Salt tolerant friction reducer

Abstract

A friction reducing treatment solution that includes water, from 100 to 500,000 ppm of total dissolved solids, and from 0.5 to 3 gallons per thousand gallons of a water-in-oil emulsion containing a water soluble polymer. The total dissolved solids include at least 10 weight percent of a multivalent cation. The water-in-oil emulsion includes an oil phase and an aqueous phase, where the oil phase is a continuous phase containing an inert hydrophobic liquid and the aqueous phase is present as dispersed distinct particles in the oil phase and contains water, the water soluble polymer, and surfactants and an inverting surfactant. The water soluble polymer is made up of 20 to 80 weight percent of a non-ionic monomer, 0.5 to 30 weight percent of a carboxylic acid containing monomer, and 5 to 70 weight percent of a cationic monomer and makes up from 10 to 35 weight percent of the water-in-oil emulsion.

We claim: 
     
       1. A friction reducing treatment solution comprising:
 water; 
 from 100 to 500,000 ppm of total dissolved solids, wherein the total dissolved solids comprise at least 10 weight percent of a multivalent cation; 
 from 0.5 to 3 gallons per thousand gallons of a water-in-oil emulsion comprising an oil phase (O) and an aqueous phase (A) at an O/A ratio of from about 1:8 to about 10:1, wherein the oil phase is a continuous phase comprising an inert hydrophobic liquid;
 wherein the aqueous phase is present as dispersed distinct particles in the oil phase and comprises water, a water soluble polymer, and surfactants; 
 wherein the water soluble polymer comprises 20 to 80 weight percent of a non-ionic monomer, 0.5 to 30 weight percent of a carboxylic acid containing monomer, and 5 to 70 weight percent of a cationic monomer; and 
 wherein the water soluble polymer comprises from 5 to 40 weight percent of the water-in-oil emulsion; and 
 
 an inverting surfactant. 
 
     
     
       2. The friction reducing treatment solution according to  claim 1 , wherein the cationic monomer is one or more selected from the group consisting of (meth)acrylamidopropyltrimethyl ammonium halides, (meth)acryloyloxyethyltrimethyl ammonium halides, (meth)acryloyloxyethyltrimethyl ammonium methyl sulfate, diallyl dimethyl ammonium halides, diallylamine, methyldiallylamine, dimethylaminoethylmethacrylate, and dimethylaminopropylmethacrylamide. 
     
     
       3. The friction reducing treatment solution according to  claim 1 , wherein the nonionic monomer is one or more selected from the group consisting of C 1 -C 3  alkyl (meth)acrylates, C 1 -C 3  N-alkyl (meth)acrylamide, (meth)acrylamide, N-vinylpyrrolidone, dimethyl(meth)acrylamide, N-vinyl acetamide, and N-vinyl formamide. 
     
     
       4. The friction reducing treatment solution according to  claim 1 , wherein the carboxylic acid containing monomer is one or more carboxylic acid containing monomers selected from the group consisting of (meth)acrylic acid, maleic acid, itaconic acid, N-(meth)acrylamidopropyl, N,N-dimethyl,amino acetic acid, N-(meth)acryloyloxyethyl, N,N-dimethyl,amino acetic acid, N-(meth)acryloyloxyethyl, N,N-dimethyl,amino acetic acid, crotonic acid, (meth)acrylamidoglycolic acid, and 2-(meth)acrylamido-2-methylbutanoic acid. 
     
     
       5. The friction reducing treatment solution according to  claim 1 , wherein the multivalent cation is one or more selected from the group consisting of iron, calcium, magnesium, manganese, strontium, barium, and zinc. 
     
     
       6. The friction reducing treatment solution according to  claim 1 , wherein the water soluble polymer has a molecular weight in the range of from about 2,000,000 to about 30,000,000. 
     
     
       7. The friction reducing treatment solution according to  claim 1 , wherein the water soluble polymer has a reduced viscosity, as determined in a Ubbelhhde Capillary Viscometer at 0.05% by weight concentration of the polymer in 1M NaCl solution, at 30° C., pH 7, of from about 10 to about 40 dl/g. 
     
     
       8. The friction reducing treatment solution according to  claim 1 , wherein the water-in-oil emulsion comprises at least one of an inhibitor or a salt. 
     
     
       9. The friction reducing treatment solution according to  claim 1 , wherein the water-in-oil emulsion comprises ammonium salt, 4-methoxyphenol, and an ethoxylated C 12 -C 16  alcohol. 
     
     
       10. The friction reducing treatment solution according to  claim 1 , wherein the inert hydrophobic liquid comprises a mixture of paraffinic hydrocarbons and napthenic hydrocarbons. 
     
     
       11. The friction reducing treatment solution according to  claim 1 , wherein the surfactants comprise a tall oil fatty acid diethanol amine, a polyoxyethylene (5) sorbitan monooleate, and a sorbitan monooleate. 
     
     
       12. The friction reducing treatment solution according to  claim 1 , wherein the molar ratio of cationic monomer to anionic monomer is at least 1.5:1. 
     
     
       13. The friction reducing treatment solution according to  claim 1 , wherein the molar ratio of cationic monomer to anionic monomer is up to 1:1.5. 
     
     
       14. A friction reducing treatment solution comprising:
 water; 
 from 100 to 50,000 ppm of total dissolved solids, wherein the total dissolved solids comprise at least 10 weight percent of a multivalent cation; 
 from 0.5 to 3 gallons per thousand gallons of a water-in-oil emulsion comprising an oil phase (O) and an aqueous phase (A) at an O/A ratio of from about 1:8 to about 10:1, wherein the oil phase is a continuous phase comprising an inert hydrophobic liquid;
 wherein the aqueous phase is present as dispersed distinct particles in the oil phase and comprises water, a water soluble polymer, and surfactants; 
 wherein the water soluble polymer comprises 20 to 80 weight percent of a non-ionic monomer, 0.5 to 30 weight percent of a carboxylic acid containing monomer, and 5 to 70 weight percent of a cationic monomer; and 
 wherein the water soluble polymer comprises from 10 to 35 weight percent of the water-in-oil emulsion; and 
 
 an inverting surfactant.