Abstract: A shaped insert that includes a top portion, and a grip length, wherein the grip length is modified to have a non-uniform cross sectional area is disclosed. In another case, a shaped insert includes a top portion, and a grip length, wherein the grip length is modified such that the insert is non-cylindrical. In another case, a shaped insert includes a top portion, and a grip length, wherein the grip length is coated in a non-uniform manner.

Abstract: A cutter element for a drill bit has a crest that defines a crest line. The crest can be non-rectilinear. The crest line of each cutter element defines an angle with respect to the axis of the rolling cone on which the cutter element is mounted. The cutter elements define different angles with respect to the cone axis and with respect to each other.

Abstract: A cutter element for a drill bit has a non-rectilinear crest. The cutter element has a base portion and an extending portion and the extending portion has either a zero draft or a negative draft with respect to the base portion. The non-positive draft allows more of the borehole bottom to be scraped using fewer cutter elements. The cutter elements having non-positive draft can be either tungsten carbide inserts or steel teeth.

Abstract: A drill bit having one or more nozzle retention bodies attached by a single orientation mounting is disclosed, as is the associated method for its manufacture. The upper end of the nozzle retention body has a fluid inlet in communication with the internal fluid plenum of the drill bit, and the lower end of the nozzle retention body includes a fluid outlet that defines an exit flow angle. The exit flow angle is angularly disposed from the longitudinal axis of the drill bit. The nozzle retention body may advantageously be chamfered or the like to provide a reduced cross-sectional area at the lower end of the nozzle retention body. The outer surface of the nozzle retention body (and attached hardened elements) may extend substantially to gage, or may fall short of that diameter.

Abstract: A cutter element for a drill bit has a non-rectilinear crest. The cutter element has a base portion and an extending portion and the extending portion has either a zero draft or a negative draft with respect to the base portion. The non-positive draft allows more of the borehole bottom to be scraped using fewer cutter elements. The cutter elements having non-positive draft can be either tungsten carbide inserts or steel teeth.

Abstract: A method for simulating the drilling performance of a roller cone bit drilling an earth formation may be used to generate a visual representation of drilling, to design roller cone drill bits, and to optimize the drilling performance of a roller cone bit. The method for generating a visual representation of a roller cone bit drilling earth formations includes selecting bit design parameters, selecting drilling parameters, and selecting an earth formation to be drilled. The method further includes calculating, from the bit design parameters, drilling parameters and earth formation, parameters of a crater formed when one of a plurality of cutting elements contacts the earth formation. The method further includes calculating a bottomhole geometry, wherein the crater is removed from a bottomhole surface.

Abstract: Enhanced inserts are formed having a cylindrical grip and a protrusion extending from the grip. An ultra hard material layer is bonded on top of the protrusion. The inserts are mounted on a rock bit and contact the earth formations off center. The ultra hard material layer is thickest at a critical zone which encompasses a major portion of the region of contact between the insert and the earth formation. Transition layers may also be formed between the ultra hard material layer and the protrusion so as to reduce the residual stresses formed on the interface between the ultra hard material and the protrusion.

Abstract: Enhanced inserts are formed having a cylindrical grip and a protrusion extending from the grip. An ultra hard material layer is bonded on top of the protrusion. The inserts are mounted on a rock bit and contact the earth formations off center. The ultra hard material layer is thickest at a critical zone which encompasses a major portion of the region of contact between the insert and the earth formation. Transition layers may also be formed between the ultra hard material layer and the protrusion so as to reduce the residual stresses formed on the interface between the ultra hard material and the protrusion.

Abstract: A cutter element for use in a drill bit, comprising a substrate and a cutting layer. The substrate comprises a grip portion and an extension portion, where the grip portion has an insert axis and an extension portion including an interface surface having a first apex. The cutting layer is affixed to the interface surface and has a cutting surface having a second apex. The cutting layer is shaped such that when a plane passing through the first apex and lying parallel to the insert axis and normal to a radius from the insert axis, the plane divides the cutting layer into major and minor portions and the major portion has a major volume that is at least 60 percent of the total volume of said cutting layer. Alternative embodiments of the present invention include variations wherein the first and second apices do not coincide and wherein the interface surface of the substrate is not axisymmetric. Using these variations, cutter elements having sizeable variations in thickness are constructed.

Abstract: A drill bit including a roller cone and fixed cutters positioned external to the roller cone and radially from the bit axis of rotation. The roller cone is located so that a drill diameter of the cone is substantially concentric with an axis of rotation of the bit. The fixed cutters can be made of tungsten carbide, polycrystalline diamond, boron nitride, or any other superhard material. The fixed cutters are positioned to either maintain the hole diameter drilled by the roller cone or to drill a larger diameter hole than the hole drilled by the roller cone. The single roller cone may be located in the center of a multi-cone bit arrangement or in the center of a PDC bit to assist in drilling the center of a wellbore. The single roller cone may be used to form a bi-center bit in combination with a reaming section. The single roller cone may also be located on an independent sub that is removably attached to the bit body.

Abstract: A drill bit having a canted or non-canted leg backface, a canted or non-canted seal in the interface between the cone backface and the shirttail, and a canted seal that can be semi-encapsulated so that there is no straight-line path across the seal.

