Douglas Edward Kenyon
Engineers at Acoma Dr, Littleton, CO

5778977, Jul 14, 1998

Jan 3, 1997

8/779855

James L. Bowzer - Houston TX
Douglas E. Kenyon - Littleton CO
Eugene E. Wadleigh - Midland TX

Marathon Oil Company - Findlay OH

E21B 4316, E21B 4318

1662521

This invention relates to the recovery of oil from an oil-bearing formation having a natural fracture network with substantial vertical communication and wherein gravity drainage is the primary means of recovery. A downwardly inflating gas-cap is pressured up with a chase gas having a density less than that of CO. sub. 2. CO. sub. 2 is injected and a CO. sub. 2 -rich displacing slug is formed at the gas-liquid hydrocarbon contact. The chase gas is injected to facilitate displacing downwardly the CO. sub. 2 -rich displacing slug to recover hydrocarbon from the reservoir. CO. sub. 2 is replaced in the displacing slug as the CO. sub. 2 is solubilized into the oil, including matrix oil, to facilitate recovery thereof. The oil is recovered through production wells in fluid communication with the reservoir, preferably the inlet to the well is below the water-liquid hydrocarbon contact at such a level to prevent free-gas production. The chase gas has a density less than that of the CO. sub.

5025863, Jun 25, 1991

Jun 11, 1990

7/535926

Hiemi K. Haines - Englewood CO
Teresa G. Monger - Parker CO
Douglas E. Kenyon - Littleton CO
Lance J. Galvin - Sugarland TX

Marathon Oil Company - Findlay OH

E21B 4318, E21B 4325

1663051

A process for the enhanced recovery of liquid hydrocarbons from a subterranean hydrocarbon-bearing formation wherein natural gas which is immiscible with the liquid hydrocarbons is injected into the formation via a well. The well is shut in for a period of time to permit the natural gas to render the liquid hydrocarbons mobile and thereafter the mobilized liquid hydrocarbons are produced from the well.