| 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. |