Abstract: A reaming tool including a body adapted to couple to a drill string at both axial ends thereof, the body including a plurality of reaming blades affixed at azimuthally spaced apart locations around the circumference of the body, wherein selected ones of the plurality of reaming blades including at least one cutter attached at a selected position and orientation. Additionally, a pilot hole conditioning section including a plurality of azimuthally spaced apart pilot blades affixed to the body longitudinally ahead of the reaming blades. Furthermore, at least one of the reaming blades formed as a single structure with an azimuthally corresponding pilot blade.

Abstract: A reaming tool that includes a body having reaming blades affixed thereto. The reaming blades each have at least one cutter attached thereto at a selected position and orientation. The plurality of reaming blades includes at least one radially most extensive reaming blade. The reaming tool further includes a pilot blade azimuthally spaced apart from the at least one radially most extensive reaming blade. The pilot blade is affixed to the body longitudinally ahead of the at least one radially most extensive reaming blade.

Abstract: A hole opener including a tool body having upper and lower ends. The upper and lower ends may be coupled to adjacent drilling tools. At least two blades are formed on the tool body and are arranged so that the hole opener is positioned concentric with a wellbore, and cutting elements are located on the blades. The at least two blades and the cutting elements are arranged to increase a diameter of a previously drilled wellbore. A hole opener including a tool body having upper and lower ends. The upper and lower ends may be coupled to adjacent drilling tools. At least two blades are formed on the tool body and are arranged so that the hole opener is positioned concentric with a wellbore, and cutting elements are located on the blades. The hole opener includes a pilot hole conditioning section. The pilot hole conditioning section includes at least two pilot blades formed on the tool body in a position axially ahead of the blades.

Abstract: A method is disclosed for drilling a wellbore. The method includes operating a turbine-type mud motor having a bi-center drill bit coupled to it, and applying an axial force to the bit which is selected so that the bit drills in a directionally stable manner. In one embodiment, the motor is a steerable motor operated to maintain a selected trajectory of the wellbore.

Abstract: An expandable reaming tool including at least two reamer pads connected to a tool body. The reamer pads are adapted to be displaced between a retracted position and an expanded position. At least one spiral blade is formed on at least one reamer pad. A plurality of cutting elements are disposed on the at least one spiral blade. An expandable reaming tool including at least two reamer pads connected to a tool body. The reamer pads are adapted to be displaced between a retracted position and an expanded position. At least one blade is formed on the at least two reamer pads. A plurality of cutting elements are disposed on the at least one blade and at least one gage protection element is disposed on a gage surface of the at least one blade. The plurality of cutting elements are arranged so as to enable the expandable reaming tool to backream a formation in a wellbore.

Abstract: A hole opener including a tool body having upper and lower ends. The upper and lower ends may be coupled to adjacent drilling tools. At least two blades are formed on the tool body and are arranged so that the hole opener is positioned concentric with a wellbore, and cutting elements are located on the blades. The at least two blades and the cutting elements are arranged to increase a diameter of a previously drilled wellbore.

Abstract: An expandable downhole tool comprises a tubular body, at least one moveable arm disposed within the tubular body and being radially translatable between a retracted position and a wellbore engaging position, and at least one piston operable to mechanically support the at least one moveable arm in the wellbore engaging position when an opposing force is exerted. A method of reaming a formation to form an enlarged borehole in a wellbore comprising disposing an expandable reamer in a retracted position in the wellbore, expanding at least one movable arm of the expandable reamer radially outwardly into engagement with the formation, reaming the formation with the at least one moveable arm to form the enlarged borehole; and mechanically supporting the at least one moveable arm in the radially outward direction during reaming.

Abstract: A reaming tool is disclosed which includes a body having reaming blades affixed thereto at azimuthally spaced apart locations around a circumference of the body. The reaming blades each have at least one cutter attached thereto at selected positions and orientations on each of the blades to minimize a net lateral force developed by the reaming tool. The tool includes a pilot hole conditioning section comprising a plurality of azimuthally spaced apart pilot blades affixed to the body longitudinally ahead of the reaming blades.

Abstract: An expandable reaming tool including at least two reamer pads connected to a tool body. The reamer pads are adapted to be displaced between a retracted position and an expanded position. At least one spiral blade is formed on at least one reamer pad. A plurality of cutting elements are disposed on the at least one spiral blade.

Abstract: An expandable reaming tool including at least two reamer pads connected to a tool body. The reamer pads are adapted to be displaced between a retracted position and an expanded position. At least one spiral blade is formed on at least one reamer pad. A plurality of cutting elements are disposed on the at least one spiral blade.

