WELL BOTTOM ZONE TREATMENT METHOD Russian patent published in 2005 - IPC

FIELD: oil industry, particularly well bottom zone treatment in carbonate reservoir.

SUBSTANCE: method involves lowering flow string sealed from bottom end and provided with filtering fitting and packer so that filtering packer is installed 2-4 m above productive formation bottom; circulating 10-15% hydrochloric acid solution in amount of 10-20 hole annuity volumes through the well; blocking flow string at well head; forcing 10-15% hydrochloric acid solution with high-gravity oil into productive formation through hole annuity, wherein high-gravity oil flow-rate is 24-35m³/day and pressure at flow string head is 0.8-1.2 MPa; opening flow string at well head; repeatedly circulating 10-15% hydrochloric acid solution in amount of 10-20 hole annuity volumes through the well along with displacing high-gravity oil in tank; repeatedly closing flow string at well head and forcing 10-15% hydrochloric acid solution with high-gravity oil into productive formation through hole annuity, wherein high-gravity oil flow-rate is 24-35m³/day and pressure at flow string head is 0.8-1.2 MPa; repeating above circulation and forcing operations; forcing all remaining acid solution with high-gravity oil during the final operation performing; installing packer above productive formation interval; performing technological time delay for 1-2 hours to provide acid reaction; performing swabbing through flow string with rate of 70-100 m³/day; lifting underground equipment for 24-48 hours; lowering screw pump and bringing the well into operation.

EFFECT: increased efficiency of well bottom zone treatment.

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