METHOD OF ISOLATING FLUSHED ZONES IN PRODUCING AND INJECTION WELLS Russian patent published in 2002 - IPC

FIELD: oil producing industry, particularly, workover of producing and injection wells. SUBSTANCE: method includes singling-out of flushed zones, cutting-out of parts of flow string corresponding to formation thickness; simultaneous removal of cemented ring; successive injection of plugging and hardening slurries. Injection is effected at pressure exceeding the formation pressure by 8-15 MPa. Then after process shut-in for time required for cement setting, noncased wellbore is reamed up to diameter exceeding bit nominal diameter by 14-18%. EFFECT: intensified oil recovery and higher oil production rate of formations by increased production rate of producing wells and equalized injectivity of injection wells.