Biography Citation for the SEG Virgil Kauffman Gold Medal Award
Contributed by Walt Lynn
It is very fitting, and arguably late, to honor Terry Fulp and Robert Greaves for their pioneering work in time-lapse seismology. Time-lapse, or 4D, seismic is often mentioned and considered in today’s industry; but it is remarkable that one of the most sophisticated and comprehensive 4D experiments was done in the early 1980s under conditions that even today are considered formidable. It is still considered one of the “textbook” cases, even though more than two decades have passed.
Terry Fulp received his bachelor’s degree in earth sciences at the University of Tulsa in 1975, his master’s in geophysics at Stanford University in 1977 (where I first met Terry and Bob Greaves), his master’s in civil engineering at the University of Colorado in 1988 and his PhD in mathematical and computer sciences at the Colorado School of Mines in 1996. It was during his tenure at ARCO, 1977-1986. that Terry, Bob, and colleagues designed, implemented, and successfully interpreted the first time-lapse series of 3D surveys over a producing field. It is also a tribute to the forward thinking of ARCO’s R&D management to fund and proceed with this project.
To truly appreciate the sophistication of the ARCO timelapse experiment, I asked Jamie Robertson (then director of ARCO’s Development Geophysics Group) to provide his recollections. I preface his kind response with the note that the Holt Sand time-lapse project was a true team effort and many people were involved, including previous Kauffman Gold Medalist Mike Batzle. However, Bob and Terry were the key people to work through and integrate the entire project. “The Holt Sand project was a reservoir engineering experiment to determine whether oxygen in-situ combustion was superior to air-driven in-situ combustion as a thermal tertiary EOR process,” Robertson said. The engineers drilled two five-well patterns (one injector surrounded by four production wells) plus a number of boreholes that were instrumented to monitor the fireflood.
Air was injected in one pattern and oxygen in the other, so there was a side-by-side comparison. Preburn drilling and coring were conducted in late 1981 to early 1982, and the patterns were ignited in March/April 1982. The air pattern was terminated in August 1982 owing to poor performance. The oxygen pattern continued until December 1982, and postburn coring in the oxygen pattern was conducted from December 1982 to February 1983.
“The EOR activity in the oxygen pattern was monitored by three 3D seismic surveys spaced over a year or so that were compared to each other in a time-lapse fashion (what is now called 4D, although ARCO never used this term). The baseline survey was acquired about January 1982, the midburn survey about August 1982 and the postburn survey about February 1983. Time-lapse data were not collected on the air pattern owing to its early termination. The receivers were single, buried, cemented geophones at about 6-m spacing; the sources were dynamite shots. Since the reservoir was at a depth of less than 2000 ft, the reservoir reflection had a center frequency of about 100 Hz. The oxygen injection plus gaseous combustion products plus thermal alteration of the reservoir rock produced an artificial bright spot at Holt Sand level that was easily detected and mapped by the midburn and postburn 3D surveys as the bright spot spread out from the injection well. The flow of the gaseous fluids was not circular around the injection well but appeared to follow paths of better porosity and to be blocked by barriers like faults as one might expect. There was a strong limestone reflector immediately below the Holt Sand. This reflector dimmed underneath the gas stream as the gas propagated outward from the injection well, so the activity in the reservoir was also mapped by this dimming at a deeper reflector. All in all, the experiment was very successful at demonstrating the usefulness of time-lapse seismic for monitoring changes to a reservoir caused by production operations.”
Considering the complexities, which include land reservoir, oxygen injection and ignition, the state of 3D, let alone 4D, processing and interpretation in the early 1980s and seismic linkage to rock properties, the Holt Sand timelapse remains one of the most comprehensive and sophisticated 4Ds to this day.
Like many geophysicists in our industry, Terry left the oil and gas industry in the late 1980s. He is now area manager, Boulder Canyon Operations Office at Hoover Dam. I have known Terry for 30 years and can personally attest to his integrity, work ethic, determination, geophysical and hydrological knowledge and insights and most important of all, his kindness, fairness and respect for his colleagues and friends. I am very proud and honored to write this citation for an incredible individual.