DEVICE FOR REPLACEMENT OF CHRISTMAS-TREE GATE VALVES ON WELLHEAD WITHOUT WELL KILLING Russian patent published in 2000 - IPC

FIELD: devices applicable in operation of drilled wells in oil and gas producing industry, in repairs of christmas-trees on wellheads without well killing, particularly, for replacement of central and annular space gate valves. SUBSTANCE: device has replaceable packers-nozzles having several version of slip grips. Grip slips are of two types, ones for cylindrical channel of Christmas tree or upper part of tubings, and the others, for channel expanding into funnel in cross-member of Christmas tree. Device has coupling and uncoupling units. This makes it possible to disconnect drive shaft and hollow rod from fixed packer-nozzle and only after this, failed gate valve with other part of device is dismantled. Mechanical action of dismantled gate valve and device part during their displacement after unfastening of flanges on long parts (drive shaft, hollow rod and others) which may protrude in case of absence of coupling and uncoupling units, is excluded. EFFECT: eliminated hazard of disturbance of packer locking and tightness, higher operate reliability of device. 6 dwg