WELL COMPLETION METHOD Russian patent published in 2015 - IPC E21B43/27 E21B43/16 

FIELD: oil and gas industry.

SUBSTANCE: well completion method involves pumping of an acid solution by circulation with a well mouth by means of a jet nozzle arranged on the end of a flexible flush-joint pipe. Simultaneously with circulation of the acid solution, the flexible flush-joint pipe is being lifted out of the well at a speed that is not higher than the speed of filling the well shaft with an acid solution. After the horizontal shaft is filled with the acid solution, squeezing of the acid solution to the formation is performed at stepped pressure rise and exposure at each step. Process exposure is performed for a reaction of the acid solution with the rock, and inert gas pumping, fixing of a level recovery curve, well killing and well development is performed. First, a tubing string with starting clutches and with a funnel on the end is lowered into the well at the interval of the shoe of the production casing. The flexible flush-joint pipe with a jet nozzle is lowered inside the tubing. Before the acid is pumped to the formation, the horizontal shaft of the well at an open annular space is filled through the flexible flush-joint pipe with a water solution of a surface active substance (SAS). When the annular space is closed, the water solution of SAS is pumped to the formation. Process exposure is performed before oil floats up into the well. Then, the acid solution is pumped via the annular space. Process exposure is performed for 2-4 hours for the reaction of the acid solution with the rock. The well shaft is flushed. The flexible flush-joint pipe with the jet nozzle is lifted out of the well. Inert gas pumping is performed via the annular space with liquid take-off via the tubing.

EFFECT: improving efficiency of acid treatment of a well.

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