DEVICE FOR SAND PLUG REMOVAL FROM WELL Russian patent published in 2008 - IPC E21B37/00 

FIELD: well operation and repair, particularly for well cleaning of sand plugs and mud with the use of coiled tubing.

SUBSTANCE: device comprises transition module including adaptor, striking shell. The striking shell comprises hollow body with pouring orifices fixedly connected with case in lower part thereof and breaking mechanism with hollow stem and two radial orifices. The hollow body has end teeth. Transition module additionally has centrator fixedly connected to adapter in upper part thereof. Transition module is telescopically connected with striking shell through spring-loaded centering sub. Upper centering sub part comprises inner annular seat. Lower part thereof has groove with lower extension. Discharge orifices are made in central part of hollow striking shell body. Breakage mechanism comprises hydraulic distribution unit located under annular working piston and connected to stem. The hydraulic distribution unit comprises cup and annular hydrodistribution piston, which are spring-loaded one relatively another. Lower end of annular hydrodistribution piston is provided with annular groove. Two figured slots shaped as parallelogram are formed in outer side surfaces of annular working piston and annular hydrodistribution piston of breakage mechanism so that the figured slots are symmetrically arranged with respect to device axis. The figured slots provide thrust stop ends engagement in lower slot parallelogram corner, which defines acute angle, created in annular working piston and in upper slot parallelogram corner, which defines acute angle, created in annular hydrodistribution piston. Two symmetric circulation orifices are formed between the figured slots. Valve assembly is arranged in working chamber of hollow centering sub and is made as mandrel with spring-loaded valve installed in upper part thereof. Mandrel center is attached to annular working piston.

EFFECT: possibility to combine percussion and rotational action on highly cemented sand plug parts, increased operational efficiency and prevention of device jamming.

12 dwg