Abstract: A drill bit includes a bit body; a plurality of gouging cutters rotatably mounted to the bit body so as to define a first profile; and a plurality of gouging cutters non-rotatably mounted to the bit body so as to define a second profile. The first profile is longitudinally ahead of the second profile in a direction of drilling of the drill bit by a selected distance.

Abstract: A reaming tool includes a reaming tool body configured to be coupled within a drill string or a string of drilling tools. A plurality of reaming blocks is attached to the reaming tool body at circumferentially spaced apart locations. At least one reaming block comprises at least a first row of gouging cutters and a second row of gouging cutters. The gouging cutters in the first row define a first profile. The gouging cutters in the second row define a second profile. The first row is rotationally ahead of the second row. The first profile at any longitudinal position along the at least one reaming block defines a larger reaming diameter than the second profile.

Abstract: A drill bit includes a bit body; a plurality of gouging cutters rotatably mounted to the bit body so as to define a first profile; and a plurality of gouging cutters non-rotatably mounted to the bit body so as to define a second profile. The first profile is longitudinally ahead of the second profile in a direction of drilling of the drill bit by a selected distance.

Abstract: A reaming tool includes a reaming tool body configured to be coupled within a drill string or a string of drilling tools. A plurality of reaming blocks is attached to the reaming tool body at circumferentially spaced apart locations. Each reaming block comprises at least one row of shear cutters and gouging cutters, the gouging cutters in the at least one row disposed rotationally ahead of the shear cutters in the at least one row.

Abstract: A reaming tool includes a reaming tool body configured to be coupled within a drill string or a string of drilling tools. A plurality of reaming blocks is attached to the reaming tool body at circumferentially spaced apart locations. Each reaming block comprises at least one row of shear cutters and gouging cutters, the gouging cutters in the at least one row disposed rotationally ahead of the shear cutters in the at least one row.

Abstract: A mill includes a mill body defining a plurality of blades extending in a direction from a center or rotation of the mill body to a gauge surface. The blades define a cutting profile having a minimum diameter at a longitudinal endmost position. The minimum diameter is smaller than a diameter of a drop ball. The cutting profile has an intermediate diameter at most equal to the diameter of the drop ball at a longitudinal distance from the endmost position greater than the diameter of the drop ball. Shear cutters are mounted on at least one of the plurality of blades, mounted such that at least one shear cutter is mounted closer to a center of rotation of the mill body with respect to other cutters mounted to the blades. At least one insert is mounted to the at least one of the plurality of blades rotationally ahead of the shear cutters.

Abstract: A mill includes a mill body defining a plurality of blades extending in a direction from a center or rotation of the mill body to a gauge surface. The blades define a cutting profile having a minimum diameter at a longitudinal endmost position. The minimum diameter is smaller than a diameter of a drop ball. The cutting profile has an intermediate diameter at most equal to the diameter of the drop ball at a longitudinal distance from the endmost position greater than the diameter of the drop ball. Shear cutters are mounted on at least one of the plurality of blades, mounted such that at least one shear cutter is mounted closer to a center of rotation of the mill body with respect to other cutters mounted to the blades. At least one insert is mounted to the at least one of the plurality of blades rotationally ahead of the shear cutters.

Abstract: A drill bit for drilling a borehole in earthen formations comprises a bit body including a cone region, a shoulder region, and a gage region. In addition the bit comprises a first primary blade and a second primary blade. Further, the bit comprises a plurality of primary cutter elements mounted to the first primary blade in different radial positions. Still further, the bit comprises a plurality of primary cutter elements mounted to the second primary blade in different radial positions. Moreover, a first primary cutter element of the plurality of primary cutter elements on the first primary blade and a first primary cutter element of the plurality of primary cutter elements on the second primary blade are each positioned in the cone region and are redundant. The shoulder region has a total cutter redundancy percentage that is less than a total cutter redundancy percentage in the cone region.

Abstract: A PDC cutter including a body formed from a substrate material, an ultrahard layer disposed on the body, and a concave cutting face perpendicular to an axis of the body is disclosed. A PDC cutter including a body formed from a substrate material, an ultrahard layer disposed on the body, and a non-planar cutting face perpendicular to an axis of the body, the cutting face including a circumferential concave portion, and an inner protrusion portion is also disclosed.

Abstract: A PDC cutter includes a body formed from a substrate material, an ultrahard layer disposed on the body, and a concave cutting face perpendicular to an axis of the body. A PDC cutter includes a body formed from a substrate material, an ultrahard layer disposed on the body, and a non-planar cutting face perpendicular to an axis of the body, the cutting face including a circumferential concave portion, and an inner protrusion portion.

Abstract: A polycrystalline diamond compact (“PDC”)cutter includes a cylindrical body formed from a substrate material, an ultrahard layer disposed on the cylindrical body, and a cutting face perpendicular to an axis of the cylindrical body, wherein the cutting face includes two or more lobes and wherein the radius of at least one lobe is between 50 and 90 percent of the radius of the cylindrical body. A PDC cutter includes a substrate, and a cutting face perpendicular to an axis of the substrate, wherein the cross-section of the cutting face comprises multiple lobes, and the cross-section of the substrate is substantially circular.

