GEAR TO REPAIR BREAK OF CASING STRING IN BOREHOLE BY CENTERING AND PRESSURE GROUTING Russian patent published in 2001 - IPC

FIELD: oil and gas industry, construction and repair of boreholes. SUBSTANCE: invention is related to construction of boreholes and repair of breaks in casing strings located in boreholes with displacement of break ends by horizontal and vertical lines. This approach provides for design of gear to repair breaks of casing strings with considerable displacement of ends of break along horizontal and vertical lines. Gear includes centering mount and aid grouting casing string. It also has aid to drill around cement stone and blades of centering mount which comes in the form of drill bit reinforced with hard alloy and linked to intake pipe. Centering mount is manufactured in the form of centering members made of easy-to-bore alloy anchored on pipe sections and connected to aid grouting casing string. It comes in the form of coupling. Its body has flushing ducts. Upper part of body of coupling has supporting ring used to attach coupling to internal part of intake pipe. External part of body of coupling and intake pipe with bits form circular protrusion. EFFECT: improved functional efficiency of gear. 3 dwg