Abstract: A stabilizer for a big hole drill stem includes a journal, i.e., a sleeve, adapted to be slipped over the stem. The sleeve has an apertured lower flange to seat on the stem stool and receive the pins thereof to prevent relative rotation of sleeve and stem. The upper end of the sleeve has a clutch jaw for interlocking with the clutch jaw on the lower end of a canister weight forming part of a drill string assembly. Also, the upper end of the sleeve, just below the clutch, has a split clamp held in frictional engagement with the sleeve in an annular groove thereabout. Just below the clamp there is an annular upper flange having stop lugs engageable between the ears of the clamp to prevent relative rotation. Rotatably mounted on the sleeve between the upper and lower flanges is a fixed blade stabilizer body. A marine bearing is provided at the inner periphery of the stabilizer to take radial loads.

Abstract: Dual conduit drill stem member includes pipe having two piece tube therewithin affixed to pipe at outer ends and inner ends coupled by composite elastomeric sleeve and telescopic metal coupling, adjacent members being connected by threaded tool joints on pipe ends and compression sealed telescopic joints on tube outer ends.

Abstract: A replaceable stabilizer comprises a steel sleeve with fixed blades adapted to be installed over the reduced lower box end of tubular rotary drill steel member prior to insertion of the taper threaded pin of a drill bit into the taper threaded drill steel box. The drill steel member may be a special sub or a regular length of drill steel with modified lower end. An internal straight thread at the upper end of the sleeve screws onto an external straight thread on the drill steel box. An annular rubber gasket secured to the upper end of the sleeve is clamped between the upper end of the sleeve and a shoulder on the steel between the main body and the reduced box end thereof. An inturned flange at the lower end of the sleeve is clamped between a shoulder provided by the mouth of the drill steel box and a shoulder on the drill bit around its taper threaded pin. Make up of the pin and box forms a rotary shouldered connection.