Abstract: Casing bits include a crown having a substantially hollow interior. The bit crown has blades over a face portion thereof, the blades including a plurality of cutting elements attached thereto. The bit crown further includes a composite inlay positioned at least within the substantially hollow interior. Casing bits also include case hardened outer surfaces radially outside the drill-out region. Casing bits further include short-substrate cutting elements. Methods of forming a casing bit are also disclosed.

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: An abrasive-impregnated cutting structure for use in drilling a subterranean formation is disclosed. The abrasive-impregnated cutting structure may comprise a plurality of abrasive particles dispersed within a substantially continuous matrix, wherein the abrasive-impregnated cutting structure exhibits an anisotropic wear resistance. One or more of the amount, average size, composition, properties, shape, quality, strength, and concentration of the abrasive particles may vary within the abrasive-impregnated cutting structure. Anisotropic wear resistance may relate to a selected direction, such as, for example, one or more of an expected direction of engagement of the abrasive-impregnated cutting structure with the subterranean formation and an anticipated wear direction. Anisotropic wear resistance of an abrasive-impregnated cutting structure may be configured for forming or retaining a formation-engaging leading edge thereof.

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 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: 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: An earth boring bit has cutting elements arranged to avoid tracking. The bit has a bit body having a bit axis of rotation. First, second and third cones are rotatably mounted to the bit body, each of the cones having a plurality of rows of cutting elements including a heel row and an adjacent row. The heel row of the first cone has at least equal the number of cutting elements as the heel rows of the other cones. The adjacent row of the second cone has at least 90 percent as many cutting elements as the heel row of the first cone. The heel row of the third cone has a pitch that is in the range from 20-50% greater than the heel rows of the first cone.

Abstract: Compacts are oriented in certain places on roller cones of an earth boring bit to increase the number of compacts in certain rows. The compacts that are pressed into holes in rows on the cones. The compacts are of tungsten carbide and have a cutting end axis and a barrel axis. The barrel axis intersects the cutting end axis at an obtuse angle. In one of the cones, the barrel axis of at least some of the compacts is rotated to have less inclination than the barrel axis of the compact nearest to it. The nearest compact may be in the same row or an adjacent row. Also, at least some of the compacts may be asymmetrical, with a cutting end axis that diverges from a barrel axis.

Abstract: Asymmetrical compacts are utilized in certain places on roller cones of an earth boring bit to increase the number of compacts in certain rows. The compacts that are pressed into holes in rows on the cones. The compacts are of tungsten carbide and have a cutting end axis and a barrel axis. The barrel axis intersects the cutting end axis at an obtuse angle. In the heel row, the barrel axis of at least some of the compacts is rotated to have less inclination than the cutting end axis. In an adjacent row to the heel row, each of the compacts has a barrel axis that is rotated to have more inclination than its cutting end axis and more inclination than the barrel axes of the heel row.

Abstract: A rotary drill bit for drilling subterranean formations configured with at least one protective structure proximate to the rotationally leading and trailing edges of a gage trimmer, wherein the at least one protective structure is positioned at substantially the same exposure as its associated gage trimmer. Particularly, the apparatus of the present invention may provide protection for gage trimmers during drilling, tripping, and/or rotation within a casing; i.e., when changing a drilling fluid. Protective structures may be configured and located according to anticipated drilling conditions including helix angles. In addition, a protective structure may be proximate to more than one gage trimmer while having a substantially equal exposure to each associated gage trimmer. Methods of use and a method of rotary bit design are also disclosed.

Abstract: A drill bit employing a plurality of discrete, post-like, abrasive, particulate-impregnated cutting structures extending upwardly from abrasive, particulate-impregnated blades defining a plurality of fluid passages therebetween on the bit face. Additional cutting elements may be placed in the cone of the bit surrounding the centerline thereof. The blades may extend radially in a linear fashion, or be curved and spiral outwardly to the gage to provide increased blade length and enhanced cutting structure redundancy. Additionally, discrete protrusions may extend outwardly from at least some of the plurality of cutting structures. The discrete protrusions may be formed of a thermally stable diamond product and may exhibit a generally triangular cross-sectional geometry relative to the direction of intended bit rotation.

Abstract: Compacts are oriented in certain places on roller cones of an earth boring bit to increase the number of compacts in certain rows. The compacts that are pressed into holes in rows on the cones. The compacts are of tungsten carbide and have a cutting end axis and a barrel axis. The barrel axis intersects the cutting end axis at an obtuse angle. In one of the cones, the barrel axis of at least some of the compacts is rotated to have less inclination than the barrel axis of the compact nearest to it. The nearest compact may be in the same row or an adjacent row. Also, at least some of the compacts may be asymmetrical, with a cutting end axis that diverges from a barrel axis.

Abstract: A rotary drill bit for drilling subterranean formations configured with at least one protective structure proximate to the rotationally leading and trailing edges of a gage trimmer, wherein the at least one protective structure is positioned at substantially the same exposure as its associated gage trimmer. Particularly, the apparatus of the present invention may provide protection for gage trimmers during drilling, tripping, and/or rotation within a casing; i.e., when changing a drilling fluid. Protective structures may be configured and located according to anticipated drilling conditions including helix angles. In addition, a protective structure may be proximate to more than one gage trimmer while having a substantially equal exposure to each associated gage trimmer. Methods of use and a method of rotary bit design are also disclosed.

