Abstract: Earth-boring tools comprise a shank comprising a distal connector including a set of threads thereon and a bit body comprising a shank connector, also comprising at least one set of threads thereon. The set of threads on the distal connector and the at least one set of threads on the shank connector are at least substantially bound together. Methods of forming such earth-boring tools are also disclosed, as well as methods of securing a bit body of an earth-boring tool to a shank.

Abstract: A drill bit having a selected gauge diameter and operable to be positioned within a casing positioned within a rock formation, the casing comprising an casing inner wall having a casing inner diameter greater than the gauge diameter, wherein the positioning of the drill bit within the casing defines a drift distance corresponding to the distance between the gauge diameter and the casing inner diameter, the drill bit comprising a blade comprising a gauge cutter operable to cut an earth formation at the gauge diameter; and a protective insert coupled the drill bit such that a portion of the protective insert extends beyond the gauge diameter by a selected overgauge distance, wherein the protective insert is operable to engage the casing inner wall to substantially prevent the gauge cutter from engaging the casing inner wall as the drill bit is positioned through a selected length of the casing.

Abstract: A drill bit system for a drilling assembly is disclosed. The drill bit system may include a chassis, a head, and one or more gauge pads. The head may include a first plurality of cutters coupled with an end of the head, and the head may be coupled with chassis. The one or more gauge pads may include a second plurality of cutters, and the one or more gauge pads may be movably coupled with the chassis.

Abstract: A drill bit system for a drilling assembly is disclosed. The drill bit system may include a chassis, a head, and a first plurality of gauge pads. The head may include a first plurality of cutters coupled with an end of the head, and the head may be movably coupled with chassis. The first plurality of gauge pads may include a second plurality of cutters, and the first plurality of gauge pads may be fixedly coupled with the chassis.

Abstract: A drill bit system for a drilling assembly is disclosed. The drill bit system may include a chassis, a head, and a first plurality of gauge pads. The chassis may be configured to be operably coupled with a first rotational motion source. The head may include a first plurality of cutters coupled with an end of the head, and the head may be rotatably coupled with chassis. The head may be configured to be operably coupled with a second rotational motion source. The first plurality of gauge pads may include a second plurality of cutters, and the first plurality of gauge pads may be fixedly coupled with the chassis.

Abstract: A drill bit stabilizing system comprising a body member having an axis and at least one recess formed in the body member housing at least one stabilizing member when in a first retracted position. The stabilizing member is positionable along a diagonal angle with the axis to a second extended operating position which extends downward and outward relative to the main body to selectively engage the surface of a pilot bore hole wall during a drilling operation so as to stabilize an under gauge drill bit used in association with the stabilizing system. The body member further comprises at least one fixed stabilizing surface positioned in an axially spaced relationship to the at least one moveable stabilizing member. The body member further comprises a gauge cutter positioned above the moveable stabilizing member and below the fixed stabilizing surface to expand the pilot hole to the final gauge.

Abstract: A hole coring system for drilling large diameter holes with a handheld tool. The drill bit is guided by a mandrel attached to the concrete and serves as a central guidepost that ensures precise centering of the drill bit. Commonly available tools may be used to rotate the drill bit. A lever arm may be attached to the tool and used to resist any torquing action. Additionally, a brace may be attached to the lever arm which may be used to resist any torquing action.

Abstract: Earth-boring tools comprise a bit body comprising a face and a plurality of blades extending radially outward over the face and forming gage regions. A shank is coupled to the bit body and includes a threaded portion for connecting to a drill string. A sleeve structure is positioned adjacent to the bit body and surrounds a portion of the shank, the sleeve structure extending from adjacent the bit body to proximate the threaded portion of the shank. An outer surface of the sleeve structure comprises a plurality of circumferentially spaced gage pads extending thereover and may comprise a plurality of breaker flats.

Abstract: An apparatus for drilling holes in a substrate wherein a mandrel is anchored to the substrate. A hollow drill bit rotates about the mandrel via a drive motor and is a guided along a length of the mandrel.

Abstract: The invention provides a fixed cutter drill bit for drilling through unconsolidated, highly abrasive formations. The bit includes a bit body having a cutting face and a side portion. The bit body comprising carbide matrix material. A plurality of blades azimuthally spaced about the cutting face and a plurality of cutters disposed along the blades. At least one gage pad is disposed along a side of the bit body and includes wear resistant gage elements formed of a material more wear resistant than the matrix material forming a portion of the gage pad. The wear resistant elements have a rounded surface and are embedded in gage pad material proximal a leading edge of the gage pad to provide a rounded wear-resistant edge or surface proximal the leading edge.

