OUTFIT TO SHORE UP WALLS OF BOREHOLE Russian patent published in 2001 - IPC

FIELD: hole drilling, namely, strengthening of drilled intervals by casings. SUBSTANCE: proposed outfit includes interconnected strings of casing and technological pipes and device for their separation. Outfit has hollow body housing intermediate branch pipe and sleeve which are fixed against uniaxial movement and are mounted for unfixing. String of technological pipes is connected to intermediate branch pipe. Device for separation of strings is linked to lower end of string of casings. Intermediate branch pipe has hole shut off by breakable plug. Branch pipe and string of technological pipes jointly form hydraulic chamber that is filled with fluid from technological string through hole in intermediate branch pipe after cutting away of plug. Casing string is fitted with hydraulic centering mounts installed in walls of string. Centering mounts are tailored for interaction with fluid of hydraulic chamber. EFFECT: enhanced quality of shore- up of walls of borehole and simplification of process. 1 cl, 4 dwg