METHOD OF TREATMENT OF WELL BOTTOMHOLE ZONE WITH LOW BED PRESSURE Russian patent published in 2015 - IPC E21B43/27 

FIELD: oil-and-gas industry.

SUBSTANCE: method of treatment of the well bottomhole zone with low bed pressure means well washing with fresh water, renewal of the production formation perforation on the basis 10 holes per running meter of well, formations saturation with fresh water to 6MPa. The first portion of hydrochloric acid solution is injected to the well in amount 2.0m³ and is held under bath mode for 2 h. Injection to the formation is performed by four stages. At first stage 6 times pulse injection to the formation of specified first portion of hydrochloric acid solution is performed under cycle mode, including injection for 1 minute at pressure 1-6MPa and holding for 5 minutes for reaction, injection of the specified portion is completed under continuous mode until complete release of the well bore from the hydrochloric acid solution. At the second stage 6 times pulse injection to the formation of the second portion of the hydrochloric acid solution is performed in volume 3.0m³ under cycle mode, including injection for 1 minute at pressure 1-6MPa and holding for 5 minutes for reaction, injection is completed under continuous mode. Then process holding for 3 h is performed for reaction. At the third stage the third portion of the hydrochloric acid solution on the basis 0.5m³ per running meter of the production formation is performed under continuous mode at pressure 1-6MPa, and holding for reaction for 3 h is performed. At the forth stage the 6 times pulse injection to the formation of the second portion of the hydrochloric acid solution is performed on the basis 1.0m³ per running meter of the production formation under cycle mode including injection for 1 minute at pressure 1-6MPa and holding for 5 minutes for reaction, injection is completed under continuous mode. Holding for 3 h for reaction is performed, then reaction products are removed by swabbing.

EFFECT: improving treatment efficiency of the well bottom-hole zone.

1 ex