COMPOSITION AND METHOD FOR SELECTION OF HYDROCARBON FLUIDS FROM UNDERGOUND RESERVOIR Russian patent published in 2017 - IPC C09K8/512 C09K8/518 E21B43/22 

FIELD: chemistry.

SUBSTANCE: invention relates to the composition comprising cross-linked swellable polymeric microparticles that can be hydrolyzed under neutral or lower value of pH, and the method of altering the water permeability of an underground formation by introducing such compositions into an underground formation. The composition for modifying the water permeability of an underground formation comprising swellable cross-linked polymeric microparticles with a mean diameter of unswollen particles of from about 0.05 to about 2000 microns, and a crosslinking agent content of from about 50 to about 200,000 ppm of at least one of the labile crosslinking agent with respect to the molar ratio of the said polymeric microparticles, capable of splitting or at neutral and lower values of pH and at about 0-900 ppm of at least one non-labile cross-linking agent, with respect to the molar ratio, wherein the said labile crosslinking agent is selected from at least one from these structures. The method of modifying the water permeability of an underground formation comprising introducing into an underground formation a composition comprising swellable cross-linked polymeric microparticles as defined above, wherein the diameter of the microparticles is less than the diameter of the pores of the underground formation and the labile crosslinking agents break under the conditions of the underground formation. The invention is developed in subclaims.

EFFECT: invention provides increased mobility and / or selection rate of hydrocarbon fluids which are present in underground formations.

18 cl, 2 ex, 5 tbl, 1 dwg