METHOD OF ELIMINATING LEAKAGE OF CASED COLUMN Russian patent published in 2009 - IPC E21B33/14 

FIELD: oil and gas production.

SUBSTANCE: method refers to oil and gas industry and can be implemented for eliminating defects of cased columns. According to the method eliminating of leakage of the cased column consists in pumping insulating composition to the point of leakage; prior to pumping there installed packers below and above leakage in the well; pumping of the said composition is carried out through a flow string into space limited with packers; pumping is performed in two portions at ratio in volume 1:1; between the portions a portion of gas is pumped; also insulating composition contains napthene acids and or their derivatives and a complex additive containing calcium chloride and aluminium hydroxide at ratio 1:1 at following ratio of components of insulating composition, wt %: napthene acids and or their derivatives 50-90, the said complex additive 10-50, while ratio of portions of insulating composition and a portion of gas is from 1:5 to 1:10.

EFFECT: eliminating behind-the casing flow and water entry and raised adhesion of cement stone to rock.