Abstract: A rolling cone rock bit includes a plurality of PDC or other cutters mounted to the leg of the drill bit and positioned to cut the corner of the bottomhole. The plurality of cutters may be the primary cutting component at gage diameter, or may be redundant to gage teeth on a rolling cutter that cut to gage diameter. Consequently, the occurrence of undergage drilling from the wear and failure of the gage row on a rolling cutter is lessened. Also included is a mud ramp that creates a large junk slot from the borehole bottom up the drill bit. The resulting pumping action of the drill bit ramp speeds up the removal of chips or drilling cuttings from the bottom of the borehole, reduces the level of hydrostatic pressure at the bottom of the borehole and minimizes the wearing effect of cone inserts regrinding damaging drill cuttings.

Abstract: The invention provides a fixed cutter drill bit for drilling through unconsolidated, highly abrasive formations. The bit includes a bit body having a cutting face and a side portion. The bit body comprising carbide matrix material. A plurality of blades azimuthally spaced about the cutting face and a plurality of cutters disposed along the blades. At least one gage pad is disposed along a side of the bit body and includes wear resistant gage elements formed of a material more wear resistant than the matrix material forming a portion of the gage pad. The wear resistant elements have a rounded surface and are embedded in gage pad material proximal a leading edge of the gage pad to provide a rounded wear-resistant edge or surface proximal the leading edge.

Abstract: A drilling device for producing undercut holes. The drilling device includes a drilling tool having an axis of rotation and a cutting portion arranged such that the cutting portion drills a hole with a longitudinal axis that is radially offset with respect to said axis of rotation and a centering device operable to apply a lateral force to said drilling tool for moving said axis of rotation towards said longitudinal axis to cause said cutting portion to form an undercut in a said hole.

Abstract: A drill bit stabilizing system comprising a body member having an axis and at least one recess formed in the body member housing at least one stabilizing member when in a first retracted position. The stabilizing member is positionable along a diagonal angle with the axis to a second extended operating position which extends downward and outward relative to the main body to selectively engage the surface of a pilot bore hole wall during a drilling operation so as to stabilize an under gauge drill bit used in association with the stabilizing system. The body member further comprises at least one fixed stabilizing surface positioned in an axially spaced relationship to the at least one movable stabilizing member. The body member further comprises a gauge cutter positioned above the moveable stabilizing member and below the fixed stabilizing surface to expand the pilot hole to the final gauge.

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 well borehole is prevented from deviating from its intended vertical path as it is being drilled by use of a sub assembly which is eccentrically weighted with respect to its axis of rotation. Such a sub assembly can comprise a straight tubular member weight relieved along one side by, for example, forming a cavity within the heavy walls of the tubular member along the side of the collar. Thus, the eccentric weight is imposed upon the drill bit without providing any protrusions or elbows which are designed to bear on the wall of the borehole. Additionally, as the cavity is contained within the heavy walls of the tubular member, drilling fluids containing various debris cannot inhabit the cavity, thus maintaining a constant eccentric weight upon the drill bit.

Abstract: A novel rolling cone rock bit includes a plurality of PDC or other cutters mounted to the leg of the drill bit and positioned to cut the troublesome corner of the bottomhole. The plurality of cutters may be the primary cutting component at gage diameter, or may be redundant to gage teeth on a rolling cutter that cut to gage diameter. Consequently, the occurrence of undergage drilling from the wear and failure of the gage row on a rolling cutter is lessened. Another inventive feature is the inclusion of a mud ramp that creates a large junk slot from the borehole bottom up the drill bit. The resulting pumping action of the drill bit ramp speeds up the removal of chips or drilling cuttings from the bottom of the borehole, reduces the level of hydrostatic pressure at the bottom of the borehole and minimizes the wearing effect of cone inserts regrinding damaging drill cuttings.

Abstract: A drill bit including improved gage pads is particularly adapted for side cutting a borehole wall. In a preferred embodiment, the drill bit gage pads alternate between an active gage pad with a cutting surface portion and a non-active gage pad with a wear-resistant surface. Gage pad cutting elements placed on a first active gage pad cooperate with gage pad cutting elements placed on other active gage pads. What results is a contiguous series of overlapping cutting elements suitable to cut the borehole wall. Non-active gage pads are preferably placed between the active cutting gage pads. These non-active gage pads have a wear-resistant surface (such as steel or diamond insert) that extends to the gage diameter. These non-active gage pads help to maintain borehole size and prevent undue torque being placed on the drill bit.

