DEVICE FOR COMBINED ACTION ON STUCK PIPE STRING Russian patent published in 1994 - IPC

FIELD: well drilling. SUBSTANCE: installed in device body for limited axial motion is rod with radial holes. Attached to rod are vibrator and piston with spherical outer surface. Installed in middle part of body is flexible member made in form of opposite segments symmetrically arranged for interaction with piston outer surface. Piston is installed in intermediate position and liquid bath is injected in sticking zone. In so doing, injected fluid actuates vibrator. Then, brought in interaction are piston side surfaces with flexible member segments to produce releasing force. By pulling pipe string upward, piston is disengaged from flexible member, and blow is delivered to body to provide combination action on stuck pipe string by effect of bath, vibration and impact, and tensioning of drill pipe (in any sequence of them and combination). EFFECT: higher efficiency. 3 dwg