CUTOFF VALVE AND METHOD OF PUMP INSTALLATION TOGETHER WITH CUTOFF VALVE Russian patent published in 2002 - IPC

FIELD: oil and gas producing industry; applicable in cutting off of tubings in process of replacement of insert sucker-rod pump during well repair without well killing. SUBSTANCE: cutoff valve has locking member including seat and gate, and pump pusher control unit engageable with locking member. Control unit has interlocking dvice in the form of latch and spring-loaded stop. Latch is installed on axle and is engageable with pusher and stop up to interlocking position in contact with pusher, and up to free and working positions, in engagement with pusher and stop. Latch lies on stop in its free position. In working position, latch does not hinder engagement of pusher with locking member. Claimed method is realized by pressing locking member out of seat before lowering of valve, lowering of pipe string with valve into casing, and lowering of pump into support. Lowering of pump into support is carried out by stages. First, it is performed up to reaching interlocking position of valve latch. Then wellhead is sealed by casing-head stuffing box, pipe string is washed and pump with pusher is lifted up to free position of valve latch. Further lowering of pump is performed up to reaching of latch working position relative to pusher and locking member. EFFECT: higher operating reliability of cutoff valve and performance of repair works in pump lowering and replacement. 2 cl, 6 dwg