Abstract: Rock bits comprising wear and fracture resistant surface of this invention include a steel bit body having at least one leg extending therefrom. A steel cone is rotatably disposed on the leg. The steel cone includes a plurality of steel cutting elements that each projecting outwardly a distance therefrom. At least a portion of the cone comprises a wear resistant surface formed from a wear resistant composite material. The wear resistant composite material is made by the process of combining powders selected from the group consisting of carbides, borides, nitrides, carbonitrides, refractory metals, cermets, Co, Fe, Ni, steel, and combinations thereof, to form a material mixture. The material mixture is applied onto a designated surface of the cone, in one form or another, when the cone is in a pre-existing rigid state. Depending on the particular application, the material mixture can be applied in as a slurry to the designated surface of the cone to form a coating thereon.

Abstract: An earth-boring bit has a bit body that is threaded at one end for connection into a drill string. At least one cantilevered bearing shaft depends inwardly and downwardly from the bit body. A cutter is mounted for rotation on each bearing shaft and includes a plurality of cutting elements arranged in generally circumferential rows. At least one wear-resistant element is secured to the bit body between the lower end of the bit body and the threaded end, the wear-resistant element being elongate or generally oblong in cross-section.

Abstract: A stabilizer for a drill string and drill bit is mounted behind the drill bit in the drilling assembly. The stabilizer comprises a tubular body having one or more stabilizer blades mounted thereon. The stabilizer blades extend radially outwardly from the stabilizer body. In a first position, the stabilizer blades are in vertical axial alignment behind the drill bit. Drill string pressure is utilized to release a locking mechanism permitting relative rotation between the stabilizer blades and the stabilizer body thereby rotating the stabilizer blades to a second position providing stabilization for the drill string and drill bit.

Abstract: A drag type casing mill/drill bit for down hole milling of a casing window and lateral drilling of a bore hole in an earth formation comprises a bit body adapted to be rotated in a defined direction. The bit body includes an operating end face having a plurality of radially extending blades formed as a part of the operating end face of the bit body. A plurality of primary cutting elements are individually mounted in pockets in one of the plurality of blades. In addition, a plurality of secondary ridge structures are mounted to each of the plurality of blades interspersed with the plurality of primary cutting elements in a pattern such that as the bit body rotates the secondary ridge structures contact the casing or the earth formation thereby protecting the primary cutting elements and allowing continuous substantially smooth casing milling and earth formation drilling.

Abstract: A drill bit is assembled to the makeup end of a drill string by means of a breakable washer comprising a ring-shaped body having an inner diameter and an outer diameter. A radially extending first surface of the ring-shaped body is planar and substantially perpendicular to a centerline axis through the body. A second radially extending surface has an angle with reference to the first surface that results in a radially diverging configuration.

Abstract: A method is disclosed for applying hardfacing to a shirttail portion of a roller cone drill bit, including masking around the shirttail portion of the bit and operating a high pressure/high velocity oxygen fuel torch to apply the hardfacing to the shirttail portion.

Abstract: The present invention is a drag-type drill bit for drilling a borehole in the earth. The bit is designed to rotate about a central axis of rotation and has a bit body having a leading face, an end face, a gauge region, and a shank for connection to a drill string, a plurality of nozzles in the bit body for delivering drilling fluid to the end face, a plurality of blades upstanding from the leading face of the bit body and extending outwardly away from the central axis of rotation of the bit. Each blade terminates in a gauge pad with a surface which faces a wall of the borehole. A first plurality of cutters are mounted on the blades at the end face of the bit body and a second plurality of cutters are mounted the gauge pads and arranged such that in operation, they cut the wall of the borehole. Each one of the second plurality of cutters has a backrake less than or equal to about 20 degrees.

Abstract: A drill bit including improved gage pads is particularly adapted for side cutting a borehole wall. In a preferred embodiment, the drill bit gage pads alternate between an active gage pad with a cutting surface portion and a non-active gage pad with a wear-resistant surface. Gage pad cutting elements placed on a first active gage pad cooperate with gage pad cutting elements placed on other active gage pads. What results is a contiguous series of overlapping cutting elements suitable to cut the borehole wall. Non-active gage pads are preferably placed between the active cutting gage pads. These non-active gage pads have a wear-resistant surface (such as steel or diamond insert) that extends to the gage diameter. These non-active gage pads help to maintain borehole size and prevent undue torque being placed on the drill bit.

