A system for centering a reinforcing member within a drilled shaft/bore hole includes a first cage member and a second cage member. The first cage member is operable to surround a first half of the reinforcing member. The second cage member is operable to surround a second half of the reinforcing member. The second cage member is operably connected to the first cage member, and the first and second cage members have identical shapes.

The invention belongs to the technical field of drills for petroleum, coal mines and exploration, and provides a whipstocking drill for an ultra-short-radius well. The whipstocking drill comprises several flexible drill rods which are sequentially connected end to end, wherein the flexible drill rod at an end portion is connected with a length compensation device, and the flexible drill rods are externally sleeved with several guide sleeves which are movably connected. The invention solves the technical problems of a long whipstocking length and an excessively large turning radius of curvature during whipstocking.

A system (100) for positioning a working tool (21) in a wellbore (1). The positioning system (100) comprises a casing element (110) with a marker (111, 112, 113) provided on an inner surface, the marker (111, 112, 113) having a distinct diameter different from the inner diameter of the casing element (110). The system further comprises a positioning tool (120) with a latching element (121, 122) adapted to form a latch (115) with the marker (111, 112, 113), and a force detector (130) adapted to detect an axial latching force (F.sub.L) applied to a tubing string (20) from the latch (115) when the casing element (110) is located within the wellbore (1) and the force detector (130) is located at a surface (2) outside the wellbore (1).

A downhole tool includes a sleeve configured to be disposed around a tubular. An expandable sealing member is coupled to and positioned at least partially around the sleeve. An end ring is coupled to and positioned at least partially around the sleeve and axially-adjacent to the expandable sealing member.

Adjustment of the angle of a bent sub or other steering feature in a drill string relative to a reference angle of a downhole sensor is facilitated by a rotatable coupling between the bent sub and the sensor. The rotatable coupling may be rotated to align the high side with a reference indicium and locked at the set angle. Rows of ceramic balls retained in circumferential channels may be provided to permit rotation while carrying tensile and compressional forces. Calibration of the sensor is facilitated and opportunities for certain measurement errors are eliminated. An embodiment provides a mechanism for locking the rotatable coupling at a desired angle. The embodiment comprises a ring with teeth that engage a downhole portion of the coupling and depressions that engage an uphole portion of the coupling.

An apparatus including an external surface portion shaped so as to mate with a docking device, and two half-shells having internal surfaces of semi-circular cross section. The apparatus further includes a plurality of segments arranged inside the two half-shells and including teeth for gripping onto a shaft, and an installation tool operable to cause the two half-shells to close around the shaft, thereby securing the apparatus to the shaft.

A shank adapter, rock drilling machine and method of mounting a shank adapter of a rock drilling machine inside a slide bearing element. The shank adapter includes a coupling head and a rotation portion at its opposite ends, and a flushing portion located therebetween. Outer diameters of the coupling head and the rotation portion are both greater than outer diameters of portions of the shank adaptor located therebetween.

A gauge carrier having a sensor, a ball carrying the sensor, and shell surrounding the ball are disclosed. The sensor can detect at least one of pressure and temperature. The ball exposes a sensor surface to allow fluid to reach the sensor surface to take measurements. The shell, ball, and sensor combined can be configured to float or sink in water. The shell can be made of a dissolvable material that, after dissolving, allows the ball and sensor to float to the surface. The gauge carrier can withstand hydrostatic pressures exceeding 10,000 psi.

A clamp assembly for connecting at least two downhole tools to a section of tubing, the clamp assembly having a first clamp part and a second clamp part. The first and second clamp parts having ends, sides, and inner and outer surfaces extending between the sides. A first clamp part end has at least two mechanical connections defining ports for receiving and securing downhole tools, wherein one of the ports is a read-out port. A hinge assembly connects the first clamp part to the second clamp part and is configured to permit the first clamp part and the second clamp part to be moved to a closed position and an open position. A fastener connects clamp sides when the first clamp part and the second clamp part are in the closed position. When in a closed position, the first and second inner clamp surfaces grip the exterior surface of the tubing.

Systems and methods for reducing friction between a casing string and a bore of a subterranean well when moving the casing string within the bore of a subterranean well include a roller bearing assembly. The roller bearing assembly has a bearing body and a plurality of spherical bearings spaced around an outer diameter of the bearing body. The bearing body is sized to be removably attached to an outer diameter of the casing string and to be stationary relative to the casing string.