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 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 turbodrill has rotor vanes and stator vanes that are asymmetric with respect to each other. The rotor blade on which the rotor vanes are disposed has a reaction of less than about 0.5. A method of designing a turbodrill comprises optimizing a first design of stator vanes and optimizing a second design of rotor vanes using computational fluid analysis.

Abstract: An insert for an impreg bit that includes coated diamond particles disposed in a matrix material, wherein the coated diamond particles include a boride, a nitride, and a carbide of a group IVA, VA, VI transition metal or silicon disposed on synthetic, natural, TSP diamonds, or combinations thereof is disclosed. A method of forming a diamond-impregnated insert, including coating a plurality of diamond particles with a coating formed from a boride, a nitride, and a carbide of a group IVA, VA, VI transition metal or silicon or mixtures thereof, and forming a diamond impregnated insert body is also disclosed.

Abstract: A down hole motor assembly with a locking mechanism, and methods for operating said down hole motor assembly. The down hole motor has a housing operatively connectable at an upper end to a drill string. A shaft is disposed within the housing and operatively connected to a motor portion of the down hole motor. A locking mechanism is configured to selectively transmit torque from the housing to the shaft when engaged.