Abstract: A modular back reamer to be used in subterranean drilling includes a drive stem, a reamer body having a plurality of receptacles, wherein the receptacles are configured to retain a cutting leg assembly, and a plurality of shims engaged within the receptacles to secure the cutting leg assemblies at a specified height.

Abstract: A method of forming a drill bit structure, the method including fixing spacers to the drill bit structure. The spacers are arranged at preselected locations on an outer surface of the drill bit structure. A hardfacing material is then applied to the drill bit structure, and the spacers are removed. Holes are machined in the drill bit structure at the preselected locations, and drilling inserts are positioned in each hole.

Abstract: A back reaming tool is disclosed which includes a tool body adapted to be coupled to a drill string, and at least cutting structure mounted to a leg and having cutting elements disposed thereon. The leg is removably coupled to the tool body.

Abstract: A method of forming a drill bit structure, the method including fixing spacers to the drill bit structure. The spacers are arranged at preselected locations on an outer surface of the drill bit structure. A hardfacing material is then applied to the drill bit structure, and the spacers are removed. Holes are machined in the drill bit structure at the preselected locations, and drilling inserts are positioned in each hole.

Abstract: A drill bit for use in a borehole at least partially containing drilling fluid includes a bit body having at least two bit components, including at least one leg, the leg having a journal segment, and a roller cone rotatably mounted upon the journal segment and forming at least one bearing cavity therebetween. Also included is an annular primary seal disposed between the leg and the roller cone, an annular secondary seal disposed between the leg and the roller cone and between the annular primary seal and the borehole and an annular space disposed between the annular primary seal and the annular secondary seal, the annular space at least partially containing fluid and being in substantially absolute fluid isolation from the bearing cavity and means for permitting the flow of fluid from the annular space to the borehole. The annular secondary seal may be primarily elastomeric and the means for permitting the flow of fluid may further permit the flow of fluid from the borehole to the annular space.

Abstract: A drill bit for use in a borehole at least partially containing drilling fluid includes a bit body having at least two bit components, including at least one leg, the leg having a journal segment, and a roller cone rotatably mounted upon the journal segment and forming at least one bearing cavity therebetween. Also included is an annular primary seal disposed between the leg and the roller cone, an annular secondary seal disposed between the leg and the roller cone and between the annular primary seal and the borehole and an annular space disposed between the annular primary seal and the annular secondary seal, the annular space at least partially containing fluid and being in substantially absolute fluid isolation from the bearing cavity and means for permitting the flow of fluid from the annular space to the borehole. The annular secondary seal may be primarily elastomeric and the means for permitting the flow of fluid may further permit the flow of fluid from the borehole to the annular space.

Abstract: A rotary cone rock bit, comprises a bit body including a plurality of legs extending therefrom, each of the legs having an outer surface that includes a leading surface and a trailing surface, a roller cone rotatably supported on each of the legs, a bearing system between each cone and the leg on which it is supported, and a lubricant reservoir in fluid communication with the bearing system. The reservoir can be provided with a wear resistant plug, if desired. In the present bit, the reservoir has at least one opening positioned in either the leg's leading surface, trailing surface, center surface, shoulder surface or some combination of these. Alternatively, the reservoir can be formed inside the bit body, preferably by means of a canister, which can be provided with venting means as desired.

Abstract: A roller cone for a rock bit is disclosed. The cone includes a cone substrate and hardfacing applied by a welding process in grooves on the exterior surface of the cone substrate. The cone also includes hardfacing applied by a thermal spraying process to insert lands on the exterior surface of the cone substrate.