Abstract: A cutter for a drill bit includes: a substrate for mounting the cutter to the drill bit; and a cutting table. The cutting table: is made from a superhard material, is mounted to the substrate, has an interface with the substrate at a lower end thereof, and has a working face at an upper end thereof. The working face has a protruding center section and a plurality of protruding ribs. Each rib extends radially outward from the center section to a side of the cutting table. Each rib has a triangular profile formed by a pair of inclined side surfaces and a ridge connecting opposing ends of the side surfaces. The working face further has a plurality of recessed bases located between adjacent ribs and each extending inward from the side.

Abstract: A completions bit for use in a wellbore includes: a shank having a coupling formed at an upper end thereof; a body mounted to a lower end of the shank; and a cutting face forming a lower end of the bit. The cutting face includes: a blade protruding from the body; a tangentially oriented leading cutter mounted to a bearing face of the blade adjacent to a leading edge of the blade at an inner portion of the cutting face; and a radially oriented leading cutter mounted to the bearing face of the blade in proximity to the leading edge thereof at an outer portion of the cutting face.

Abstract: A bit for drilling a wellbore includes: a shank having a coupling formed at an upper end thereof; a body mounted to a lower end of the shank; and a cutting face forming a lower end of the bit. The cutting face includes: a blade protruding from the body; a leading cutter including: a substrate mounted in a pocket formed in a leading edge of the blade; and a cutting table made from a superhard material and mounted to the substrate; and a shock stud having a nonplanar working portion made from a composite material and mounted in a lower face of the blade at a position trailing the leading cutter. The composite material comprises a ceramic or cermet matrix impregnated with a superhard material.

Abstract: A bit for drilling a wellbore includes: a body; and a cutting face including: a blade protruding from the body; and a row of cutters, each cutter including: a substrate mounted in a pocket formed adjacent to a leading edge of the blade; and a cutting table made from a superhard material, mounted to the substrate, and having a working face. A first subset of the row of cutters is oriented at a negative side rake angle. A second subset of the row of cutters is oriented at a zero or slightly positive side rake angle. The first and the second subsets are alternating. An innermost cutter of the first subset has a maximum absolute value of the negative side rake angle. The absolute value negative side rake angles of the rest of the cutters decrease as their distance from a center of the cutting face increases.

Abstract: A cutter for a drill bit includes: a substrate for mounting the cutter to the drill bit; and a cutting table. The cutting table: is made from a superhard material, is mounted to the substrate, has an interface with the substrate at a lower end thereof, and has a working face at an upper end thereof. The working face has a protruding center section and a plurality of protruding ribs. Each rib extends radially outward from the center section to a side of the cutting table. Each rib has a triangular profile formed by a pair of inclined side surfaces and a ridge connecting opposing ends of the side surfaces. The working face further has a plurality of recessed bases located between adjacent ribs and each extending inward from the side.

Abstract: A system and method of fabricating a percussion tool that includes one or more surfaces modified using the ferritic nitrocarburization process. The percussion tool includes a piston positioned in sliding contact within a casing. The piston includes an inner wall and an outer wall, where the inner wall defines a passageway extending longitudinally therethrough. The outer wall is positioned in close fitting relationship with an internal surface of the casing. One or more surfaces of at least one of the casing's internal surface and/or the piston's outer wall are modified using the ferritic nitrocarburization process.

Abstract: A bit for drilling a wellbore includes: a shank having a coupling formed at an upper end thereof; a body mounted to a lower end of the shank; and a cutting face forming a lower end of the bit. The cutting face includes: a blade protruding from the body; a leading cutter including: a substrate mounted in a pocket formed in a leading edge of the blade; and a cutting table made from a superhard material, mounted to the substrate, and having a non-planar working face with a cutting feature; and a backup cutter mounted in a lower face of the blade at a position trailing the leading cutter and made from a composite material including a ceramic or cermet matrix impregnated with a superhard material.

Abstract: A method for drilling out a plug includes directing a hybrid rotary cone drill bit having a plurality of rotary cones into a borehole lined with a casing. A body of the plug is drilled out using milled teeth formed in the hybrid rotary cone drill bit. A slip of the plug is drilled out using cutter inserts secured into the rotary cone where the slip contacts the casing. The drilled out plug is directed up the borehole using a drilling fluid.

Abstract: A bit for drilling a wellbore, includes: a bit body; and a cutting face having an inner cone section and an outer shoulder section. The cutting face includes: a plurality of blades protruding from a bottom of the bit body, each blade extending from a center of the cutting face to the shoulder section; and a plurality of shear cutters mounted along leading edges of the blades. An inner shear cutter of each blade is located in the cone section. Each inner shear cutter includes: a superhard cylindrical cutting table; and a hard substrate having a cylindrical portion attached to the cutting table and a reduced portion extending therefrom. A diameter of the cutting table and the cylindrical portion is greater than a diameter of a majority of the reduced portion. A length of the reduced portion is at least twice that of the cylindrical portion.

