SALTPROOF FRICTION REDUCER Russian patent published in 2020 - IPC C09K8/588 C09K8/68 C09K8/92 E21B43/22 E21B43/26 

FIELD: chemistry.

SUBSTANCE: invention relates to production of hydrocarbons, specifically to compositions and methods for treating an underground formation. Frictional-reducing treatment solution for near-wellbore, containing water, 100 from 500,000 ppm of total amount of dissolved solid substances, and 0.5 to 3 gallons (1.89 to 11.36 liters) per thousand gallons (3785.41 liter) of water-in-oil emulsion containing water-soluble polymer, and inverting surface-active substance. In the emulsion, the oil phase is a dispersed phase containing an inert hydrophobic liquid, the aqueous phase is present in the form of dispersed separate particles in the oil phase and contains water, surfactants. Water-soluble polymer contains 20–80 wt. % non-ionic monomer, 0.5–30 wt. % monomer containing carboxylic acid, and 5–70 wt. % cationic monomer and contains in one embodiment 5–40 wt. %, and in another embodiment 10–35 wt. % of emulsion of water in oil. Method of treating part of an underground formation involves turning the water emulsion in oil by adding it to water to obtain said solution and introducing it into a part of the underground formation. Invention is developed in dependent items of the formula.

EFFECT: technical result is the increase in the treatment efficiency.

19 cl, 7 tbl, 3 ex