Abstract: The present invention provides a bit with cutting structures or inserts that include diamond particles, in which the diamond-impregnated inserts are surrounded by substantially diamond-free support members. The diamond-impregnated inserts are manufactured separately from the bit body. Once formed, the diamond-impregnated inserts are affixed to the substantially diamond-free support members on bit body by brazing or other means of attachment. The total thermal exposure of the diamond particles during manufacture in accordance with the present invention is significantly lower than the total manufacturing-related thermal exposure in previously known diamond-impregnated cutting structures. Furthermore, the substantially diamond-free support members allow the bit to continue cutting through a formation without an increased contact area, as experienced by bits with diamond-impregnated ribs. Thus, the operating life of the cutting structures, and therefore the life of the bit itself, is increased.

Abstract: A hole opener including a tool body having upper and lower ends. The upper and lower ends may be coupled to adjacent drilling tools. At least two blades are formed on the tool body and are arranged so that the hole opener is positioned concentric with a wellbore, and cuffing elements are located on the blades. The at least two blades and the cutting elements are arranged to increase a diameter of a previously drilled wellbore.

Abstract: A bi-center drill bit is disclosed which includes a bit body having pilot blades and reaming blades distributed azimuthally around the body. The blades have cutting elements disposed thereon at selected positions. The body and blades define a longitudinal axis of the bit and a pass-through axis of the bit. In one aspect, selected ones of the pilot blades include thereon, longitudinally between the pilot blades and the reaming blades, a pilot hole conditioning section including gage faces. The gage faces define a diameter intermediate a pilot hole diameter and a pass-through diameter defined, respectively, by the pilot blades and the reaming blades.

Abstract: A hole opener including a tool body having upper and lower ends. The upper and lower ends may be coupled to adjacent drilling tools. At least two blades are formed on the tool body and are arranged so that the hole opener is positioned concentric with a wellbore, and cutting elements are located on the blades. The at least two blades and the cutting elements are arranged to increase a diameter of a previously drilled wellbore.

Abstract: A reaming tool which includes a body having reaming blades affixed thereto at azimuthally spaced apart locations around a circumference of the body is shown and described. The reaming blades each have at least one cutter attached thereto at selected positions and orientations on each of the blades to minimize a net lateral force developed by the reaming tool. The tool includes a pilot hole conditioning section having a plurality of azimuthally spaced apart pilot blades affixed to the body longitudinally ahead of the reaming blades.

Abstract: An expandable reaming tool including at least two reamer pads connected to a tool body. The reamer pads are adapted to be displaced between a retracted position and an expanded position. At least one spiral blade is formed on at least one reamer pad. A plurality of cutting elements are disposed on the at least one spiral blade.

Abstract: A drill bit including a bit body and a plurality of blades formed in the bit body. The blades are formed, at least in part, from a base matrix material that on one embodiment is impregnated with abrasive particles. One side of the bit is formed, with respect to its axis of rotation, to a smaller radius than the opposite side of the bit. The asymmetry of the bit enables the bit to drill a larger diameter hole than a pass through diameter of the bit. The opposite side defines a contact angle between the bit and a formation. In one embodiment, the contact angle is at least 140 degrees. In one embodiment, a plurality of inserts may be located on the blades to provide gage protection. In another embodiment, the bit may also include a gage sleeve that helps keep the bit stabilized in the wellbore.

Abstract: A bi-center drill bit includes pilot and reaming blades affixed to a body at azimuthally spaced locations. The blades have PDC cutters attached at selected positions. In one aspect, the pilot blades form a section having length along the bit axis less than about 80 percent of a diameter of the section. In another aspect, selected pilot blades and corresponding reaming blades are formed into single spiral structures. In another aspect, shapes and positions of the blades and inserts are selected so that lateral forces exerted by the reaming and the pilot sections are balanced as a single structure. Lateral forces are preferably balanced to within 10 percent of the total axial force on the bit. In another aspect, the center of mass of the bit is located less than about 2.5 percent of the diameter of the bit from the axis of rotation. In another aspect, jets are disposed in the reaming section oriented so that their axes are within about 30 degrees of normal to the axis of the bit.

Abstract: A reaming tool is disclosed which includes a body having reaming blades affixed thereto at azimuthally spaced apart locations around a circumference of the body. The reaming blades each have at least one cutter attached thereto at selected positions and orientations on each of the blades to minimize a net lateral force developed by the reaming tool. The tool includes a pilot hole conditioning section comprising a plurality of azimuthally spaced apart pilot blades affixed to the body longitudinally ahead of the reaming blades.

Abstract: A bi-center drill bit is disclosed which includes a bit body having pilot blades and reaming blades distributed azimuthally around the body. The blades have cutting elements disposed thereon at selected positions. The body and blades define a longitudinal axis of the bit and a pass-through axis of the bit. In one aspect, selected ones of the pilot blades include thereon, longitudinally between the pilot blades and the reaming blades, a pilot hole conditioning section including gage faces. The gage faces define a diameter intermediate a pilot hole diameter and a pass-through diameter defined, respectively, by the pilot blades and the reaming blades.