DEVICE FOR CLEANING OF CASING INTERNAL SURFACE Russian patent published in 1997 - IPC

FIELD: well drilling equipment, in particular, devices for well overhaul. SUBSTANCE: device includes body with central channel and extensible cutting members connected with spring-loaded piston installed in body for axial motion. Device has wedge engageable with piston. Working surface of wedge has recesses, mating the projections of cutting members and angle at wedge top exceeds the angle of friction between material of wedge working surfaces and cutting members. Working surface of cutting members is made in the form of multistart cylindrical thread. Application of the device for cleaning of casing internal surfaces from cement crust and other sediments directly in the course of well drilling makes it possible without performance of additional operations to prevent sticking of geophysical instruments, in particular, perforating apparatuses, subsurface equipment (packers, subsurface pumps) and to preclude contamination of subsurface pumps with organomechanical sediments from walls of flow strings. EFFECT: higher efficiency. 2 cl, 1 dwg