Abstract: A downhole tool conveyed via tubing within a wellbore at a wellsite comprises a hydraulic tool driven by fluid pumped to the hydraulic tool via the tubing. The downhole tool further comprises a valve in fluid communication between the tubing and the hydraulic tool. The valve is configurable in the wellbore between an expanded position, establishing a bypass diverting at least a portion of the pumped fluid away from the hydraulic tool, and a compressed position, closing the bypass.

Abstract: A drill bit for drilling a borehole in an object, the drill bit having a central longitudinal axis and comprising a bit body provided with a central shank for connecting the drill bit to a drilling system. The drill bit further comprises at least one cutting arm, each cutting arm being provided with a set of cutters for cutting the object and being coupled to the bit body allowing the cutting arm to pivot between a radially retracted position and a radially expanded position.

Abstract: An under reamer for expanding a borehole through an earthen formation is taught. The under reamer includes: a mandrel including an end for connection into a drill string and an opposite end and a housing including an inner bore, telescopically disposed over the mandrel and axially moveable relative to the mandrel but rotationally moveable with the mandrel. A plurality of under reamer arms are carried on the housing, the under reamer arms are formed as blocks including cutter-supporting portions in which poly-crystalline diamond compact cutters are mounted. The under reamer arms are moveable by driving the housing axially over the mandrel between a retracted position extending into the bore of the housing and an expanded position wherein the under reamers arms are pivoted out of the housing inner bore and supported therebehind by the mandrel such that the cutter-supporting portions are exposed for use to enlarge a borehole.

Abstract: An expandable drill bit comprises a body for mounting on a support string and two roller cutters mounted on the body. The cutters are movable between a smaller diameter first configuration and a larger diameter second configuration. In one embodiment the bit is adapted to drill with the cutters in both the first and second configurations.

Abstract: A sub-surface borehole underreamer is disclosed having freely rotatable precessing diamond cutters attached to extendable arms connected to the body of the underreamer. The diamond cutting face is skewed to a degree that tangential contact of the peripheral edge of the diamond cutter causes the rotating cutter to precess as the underreamer body is rotated by a drill string.

Abstract: An anchoring bolt (1), which can produce a conical undercut by rotation in a cylindrical hole and serves simultaneously as a securing element has a connection portion (2), a shaft (4) and an insertion portion (5). The insertion portion (5) has an axially extending slot (6) forming two spreadable branches (8,9), into which slot a movable spreading wedge (18) can be driven in with its tapered end. The branches (8, 9) are each provided with drillings (14, 15) receiving hard metal pins (16, 17) of which the front edges, in the rotation direction, are more protuberant than the rear edges so as to form a clearance angle .alpha..

Abstract: A boring tool for radial widening or enlargement of a cylindrical bottom, foundation, or anchor bore. The boring tool comprises a tubular tool body having a tool shank provided for clamping in a driving machine or prime mover, and an enlarging spindle guided in the tool body and adapted to be supported on the bottom of the bore. When entering into the tool body, the enlarging spindle radially adjusts the cutting parts or elements provided for carrying out the enlargement. The tool body is formed of radially resilient segments which extend in the axial direction and delimit longitudinal slots which are open toward the front end of the tool. Cutting parts or elements are arranged on the free ends of the segments, with each part having an axial working which extends in the circumferential direction of the tool body, with those working surfaces which are adjacent one another in the circumferential direction forming the front end face of the tool body.

Abstract: An underreamer includes a mounting member and a plurality of cutter arms. Means pivotally mounts the cutter arms on the mounting member. Overridable means is operable for holding the cutter arms relatively outward in an underreaming position. The overriding means is operable to allow the cutter arms to move relatively inward upon forces on the cutter arms above a predetermined level.