METHOD FOR TREATING THE BOTTOMHOLE ZONE OF A PRODUCTION WELL OPERATED BY A SUBMERSIBLE ELECTRIC CENTRIFUGAL PUMP Russian patent published in 2021 - IPC E21B43/27 

FIELD: oil industry.

SUBSTANCE: method includes a submersible electric centrifugal pump lowered into a production well on a pipe string, conducting a well research, acid injection into the bottomhole zone of a production well, the well exposure and then extraction of oil from the production well. At the same time, at the wellhead, a pumping unit, acid tank truck, anti-corrosion liquid tank truck and a gutter container are installed and hydraulically tied together. After that, the well is examined by beating the liquid level in the well annulus. Further, when the submersible electric centrifugal pump is operating, an anti-corrosion liquid is injected into the well annulus in a volume of 1.5-3 m³, without exceeding the injection pressure of 2.0 MPa, while the submersible electric centrifugal pump pumps oil from the well into the line. Then the submersible electric centrifugal pump is turned off and the liquid level in the well annulus is expected to decrease. After that, the well is examined by repeated beating of the liquid level in the well annulus, and acid is injected into the well annulus. Further, by pumping anti-corrosion liquid into the well annulus in 1.1 volumes of the well annulus, without exceeding the injection pressure of 3.0 MPa, the acid is pumped from the annulus through the bottomhole zone of the well into the oil reservoir. Exposure of the production well to the acid reaction in the bottomhole zone is carried out, the submersible electric centrifugal pump is started and the waste liquid is pumped out of the reservoir into the gutter container to neutral pH by submersible electric centrifugal pump, after which oil is taken from the production well.

EFFECT: technical result is reduction of the negative effect of acid on the production casing and underground equipment, elimination of environmental pollution due to acid spill at the wellhead during installation and dismantling of equipment at the wellhead, while reducing the cost of implementing the method and reducing the duration of the treatment process of the bottomhole zone of the producing well.

1 cl, 3 dwg