METHOD OF SEALING PRODUCTION CASING Russian patent published in 2016 - IPC E21B33/122 

FIELD: oil industry.

SUBSTANCE: invention relates to oil industry, in particular, to methods of production string sealing in vertical, inclined or horizontal shaft of production well. Method involves performance of geophysical survey in the well in order to determine leakage interval of the production string, running on the pipe string in wells of upper and lower packers interconnected by a tube, setting of top and bottom packers in the well above and below the leakage interval and extraction of the pipe string from well. Note here that after determination of intervals of leakage of production string is determined upper and lower intervals of cutting the production string. Then from the wellhead to the production casing string is equipped from below with hydraulic downhole motor and cutting device and cutting the production string from top to bottom, first, in the upper interval of cutting the production string, and then in the lower interval of cutting the production string. Drilling pipe string is lifted with hydraulic downhole motor and cutting device at the wellhead and replace the cutter on expanding reamer and well production string is lowered to the pipe string with hydraulic downhole motor and expandable underreamer at the end and sequence of broken cement stone residues are removed at first from the top, and then from the lower intervals of cutting the production string. After that, drilling pipe string is removed with the expandable underreamer from well production string. At the wellhead from bottom to top: a rigid centralizer, lower water-swellable packer, pipe, upper water-swellable packer, a drillable packer with setting tool. Layout is lowered on process pipe string in well production string so that upper and lower water-swellable packers can be arranged opposite the upper and lower intervals of cutting the production string, and hydraulic drillable packer in the production string with the help of the setting tool. Withdraw the pipe string with wetting tool from the well production string, the layout remains in the specified interval of well production string and is held for swelling, the setting of top and bottom water in the well.

EFFECT: technical result consists in improvement of reliability and efficiency of production string sealing, as well as possibility of implementing methods in inclined or horizontal well bore.

1 cl, 4 dwg