Friction reducing composition and method
AssigneeClearwater, Inc.
InventorsKevin M. Schwartz, Kevin W. Smith
Life of this patent
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Abstract
Water soluble nonionic friction reducers and added to coacervate gels having excellent shear viscosities and other properties. A preferred gel comprises poly diallyl dimethyl ammonium chloride, a lesser amount of sodium lauryl sulfonate, and lauryl alcohol. Excellent friction reducing properties are manifested; a particularly practical use for the compositions is in subterranean formation fracturing.
Claims32
An aqueous gel comprising water and, by weight based on the water, (a) 0.1% to 5% of an anionic or cationic polymer, (b) a lesser amount but at least 0.01% of a surfactant having from 8 to 22 carbon atoms and a charge opposite that of said polymer, (c) from 0.001 to 5% of a hydrophobic alcohol, (d) up to 5% of an amphoteric surfactant, and (e) up to 5% of an amine oxide, said gel having a Zeta Potential of an absolute value of at least 20 millivolts.
Method of making an aqueous gel comprising adding to water 0.1% to 5%, by weight based on the water, cationic polymer and a lesser amount but at least 0.01% by weight of an anionic surfactant having from 8 to 22 carbon atoms, in the presence of 0.001% to 5% linear or branched alkyl alcohol of the general formula CMH2M+2−N(OH)N, where M is a number from 6-23, and N is I when M is 6-12, but where M is 13-23, N may be a number from 1 to 3, and optionally in the presence of at least one of (a) up to 5% by weight amphoteric surfactant and (b) up to 5% by weight amine oxide, the ratio of said cationic polymer to said anionic surfactant being effective to provide a Zeta Potential having an absolute value of at least 20 millivolts.
An aqueous gel comprising a water-soluble polymer in an amount no greater than 1% by weight, having at least one of (a) a zero shear viscosity of at least 45,000 following the zero shear viscosity extrapolation procedure of Asadi, Conway and Barree in SPE 73755 or (b) a “10/100 20/40” settling rate result at 60 minutes of no more than 8 millimeters.
An aqueous composition useful for conserving energy in the transportation of aqueous fluids through pipes comprising water and, by weight based on the water, (A) a gel comprising (a) 0.1% to 5% of an anionic or cationic polymer, (b) a lesser amount but at least 0.01 % of a surfactant having from 8 to 22 carbon atoms and a charge opposite that of said polymer, (c) from 0.001 to 5% of a hydrophobic alcohol, (d) up to 5% of an amphoteric surfactant, and (e) up to 5% of an amine oxide, said gel having a Zeta Potential of an absolute value of at least 20 millivolts, and (B) at least 0.0001% water soluble nonionic friction reducer.
Composition useful for friction reduction in aqueous systems comprising (A) a coacervate gel comprising (a) a cationic or anionic polymer and (b) a lesser amount of an oppositely charged surfactant, in a ratio to provide a Zeta Potential of 20 millivolts or higher, or −20 millivolts or lower, and (c) a small amount of a hydrophobic alcohol having 6 to 23 carbon atoms, and (B) a nonionic water soluble friction reducer, said nonionic water soluble friction reducer being present in said composition useful for friction reduction in a weight ratio to said anionic or cationic polymer of 0.001:1 to 5:1.
Dependencies are inferred from the claim text.