DEVICE FOR DEPRESSION CLEANING OF WELL FACES Russian patent published in 2007 - IPC E21B37/00 

FIELD: oil and gas extractive industry, possible use for cleaning wells from slurry, sand, paraffin and other hard to extract sedimentations.

SUBSTANCE: device includes depression chamber with separating piston, hydrodynamic action device, hydraulically connected by means of connecting sleeve to slurry-receiving chamber, gate valve in lower section of slurry receiving chamber. Upper part of piston is equipped with sub having shelves on lower end. Sub is connected to tubing column, while its lower part is provided with windows and is built into depression chamber, relatively to which in transporting position separating piston is held by shear elements with possible limited axial-only downward movement. In transport position windows of piston are hermetically, by means of packing elements, are sealed by depression chamber. Upper end of depression chamber is provided with recesses, made with possible interaction with shelves of lower end of sub. Depression chamber is connected to hydrodynamic action device by means of sleeve. Hydrodynamic action device is made in form of differential valve, mounted in upper part of slurry-receiving chamber and spring-loaded relatively to depression chamber. Depression and slurry-receiving chambers are made with possible approach during rotation relatively to each other. Slurry-receiving chamber on outside is equipped downwardly with packing and holding mechanisms. Packing mechanism is made in form of upper stop with radial channels, elastic sleeve and conic lower stop, made with possible limited upward movement relatively to slurry-receiving chamber. Holding mechanism is made in form of bushing with spring localizers and dies spring-loaded towards inside, made with possible interaction with conic lower stop of packing mechanism. Lower end receiving section of slurry-receiving chamber is made in form of pipe spider and is screwed to slurry-receiving chamber by means of an adapter. Lower end receiving part is made with possible interaction with face without rotation and approach to slurry-receiving chamber during relative rotation relatively to one another. Slurry-receiving chamber is additionally provided with radials apertures closed in transport position by upper stop, which are made with possible combination with radial channels of upper stop. Upper stop of packing mechanism and bushing of holding mechanism are held in transport position relatively to slurry-receiving chamber by means of shear screws. Plug-valve is built in above separating piston, made in form of stripping valve.

EFFECT: increased reliability, lower costs.

2 dwg