METHOD FOR PERFORATING WELL AND PROCESSING BOTTOM-HOLE CARBONATE FORMATION ZONE Russian patent published in 2018 - IPC E21B43/112 E21B43/22 E21B43/25 

FIELD: oil and gas industry.

SUBSTANCE: invention relates to oil and gas production industry, to well operation, namely to methods of secondary opening and processing a bottom-hole carbonate formation zone. Method includes running into the production column (PC) of mounted on a tubing string (TS) packer and a hydromechanical piercing punch, installation of a packer in the PC with subsequent opening of the PC by feeding a working fluid into the perforator under pressure, piercing the punches of the perforations in the PC, blurring caverns by feeding the working fluid into the formed perforations of the PC through the jetting channels of the punches of the perforator. Before the running of the TS into PC, the carbonate formation is examined for inflow and the interval with a low oil inflow is determined. Fill the PC well with a viscoelastic composition from the face to the roof of the perforated carbonate formation. At the wellhead at the lower end of the TS, an assembly is collected from the bottom up, including a piercing hydromechanical perforator, a circulation valve, a mechanical packer, a swivel limiter. Run the assembly on the tubing into PC, placing the punch punches in the interval of the carbonate formation with a low inflow. Packer is placed above the top of the carbonate formation. Open the annular valve and put the packer. Piercing hydromechanical perforation is stepped stepwise with increasing pressure of the working fluid in the TS 5.0–8.0–10.0–12.0 MPa to obtain two symmetrical perforations in the PC located at an angle of 180°. At a pressure of 12 MPa, the working fluid is replaced with a 15 % aqueous solution of hydrochloric acid. Injection pressure is adjusted to 15.0 MPa. Through the jetting channels of the piercers, erosion of the caverns is made within 15 minutes. Remaining 15 % aqueous hydrochloric acid solution is poured from the tubing column through the cavities into the bottomhole zone of the carbonate formation. Pressure in the TS is reset to zero and the well is left to the technological holding. Viscoelastic composition and reaction products of a 15 % aqueous solution of hydrochloric acid with the carbonate formation rock are recovered. Through TS holes in the circulation valve and perforations of the PC wells into the bottomhole zone of the carbonate formation, pour in and extrude the solvent in the volume at a rate of 1.0 m³ per 1 m of the height of the carbonate layer.

EFFECT: improved efficiency of erosion of caverns, improved cleaning of the bottomhole zone of the carbonate layer, and improved reliability of the method implementation are provided.

1 cl, 5 dwg