Shang Te Chou, 706262 Provence Rd, San Gabriel, CA 91775

5351757, Oct 4, 1994

Dec 18, 1992

7/993478

Shang Chou - Anaheim CA
Jae Bae - Anaheim CA

Chevron Research and Technology Company - San Francisco CA

E21B 33138
E21B 4320
E21B 4322

166270

A method for emplacing a silicate gel to improve the sweep efficiency of a water, gas, or steam flood operation by reducing the permeability of high-permeability thief zones is disclosed. Controlled quantities of a silicate solution and either a gas or a gas and an organic acid are injected into a well to infiltrate and generate a controlled amount of a silicate gel of a controlled SiO. sub. 2 concentration in the high-permeability thief zones, to reduce the permeability thereof. Base agents and weak acids may be added to control gel generation rate. Methods for selective emplacement of silicate gels into thief zones through a well without selective injection facilities are also disclosed.

6269881, Aug 7, 2001

Dec 17, 1999

9/466243

Shang Chou - Fullerton CA
Curtis B. Campbell - Hercuies CA

Chevron U.S.A. Inc - San Francisco CA
Chevron Chemical Company LLC - San Francisco CA

B01F 1700
E21B 4322

1662701

An oil recovery process is disclosed which uses a particular class of alkylaryl sulfonate surfactants. The surfactants are derived from an alpha-olefin stream having a broad distribution of even carbon numbers ranging from 12 to 58. The olefin stream is reacted with aromatic feedstock, such as benzene, toluene, xylene, or a mixture thereof to form alkylates, and then reacted with SO3 to form sulfonic acids. The resulting surfactant has high solubilization and ultra-low interfacial tension with crude oils, especially waxy crude oil, having a broad distribution of carbon numbers.

5234054, Aug 10, 1993

Sep 12, 1991

7/758040

Shang Chou - Anaheim CA

Chevron Research and Technology Company - San Francisco CA

E21B 33138
E21B 4322
E21B 4324

166272

A method for improving the sweep efficiency of gas or steam flooding operations by reducing the permeability of relatively high permeability thief zones of an oil bearing subterranean reservoir having heterogeneous and/or fracture permeability and that is penetrated by at least one well is disclosed. A controlled quantity of a surfactant is injected into a high-permeability zone of a reservoir. Controlled quantities of a gas and a subsequent surfactant are then injected, simultaneously or alternatively into the same well, so that a controlled amount of foam having a controlled quality is generated in the high permeability zone, thereby reducing permeability. Following foam emplacement, a chase gas may be injected, and the steps of injecting surfactant and gas may be repeated as necessary to lower the gas-oil ration of non-problem offset producing wells to a preset limit.