Texaco Inc.

Jim Maddox, Jr

Jack F Tate

Russell D Shupe

Vernon H Schievelbein

Bobby G Harnsberger

Ricardo L Cardenas

A method for modifying a sulfonate surfactant flooding system so as to permit the use of fluids of increased salinity in the polymer drive. Sulfonate systems are altered by adding about 0.05% to about 1.0% by weight of a divalent metal cation to give a total concentration of about 0.1% to about 1.0% by weight of divalent metal cation to one or more surfactant slugs of the surfactant flooding system, and adding about 0.1% to about 1.5% by weight of a sulfate or sulfonate solubilizer to the polymer drive fluid. The concentration of oil soluble petroleum sulfonates may also be decreased while the concentration of water soluble petroleum sulfonates may be increased without a decrease in surfactant slug performance.

Surfactant flooding system

The disclosed invention is a one step or two step process for extracting surfactant from produced emulsions of oil, water and surfactants, concentrating the surfactants into a relatively small volume emulsion middle phase that can be reutilized in surfactant flooding and separating substantial quantities of salable oil from the emulsions. In the two step process, a sulfonated alkyl benzene is added and mixed with the emulsion, which partitions upon settlement into three phases, a clean oil phase, a first microemulsion middle phase and an aqueous phase. An ethoxylated phenol is then added and mixed to the first middle phase to yield at least two more similar phases with the middle phase containing the concentrated surfactants. Alternately, the sulfonated alkyl benzene and the ethoxylated phenol can be combined and added in a one step extraction process.

Method of extracting and reutilizing surfactants from emulsions using

Disclosed is a method for extracting surfactants from produced emulsions of oil, water and surfactant and concentrating the surfactants into a relatively small volume, surfactant-rich, middle phase that can be reutilized in surfactant flooding. A first extraction is performed with an aqueous solution of a first extracting compound, which yields three phases after separation, a substantially water-free and surfactant-free crude oil phase, a first surfactant-rich middle phase and an oil-free aqueous phase. The first extracting compounds employed are the alkali metal salts and ammonium salts of cumene sulfonate, propyl benzene sulfonate, ethyl benzene sulfonate, methyl ethyl benzene sulfonate, diethyl benzene sulfonate, methyl propyl benzene sulfonate, xylene sulfonate and dicyclopentadiene sulfonate. A second extraction is then performed by mixing a second extracting compound with the first middle phase, which yields three phases after separation, a water-free and surfactant-free oil phase, a second surfactant-rich middle phase and an oil-free aqueous phase. The second extracting compound is a alkanol having two to four carbon atoms.

Method of extracting and reutilizing surfactants from emulsions with

An invention for extracting surfactants from produced emulsions of oil, water and surfactant and concentrating the surfactants into a relatively small volume, emulsion phase that can be reutilized in surfactant flooding. The two phases left behind in the extraction are a substantially water-free and surfactant-free crude oil phase and an oil-free aqueous phase. The extracting compounds employed are the alkali metal salts and ammonium salts of cumene sulfonate, propyl benzene sulfonate, ethyl benzene sulfonate, methyl ethyl benzene sulfonate, diethyl benzene sulfonate, methyl propyl benzene sulfonate, xylene sulfonate and dicyclopentadiene sulfonate.

Method of extracting and reutilizing surfactants from emulsions

Many petroleum formations contain water having high salinity and/or high concentrations of divalent ions such as calcium or magnesium dissolved therein, and are additionally at temperature from about 70.degree. F. to about 300.degree. F. Most surfactants and polymers suitable for use in fluids or emulsions used in oil recovery operations are either ineffective in high salinity or high hardness waters, or cannot tolerate the higher temperatures encountered in many such formations. A water-external phase, viscous emulsion containing a water soluble and/or dispersible alkylpolyalkoxyalkylene sulfonate or alkylarylpolyalkoxyalkylene sulfonate and as a phase stabilizing additive, a water dispersable and/or soluble petroleum sulfonate, is an effective fluid for flooding oil formations containing brine whose salinity is from 70,000 to 220,000 parts per million total dissolved solids and also having temperatures as high as 300.degree. F. The emulsion is phase stable over a wide range of formation temperatures and water salinities and hardness values.

Emulsion oil recovery process usable in high temperature, high salinity

Many petroleum formations contain water having high salinity and/or high concentrations of divalent ions such as calcium or magnesium dissolved therein, and are additionally at temperatures from about 70.degree. F. to about 300.degree. F. Most surfactants suitable for use in oil recovery operations are either ineffective in high salinity or high hardness waters, or cannot tolerate the higher temperatures encountered in many such formations. A water-external phase emulsion, microemulsion or micellar dispersion containing a water soluble alkylpolyalkoxyalkylene sulfonate or alkylarylpolyalkoxyalkylene sulfonate and a water-insoluble polyethoxylated aliphatic alcohol (including alkanols) or polyethoxylated alkylphenol nonionic surfactant is an effective fluid for flooding in formations containing water whose salinity is from 70,000 to 220,000 parts per million total dissolved solids and also having temperatures as high as 300.degree. F. The fluid is phase stable over a wide range of formation temperatures and water salinities and hardness values.

