METHOD OF EXTRACTING STUCK PIPES STRING OF FLEXIBLE PIPES FROM WELL Russian patent published in 2016 - IPC E21B31/12 

FIELD: oil and gas industry.

SUBSTANCE: invention relates to extraction of the frozen flexible pipe from an emergency well under pressure. Method includes holdup the frozen pipe by spider rams of a preventer stack, its sealing and cutting by shear rams, removing of the cut part from the well, passing through the injector of a flexible pipe of a smaller diameter with a check valve and an adapter to the level above the shear rams of the preventer stack, unfastening of surface equipment of a CT unit above the preventer stack from the mouth of the repaired well, disconnection and suspension of it with the help of a lifting mechanism, drawing of the flexible pipe from the injector, installation on the wellhead gate chamber, lowering into it of a shear assembly of a pipe cutter, downhole motor and hydraulic anchor, connection of the shear assembly to the adapter of the flexible pipe and lowering of it, together with the shear assembly, into the well, attachment by means of the anchor. Then there is performed cutting of the frozen pipe during circulation of a washing liquid, lifting of the flexible pipe with the shear assembly to the preventer stack, unfastening of the surface equipment of the CT unit above the preventer with pipe rams from the wellhead, its disconnection and suspension, extraction from the chamber of the shear assembly, removal of the cut part of the previously frozen part from the well. Then, a fishing assembly from a catcher, hydraulic jack, downhole motor and hydraulic anchor are lowered into the sluice chamber, the disconnected part of surface is installed on the CT unit, a flexible pipe of a smaller diameter with a fishing assembly is lowered into the well for a depth which is 1-2 m above the cut head of the frozen pipe, the fishing assembly is introduced into the inner cavity of the frozen pipe, the catcher is rotated for gripping and fixing with the frozen pipe by means of a downhole motor, the fishing assembly is fixed in the inner cavity of the production string with the help of a hydraulic anchor of a larger diameter, the frozen pipe string is drawn out from the well with the help of a jack.

EFFECT: higher efficiency of extraction of a flexible pipe string.

1 cl, 3 dwg