Abstract: In one aspect, the invention provides a method for modeling the performance of a fixed cutter bit drilling an earth formation. In one embodiment, the method includes selecting a drill bit and an earth formation to be represented as drilled, simulating the bit drilling the earth formation, displaying the simulating, and adjusting at least one parameter affecting the performance. The method of design is used to make a fixed cutter drill bit. In another embodiment the method includes numerically rotating the bit, calculating bit interaction with the earth formation during the rotating, and determining the forces on the cutters during the rotation based on the calculated interaction with earth formation and empirical data.

Abstract: A bottom hole assembly containing a drill bit. The drill bit additionally has a plurality of primary cutter elements mounted thereto. The plurality of cutter elements comprise one or more first cutter elements and one or more second cutter elements. The second cutter element differs from the first cutter element in at least one cutter element property. The first cutter element has a diamond body containing a first region comprising an infiltrant material disposed within the interstitial regions. The first region is located remote from the working surface of the diamond body. The first cutter element also contains a second region comprising interstitial regions that are substantially free of the infiltrant material. The second region is located along at least the working surface of the diamond body. Also included are a cutter element, method of designing a bottom hole assembly as well as method of designing a drill bit.

Abstract: An improved cutter for fixed cutter drill bits includes a base portion with a longitudinal axis that extends through a center of the base portion and a cutting face which is generally centered with the base portion. The cutting face has a periphery edge geometry comprising a first arcuate segment and a second arcuate segment spaced apart and arranged opposite each other with linear edge segments disposed there between forming sides of the cutting face. The cutting face spans a maximum edge-to-edge dimension L in a first direction that corresponds to a major axis of the cutting face. The cutting face spans a maximum edge-to-edge dimension W in a second direction, which is perpendicular to the first direction, and W is less than L.

Abstract: Self relieving seals of this invention comprise an elastomeric seal body having a first sealing surface and a second sealing surface for contact with respective drill bit sealing surfaces. The seal includes a pair of external surfaces that each extend along the seal body between the first and second sealing surfaces. The seal includes one or more relief ports that are disposed through the seal body and that have openings through each of the seal body external surfaces. The relief port can be specially configured, e.g., have different diameter sections of constant or variable dimensions, to provide a degree of control over pressure equalization through the seal body when the seal is loaded within the drill bit. The seal may include an element, e.g., solid, tubular, or porous, disposed within the relief port to provide a further desired degree of control over pressure equalization through the seal when the seal is loaded within the drill bit.

Abstract: Disclosed within is a drill bit with a plural set of blades having redundant cutter elements and single sets of blades having unique cutter element arrangements. The redundant cutter elements have equivalent longitudinal and axial spacing as corresponding cutter elements. The distance from a longitudinal axis of the bit to a redundant cutter element is equivalent to the distance from the longitudinal axis to the corresponding cutter element.

Abstract: A drill bit for drilling a borehole in earthen formations. In an embodiment, the bit comprises a bit body having a bit axis and a bit face. In addition, the bit comprises a pin end extending from the bit body opposite the bit face. Further, the bit comprises a plurality of gage pads extending from the bit body, wherein each gage pad includes a radially outer gage-facing surface. The gage-facing surfaces of the plurality of gage pads define a gage pad circumference that is centered relative to a gage pad axis, the gage pad axis being substantially parallel to the bit axis and offset from the bit axis.

Abstract: Self relieving seals of this invention comprise an elastomeric seal body having a first sealing surface and a second sealing surface for contact with respective drill bit sealing surfaces. The seal includes a pair of external surfaces that each extend along the seal body between the first and second sealing surfaces. The seal includes one or more relief ports that are disposed through the seal body and that have openings through each of the seal body external surfaces. The relief port can be specially configured, e.g., have different diameter sections of constant or variable dimensions, to provide a degree of control over pressure equalization through the seal body when the seal is loaded within the drill bit. The seal may include an element, e.g., solid, tubular, or porous, disposed within the relief port to provide a further desired degree of control over pressure equalization through the seal when the seal is loaded within the drill bit.

