DEVICE FOR REPAIR OF PRODUCTIVE STRING BY CEMENTATION Russian patent published in 1997 - IPC

FIELD: operation of oil and gas wells. SUBSTANCE: cementation of productive tube strings is performed in case of string breakage, displacement and eccentric dislocation of broken ends of tubes, etc. Repair is made effective by centering tube ends, using device having body which carries centering unit and ball valve which is positioned in lower part of body. Located in upper part of body is cylinder with piston. They are interconnected by shear pins and form a chamber in combination with body. Chamber is hydraulically connected with body inner space. Centering unit is made of two flexible adapters which are divided by cylindrical partition. Upper end of centering unit is connected with cylinder by threaded joint. Lower end of centering unit is provided with pad. EFFECT: simplified and more reliable repair procedure. 3 dwg