Donald E Mcclure

US Patent:

54657903, Nov 14, 1995

Filed:

Apr 11, 1994

Appl. No.:

8/226189

Inventors:

Donald C. McClure - Parker CO
Hiemi K. Haines - Englewood CO

Assignee:

Marathon Oil Company - Findlay OH

International Classification:

E21B 4322

US Classification:

166273

Abstract:

A process for recovering oil from a multiple-layered heterogeneous reservoir with a higher oil saturation in the lower permeability layers than in the higher permeability layers. An aqueous surfactant solution is injected into the formation, where it imbibes into the lower permeability layers and displaces a first quantity of oil into the higher permeability layers. Next, a first aqueous fluid is injected to sweep the displaced oil from the higher permeability layers into at least one production well. A gas is injected into the formation to displace a second quantity of oil from the lower permeability layers. The second aqueous fluid is injected to sweep the displaced oil into at least one production well. The process may be repeated one or more times.