PROCESS OF RESTORATION OF WELLS UNFIT FOR FURTHER USE Russian patent published in 2001 - IPC

FIELD: gas and oil industry. SUBSTANCE: invention is intended for restoration of operational gas wells unfit for further use with gas hydrate plug in space of tubing and casing strings if logging cable is positioned in them. Process of restoration of gas operational wells with gas hydrate plug in space of casing and tubing strings which carry logging cable with down-hole logging instrument suspended from it is carried out by way of thermal destruction of gas hydrate plug and is based on forcing of hot technological fluid with temperature not below temperature of dehydration of gas hydrates. With this in mind fluid is pumped over pipes of smaller diameter sunk concentrically into operational tubing string which shoe is fitted with non-return valve for passage of logging cable and prevention of ejection of stratal fluid. Logging cable also passes through washing shackle equipped with lubricator. Split parts of cable are linked with the aid of connector that includes lengthened cable clamps. Elevator is employed for installation of cable of butt of tubing string. Preparation operation includes cutting of cable above well-head, dismantling of logging preventer with lubricator from spout valves and their upper part. Well-head is fitted with antiejection equipment, logging cable being passed through it in advance. Free end of cable is attached to anchored winch with tension never exceeding half of cable breaking load. Assembly in joint " working adapter-coupling " is unscrewed after setting of assembly of tubing string of smaller diameter on tool extractor coil. Cable is attached to coupling with lengthened clamp, is cut above clamp and cable ends are interconnected by means of connector. EFFECT: increased efficiency of operation, reduced time and expenses for restoration and putting into service of gas wells unfit for use. 7 dwg