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: Self relieving seals of this invention comprise an elastomeric seal body having a first sealing surface and a second sealing surface for contact with respective drill bit sealing surfaces. The seal includes a pair of external surfaces that each extend along the seal body between the first and second sealing surfaces. The seal includes one or more relief ports that are disposed through the seal body and that have openings through each of the seal body external surfaces. The relief port can be specially configured, e.g., have different diameter sections of constant or variable dimensions, to provide a degree of control over pressure equalization through the seal body when the seal is loaded within the drill bit. The seal may include an element, e.g., solid, tubular, or porous, disposed within the relief port to provide a further desired degree of control over pressure equalization through the seal when the seal is loaded within the drill bit.

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 rotary cutter mount for an earth-boring cutter includes a bearing journal adapted to be coupled to a cutter body. A first mounting end of the bearing journal is shaped to enable rotationally fixed positioning in a corresponding yoke. The yoke is operatively coupled to the body of the cutter. A ball race is formed in an exterior surface of the journal. A ball loading passage is formed in the journal. The ball loading passage has an exit hole on the race. The hole is positioned so that it is disposed in a rotary orientation which is at a selected angular displacement from the maximum radial loading on the journal. The first mounting end and the corresponding yoke are adapted to enable a plurality of rotary orientations. Each of the rotary orientations is such that the hole is oriented other than in the direction of maximum radial loading.

Abstract: Self relieving seals of this invention comprise an elastomeric seal body having a first sealing surface and a second sealing surface for contact with respective drill bit sealing surfaces. The seal includes a pair of external surfaces that each extend along the seal body between the first and second sealing surfaces. The seal includes one or more relief ports that are disposed through the seal body and that have openings through each of the seal body external surfaces. The relief port can be specially configured, e.g., have different diameter sections of constant or variable dimensions, to provide a degree of control over pressure equalization through the seal body when the seal is loaded within the drill bit. The seal may include an element, e.g., solid, tubular, or porous, disposed within the relief port to provide a further desired degree of control over pressure equalization through the seal when the seal is loaded within the drill bit.

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 a canister or the like, which can be provided with a venting as desired.

Abstract: A rotary cutter mount for an earth-boring cutter includes a bearing journal adapted to be coupled to a cutter body. A first mounting end of the bearing journal is shaped to enable rotationally fixed positioning in a corresponding yoke. The yoke is operatively coupled to the body of the cutter. A ball race is formed in an exterior surface of the journal. A ball loading passage is formed in the journal. The ball loading passage has an exit hole on the race. The hole is positioned so that it is disposed in a rotary orientation which is at a selected angular displacement from the maximum radial loading on the journal. The first mounting end and the corresponding yoke are adapted to enable a plurality of rotary orientations. Each of the rotary orientations is such that the hole is oriented other than in the direction of maximum radial loading.

Abstract: A rotary drill bit for boring a bore hole in an earthen formation includes a bit body having a pin end, a cutting end and a longitudinal axis and including at least two legs extending from the cutting end. Each of the legs includes a leading side surface, a trailing side surface, and a shoulder, and each of the legs further includes a bearing and a cutter cone rotatably supported on the bearing. The bit body further including a fluid flow system that includes a flowway in the pin end. The flowway is in fluid communication with at least one exit port in the cutting end. The bit body further includes a neck between the shoulders and the pin end and a hard, wear-resistant material on at least a portion of the neck.

Abstract: A roller cone drill bit is disclosed which includes a bit body having at least one leg depending from the bit body. The leg has a journal formed on it at a lower end. The bit body includes an air channel extending at least from an interior of the bit body to the seal area of the journal. A roller cone is sealingly, rotatably mounted on the journal. The cone has a plurality of cutting elements disposed on it. The bit includes a backflow valve disposed in the bit body, so that an intake end of the air channel is disposed upstream of the backflow valve. In one embodiment, the backflow valve is disposed in a connection end of the bit body, and the air channel includes a flow tube extending from the air passage in the bit body to the backflow valve so that its intake end is upstream of the backflow valve.

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 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.

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 can be pressured-balanced with fluid in the bit plenum or the borehole annulus, or maintained at some desired differential with respect to either 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.