METHOD OF LIFTING FORMATION FLUID AND PUMPING UNIT FOR REALIZATION OF THIS METHOD Russian patent published in 2007 - IPC F04B47/02 

FIELD: oil production; lifting fluid from wells of any depth by means of plunger-type suction unit.

SUBSTANCE: proposed method includes lowering suction unit with plunger and valve into tubing string mounted inside casing string at access of fluid from hole-bottom region into casing-string annulus and above-plunger space into interior of tubing string. Plunger forms rarefaction in hole-bottom region. Plunger valve is urged into opened position at the beginning of lowering the plunger and is urged into closed position at the beginning of lifting the plunger. At lowering the plunger, above-plunger space in tubing string is urged into shut-off position above plunger valve at distance of plunger travel and is opened during lift of plunger. Pumping unit includes casing string, tubing string and packer with passages connecting the hole-bottom region with casing-tubing annulus which is mounted in hole-bottom region. Suction unit has plunger in whose bore valve is mounted and its body is provided with passages connecting the under-plunger space with under-valve space located in tubing string; oil well tubing has holes above packer for connection of string-casing annulus with interior of tubing. Drive traction member is connected with plunger valve. Unit is provided with cutoff valve mounted on traction member above plunger valve at distance of plunger travel for engagement with respective packer mounted additionally in tubing. Cutoff valve is spring-loaded in longitudinal direction relative to traction member. Traction member is provided with stop-limiter. Drive member is made in form of rod and plunger is provided with adjustable weight in its lower part. Working surfaces of valves and surfaces of packers engageable with them, as well as working surfaces of plungers are provided with wear-resistant coats.

EFFECT: avoidance of leakage of fluid being lifted from above-plunger space during downward motion of plunger.

5 cl, 2 dwg