DEVICE FOR CUTTING PIPES IN WELL Russian patent published in 1994 - IPC

FIELD: well recovery and repair. SUBSTANCE: device has sleeve rigidly connected to body lower end. Sleeve has radial channels and perforated partition. The latter is installed in sleeve hollow above its radial channels. Arranged in sleeve hollow under partition are balls for closing radial channels during device rotation. Piston is accommodated under cutters and made with periphery holes to communicate hollow of pipe string through filter tube, sleeve hollow, piston periphery and body ports with well space behind body. required load exerted on cutters is built up by increased pressure differential under piston. EFFECT: higher reliability and simplified design. 2 dwg