Abstract: A rotary drag bit for drilling subterranean formations includes a bit body having a face extending from a centerline to a gage. A plurality of blades may be disposed on the face, and may generally extend radially outwardly toward the gage. The bit may further include a plurality of discrete impregnated cutting posts, each of which may extend outwardly from an associated blade. Each discrete impregnated cutting post angles generally toward a front edge of the associated blade and generally toward the intended direction of rotation of the bit. The rotary drag bit may further include a plurality of matrix pockets disposed on the blades. The discrete impregnated cutting posts may be housed within corresponding matrix pockets.

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 the tool crown and a distal end remote from the tool crown.

Abstract: Systems, program product, and methods are provided which include analyzing the drillability of a subterranean formation and a database of performance characteristics for drilling bits to facilitate bit design optimization and selection for that formation. Using component subterranean formation data, computer models can be generated for the drillability of a target section in terms of physical, mechanical, and micro-structural properties, and for postulated suitable drilling bit performance characteristics based on physical, mechanical, and micro-structural properties of the target section. The drilling bit performance characteristics are then updated by quantifying effects of the drilling system to be employed. Each performance characteristic can be normalized and plotted on its own axis for easy comparison. Next, a candidate drilling bit design is selected from a library of computer models of drilling bit characteristics for a suite of drilling bit designs.

Abstract: A rotary drag bit includes a primary cutter row comprising at least one primary cutter mounted on a blade, at least some cutters in the primary cutter row having a portion of a cutting surface thereof covered by a portion of the blade. A backup cutter row comprising at least one cutter may also be included, and at least a portion of a cutting surface of at least some cutters in the backup cutter row is covered by a portion of the blade. Enhanced support for cutters is provided against impact loading.

Abstract: A drill bit includes a bit body having a face on which two different types of cutters are disposed, the first type being cutting elements suitable for drilling at least one subterranean formation and the second type being at least one of an abrasive cutting structure and an abrasive cutting element suitable for drilling through a casing shoe, reamer shoe, casing bit, casing or liner string and cementing equipment or other components, as well as cement. Methods of forming earth-boring tools include disposing at least one abrasive cutting structure or element on the earth-boring tool. Methods of drilling with earth-boring tools including drilling with at least one abrasive cutting structure or element.

Abstract: A rotary drilling apparatus and method for drilling subterranean formations, including a body being provided with at least one cutter thereon exhibiting reduced, or limited, exposure to the formation, so as to control the depth-of-cut of the at least one cutter, so as to control the volume of formation material cut per rotation of the drilling apparatus, as well as to control the amount of torque experienced by the drilling apparatus and an optionally associated bottomhole assembly regardless of the effective weight-on-bit are all disclosed. The exterior of the drilling apparatus may include a plurality of blade structures carrying at least one such cutter thereon and including a sufficient amount of bearing surface area to contact the formation so as to generally distribute an additional weight applied to the drilling apparatus against the bottom of the borehole without exceeding the compressive strength of the formation rock.

Abstract: A rotary drilling apparatus and method for drilling subterranean formations, including a body being provided with at least one cutter thereon exhibiting reduced, or limited, exposure to the formation, so as to control the depth-of-cut of the at least one cutter, so as to control the volume of formation material cut per rotation of the drilling apparatus, as well as to control the amount of torque experienced by the drilling apparatus and an optionally associated bottomhole assembly regardless of the effective weight-on-bit are all disclosed. The exterior of the drilling apparatus may include a plurality of blade structures carrying at least one such cutter thereon and including a sufficient amount of bearing surface area to contact the formation so as to generally distribute an additional weight applied to the drilling apparatus against the bottom of the borehole without exceeding the compressive strength of the formation rock.

Abstract: Earth-boring tools include wear-resistant materials disposed in at least one recess formed in an exterior surface of a body thereof. Exposed surfaces of the wear-resistant material are substantially level with exterior surfaces of the body adjacent the wear-resistant material. In some embodiments, recesses may be formed in formation-engaging surfaces of blades of earth-boring rotary tools, adjacent one or more inserts secured to bodies of earth-boring tools, or adjacent one or more cutting elements secured to bodies of earth-boring tools. Methods of forming earth-boring tools include filling one or more recesses formed in an exterior surface of a body with wear-resistant material and causing exposed surfaces of the wear-resistant material to be substantially level with the exterior surface of the body.

Abstract: A rotary drilling apparatus and method for drilling subterranean formations, including a body being provided with at least one cutter thereon exhibiting reduced, or limited, exposure to the formation, so as to control the depth-of-cut of the at least one cutter, so as to control the volume of formation material cut per rotation of the drilling apparatus, as well as to control the amount of torque experienced by the drilling apparatus and an optionally associated bottomhole assembly regardless of the effective weight-on-bit are all disclosed. The exterior of the drilling apparatus may include a plurality of blade structures carrying at least one such cutter thereon and including a sufficient amount of bearing surface area to contact the formation so as to generally distribute an additional weight applied to the drilling apparatus against the bottom of the borehole without exceeding the compressive strength of the formation rock.

Abstract: A drill bit includes a bit body having a face on which two different types of cutters are disposed, the first type being cutting elements suitable for drilling at least one subterranean formation and the second type being at least one of an abrasive cutting structure and an abrasive cutting element suitable for drilling through a casing shoe, reamer shoe, casing bit, casing or liner string and cementing equipment or other components, as well as cement. Methods of forming earth-boring tools include disposing at least one abrasive cutting structure or element on the earth-boring tool. Methods of drilling with earth-boring tools including drilling with at least one abrasive cutting structure or element.

