GEL-FORMING LIQUIDS CONTAINING QUATERNARY AMMONIUM SALTS AS GEL TIME MODIFIERS AND METHODS OF THEIR USE Russian patent published in 2014 - IPC E21B33/138 C09K8/512 

FIELD: oil and gas industry.

SUBSTANCE: group of inventions is related to methods and composites to reduce quantity of water drained from subsurface formations and more specifically to methods and composites used for treatment of subsurface formations. The method for reduction of water permeability of the subsurface formation includes introduction of a gel-forming liquid to at least a part of the subsurface formation and holding of the gel-forming liquid till gel is formed in the subsurface formation. At that the gel-forming liquid contains a water basic liquid, a base polymer, an organic cross-linking agent and a gel-forming time modifier. At that the base polymer contains an acrylamide monomeric unit. The gel-forming time modifier contains quaternary ammonium salt and reduces time of gel forming for treatment. The organic cross-linking agent can contain a polymer selected out of a group consisting of polyethyleneimine, polyvinylamine, any of their derivatives, any of their salts and any combination of these.

EFFECT: improving efficiency of gel-forming.

22 cl, 3 ex, 4 dwg