Abstract: How Well Do We Know the Natural Gas Resource Potential of the Arkoma Basin in Arkansas and Oklahoma?

HORN, BRIAN W., Amoco Production Co., Denver CO;THOMAS J. WOODS, Ziff Energy Group Ltd., Houston, TX; andJOHN B. CURTIS, Colorado School of Mines, Golden CO

Current estimates for the ultimate recovery of natural gas in the Arkoma basin are in the range of 13-15 Tcf, of which, approximately 4.5 Tcf are remaining proved reserves. Recent studies by the Potential Gas Committee and the US Geological Survey have concluded that an additional 2-4 Tcf exists as the potential resource for a total of 16-18 Tcf as the ultimate recoverable resource. However, analysis of field size distributions and production data suggests that 34-38 Tcf is a more reasonable estimate of the ultimate recoverable resource, which implies a remaining potential resource of 20-24 Tcf for the Arkoma basin.

The current size range of producing gas fields in the basin shows a bimodal distribution centered around class 8 (0.5-3.1 Bcf) and class 12 (8-50 Bcf) field sizes. If an exponential distribution is assumed for the basin's ultimate recoverable resource, a distribution normalized on a class 12 field size yields an estimate of 20-24 Tcf as the remaining recoverable resource. This estimate is corroborated by analyzing historical production and completion trends for the basin and extrapolation of reserve additions over the next 10-20 years. These data suggest that 4-5 Tcf could be added to the existing reserve base within the next ten years and indicate significant potential of this previously unrecognized resource. Separation of the historical production data into discrete depth intervals yields a better understanding of current producing trends by formation, structural configuration and reservoir quality through time. Integration of these data into a regional geologic context allows a high-resolution prediction of the ultimate resource potential and forms the basis for evaluating areas of future exploration.

AAPG Search and Discovery Article #90936©1998 AAPG Southwest Section Meeting, Wichita Falls, Texas