Abstract: A drill bit includes a bit body having a face on which two different types of cutters are disposed, the first type being cutting elements suitable for drilling at least one subterranean formation and the second type being at least one of an abrasive cutting structure and an abrasive cutting element suitable for drilling through a casing shoe, reamer shoe, casing bit, casing or liner string and cementing equipment or other components, as well as cement. Methods of forming earth-boring tools are also disclosed.

Abstract: A rotary drilling apparatus and method for drilling subterranean formations, including a body being provided with at least one cutter thereon exhibiting reduced, or limited, exposure to the formation, so as to control the depth-of-cut of the at least one cutter, so as to control the volume of formation material cut per rotation of the drilling apparatus, as well as to control the amount of torque experienced by the drilling apparatus and an optionally associated bottomhole assembly regardless of the effective weight-on-bit are all disclosed. The exterior of the drilling apparatus may include a plurality of blade structures carrying at least one such cutter thereon and including a sufficient amount of bearing surface area to contact the formation so as to generally distribute an additional weight applied to the drilling apparatus against the bottom of the borehole without exceeding the compressive strength of the formation rock.

Abstract: A rotary drag bit includes a primary cutter row comprising at least one primary cutter mounted on a blade, at least some cutters in the primary cutter row having a portion of a cutting surface thereof covered by a portion of the blade. A backup cutter row comprising at least one cutter may also be included, and at least a portion of a cutting surface of at least some cutters in the backup cutter row is covered by a portion of the blade. Enhanced support for cutters is provided against impact loading.

Abstract: A rotary drag bit includes a primary cutter row comprising at least one primary cutter and a multiple backup cutter group. The multiple backup cutter group comprises a first and second trailing cutter row, each comprising at least one cutter positioned to follow the at least one primary cutter. The rotary drag bit life is extended by the multiple backup cutter groups making the bit more durable and extending the life of the cutters. Further, the cutters of the multiple backup cutter group are configured to selectively engage a subterranean formation material being drilled, providing improved bit life and reduced stress upon the cutters. Other embodiments of rotary drag bits are provided.

Abstract: A drill bit having a bit body includes a blade face surface on at least one blade extending longitudinally and radially outward over a face of the bit body. The blade face surface of the at least one blade includes a contact zone and a sweep zone. The sweep zone rotationally trails the contact zone with respect to a direction of intended bit rotation about a longitudinal axis of the bit body provides reduce rubbing contact when engaging with a subterranean formation.

Abstract: An earth-boring bit comprising a bit body configured at its upper extent for connection into a drillstring. A selected number of fixed blades extend downward from the bit body and a selected number of rolling cutters are mounted for rotation on the bit body. A plurality of rolling-cutter cutting elements are arranged on each rolling cutter and a plurality of fixed-blade cutting elements are arranged on each fixed blade. The selected number of fixed blades exceeds the selected number of rolling cutters by at least one.

Abstract: A rotary drilling apparatus and method for drilling subterranean formations, including a body being provided with at least one cutter thereon exhibiting reduced, or limited, exposure to the formation, so as to control the depth-of-cut of the at least one cutter, so as to control the volume of formation material cut per rotation of the drilling apparatus, as well as to control the amount of torque experienced by the drilling apparatus and an optionally associated bottomhole assembly regardless of the effective weight-on-bit are all disclosed. The exterior of the drilling apparatus may include a plurality of blade structures carrying at least one such cutter thereon and including a sufficient amount of bearing surface area to contact the formation so as to generally distribute an additional weight applied to the drilling apparatus against the bottom of the borehole without exceeding the compressive strength of the formation rock.

Abstract: A rotary drag bit for drilling subterranean formations and a method of forming a rotary drag bit for drilling subterranean formations comprising a bit body having a face extending from a centerline to a gage; a plurality of blades on the face generally extending radially outwardly toward the gage; and a plurality of discrete impregnated cutting posts; wherein each discrete impregnated cutting post extends outwardly from an associated one of the plurality of blades; and wherein each discrete impregnated cutting post angles generally towards a front edge of the associated blade of the discrete impregnated cutting post and generally towards the direction of rotation of the rotary drag bits. The rotary drag bit may further comprise a plurality of matrix pockets disposed on the plurality of blades, wherein the discrete impregnated cutting posts may be housed within one of the plurality of matrix pockets.

Abstract: A rotary drag bit includes a primary cutter row comprising at least one primary cutter, and at least two additional cutters configured relative to one another. In one embodiment, the cutters are backup cutters of a backup cutter group located in respective first and second trailing cutter rows, oriented relative to one another, and positioned to substantially follow the at least one primary cutter. The rotary drag bit life is extended by the backup cutter group, making the bit more durable and extending the life of the cutters. In other of the embodiments, the cutters are configured to selectively engage a subterranean formation material being drilled, providing improved bit life and reduced stress upon the cutters. Still other embodiments of rotary drag bits include backup cutter configurations having different backrake angles and siderake angles, including methods therefor.

Abstract: Systems, program product, and methods are provided which include analyzing the drillability of a subterranean formation and a database of performance characteristics for drilling bits to facilitate bit design optimization and selection for that formation. Using component subterranean formation data, computer models can be generated for the drillability of a target section in terms of physical, mechanical, and micro-structural properties, and for postulated suitable drilling bit performance characteristics based on physical, mechanical, and micro-structural properties of the target section. The drilling bit performance characteristics are then updated by quantifying effects of the drilling system to be employed. Each performance characteristic can be normalized and plotted on its own axis for easy comparison. Next, a candidate drilling bit design is selected from a library of computer models of drilling bit characteristics for a suite of drilling bit designs.