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 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.

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 repaired polycrystalline diamond cutter and method for fabricating the same. The cutter includes a damaged substrate that includes at least one void therein, a polycrystalline diamond table coupled to the damaged substrate, and a build-up compound disposed within the voids formed about the damaged substrate. The damaged substrate and the build-up compound collectively form a full circumference. The method includes obtaining a damaged cutter that includes a polycrystalline diamond table coupled to a damaged substrate having at least one void formed therein, bonding a build-up compound within the at least one void and forming a processed PDC cutter, and removing a portion of the build-up compound from the processed PDC cutter and forming the repaired cutter.

Abstract: A retainer and guide ring includes a first ring half and a second ring half that when placed adjacent to one another forms a complete ring. The retainer and guide ring also includes a kerf that is formed between ends of each of the first and second ring halves, which ranges from about zero inches to about 0.010 inches. In some exemplary embodiments, the retainer and guide ring is formed by obtaining two identical rings and making a cut along an edge of the diameter on each ring thereby forming a larger ring arc and a smaller ring arc for each of the rings. The two larger ring arcs are used to form the retainer and guide ring. In another exemplary embodiment, the retainer and guide ring is formed by obtaining a single ring and making a cut along the diameter.

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 choke assembly for controlling air flow into a piston of a percussion tool for downhole drilling includes a choke and a choke adapter. The choke comprises a choke body and a choke opening in the choke body for fluid to flow therethrough. The choke further includes one or more arm slots formed into the choke body between an inner wall of the choke body and an outer wall of the choke body. The one or more arm slots are designed to receive one or more arms of a choke change tool. The choke adapter has an adapter opening extending through the choke adapter. The choke is sized to fit in the adapter opening. The choke is removable from the choke adapter after the choke is inserted into the adapter opening.

Abstract: A post manufacture method and apparatus for reducing residual stresses present within a component. The component includes a substrate, a polycrystalline structure coupled thereto, and residual stresses present therein. The method includes obtaining a component from a component category, determining a critical temperature and a critical time period for the component category at which the component becomes structurally impaired, determining a heat treatment temperature and a heat treatment time period based upon the critical temperature and the critical time period, and heating one or more remaining components from the component category to the heat treatment temperature for the heat treatment time period. The apparatus includes a heater defining a heating chamber and a molten bath positioned within the heating chamber. The components are placed within the pre-heated molten bath and isolated from oxygen during heating to the heat treatment temperature for the heat treatment time period.