Abstract: A drill bit employing a plurality of discrete, post-like abrasive particulate-impregnated cutting structures extending upwardly from abrasive particulate-impregnated blades defining a plurality of fluid passages therebetween on the bit face. Additional cutting elements may be placed in the cone of the bit surrounding the centerline thereof. The blades may extend radially in a linear fashion, or be curved and spiral outwardly to the gage to provide increased blade length and enhanced cutting structure redundancy. Additionally, discrete protrusion may extend outwardly from at least some of the plurality of cutting structures. The discrete protrusions may be formed of a thermally stable diamond product and may exhibit a generally triangular cross-sectional geometry relative to the direction of intended bit rotation.

Abstract: Asymmetrical compacts are utilized in certain places on roller cones of an earth boring bit to increase the number of compacts in certain rows. The compacts that are pressed into holes in rows on the cones. The compacts are of tungsten carbide and have a cutting end axis and a barrel axis. The barrel axis intersects the cutting end axis at an obtuse angle. In the heel row, the barrel axis of at least some of the compacts is rotated to have less inclination than the cutting end axis. In an adjacent row to the heel row, each of the compacts has a barrel axis that is rotated to have more inclination than its cutting end axis and more inclination than the barrel axes of the heel row.

Abstract: A drill bit employing a plurality of discrete, post-like diamond grit impregnated cutting structures extending upwardly from abrasive particulate-impregnated blades defining a plurality of fluid passages therebetween on the bit face. PDC cutters with faces oriented in the general direction of bit rotation are placed in the cone of the bit, which is relatively shallow, to promote enhanced drilling efficiency through softer, non-abrasive formations. A plurality of ports, configured to receive nozzles therein are employed for improved drilling fluid flow and distribution. The blades may extend radially in a linear fashion, or be curved and spiral outwardly to the gage to provide increased blade length and enhanced cutting structure redundancy.

Abstract: A cutting assembly comprised of first and second superabrasive cutting elements including at least one rotationally leading cutting element having a cutting face oriented generally in a direction of intended rotation of a bit on which the assembly is mounted to cut a subterranean formation with a cutting edge at an outer periphery of the cutting face, and a rotationally trailing cutting element oriented substantially transverse to the direction of intended bit rotation and including a relatively thick superabrasive table configured to cut the formation with a cutting edge located between a beveled surface at the side of the superabrasive table and an end face thereof. A rotationally trailing cutting element may be associated with and disposed at a location on the bit at least partially laterally intermediate locations of two rotationally leading cutting elements. Drill bits equipped with the cutting assembly are also disclosed.

Abstract: A rock bit has a body and three cutters that include generally conical surfaces, at least one of which contains an outermost, circumferential row of heel teeth that dislodge cuttings from the borehole wall and bottom. The heel teeth form a corner with the borehole wall with successive contact points defined by the path of outer edges of the heel teeth while rotating into, and prescribing, the corner as it spirals downwardly during drilling. The rotational axis of the cutter is offset from the geometric centerline or intended rotational axis of the bit. Stabilizing pads extend outwardly from the body, each concluding in a surface that contains a low-friction, wear-resistant surface that engage the wall of the borehole. The center of each surface is located directly across from the contact point of an opposed cutter.

Abstract: An earth-boring bit has a bit body and at least one cantilevered bearing shaft depending inwardly and downwardly from the bit body. A cutter is mounted for rotation on the bearing shaft and includes a plurality of cutting elements arranged in generally circumferential rows including an outer or heel row of cutting elements. At least one of the cutting elements in the heel row has an outermost surface at least partially formed of super-hard material that defines a cutting edge for shearing engagement with the sidewall of the borehole as the cutters roll and slide over the bottom of the borehole during drilling operations.

Abstract: An earth-boring bit has a bit body and at least a pair of cantilevered bearing shafts depending downwardly and inwardly therefrom. A first cutter is mounted for rotation on one of the bearing shafts and has a region of contact with the sidewall of the borehole. A second cutter is mounted for rotation on another of the bearing shafts and has a region of contact with the sidewall of the borehole that is non-opposite that of the first cutter. Stabilization is provided by a stabilizer pad carried on the bit body and arranged to be opposite the contact regions of the first and second cutters.

Abstract: An earth-boring bit has a bit body and at least one cutter rotatably secured to the bit body. The cutter has a cutter shell surface including a gage surface and a heel surface. A plurality of cutting elements inserts are arranged in generally circumferential rows on the cutter. At least one chisel-shaped cutting element is secured to the gage surface. The chisel-shaped cutting element has a pair of surfaces converging to define a circumferential crest and is tilted toward the heel surface such that a line drawn through the center of the cutting element and its crest defines an acute angle of between about 15 and 75 degrees with the gage surface of the cutter.