METHOD FOR WELL OPERATION AT SIMULTANEOUS SEPARATE PUMPING OF WORKING MEDIUM Russian patent published in 2013 - IPC E21B43/14 

FIELD: oil and gas industry.

SUBSTANCE: method includes assembling at the mouth and descending into the well of long string with packer and short string. Preliminary the operated string is gauged by the gauge with length not less than packer's length, there defined is an interval of link for packer not less than 3.5 m long with concrete in behind-the-casing space, the packer is descended at the casing string, there performed is an exploration with determination of intake of disintegrated formations, the packer is lifted. At long string assembling prior to packer installation there assembled is a branch pipe with locking ring and highly pressurised couplings or couplings with sealant on thread that have external diameter reduced by 2 mm compared to the standard, above the packer there mounted is a pipe branch with couplings, one pipe of casing string with reference pipe branch, then the casing string is assembled on highly pressurised couplings or couplings with sealant on thread, the packer is mounted, there performed is a tensioning of long string by load exceeding the string dead weight by 2-3 t, the long string is fixed in eccentric at well mouth, eccentric is fixed in wellhead equipment. At short string installation the tubing is assembled on couplings with sealant on thread, the string bottom is equipped with coupling, short string includes additional pipe branches, by which the couplings of one string are located between the couplings of the other string, after descending of each 4-6 tubes the short string is lifted and descended at the length of 1 tube not less than 2 times, the shoe of the short string is located above the roof of upper formation by 20-30 m. The well is filled with anti-corrosion fluid above the level of short string bottom. For string installation there used are the tubes with internal anti-corrosion and antifouling smooth coating. There performed is the string gauging by gauge with polyamide coating.

EFFECT: increase of method efficiency due to exclusion of string twisting relatively each other, thread loosening and tubes turn-away, exclusion of pressure-tightness failure.

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