Abstract: An earth-boring tool includes a body, a plurality of fixed blades, a first plurality of cutting elements secured to the plurality of fixed blades, a plurality of removable blade assemblies removably coupled to the body, and a second plurality of cutting elements secured to the plurality of removable blade assemblies, each cutting element of the second plurality of cutting elements exhibiting an aggressiveness that is less than an aggressiveness of each cutting element of the first plurality of cutting elements. A method of forming an earth-boring tool includes forming a body and a plurality of fixed blades extending from the body, securing a first plurality of cutting elements to the plurality of fixed blades, removably coupling at least one removable blade assembly to the body, and securing a second plurality of cutting elements to the at least one removable blade assembly.

Abstract: An earth-boring tool includes a body, a plurality of fixed blades, a first plurality of cutting elements secured to the plurality of fixed blades, a plurality of removable blade assemblies removably coupled to the body, and a second plurality of cutting elements secured to the plurality of removable blade assemblies, each cutting element of the second plurality of cutting elements exhibiting an aggressiveness that is less than an aggressiveness of each cutting element of the first plurality of cutting elements. A method of forming an earth-boring tool includes forming a body and a plurality of fixed blades extending from the body, securing a first plurality of cutting elements to the plurality of fixed blades, removably coupling at least one removable blade assembly to the body, and securing a second plurality of cutting elements to the at least one removable blade assembly.

Abstract: An earth-boring tool having at least one cutting element with a multi-friction cutting face provides for the steering of formation cuttings as the cuttings slide across the cutting face. The multi-friction cutting element includes a diamond table bonded to a substrate of superabrasive material. The diamond table has a cutting face formed thereon with a cutting edge extending along a periphery of the cutting face. The cutting face has a first area having an average surface finish roughness less than an average surface finish roughness of a second area of the cutting face, the two areas separated by a boundary having a proximal end proximate a tool crown and a distal end remote from the tool crown.

Abstract: A hybrid earth-boring bit comprising a bit body having a central axis, at least one, preferably three fixed blades, depending downwardly from the bit body, each fixed blade having a leading edge, and at least one rolling cutter, preferably three rolling cutters, mounted for rotation on the bit body. A rolling cutter is located between two fixed blades.

Abstract: Earth-boring rotary drill bits include heel portions exhibiting reduced aggressiveness. Earth-boring rotary drill bits may comprise a bit body and a plurality of roller cones coupled to the bit body. Each roller cone comprises a plurality of rows of cutting elements, and a continuous disk heel located further from an axis of rotation of the roller cone than the at least one row of cutting elements, the continuous disk heel exhibiting a reduced amount of aggressiveness compared to the at least one row of cutting elements.

Abstract: A hybrid earth-boring bit comprising a bit body having a central axis, at least one, preferably three fixed blades, depending downwardly from the bit body, each fixed blade having a leading edge, and at least one rolling cutter, preferably three rolling cutters, mounted for rotation on the bit body. A rolling cutter is located between two fixed blades.

Abstract: Cutting elements include a volume of superabrasive material. The volume of superabrasive material comprises a front-cutting surface, an end-cutting surface, a cutting edge, and lateral side surfaces extending between and intersecting each of the front-cutting surface and the end-cutting surface. An earth-boring tool may comprise a bit body and at least one cutting element attached to the bit body. Methods of forming cutting elements comprise forming a volume of superabrasive material comprising forming a front-cutting surface, an end-cutting surface, a cutting edge, and lateral side surfaces extending between and intersecting each of the front-cutting surface and the end-cutting surface. Methods of forming earth-boring tools comprise forming a cutting element and attaching the cutting element to an earth-boring tool.

Abstract: Cutting elements, earth-boring drill bits having such cutting elements and related methods include a cutting element having a superabrasive table positioned on a substrate, and at least one recessed surface in a cutting face of the superabrasive table.

Abstract: Cutting elements, earth-boring drill bits having such cutting elements and related methods include a cutting element having a superabrasive table positioned on a substrate, and at least one recessed surface in a cutting face of the superabrasive table.

Abstract: Methods of drilling earth formations may involve removing a portion of an underlying earth formation utilizing cutting elements of an earth-boring drill bit. A rotational speed of the drill string may be sensed utilizing a first sensor. A rate of penetration of the drill string during advancement of the earth-boring drill bit may be sensed utilizing a second sensor. An instantaneous average depth of cut of cutting elements of the earth-boring drill bit may be determined utilizing a control unit to calculate the instantaneous average depth of cut based on a sensed rotational speed of the drill string and a sensed speed of advancement of the drill string. The weight on the earth-boring drill bit may be increased utilizing the drawworks when the instantaneous average depth of cut is less than the predetermined minimum depth of cut.

