DEVICE FOR RELEASING STUCK DRILL PIPE STRING Russian patent published in 1994 - IPC

FIELD: drilling of wells. SUBSTANCE: device has body accommodating flexible seat for drop working member. Flexible seat is made in form of guides rigidly secured in body inclined relative to axis and spring-loaded stops movably installed on guides. Drop working member has axial channel with attachment and protrusion in upper part to interact when moving upward together with spring-loaded stops of seat. Body above flexible seat has additional seat for drop vibrator. EFFECT: higher efficiency. 2 cl, 1 dwg