Abstract: Future Natural Gas Supply from the OCS
In recent years, significant discussions have concentrated on the future natural gas supply, deliverability and demand for the U.S. Energy Information Administration's (EIA) demand prediction and the recent National Petroleum Council's study report indicate that the natural gas demand for the U.S. could reach as high as 30 Tcf by 2010. The 1998 natural gas production, including synthetic gas, in the U.S. was only 19 Tcf. The demand for natural gas for that year was met by about 3 Tcf of import from Canada and a miniscule LNG import (0.1 Tcf). Planners are concerned, as to where the additional 11 Tcf supply is going to come from. How much additional import, may be expected from Canada? Can additional LNG import or Gas To Liquid (GTL) conversion be an answer to bringing the stranded gas to the area of demand? Can this be an opportunity for the producers? If so, in which area the investment should be made? These are some of the questions being pondered.
At present, more than a quarter of the nation’s natural gas production comes from the OCS, primarily from the Gulf of Mexico (GOM). Most of the gas production in the GOM, at present comes from the shelf (<200m water-depth). However, the production from the slope and deeper water is steadily increasing. Concerns have been expressed in various sectors that the production decline rate, which has been variously cited as high as 50% for the shelf, may significantly reduce the production from the GOM. An analysis of the production data for the last ten years, however dispels such notion. While the production rates from earlier completions have declined significantly, higher production from newer completions offsets any decline. The per completion production rate for non associated gas has remained steady at around 1Bcf/completion, the production rate of the associated gas increased steadily, during the last ten years from about 0.11 MMcf to about 0.16 MMcf/completion. More than 75% of the total GOM monthly production comes from completions that are 4 or less years old. To sustain or to increase the present production rate, a robust drilling, and completion rates need to be maintained. The present gas and oil price assures such an activity. Within the confines of our presently assessed resources, the gas production from the GOM may be increased from the present average of 5.1 Tcf/yr to a maximum of 6.7 Tcf by 2012.
AAPG Search and Discovery Article #90911©2000 AAPG Pacific Section and Western Region Society of Petroleum Engineers, Long Beach, California