Abstract: A cutter element for a drill bit has a non-rectilinear crest. The cutter element has a base portion and an extending portion and the extending portion has either a zero draft or a negative draft with respect to the base portion. The non-positive draft allows more of the borehole bottom to be scraped using fewer cutter elements. The cutter elements having non-positive draft can be either tungsten carbide inserts or steel teeth.

Abstract: Enhanced inserts are formed having a cylindrical grip and a protrusion extending from the grip. An ultra hard material layer is bonded on top of the protrusion. The inserts are mounted on a rock bit and contact the earth formations off center. The ultra hard material layer is thickest at a critical zone which encompasses a major portion of the region of contact between the insert and the earth formation. Transition layers may also be formed between the ultra hard material layer and the protrusion so as to reduce the residual stresses formed on the interface between the ultra hard material and the protrusion.

Abstract: Dual functioning seals for use in forming a lubricant seal in a rotary rock bit comprise an annular elastomeric seal body having a dynamic seal surface for sealing against a dynamic surface and a static seal surface for sealing against a static surface. The seal body has an asymmetric axial cross-sectional geometry the dynamic seal surface having a greater radius of curvature than that of the static seal surface. The dynamic and static seal surfaces are formed from different elastomeric materials, and the dynamic seal surface is formed from an elastomeric material that is harder and more wear resistant than the elastomeric material used to form the static seal surface. A rotary rock bit seal constructed in this manner is well adapted to accommodate the different operating conditions and sealing requirements that exist both at the dynamic and static surfaces of the seal to ensure optimal seal performance and, thereby enhance the service life of the rock bit.

Abstract: Dual functioning seals for use in forming a lubricant seal in a rotary rock bit comprise an annular elastomeric seal body having a dynamic seal surface for sealing against a dynamic surface and a static seal surface for sealing against a static surface. The seal body has an asymmetric axial cross-sectional geometry the dynamic seal surface having a greater radius of curvature than that of the static seal surface. The dynamic and static seal surfaces are formed from different elastomeric materials, and the dynamic seal surface is formed from an elastomeric material that is harder and more wear resistant than the elastomeric material used to form the static seal surface. A rotary rock bit seal constructed in this manner is well adapted to accommodate the different operating conditions and sealing requirements that exist both at the dynamic and static surfaces of the seal to ensure optimal seal performance and, thereby enhance the service life of the rock bit.

Abstract: A cutter element for a drill bit. The cutter element has a non-rectilinear crest. The non-rectilinear or curvilinear crest provides an advantageous distribution of the cutting forces across the body of the cutter elements and thus improves bit life. The curvilinear crest also allows the cutter element to more efficiently lift the portion of the formation that is being cut, thereby improving cutting action in certain formations. The cutter elements can have either positive or non-positive draft and can be tungsten carbide inserts.

Abstract: A high performance rock bit journal seal is formed from a composite material comprising an elastomeric material and a nonelastomeric polymeric material. The polymeric material is preferably in the form of fibers compiled or woven into a sheet. The elastomeric material may include one or more lubricant additives. The composite seal material comprises a number of repeating sheets of polymeric fabric that are bonded together with the elastomeric material. The seal can either be formed entirely of the composite seal material or partially of the composite material, in which case it is preferred that the seal wear or dynamic surface be formed from the composite material and the remaining portion of the seal be formed from an elastomeric material. The seal can be used as a primary journal seal, or as a secondary journal seal in a dual seal bit.

Abstract: A steel tooth, particularly suited for use in a rolling cone bit, includes a root region, a cutting tip spaced from the root region and a gage facing surface therebetween. The gage facing surface includes a knee, and is configured such that the cutting tip is maintained at a position off the gage curve. So positioned, the cutting tip is freed from having to perform any substantial cutting duty in the corner on the borehole corner, and instead may be configured and optimized for bottom hole cutting duty. The knee on the gage facing surface is configured and positioned so as to serve primarily to cut the borehole wall. It is preferred that the knee be positioned off gage, but that it be closer to the gage curve than the cutting tip.

Abstract: A high performance rock bit journal seal is formed from a composite material comprising an elastomeric material and a nonelastomeric polymeric material. The polymeric material is preferably in the form of fibers woven into a sheet. The elastomeric material includes at least one lubricant additive. The composite seal material comprises a number of repeating sheets of polymeric fabric that are bonded together with the elastomeric material. In one embodiment, the seal includes a body formed entirely from the composite material, in which case both the static and dynamic seal surfaces are the same. In another embodiment, the seal includes a first body portion formed from the composite material, and a remaining body portion formed from a noncomposite elastomeric seal material.

Abstract: Dual functioning seals for use in forming a lubricant seal in a rotary rock bit comprise an annular elastomeric seal body having a dynamic seal surface for sealing against a dynamic surface and a static seal surface for sealing against a static surface. The seal body has an asymmetric axial cross-sectional geometry the dynamic seal surface having a greater radius of curvature than that of the static seal surface. The dynamic and static seal surfaces are formed from different elastomeric materials, and the dynamic seal surface is formed from an elastomeric material that is harder and more wear resistant than the elastomeric material used to form the static seal surface. A rotary rock bit seal constructed in this manner is well adapted to accommodate the different operating conditions and sealing requirements that exist both at the dynamic and static surfaces of the seal to ensure optimal seal performance and, thereby enhance the service life of the rock bit.