DEPRESSION WELL BOTTOM CLEANING DEVICE Russian patent published in 2006 - IPC E21B37/00 

FIELD: oil production industry, particularly to clean well bottom of mud, sand, paraffin and other deposits.

SUBSTANCE: device comprises depression chamber with separating piston, hydrodynamic action application means, which is hydraulically communicated with mud receiving chamber by means of connection clutch and valve gate arranged in lower part of mud receiving chamber. Upper piston part is provided with sub connected to flow string. Lower piston part has windows and is installed in depression chamber. In transport position separating piston is fixed with shear members with respect to depression chamber so that the separating piston may perform limited downward displacement by means of finger fixedly connected to depression chamber. The finger passes in vertical groove made on outer separating piston surface. In transport position separating piston windows are sealed with depression chamber. The chamber is connected with hydrodynamic action application means by means of clutch. The hydrodynamic action application means is made as differential valve installed in upper part of mud receiving chamber and spring-loaded with respect to depression chamber. Depression and mud receiving chambers may be brought together by mutual chamber rotation. Mud receiving chamber is provided with packing and fixing mechanisms. The packing mechanism is made as upper stop with radial channels and also includes elastic collar and conical lower stop. The packing mechanism components may perform limited upward displacement with respect to mud receiving chamber. The fixing mechanism is made as bush with springing centralizers and jaws, which may cooperate with conical lower stop of the packing means. Lower end receiving part of mud receiving chamber is made as tube basket and is threaded with it by means of adapter. Lower end receiving part is provided with fishing wings located inside the receiving part and may cooperate with well bottom without lower end receiving chamber rotation and approaching to mud receiving chamber during mutual rotation thereof. Mud receiving chamber additionally has radial orifices closed with upper stop in transport position. The radial orifices may be registered with radial orifices of upper stop. In transport position upper stop of lacking mechanism and bush of fixing mechanism are secured with respect to mud receiving chamber with shear screws. Plug valve made as dropping valve is installed above separating piston.

EFFECT: increased reliability and ecological safety, reduced costs.

2 dwg