METHOD OF LOST CIRCULATION CONTROL IN WELL REPAIR AND ISOLATION OPERATIONS (VERSIONS) Russian patent published in 2000 - IPC

FIELD: oil producing industry, particularly, well workover. SUBSTANCE: method includes determination of water inflow profile and injection of isolating material; cutting out of flow string part corresponding to thickness of producing formation; simultaneous cutting out of cement stone; installation of cement bridge above lower end of cutout part of flow string above floor of producing formation. According to the second version, one part of flow string is cutout from floor and above roof of producing formation for height of at least, 5 m. Cement stone is cutout simultaneously. Rundown into flow string is pipe of smaller diameter. Space between strings is cemented and string of lower diameter is perforated in oil-bearing part of formation. EFFECT: higher reliability of isolation. 2 cl