FORMATION WATER ISOLATION METHOD Russian patent published in 2006 - IPC E21B33/13 C09K8/46 C09K8/58 

FIELD: oil and gas industry, particularly reduction of gas, oil and gas-condensate well flooding.

SUBSTANCE: method involves serially injecting calcium chloride and sulfate solutions containing equivalent amount of gypsum-forming ions and sodium silicate solution in well. 0.3-0.5% carboxymethyl cellulose solution is added to sodium silicate solution having density of 1.200-1.300 g/cm³ so that above substances are taken with rate of 1:0.3 to provide cross-linking thereof and bulky sediments forming.

EFFECT: increased efficiency due to possibility to use silicate-polymeric solution, which provides forming of cross-linked heat stabilized structure having elastic-plastic properties and bulky sediments, which reduce relative rock permeability.

1 tbl, 1 dwg