hand.
You have published many research papers. Have you ever thought of writing a book on experimental rock physics? The reason I ask this is because research papers are usually scattered in different journals, and someone of your caliber can distill the essence of all that in the form of a book. It not only is summarized for posterity but easier to read by the younger generation. Your comments?
I toy with the idea of writing a book on petrophysics or shale gas, not rock physics. I think the rock physics is covered adequately by the Mavko, Mukerji and Dvorkin handbook. However, I see a real need for a good practical focused textbook in petrophysics. This field has evolved so much in the past few years and these advances need to be codified. There is so much interest and activity in shales but no centralized repository of knowledge, so I view this as an opportunity too.
I gather you give courses on different topics like Rock Properties, etc. Is that right? Have you given a course at the CSEG DoodleTrain?
I have taught a number of courses which include AVO, pore pressure prediction, petrophysics, well logging fundamentals, seismic reservoir modeling and fundamentals of rock physics. I have never given a course at the CSEG DoodleTrain, but then I have never been asked to!
What are your other interests?
I enjoy bicycle riding, woodworking, gardening, reading a good book and computing.
What would be your message to young entrants who have just taken geophysics as a profession?
Read, read, read, be prepared and don’t be afraid to take a risk. See what is possible—not what is not!
What has helped make you a successful scientist?
Without a doubt it has been a strong combination of good teachers, role models, opportunities and an incredibly supportive family. There is always a balance in life and without the implicit support of my wife of 42 years and my two daughters, I would not have had the opportunity to engage in research.
Carl, thank you very much for giving us this opportunity to engage you in a chat. I have enjoyed it.