WELL PREOPERATIONAL CLEANUP DEVICE Russian patent published in 2014 - IPC E21B37/00 

FIELD: oil-and-gas industry.

SUBSTANCE: device comprises electrically driven centrifugal pump at operation tubing to make annulus with well shaft, starting coupling connecting said pump with said tubing with wall accommodating aerators communicating tubing channel with said annulus and shut off by hollow shutoff valve displacing along production tubing with the help of cable controlled from the well mouth. Valve is equipped with radial channels and top axial holes communicating said pump with tubing channel. Valve radial channels can communicate with starting coupling aerators via hydraulic chamber after limited axial displacement of the valve relative to starting coupling. Cable is connected with weight having outer circular groove made at its lower end to receive split lock ring to lock and to release said cable with said weight relative to the valve. Inner circular groove is made in valve top section to receive outer lock ring to be locked in inner teeth cut at starting coupling end.

EFFECT: higher efficiency and reliability of device operation.

2 dwg