Texaco Inc.

Gabriel Prukop

Vernon H Schievelbein

Samir S Ashrawi

Chhiv K Chea

A method for improving the injectivity of an injection well for water or gas injection into an underground hydrocarbon formation which comprises injecting into the formation through an injection well a sufficient amount of a solvent-in-water microemulsion comprising about 0.5% to about 5% by weight of an alkoxylated linear alcohol having about 10 to about 16 carbon atoms in the linear alcohol moiety and an average of about 5 to about 12 alkoxylate groups, about 0.5% to about 5% by weight of an alkylbenzene sulfonate having an alkyl chain of about 8 to about 20 carbon atoms, about 1% to about 10% by weight of an ethylene glycol alkylether solvent, and water.

Microemulsion method for improving the injectivity of a well

The invention is a method of recovering heavy oil from an underground reservoir by surfactant flooding which comprises injecting an aqueous surfactant solution comprising about 0.1% to about 5% by weight of an alkoxylated nonionic or ionic surfactant through an injection well into an underground reservoir containing a heavy oil having an average API gravity below about 20.degree. and a reservoir temperature above about 150.degree. F., where the alkoxylated surfactant must have sufficient alkylene oxide groups comprised of ethylene oxide or propylene oxide to have a cloud point above about 100.degree. F. and below reservoir temperature, and to be water-soluble in the surfactant solution to be injected at a temperature below its cloud point, and have a sufficiently large hydrophobe to be soluble in the reservoir's heavy oil at a temperature equal to or greater than reservoir temperature.

Alkoxylated surfactant system for heavy oil reservoirs

The disclosed invention is a method of injecting a solution or emulsion containing about 0.05% to about 10% by weight of urea as a sacrificial agent for surfactants into an underground formation in enhanced oil recovery operations, said underground formation having a temperature greater than about 130.degree. F.

Method of using urea as a sacrificial agent for surfactants in enhanced

A method is disclosed for increasing the recovery of oil in enhanced oil recovery operations employing anionic surfactant by blending a taurine with said anionic surfactant. The taurine may also increase the salt and divalent ion tolerance of the anionic surfactant.

Use of taurine additives in enhanced oil recovery with anionic

The invention is a method for recovering hydrocarbons from an underground hydrocarbon reservoir penetrated by at least one injection well and at least one production well, which comprises injecting into the reservoir through an injection well an aqueous caustic solution comprising greater than 0.1% and less than 1.0% lignosulfonate by weight to shift the optimal salinity for enhanced oil recovery of the caustic solution to a relatively higher salinity, and producing hydrocarbons and other fluids through a production well.

Adding lignosulfonate to caustic floods to shift optimal salinity to a

The invention extracts surfactants from produced emulsions of oil, water and surfactants from enhanced oil recovery operations and concentrates the surfactants into an aqueous solution. The produced emulsion is mixed with an alkali metal chloride salt, and butanol or pentanol, and allowed to separate into two phases, an oleic phase and an aqueous phase. The oleic phase is then mixed with fresh water containing about 1% to about 10% by weight of isopropanol, ethanol or methanol, and the mixture is allowed to separate into at least two phases, a substantially water-free and surfactant-free crude oil phase and an aqueous phase containing virtually all of the enhanced oil recovery surfactants originally within the produced emulsion. The surfactants in the aqueous phase may be reutilized for further enhanced oil recovery operations.

Growing community of inventors

Houston, TX, United States of America

Gabriel Prukop