Title: President’s Column
Author: Bruce Kelso
Publication: The Outcrop, November 2003, p. 3
RMAG has been recognized over the years for organizing and hosting outstanding technical meetings and symposia. The 2003 Fall Symposium, Petroleum Systems and Reservoirs of Southwest Wyoming, held on September 19th, has to be considered one of RMAG’s premier technical events over the past several years. I have received numerous comments, calls and letters from some of the 388 attendees similar to these: “I don’ t think RMAG could top this meeting, but please try;” “Excellent technical program;” “Thought provoking program” and; “Great job, keep up the good work.” The entire Symposium organizing committee, led by Steve Goolsby and Mike Wilson, needs to be congratulated on a job well done. To the authors and presenters of the papers at this meeting, RMAG thanks you for your contributions and efforts towards the success of this meeting. And finally, special acknowledgement is extended to the companies and individuals who provided financial support for this event.
The focus of the meeting was centered on the controversy related to basin-centered gas accumulations (BCGA) versus more conventional structural and stratigraphic traps in low-permeability gas reservoirs of the Green River basin. This controversy was brought to the forefront last May by presentations at the national AAPG meeting in Salt Lake City. Since that time, numerous discussions and debates have occurred in public forums, office hallways, and in private meetings. As I stated earlier this summer in my July column, controversy surrounding geologic models and theories is good for the advancement of our industry. At the very least, they cause us to reflect on the issues while seeking evidence in support of one theory or another. For example, I received a letter from one conference attendee who included a 1964 AAPG Bulletin article by J. J. Arps that summarized, explained and discussed “sweet spots” and unexpected water production in low permeability reservoirs with an example from Wyoming. While this paper was written nearly 40 years ago, it contains fundamental engineering concepts of capillary pressure and relative permeability related to reservoir fluids and trapping mechanisms, with a direct bearing on the BCGA controversy.
As the controversy unfolds and evolves over hydrocarbon trapping mechanisms in the Green River and other western, low-permeability basins, I suspect there will be no right or wrong answer. Both viewpoints, the basin centered gas accumulation with production from “sweet spots” and production from conventional stratigraphic and structural traps in pervasively wet reservoirs, provide compelling evidence in support of each case. The nature of our industry and science drives us towards a better understanding of the reservoirs from which we exploit hydrocarbons. Controversies such as this provide us the opportunity to re-evaluate our exploration models and undoubtedly will result in new concepts and a better understanding of the low permeability hydrocarbon resources found in many western basins.
If you were in attendance at the Petroleum Systems and Reservoirs of Southwest Wyoming Symposium, I hope that you came away pondering the topics of the day’s presentations. If you were not able to attend, you can anticipate encountering future discussions and presentations on similar topics. Once again, I commend the organizing committee for their outstanding efforts on this highly successful meeting.