COMPOSITION AND METHOD OF SELECTING HYDROCARBON FLUIDS FROM UNDERGROUND TANKS Russian patent published in 2018 - IPC C09K8/512 C09K8/86 E21B43/22 

FIELD: manufacturing technology.

SUBSTANCE: invention relates to a composition comprising crosslinked swellable polymeric microparticles and a method for altering the permeability of a subterranean formation. Fluid injection composition for extracting a hydrocarbon fluid from a subterranean formation, containing aqueous medium and from about 100 ppm to about 50,000 ppm crosslinked polymer microparticles, based on the active polymer in the composition, wherein said crosslinked microparticles contain from about 0.9 to about 20 mole % of one or more labile crosslinking agents, are characterized by a distribution of swollen particles in size and rheological properties that are suitable for slowing the underground flow of water, and said mobile crosslinking agents are capable of being cleaved at a neutral or lower pH. Method for increasing the production rate of hydrocarbon fluids in a subterranean formation, comprising: introducing into the subterranean formation the above composition of injected fluid and recovering the hydrocarbon fluid. Invention is developed in dependent items of the formula.

EFFECT: technical result is increase in the treatment efficiency.

8 cl, 1 dwg, 2 ex, 6 tbl