A fluid containing a dual surfactant system and a process using the fluid for recovering petroleum from petroleum formations containing high salinity water, e.g. from 50,000 to 225,000 parts per million which may include from about 200 to about 14,000 parts per million polyvalent ions such as calcium and/or magnesium dissolved therein and a method of using said fluid in a surfactant flooding oil recovery process. The surfactant system comprises a water-soluble salt of petroleum sulfonate or an alkyl or alkylaryl sulfonate wherein the alkyl chain may have from 5 to 25 carbon atoms, plus a phosphate ester surfactant with an average molecular weight not to exceed 1000. The surfactant combination is stable up to at least 225.degree. F and resistant to bacterial attack and inhibits scale formation.

Oil recovery process usable in high temperature formations containing

Many petroleum formations contain water having high salinity and/or high concentrations of divalent ions such as calcium or magnesium dissolved therein, and are additionally at temperature from about 70.degree. F. to about 300.degree. F. Most surfactants suitable for use in oil recovery operations are either ineffective in high salinity or high hardness waters, or cannot tolerate the higher temperatures encountered in many such formations. An aqueous fluid containing a water soluble alkylpolyalkoxyalkyl sulfonate or alkylarylpolyalkoxyalkyl sulfonate and a water-insoluble polyethoxylated aliphatic alcohol or polyethoxylated alkylphenol nonionic surfactant is effective in formations containing water whose salinity is from 70,000 to 220,000 parts per million total dissolved solids and also having temperatures as high as 300.degree. F. The fluid is phase stable over a wide range of formation temperatures and water salinities and hardness values.

Surfactant oil recovery process usable in high temperature, high

A three surfactant system usable in high temperature petroleum formations containing water having from about 200 to about 14,000 parts per million polyvalent ions such as calcium and/or magnesium dissolved therein and a pH of from 5 to 9, and a method of using said surfactant system for recovering petroleum from high temperature subterranean petroleum-containing formations. The three component surfactant system comprises (1) water-soluble salt of an alkyl or alkylaryl sulfonate wherein the alkyl chain may have from 5 to 25 carbon atoms, (2) a phosphate ester surfactant with an average molecular weight not to exceed 1000, and (3) a surfactant having the following betaine related structure: ##STR1## wherein R is an alkyl group having from 12 to 24 carbon atoms, and n is an integer from one to five. The surfactant combination is stable up to at least 225.degree. F and resistant to bacterial attack and inhibits scale formation.

Surfactant oil recovery process usable in high temperature formations

Composition and method for the treatment of inorganic mineral scale, particularly calcium and/or barium sulfate scale, using a treating composition consisting of a water-soluble sulfonated ethoxylated alkylphenol of prescribed formula in an amount of from about 0.0005 to about 0.005%, on a weight basis.

Method for treating scale

Composition and method for the treatment of inorganic mineral scale particularly calcium and/or barium sulfate scale, using a treating composition consisting of a water-soluble sulfonated ethoxylated alcohol of prescribed formula in an amount of from about 0.0005% to about 0.005%, on a weight basis.

Composition and method for treating scale

Composition and method for the treatment of scale, particularly calcium and/or barium sulfate scale, using an alkyl benzene sulfonate, including the alkali metal and ammonium salts thereof, said alkyl group containing from about 8 to about 14 carbon atoms at a concentration of from about 10 to about 50 ppm on a weight basis.

Composition and method for the treatment of scale, particularly calcium and/or barium sulfate scale, using a treating composition consisting of about one part by weight of a sulfated/sulfonated polyethoxy alkyl phenol containing from about 8 to about 14 carbon atoms in the alkyl group and from about 4 to about 10 ethoxy groups, in admixture with from about 1 to 3 parts by weight of a C.sub.8 -C.sub.14 alkyl benzene sulfonate, including the alkali metal and ammonium salts of one or both compounds, and mixtures thereof.

Method for controlling scale

The production of hydrocarbons from a subterranean hydrocarbon-bearing formation is stimulated by injecting into the formation an aqueous solution of a compound hereinafter described. The elimination of plugging of capillary openings within the formation and mineral scale deposition on production equipment due to post-precipitation of dissolved salts subsequent to treatment by means of said compound results in a substantial improvement in hydrocarbon recovery.

Method for oil recovery

The production of hydrocarbons from a subterranean hydrocarbon-bearing formation containing acid-soluble components, such as one composed at least in part of dolomite or limestone, is stimulated by injecting into the formation a composition comprising an aqueous solution of a mineral acid having dissolved therein a compound hereinafter described. The elimination of plugging of capillary openings within the formation and mineral scale deposition on production equipment due to post-precipitation of dissolved salts subsequent to acidization by means of the said compound results in a substantial improvement in hydrocarbon recovery.

Growing community of inventors

Houston, TX, United States of America

Jim Maddox, Jr