Abstract: A rolling cone drill bit includes a cutter element having a cutting portion with a chisel crest and a pilot portion extending beyond the chisel crest. The pilot portion includes a cutting surface that may be generally conical, or form a second chisel crest. The cutting tip of the pilot portion is supported by buttress portions which emerge from and extend beyond the flanks of the chisel crest to provide additional strength and support for the material of the pilot portion that extends beyond the height of the chisel crest.

Abstract: A method for designing a drill bit that involves simulating a drill bit having cutting elements disposed thereon is provided. In particular, the method involves determining at least one drilling performance parameter while simulating drilling in a selected earth formation.

Abstract: A drill bit having cutting elements disposed on a roller cone surface in a non-linear pattern, wherein at least one of the cutting elements is asymmetrical to its axis of orientation. Also, a method for selecting and adjusting a cutting element orientation based on crater profile geometry which results in increased bottom hole coverage.

Abstract: A rolling cone drill bit is provided that has gage inserts on the first row from the bit axis to cut to full gage diameter that have a cutting portion enhanced with a layer of super abrasive material. The gage cutting surface has a center axis that is canted to be more normal to the gave curve such that its point of contact at gage is away from the thinner portion of the layer of super abrasive material.

Abstract: A method for designing a roller cone drill bit having a plurality of cutting elements in a row. The method includes defining a pitch pattern for the plurality of cutting elements such that a first group of adjacent cutting elements are arranged in a first pitch and a second group of adjacent cutting elements are arranged in a second pitch in the row, wherein the first group of adjacent cutting elements have a different extension length than the second group of adjacent cutting elements, evaluating the pitch pattern of the plurality of cutting elements in the row, and modifying at least one of the plurality of cutting elements based on the evaluating of the pitch pattern of the plurality of cutting elements.

Abstract: A roller cone drill bit for drilling earth formation may include rows arranged on each of the cones such that when viewed in routed profile, cutting element profiles partially overlap with other cutting element profiles and at least the first three interior rows adjacent a gage row each have a cutting element count selected from the group of 16, 18, 21 and 26 cutting elements.

Abstract: A roller cone drill bit is disclosed which includes a bit body adapted to be coupled to a drill string. A bearing journal depends from the bit body. A single roller cone is rotatably attached to the bearing journal. The roller cone has a plurality of inserts disposed at selected positions about the cone. The journal defines a rotation angle with respect to an axis of rotation of the bit such that the roller cone includes a wall contact zone and a bottom contact zone. At least one of the inserts disposed in the wall contact zone has an extension portion terminating in a substantially planar upper surface.

Abstract: A rolling cone drill bit includes a cutter element having a cutting portion with a chisel crest and a pilot portion extending beyond the chisel crest. The pilot portion includes a cutting surface that may be generally conical, or form a second chisel crest. The cutting tip of the pilot portion is supported by buttress portions which emerge from and extend beyond the flanks of the chisel crest to provide additional strength and support for the material of the pilot portion that extends beyond the height of the chisel crest.

Abstract: A drill bit for cutting a borehole comprises a bit body. In addition, the drill bit comprises a rolling cone cutter mounted on the bit body and adapted for rotation about a cone axis. Further, the drill bit comprises at least one insert having a base portion secured in the rolling cone cutter and a cutting portion extending therefrom. The cutting portion includes a pair of flanking surfaces that taper towards one another to form an elongate chisel crest including a first crest end, a second crest end, and an apex positioned therebetween. A transverse radius of curvature at the first crest end is less than a transverse radius of curvature at the apex, and a transverse radius of curvature at the second crest end is less than the transverse radius of curvature at the apex.

Abstract: A roller cone drill bit is disclosed which includes a bit body adapted to be coupled to a drill string. A bearing journal depends from the bit body. A single roller cone is rotatably attached to the bearing journal. The roller cone has a plurality of inserts disposed at selected positions about the cone. The journal defines a rotation angle with respect to an axis of rotation of the bit such that the roller cone includes a wall contact zone and a bottom contact zone. At least one of the inserts disposed in the wall contact zone has an extension portion terminating in a substantially planar upper surface.