Abstract: A bit for downhole use includes: a leg having a mid shirttail and a lower bearing shaft; a roller cone rotatably mounted to the bearing shaft; a row of gage cutters, a row of inner cutters, and a nose cutter, each cutter mounted to or formed on the roller cone; and a gland formed in an inner surface of the roller cone. The gland has: a face; an outer surface; a fillet connected to the outer surface; a corner connecting the face and the outer surface; and an elastomeric o-ring captured in the gland and squeezed between the outer surface and the bearing shaft. A radius of the fillet is greater than one-half of a cross-sectional diameter of the o-ring.

Abstract: A bit for drilling with a casing or liner string includes: a tubular stem made from a high strength metal or alloy; a head: having a cutting face with an inner cone, an outer shoulder, and an intermediate nose between the cone and the shoulder; attached to an end of the stem; and made from a nonferrous metal or alloy; a plurality of blades formed integrally with the head, made from the nonferrous metal or alloy, and each extending from a center of the cutting face to the shoulder; a plurality of superhard cutters mounted along each blade; a plurality of gauge pads formed integrally with the stem; and a flush joint formed between each blade and a respective gauge pad. A yield strength of the high strength metal or alloy is at least twice a yield strength of the nonferrous metal or alloy.

Abstract: A rock bit for blast hole drilling includes: a bit body having a coupling formed at an upper end thereof, a plurality of lower legs, a dome formed between the legs, and a bore formed through the coupling and the dome; a plurality of skirts, each skirt covering a gap formed between adjacent legs and each skirt mounted to edges of adjacent legs; a plurality of roller cones, each rotary cone rotatably mounted to a respective bearing shaft of a respective leg; a row of gage cutters mounted to each roller cone; a row of inner cutters mounted to each roller cone; one or more nose cutters mounted to each roller cone; and a center jet secured in the bore. Each cutter is an insert.

Abstract: A hybrid bit for use in a wellbore includes: a body having a shank for connection to a drilling motor or drill pipe and a plurality of legs attached to the shank; and a plurality of cutting structures. The cutting structures include a roller cone mounted to a first one of the legs and a fixed mill mounted to a second one of the legs and including a pad dressed with a cermet material.

Abstract: A method for testing thermal fatigue resistance of a shear cutter includes: engaging the shear cutter with a rotating target cylinder; moving the shear cutter along the rotating target cylinder until the shear cutter is heated to a threshold temperature; cooling the shear cutter in response to heating of the shear cutter to the threshold temperature; and repeating the heating and cooling of the shear cutter.

Abstract: A method of manufacturing a roller cone for a drill bit includes: selectively carburizing a land of the roller cone between a plurality of spots on the land for protection against erosion; after carburization, forming sockets in the roller cone at the spots; and mounting cermet inserts in the sockets.

Abstract: A system and method of fabricating a percussion tool that includes one or more surfaces modified using the ferritic nitrocarburization process. The percussion tool includes a piston positioned in sliding contact within a casing. The piston includes an inner wall and an outer wall, where the inner wall defines a passageway extending longitudinally therethrough. The outer wall is positioned in close fitting relationship with an internal surface of the casing. One or more surfaces of at least one of the casing's internal surface and/or the piston's outer wall are modified using the ferritic nitrocarburization process.

Abstract: A drill bit for drilling a hole in an earth formation includes a bit body and a blade extending from the bit body. The blade has a leading section, a top section, and a plurality of transition sections extending between the leading section and the top section. The drill bit further includes a plurality of cutters. Each cutter is positioned in a respective cutter pocket formed in the blade. Each cutter extends beyond the top section of the blade, and each transition section of the blade is between adjacent cutter pockets. The drill bit further includes a plurality of abrasion resistant inserts. Each abrasion resistant insert is positioned in a respective insert pocket formed in the blade. The plurality of abrasion resistant inserts are designed to cut into an earth formation. At least a portion of each abrasion resistant insert is disposed at a respective transition section of the blade.

Abstract: A method for testing thermal fatigue resistance of a shear cutter includes: engaging the shear cutter with a rotating target cylinder; moving the shear cutter along the rotating target cylinder until the shear cutter is heated to a threshold temperature; cooling the shear cutter in response to heating of the shear cutter to the threshold temperature; and repeating the heating and cooling of the shear cutter.

Abstract: A mill-drill cutter for an earth boring bit includes a cutting structure secured to a substrate. The cutting structure has a drilling edge, and the substrate has a milling edge. The substrate is configured to be received in a cutter pocket of the earth boring bit. The drilling edge of the cutting structure is disposed radially internal to the milling edge of the substrate.

Abstract: A method of manufacturing a roller cone for a drill bit includes: selectively carburizing a land of the roller cone between a plurality of spots on the land for protection against erosion; after carburization, forming sockets in the roller cone at the spots; and mounting cermet inserts in the sockets.