METHOD FOR ELIMINATION OF BREAKDOWN WHEREIN DRILLING TOOL IS STUCK IN CENTRAL PORTION OF DRILLED WELL Russian patent published in 1994 - IPC

FIELD: drilling practice. SUBSTANCE: method involves determining the point of sticking, putting a cement plug above sticking point, determining direction of natural curving of well, drilling a new shaft with deflecting tool in loosened zone around main shaft in the direction away from natural curving, then drilling along stuck tool alternating it with flushing until getting into the already drilled shaft below the lower end of stuck tool. In hard rocks, level with the stuck tool and below it, charges are exploded in new shaft, alternating blasts with drilling from above. EFFECT: speedier elimination of breakdowns achieved by more accurate hitting of the initially-drilled shaft, and lower expenditures for restoration of well. 2 cl, 2 dwg