DEVICE FOR REPAIR OF OIL AND GAS WELLS Russian patent published in 1999 - IPC

FIELD: oil and gas production industry. SUBSTANCE: device is used for carrying out isolation operations in producing wells when cementation ring in casing clearance is disturbed. Device has container for delivering cement slurry to required depth. Container is closed at top by standard coupling head for connection through cable lug to multiple-conductor logging cable. Container is closed at bottom by stopper. Installed in upper part of container is pump for filling container with cement slurry through charging openings in its wall, and also for delivering washing fluid inside container and creation of required pressure on cement slurry. Located in upper part of container is instrument for measuring natural radioactivity of environmental medium, and located in lower part of container is perforator. Wall of container against perforator has relief openings closed by flexible sheathing. Accuracy of positioning container at required depth, and also position of boundaries of cementation interval are controlled by recording diagram of natural radioactivity. Application of aforesaid device improves efficiency and reliability of isolation operations. Principle of operation of device requires no hermetic separation of upper part of operating string from lower part and this simplifies design and adds reliability. EFFECT: higher efficiency. 1 dwg