Drill-string shock absorber unit, used in deep drilling

摘要

An original sliding, shock-absorbing coupling section (1) is installed in a drill-string for deep drilling. Drilling fluid pumped to the tool, returns externally to the string. The new section has upper and lower tubes, connected by rotary threaded couplings transmitting torque, to upper and lower sections of the string. The upper and lower tube sections have collar (5) and spigot (4) construction, fitting together with tolerance leaving gaps essentially parallel and perpendicular to the string axis. Collar and spigot sections permit a standard working stroke over a length of 1-200 cm by axial sliding. The collar is fitted secure against tension on the spigot, with surfaces transmitting tension and/or pressure.