METHOD TO ISOLATE HIGHLY-PERMEABLE WELL BOTTOM ZONE AREAS Russian patent published in 2007 - IPC E21B43/22 

FIELD: oil industry, particularly to isolate lost-circulation zones in injection wells or water inflow zones in producing wells drilled in carbonate reservoirs.

SUBSTANCE: method involves injecting aqueous suspension of waste product obtained during desulfurization, for instance from sour oil preparation plant, namely 3-6% aqueous sulfur suspension, in well; preliminarily forcing thereof through well to increase injection pressure by 0.8-1.0 MPa relatively initial injection pressure; injecting 13-15% hydrochloric acid solution along with forcing thereof with oil under 1-2 MPa pressure taken in amount of 0.4-0.5 m³ per 1 r.m of productive reservoir; executing technological time-delay for 1.5-2.5 hours; substituting oil in well for 13-15% hydrochloric acid solution; injecting 13-15% hydrochloric acid solution under 1-2 MPa pressure in amount of 0.9-1.1 m³ per 1 r.m of productive reservoir; performing technological time-delay for 3.5-4.5 hours; providing hydroimpulsive injection of 13-15% hydrochloric acid solution in 5-7 cycles in above regime; flushing well with oil and removing reaction products from bottom zone by swabbing operation.

EFFECT: increased efficiency.

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