METHOD FOR SEALING DEFECT IN WORKING COLUMN OF PRODUCTION WELL (OPTIONS) Russian patent published in 2021 - IPC E21B33/10 

FIELD: mining industry.

SUBSTANCE: group of inventions relates to methods for sealing the defect in the working column of the production well. The method for sealing the defect in the working column of the production well includes detecting the interval of the defect in the working column, conducting insulation works and starting up. The interval of the defect in the working column is determined in an operating production well equipped with a rod depth pump by the inter-pipe space under the level of liquid in the well. At the same time, the value of the inflow or absorption of liquid in the interval of the defect in the well and the inflow of liquid into the well from the productive reservoir are determined. According to the first option, if the ratio of the inflow or absorption of liquid in the interval of the defect to the inflow of liquid from the reservoir is less than 0.1, then a bottom-up arrangement is assembled at the mouth of the production well: a plug, a perforated branch pipe, a pipe column, in which a lock support, a valve for grazing gas, and a packer are placed from bottom to top. Then the assembled arrangement is lowered into the working well column, the packer is landed below the defect, but above the productive reservoir, and the tightness of the packer landing is checked by pumping the process liquid through the pipe column with the annulus valve open, without exceeding the permissible pressure on the reservoir. Then the plug-in rod pump is lowered into the pipe column and placed in the locking support of the pipe column, after which the drive of the rod column of the plug-in rod depth pump is started. According to the second option, if the ratio of the inflow or absorption of liquid in the interval of the defect to the inflow of liquid from the reservoir is 0.1 or more, then the production equipment is removed from the well and acoustic cementometry is performed in the interval 10 m above and below the interval of the defect of the working column of the production well. The quality of the cement ring behind the working column of the production well is determined. In the presence of a solid cement ring behind the working column of the production well in the interval of the defect and with rock permeability in the interval of the defect up to 1.5 mcm², a blind packer is lowered on the working column below the defect. The packer is installed. The defect is drained with acid in the volume of 2.0 m³. The drilled packer is lowered on the column of process pipes, and it is landed above the defect. Next, the defect of the working column of the production well is plugged by cyclic injection of alternating portions of low-modulus liquid glass and cement mortar with an increase in the volume of injection in each cycle of each component by 0.3 m³. After plugging, the production equipment is lowered into the well and the production well is put into operation. In the absence or partial presence of a cement ring behind the working column of the production well or with rock permeability in the interval of the defect of the working column of the production well from 1.5 mcm² or more, drainage of the defect before plugging is not performed.

EFFECT: reducing the time and increasing reliability of sealing.

2 cl, 7 dwg