SELECTIVE WATER INFLUX INSULATION METHOD Russian patent published in 2010 - IPC E21B33/138 

FIELD: oil and gas production.

SUBSTANCE: method involves subsequent pumping of acid solution and deposit-forming compound to the bed. After deposit-forming compound is pumped to the bed, there subsequently pumped is gel-forming compound and cement grout bank. As acid solution, there used is hydrolysis acid, as deposit-forming compound there used is composition on the basis of sodium bisulphate, which contains, wt %: sodium bisulphate 3-20; 5-20% solution of techincal lignosulphonate in water with mineralisation of up to 18 g/l 3-20; organic-silicon water-repellent agent is the rest, as gel-forming compound it contains polyacrylamide, sodium bichromate and technical lignosulphonate at the following component ratio, vol %: polyacrylamide - 0.5-1.0; sodium bichromate - 0.1-0.2; techincal lignosulphonate - 0.2-0.4; water - the rest. Cement grout can be modified with anionic surface-active substances plasticising agent addition with volume of 10-20%.

EFFECT: increasing water influx insulation efficiency in beds which are non-homogenous as to permeability.

2 cl, 3 tbl, 2 ex