Polymeric gel system and use in hydrocarbon recovery
AssigneeClearwater International, LLC
InventorsKevin N. Schwartz, Kevin W. Smith, Shih-Ruey T. Chen
Life of this patent
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Abstract
Coacervate gels having excellent shear viscosities and other properties are made with anionic or cationic polymers, a smaller amount of a surfactant having a charge opposite that of the polymer, and a hydrophobic alcohol. The Zeta Potential of the gel is maintained at an absolute value of at least 20. Optional gel promoting additives include betaines and amine oxides. A preferred gel comprises poly diallyl dimethyl ammonium chloride, a lesser amount of sodium lauryl sulfonate, and lauryl alcohol. The gels are particularly useful in well drilling fluids and well fracturing fluids.
Claims17
A method for treating a well, comprising:
- forming a well treatment fluid having a zeta potential of an absolute value of at least 20 millivolts by combining water and fluid compounds, based by weight of the water, wherein the fluid compounds comprise:
- a cationic polymer at a level within a range from about 0.1% to about 5%;
- an anionic surfactant having from 8 to 22 carbon atoms at a level within a range from about 0.01% to about 2%;
- and
- a linear or branched alkyl alcohol at a level within a range from about 0.001% to about 5%, the linear or branched alkyl alcohol has the general formula of CMH2M+2−N(OH)N, where M is a number from 6-23, and N is 1 when M is 6-12, but where M is 13-23, N is a number from 1 to 3;
- and
- introducing the well treatment fluid into the well.
A method for treating a well extending through a formation, comprising:
- forming a well treatment fluid by combining:
- water;
- 0.1% to 5%, by weight based on the water, of a cationic polymer;
- 0.01% to 2%, by weight based on the water, of an anionic surfactant having from 8 to 22 carbon atoms;
- and
- 0.001% to 5%, by weight based on the water, of a 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 1 when M is 6-12, but where M is 13-23, N may be a number from 1 to 3;
- adding a propping agent to the well treatment fluid;
- fracturing the formation containing the well treatment fluid;
- and
- adding a gel breaker to the well treatment fluid to reduce the viscosity of the well treatment fluid.
Dependencies are inferred from the claim text.