Inventors:
Alfred Brown - Houston TX
Mohan V. Kudchadker - Houston TX
James E. Varnon - Midland TX
Lawrence E. Whittington - Katy TX
Assignee:
Texaco Inc. - White Plains NY
International Classification:
E21B 33138
E21B 4322
E21B 4330
Abstract:
Disclosed is a method for conducting an enhanced oil recovery process comprising injecting an oil displacing fluid into an injection well and recovering petroleum displaced by the fluid from one or more spaced-apart production wells, by an improved method in which the sweep efficiency or horizontal conformance of the displacement process is increased. A fluid is injected into the producing well, which fluid has a viscosity not substantially greater than the viscosity of water at the conditions of injection, but which reacts with oil present in the formation, forming a viscous emulsion which restricts the flow of fluids through the portion of the formation contacted by the emulsion-forming fluid. As a result of this treatment, there is a reduction in tendency for the displaced and injected fluids to form cusps as they approach the production well, thereby failing to sweep substantial portions of the formation. The injected fluid contains one or more surfactants specifically tailored to form a viscous emulsion with the particular formation crude oil and formation water or brine exhibiting maximum viscosity at formation conditions.