METHOD FOR HYDROCHLORIC ACID TREATMENT OF THE BOTTOM-HOLE ZONE OF AN OIL RESERVOIR Russian patent published in 2023 - IPC E21B43/27 E21B43/16 

FIELD: mining industry.

SUBSTANCE: invention relates to methods for intensifying oil production from carbonate reservoirs by treating the bottom-hole zone of the formation (BHZF) with acid compositions. The method for conducting hydrochloric acid treatment of the bottom-hole zone of an oil reservoir includes the descent into the well of a tubing string column with a packer, sealing the annular space with a packer and pumping acid solution into the reservoir. At the same time, the tubing string column above the formation has an electric centrifugal pump with a thermomanometric system (TMS), which includes a pH meter. A standard check valve is installed in the tubing string above the pump. A bypass valve is located above the check valve to organize the movement of fluid from the tubing string into the annular space of the well. An electromagnetic packer is opened above the bypass valve and the annular space is sealed. Hydrochloric acid of the calculated volume is pumped into the reservoir through a bypass valve. Water with a neutral pH value is placed between the reservoir and the TMS. After the chemical reaction of hydrochloric acid with carbonate elements of the reservoir, the reverse movement of the reservoir fluid into the well is organized by turning on the electric centrifugal pump into action. When the hydrochloric acid residues of the TMS zone reach a pH meter reading of less than a neutral value of the medium, the operation of the electric centrifugal pump is stopped and this composition with unreacted acid is brought back to the reservoir using a pumping unit at the wellhead. Cyclic movement of hydrochloric acid in the well between the reservoir and the electric centrifugal pump is carried out in a turbulent mode until hydrochloric acid is neutralized with fixation of the neutral pH value of the medium in the TMS zone.

EFFECT: increase in the flow of reservoir oil into wells with the exception of the problem of disposal of acid solution residues due to the organization of complete neutralization of hydrochloric acid while maintaining the characteristics of the electric centrifugal pump.

1 cl, 1 dwg