Surfactant blends for well operations
AssigneeAtlantic Richfield Company
InventorsAlbert F. Chan, Kieu T. Ly
Life of this patent
Estimating the term…
Abstract
Blends of alkyl polyglycoside surfactants having an alkyl chain length of C11 to C16 and blends of alkyl polyglycoside surfactants, in the presence of an ethoxylated alcohol cosurfactant, will form Winsor type III microemulsions in a water-oil mixture in a hydrophile-lipophile balance range of at least about 9.8 to 10.8 at 130.degree. F. wherein the water may be a chloride brine. The compositions are particularly useful in oil and gas well cleanout operations, formation acidizing, and well cementing operations and provide superior cleaning ability for removal of oil based drilling fluids, hydrocarbons and oil based pipe sealant and lubricant compositions, for example.
Claims17
A method for cleaning oil based contaminants from a wellbore using a surfactant composition having a predetermined solubilization in fluids comprising oil and water in the wellbore and wherein said surfactant composition is made up of a first surfactant consisting essentially of an alkyl polyglycoside and a second surfactant consisting essentially of at least one of an alkyl polyglycoside and a linear ethoxylated alcohol, comprising the steps of:
- (a) determining the concentrations of the first surfactant and the second surfactant which will provide said predetermined solubilization by mixing a known volume of oil together with a known volume of a solution of surfactant composition and one of water or brine, measuring the volume of a type III microemulsion occupying a volume previously occupied by the oil and measuring the volume of said microemulsion previously occupied by said water or brine and surfactant solution;
- (b) varying the concentrations of the first and second surfactants, respectively, in said solution and repeating step (a) until said predetermined solubilization is provided in a range of concentration of said first surfactant and said second surfactant which forms said microemulsion;
- and,
- (c) circulating a solution containing a concentration of the first surfactant and the second surfactant having the predetermined solubilization through the wellbore to remove oil based contaminants therefrom.
In an acidizing operation for improving the productivity of a subterranean earth formation interval adjacent to a well, the improvement characterized by:
- injecting an acid solution into said earth formation interval through said well, said acid solution comprising an aqueous solution of an acid selected from a group consisting of acetic acid, formic acid and hydrochloric acid in a concentration of 1.0% to 15.0% by weight, and a surfactant composition in said acid solution consisting essentially of a first surfactant consisting essentially of an alkyl polyglycoside having an alkyl chain length of C11 to C16 and a second surfactant consisting essentially of at least one of an alkyl polyglycoside and a linear ethoxylated alcohol and said surfactant composition is present in said solution in a range of 0.5% to 10% by weight;
- and
- injecting said acid solution with said surfactant composition into said formation interval to dissolve at least portions of said formation interval and solubilize oil-based substances in said formation interval.
A method for improving the wetting action and hydration of cementitious material in a cement composition for a cementing operation in a well including the steps of:
- providing a cement composition comprising a cementitious material selected from a group consisting of Portland cement, slag, calcium carbonate, calcium aluminate, calcium sulfate, and magnesium/calcium oxide, water and a surfactant composition comprising a first surfactant characterized by an alkyl polyglycoside having an alkyl chain length of C11 to C16 and a second surfactant comprising an alkyl polyglycoside wherein the concentration of the first surfactant and the second surfactant together in said water is 0.1% to 5.0% by weight and the concentration of the surfactants provides at least one of a type I and type III microemulsion in the presence of both water and oil;
- and
- injecting said cement composition into said well.
A method for improving cement bonding in a cementing operation in a well including the steps of:
- providing a cement composition comprising a cementitious material selected from a group consisting of Portland cement, slag, calcium carbonate, calcium aluminate, calcium sulfate and magnesium/calcium oxide, water and a surfactant composition consisting essentially of a first surfactant characterized by an alkyl polyglycoside having an alkyl chain length of C11 to C16 and a second surfactant consisting essentially of at least one of an alkyl polyglycoside and a linear ethoxylated alcohol wherein the concentration of the first surfactant and the second surfactant together in said water is 0.5% to 10.0% by weight and the concentration of the surfactants provides a type III microemulsion in the presence of both water and oil;
- and
- injecting said cement composition into said well to dissolve oil-based materials present on the surfaces of the wellbore wall and any structures disposed in said well coming into contact with said cement composition to improve the bonding of said cement composition to said surfaces.
A method for using a surfactant composition having a predetermined solubilization in oil and water and wherein said surfactant composition is made up of a first surfactant comprising an alkyl polyglycoside and a second surfactant comprising at least one of an alkyl polyglycoside and a linear ethoxylated alcohol, comprising the steps of:
- (a) determining the concentrations of the first surfactant and the second surfactant which will provide said predetermined solubilization by mixing a known volume of oil together with a known volume of a solution of surfactant composition and one of water or brine, measuring the volume of a type III microemulsion occupying a volume previously occupied by the oil and measuring the volume of said microemulsion previously occupied by said water or brine and surfactant solution;
- (b) varying the concentrations of the first and second surfactants, respectively, in said solution and repeating step (a) until said predetermined solubilization is provided in a range of concentration of said first surfactant and said second surfactant which forms said microemulsion;
- and,
- (c) mixing said first surfactant and said second surfactant in a concentration of said first surfactant and said second surfactant having said predetermined solubilization in the aqueous phase of a cement slurry;
- and
- (d) circulating said cement slurry into a well.
Dependencies are inferred from the claim text.