GAS WELL CONSERVATION METHOD Russian patent published in 2007 - IPC E21B33/13 

FIELD: oil and gas production industry, particularly for conservation of gas well drilled in permafrost rock.

SUBSTANCE: method involves killing well; removing production tubing from well; injecting blocking liquid having density exceeding that of plugging Portland-cement mix; arranging bridge over productive reservoir by injection of above plugging mix into predetermined interval; providing plugging mix hardening; injecting additional slurry including plugging Portland-cement in amount of 86-89% by weight, hydrocarboaluminate additive in amount of 2-7% by weight, gypsum in amount of 2-7% by weight, plasticizer in amount of 0.1-0.2 % by weight and water as remainder along with pressure maintenance in tube and annular spaces of the well; checking cement bridge strength and air-tightness and filling well bore and permafrost rock interval with gas condensate.

EFFECT: increased plugging mix flowability and prevention of space creation between inner sides of productive tubing and cement stone.

1 dwg