DEVICE FOR CEMENTING OF ADDITIONAL CASING STRING Russian patent published in 2003 - IPC

FIELD: oil-gas producing industry, particularly, construction and repair of wells whose casing string got out of order. SUBSTANCE: device has sealing unit, packer, check valve, filling unit and seals. Sealing unit includes body with toothed cut. Packer is installed on body and consists of collar, upper and lower stops. Upper stop is connected with sub by shear members. Filling unit includes body accommodating adjusting bushing. Bodies of sealing and filling units are interconnected in length by means of sub and branch pipe. Sealing unit body has longitudinal recesses and movable bushing installed inside body and connected by means of shear members to packer upper stop through longitudinal recesses. Packer lower stop is connected by means of shear members with body. Filling unit has knocked-off valves installed in body. Adjusting bushing of body is made with circular external recess for retaining ring on body. Filling unit has also supporting bushing located inside adjusting bushing and is connected by shear members with adjusting bushing and body end piece. Knocked-off valves are installed for engagement with nipple installed on lower end of tubing. Inner diameter of adjusting bushing is somewhat less than outer diameter of coupling connecting the nipple with tubing. EFFECT: simplified design, high operate reliability and simplified cementing technology. 3 cl, 3 dwg