Abstract: Cutting elements for earth-boring tools include one or more recesses and/or one or more protrusions in a cutting face of a volume of superabrasive material. The superabrasive material may be disposed on a substrate. The cutting face may be non-planar. The recesses and/or protrusions may include one or more linear segments. The recesses and/or protrusions may comprise discrete features that are laterally isolated from one another. The recesses and/or protrusions may have a helical configuration. The volume of superabrasive material may comprise a plurality of thin layers, at least two of which may differ in at least one characteristic. Methods of forming cutting elements include the formation of such recesses and/or protrusions in and/or on a cutting face of a volume of superabrasive material. Earth-boring tools include such cutting elements, and methods of forming earth-boring tools include attaching such a cutting element to a tool body.

Abstract: A hybrid earth-boring bit comprising a bit body having a central axis, at least one, preferably three fixed blades, depending downwardly from the bit body, each fixed blade having a leading edge, and at least one rolling cutter, preferably three rolling cutters, mounted for rotation on the bit body. A rolling cutter is located between two fixed blades.

Abstract: An earth-boring rotary tool includes a tool body, at least one fixed blade associated with the tool body and configured to carry a fixed cutting element, and at least one leg configured to carry a rolling cutter. The tool body has a slot extending longitudinally generally parallel to a longitudinal axis defining an axial center of the tool body. The slot is at least partially defined by a first sidewall, a second sidewall opposing the first sidewall, a third sidewall extending between the first sidewall and the second sidewall, and an axial end wall of the tool body. A portion of the leg is disposed within the slot of the tool body and abuts the first sidewall of the tool body. A wedge is disposed within the slot and pins the leg to the tool body within the slot.

Abstract: An earth-boring rotary tool includes a tool body, at least one fixed blade associated with the tool body and configured to carry a fixed cutting element, and at least one leg configured to carry a rolling cutter. The tool body has a slot extending longitudinally generally parallel to a longitudinal axis defining an axial center of the tool body. The slot is at least partially defined by a first sidewall, a second sidewall opposing the first sidewall, a third sidewall extending between the first sidewall and the second sidewall, and an axial end wall of the tool body. A portion of the leg is disposed within the slot of the tool body and abuts the first sidewall of the tool body. A wedge is disposed within the slot and pins the leg to the tool body within the slot.

Abstract: A cutting element for an earth-boring tool includes a volume of superabrasive material having a cutting face and a shaped feature on the cutting face. The shaped feature may include at least one of a recess extending into the volume of superabrasive material from the cutting face and a protrusion extending outward from the cutting face. A first portion of the cutting face may have a first surface roughness, and a second portion of the cutting face may have a second surface roughness greater than the first surface roughness of the first portion of the cutting face. The volume of superabrasive material may be disposed on a substrate. Methods of forming cutting elements may include forming one or more shaped features in a cutting face of the cutting elements. Earth-boring tools may include such cutting elements.

Abstract: Methods of drilling earth formations may involve removing a portion of an underlying earth formation utilizing cutting elements of an earth-boring drill bit. A rotational speed of the drill string may be sensed utilizing a first sensor. A rate of penetration of the drill string during advancement of the earth-boring drill bit may be sensed utilizing a second sensor. An instantaneous average depth of cut of cutting elements of the earth-boring drill bit may be determined utilizing a control unit to calculate the instantaneous average depth of cut based on a sensed rotational speed of the drill string and a sensed speed of advancement of the drill string. The weight on the earth-boring drill bit may be increased utilizing the drawworks when the instantaneous average depth of cut is less than the predetermined minimum depth of cut.

Abstract: Cutting elements, earth-boring drill bits having such cutting elements and related methods include a cutting element having a superabrasive table positioned on a substrate, and at least one recessed surface in a cutting face of the superabrasive table.

Abstract: An earth-boring tool having at least one cutting element with a multi-friction cutting face provides for the steering of formation cuttings as the cuttings slide across the cutting face. The multi-friction cutting element includes a diamond table bonded to a substrate of superabrasive material. The diamond table has a cutting face formed thereon with a cutting edge extending along a periphery of the cutting face. The cutting face has a first area having an average surface finish roughness less than an average surface finish roughness of a second area of the cutting face, the two areas separated by a boundary having a proximal end proximate a tool crown and a distal end remote from the tool crown.

Abstract: Cutting elements include a volume of superabrasive material. The volume of superabrasive material comprises a front-cutting surface, an end-cutting surface, a cutting edge, and lateral side surfaces extending between and intersecting each of the front-cutting surface and the end-cutting surface. An earth-boring tool may comprise a bit body and at least one cutting element attached to the bit body. Methods of forming cutting elements comprise forming a volume of superabrasive material comprising forming a front-cutting surface, an end-cutting surface, a cutting edge, and lateral side surfaces extending between and intersecting each of the front-cutting surface and the end-cutting surface. Methods of forming earth-boring tools comprise forming a cutting element and attaching the cutting element to an earth-boring tool.

Abstract: Earth-boring rotary drill bits include heel portions exhibiting reduced aggressiveness. Earth-boring rotary drill bits may comprise a bit body and a plurality of roller cones coupled to the bit body. Each roller cone comprises a plurality of rows of cutting elements, and a continuous disk heel located further from an axis of rotation of the roller cone than the at least one row of cutting elements, the continuous disk heel exhibiting a reduced amount of aggressiveness compared to the at least one row of cutting elements.