METHOD OF REINFORCEMENT OF LINING OF GAS WELLS Russian patent published in 2001 - IPC

FIELD: oil and gas industry. SUBSTANCE: method can be used to seal and restore gas-tightness of lining while conducting repair-insulation operations in gas and gas-condensate wells in process of their drilling and operation. Method specifically refers to cement ring. Method of reinforcement of lining of gas wells includes treatment of cement stone by pumping aqueous solution of electrolyte into hole clearance with subsequent formation of additional pressure. Solution of inorganic salt forming insoluble or difficult-to- solve precipitate after interaction with calcium hydroxide of cement stone, for instance, solution of aluminum sulfate in concentration of 9.0-23.0 per cent by mass is used as aqueous solution of electrolyte. Additional pressure is formed not before than 2 hours after pumping of solution of inorganic salt. EFFECT: restoration of gas-tightness of cement ring under conditions of small values of specific acceptance of wells, prevention of interstring gas flows over. 1 cl, 1 tbl