Abstract: Drill bits comprise a plurality of steel cutting teeth each having a crest positioned at a tip portion of each tooth, a first flank surface extending from the crest to the cone, a second flank surface opposite the first flank surface and extending from the crest to the cone, and edge surfaces extending from the crest to the cone and interposed between the first and second flank surfaces. Each cutting tooth includes corners that extend from the crest to the cone that are defined by the interface between the first and second flank surfaces and the edge surfaces. A wear resistant surface is positioned on selective tooth surfaces comprising at least the crest and a portion of one or more of the corners. The wear surface is not disposed on at least a surface portion of one of the first and second flank surfaces and the edge surfaces.

Abstract: A method for designing a roller cone drill bit having a plurality of cutting elements in a row. The method includes defining a pitch pattern for the plurality of cutting elements such that a first group of adjacent cutting elements are arranged in a first pitch and a second group of adjacent cutting elements are arranged in a second pitch in the row; evaluating the pitch pattern of the plurality of cutting elements in the row; and modifying at least one of the plurality of cutting elements, based on the evaluating the pitch pattern of the plurality of cutting elements.

Abstract: A rolling cone drill bit is provided that has gage inserts on the first row from the bit axis to cut to full gage diameter that have a cutting portion enhanced with a layer of super abrasive material. The gage cutting surface has a center axis that is canted to be more normal to the gage curve such that its point of contact at gage is away from the thinner portion of the layer of super abrasive material.

Abstract: A method for evaluating a cutting arrangement for a drill bit includes selecting a cutting element arrangement for the drill bit and calculating a score for the cutting arrangement. This method may be used to evaluate the cutting efficiency of various drill bit designs. In one example, this method is used to calculate a score for an arrangement based on a comparison of an expected bottom hole pattern for the arrangement with a preferred bottom hole pattern. The use of this method has lead to roller cone drill bit designs that exhibit reduce tracking over prior art bits.

Abstract: A method for evaluating a cutting arrangement for a drill bit includes selecting a cutting element arrangement for the drill bit and calculating a score for the cutting arrangement. This method may be used to evaluate the cutting efficiency of various drill bit designs. In one example, this method is used to calculate a score for an arrangement based on a comparison of an expected bottomhole pattern for the arrangement with a preferred bottomhole pattern. The use of this method has lead to roller cone drill bit designs that exhibit reduce tracking over prior art bits.

Abstract: A method for designing a roller cone drill bit having a plurality of cutting elements in a row. The method includes defining a pitch pattern for the plurality of cutting elements such that a first group of adjacent cutting elements are arranged in a first pitch and a second group of adjacent cutting elements are arranged in a second pitch in the row; evaluating the pitch pattern of the plurality of cutting elements in the row; and modifying at least one of the plurality of cutting elements, based on the evaluating the pitch pattern of the plurality of cutting elements.

Abstract: A rolling cone drill bit is provided that has gage inserts on the first row from the bit axis to cut to full gage diameter that have a cutting portion enhanced with a layer of super abrasive material. The gage cutting surface has a center axis that is canted to be more normal to the gave curve such that its point of contact at gage is away from the thinner portion of the layer of super abrasive material.

Abstract: A roller cone drill bit is disclosed which includes a bit body adapted to be coupled to a drill string. A bearing journal depends from the bit body. A single roller cone is rotatably attached to the bearing journal. The roller cone has a plurality of inserts disposed at selected positions about the cone. The journal defines a rotation angle with respect to an axis of rotation of the bit such that the roller cone includes a wall contact zone and a bottom contact zone. At least one of the inserts disposed in the wall contact zone has an extension portion terminating in a substantially planar upper surface.

Abstract: A rolling cone drill bit is provided that has gage inserts on the first row from the bit axis to cut to full gage diameter that have a cutting portion enhanced with a layer of super abrasive material. The gage cutting surface has a center axis that is canted to be more normal to the gage curve such that the its point of contact at gage is away from the thinner portion of the layer of super abrasive material.

Abstract: The present invention generally relates to positioning and/or orienting inserts on a gage row and/or a first inner row to optimize the duty among inserts on the gage row and/or insert row of cutting a sidewall and bottom hole of a bore hole such that wear and breakage of inserts are reduced and the life of the bit is enhanced.