Abstract: A drill bit for drilling a borehole in earthen formations comprising a bit body having a bit axis and a bit face. In addition, the drill bit comprises a primary blade extending radially along the bit face, the primary blade including a cutter-supporting surface that defines a blade profile in rotated profile view extending from the bit axis to an outer radius of the bit body. The blade profile is continuously contoured and includes a plurality of concave regions. Further, the drill bit comprises a plurality of cutter elements mounted to the cutter-supporting surface of the primary blade. Each cutter element on the primary blade has a forward-facing cutting face with a cutting edge adapted to penetrate and shear the earthen formation.

Abstract: A drill bit for drilling a borehole in earthen formations comprising a bit body having a bit axis and a bit face. In addition, the drill bit comprises a primary blade extending radially along the bit face, the primary blade including a cutter-supporting surface that defines a blade profile in rotated profile view extending from the bit axis to an outer radius of the bit body. The blade profile is continuously contoured and includes a plurality of concave regions. Further, the drill bit comprises a plurality of cutter elements mounted to the cutter-supporting surface of the primary blade. Each cutter element on the primary blade has a forward-facing cutting face with a cutting edge adapted to penetrate and shear the earthen formation.

Abstract: A drill bit for drilling a borehole in earthen formations comprising a bit body having a bit axis and a bit face. In addition, the drill bit comprises a primary blade extending radially along the bit face, the primary blade including a cutter-supporting surface that defines a blade profile in rotated profile view extending from the bit axis to an outer radius of the bit body. The blade profile is continuously contoured and includes a plurality of concave regions. Further, the drill bit comprises a plurality of cutter elements mounted to the cutter-supporting surface of the primary blade. Each cutter element on the primary blade has a forward-facing cutting face with a cutting edge adapted to penetrate and shear the earthen formation.

Abstract: In an embodiment, a drill bit for drilling a borehole comprises a bit body having a bit axis and a bit face. In addition, the drill bit comprises a primary blade extending radially along the bit face. Further, the drill bit comprises a plurality of primary cutter elements mounted to the primary blade. The primary blade is free of backup cutter elements. Still further, the drill bit comprises a secondary blade extending radially along the bit face. Moreover, the drill bit comprises a plurality of primary cutter elements mounted to the secondary blade. In addition, the drill bit comprises a first plurality of backup cutter elements mounted to the secondary blade in a first backup row that trails the primary row. Further, the drill bit comprises a second plurality of backup cutter elements mounted to the secondary blade in a second backup row that trails the first backup row.

Abstract: A drill bit for drilling a borehole comprises a bit body having a bit face. In addition, the drill bit comprises a plurality of primary blades. Further, the drill bit comprises a plurality of primary cutter elements mounted to each primary blade and at least one backup cutter element mounted to each primary blade. Still further, the drill bit comprises a plurality of secondary blades. Moreover, the drill bit comprises a plurality of primary cutter elements mounted to each secondary blade. The ratio of the total number of backup cutter elements mounted to the plurality of primary blades to the total number of backup cutter elements mounted to the plurality of secondary blades is greater than 2.0. Each backup cutter element on each primary blade has substantially the same radial position as one of the primary cutter elements on the same primary blade.

Abstract: A PDC cutter including a body formed from a substrate material, an ultrahard layer disposed on the body, and a concave cutting face perpendicular to an axis of the body is disclosed. A PDC cutter including a body formed from a substrate material, an ultrahard layer disposed on the body, and a non-planar cutting face perpendicular to an axis of the body, the cutting face including a circumferential concave portion, and an inner protrusion portion is also disclosed.

Abstract: A polycrystalline diamond compact (“PDCD”) cutter includes a cylindrical body formed from a substrate material, an ultrahard layer disposed on the cylindrical body, and a cutting face perpendicular to an axis of the cylindrical body, wherein the cutting face includes two or more lobes and wherein the radius of at least one lobe is between 50 and 90 percent of the radius of the cylindrical body. A PDC cutter includes a substrate, and a cutting face perpendicular to an axis of the substrate, wherein the cross-section of the cutting face comprises multiple lobes, and the cross-section of the substrate is substantially circular.

Abstract: A drill bit for drilling a borehole in a formation, the drill bit including a bit body having a bit face including a cone region, a nose region, a shoulder region, and a gage region, at least one disjointed blade disposed on the bit face, the disjointed blade including a first section beginning proximate a central axis of the bit and extending less than full gage, and a second section beginning a selected distance from the central axis and extending to full gage, and a plurality of cutting elements mounted on the at least one disjointed blade is disclosed.

Abstract: A bit having improved dropping tendencies includes a first plurality of cutters in an active region and a second plurality of cutters in a passive region. The second plurality of cutters has unique radial positions with respect to the first plurality of cutters. The first and the second pluralities of cutters also have cutting tips that extend to the primary cutting profile of the bit. A third plurality of cutters is located in the passive region with cutting tips positioned recessed from the primary cutting profile. A forth plurality of cutters is positioned as back up cutters in the active, region and includes cutters positioned in radial locations such that they overlap, when viewed in rotated profile, with cutters in the third plurality of cutters. The fourth plurality of cutters has cutting tips positioned to extend to the primary cutting profile. The cutters on the bit are arranged such that an imbalance force vector exists on the bit when used to drill though earth formation.