Abstract: The present invention is a bi-center drill bit designed to drill out the cement and other material in the casing and then proceed to drill out the full gauge drilling diameter borehole with a diameter greater than the inside of the casing. The bi-center drill bit is configured with non-drilling bearing elements that contact with the casing when the bit is drilling the cement without allowing the gauge cutting elements of the bi-center drill bit to contact the casing. The bi-center drill bit also has a cutting element configuration which prevents reverse scraping of the cutting elements when drilling both the cement and the formation.

Abstract: A rotary drill bit having a plurality of circumferentially spaced gage pads for drilling bore holes of a preselected trajectory, including lateral or deviated bore holes, in subterranean formations. Each gage pad is provided with, or alternatively associated with, at least one aggressive gage, or side, cutting element having a preselected relative degree of aggressiveness. Selected circumferentially spaced gage pads comprise at least one gage cutting element, or cutting region, disposed thereon and/or comprise alternative gage-cutting elements longitudinally proximate and exclusively associated with a selected gage pad. At least one such gage-cutting element provides more aggressive gage-cutting than at least one other, less aggressive gage-cutting element disposed on, or associated with, a different gage pad.

Abstract: A rotary drag bit suitable for directional drilling. The bit includes a bit body from which extend radially-oriented blades carrying PDC cutters. The blades extend to primary gage pads, above which secondary gage pads are either longitudinally spaced or rotationally spaced, or both, defining a gap or discontinuity between the primary and secondary gage pads through which drilling fluid from adjacent junk slots may communicate laterally or circumferentially. Longitudinally leading edges of the secondary gage pads carry cutters for smoothing the sidewall of the borehole. The cutters are preferably configured and oriented so as to provide a relatively aggressive cutting edge to the formation in both longitudinal and rotational directions of bit movement, the cutting edges lying adjacent cutting surfaces preferably disposed at negative rake angles to the formation material of the borehole wall for enhanced durability.

Abstract: A fixed cutter, or rotary drag, bit for drilling subterranean formations, exhibiting an enhanced resistance to bit balling and an improved rate of penetration. The bit includes an auger-like blade configuration, wherein positively raked, relatively tall blades lean rotationally forward to provide increased clearance and volume between the bit face and the formation to facilitate removal of cuttings coming off the tops of the cutters from the bit face. The blades are each substantially contiguous with an elongated, helical gage pad raked rotationally forwardly in the manner of the blades, the longitudinal lengths of the gage pads and the radially outer edges of the blades in combination with their slope providing a stabilizing structure which substantially completely circumferentially encompasses the bit body. The slope or pitch of the helix angle of the blade edges and gage pads may be varied as desired to optimize hydraulic efficiency, cutter requirements of directional drilling, and stability needs.

Abstract: A rotary drag bit suitable for directional drilling. The bit includes a bit body from which extend radially-oriented blades carrying PDC cutters. The blades extend to primary gage pads, above which secondary gage pads are either longitudinally spaced or rotationally spaced, or both, defining a gap or discontinuity between the primary and secondary gage pads through which drilling fluid from adjacent junk slots may communicate laterally or circumferentially. Longitudinally leading edges of the secondary gage pads carry cutters, such as chisel-shaped cutters for smoothing the sidewall of the borehole. The cutters are preferably configured and oriented so as to provide a relatively aggressive cutting edge to the formation in both longitudinal and rotational directions of bit movement. Cutters may likewise be disposed on the trailing ends of the secondary gage pads to provide an up-drill capability to facilitate removal of the bit from the borehole.

Abstract: An earth boring drill bit including replaceable gage pads. The gage pads and the corresponding surface of the earth boring drill bit may include complementary securing elements which mutually engage one another. The gage pad may be removably affixed to the earth boring drill bit by an affixation element, such as a bolt, a mechanical locking element, brazing, welding, mechanical affixation, or another known technique. The invention also includes a method of testing differently configured gage pads employing a single earth boring drill bit, a method of replacing the gage pads of an earth boring drill bit at the drilling site, a method of customizing an earth boring drill bit to include one or more gage pads of desired configuration, and a method of altering the balance or net imbalance of an earth boring drill bit by replacing at least one gage pad thereof.

Abstract: A drill bit including improved gage pads is particularly adapted for side cutting a borehole wall. In a preferred embodiment, each gage pad preferably includes a cutting surface portion and a wear-resistant surface. Gage pad cutting elements placed on a first gage pad cutting surface portion cooperate with gage pad cutting elements on other gage pads to reduce the torque on each gage pad cutting surface. The cutting elements may be made more aggressive by the reduction of a wear-resistant surface trailing the cutting elements. The wear-resistant surface on the first gage pad is varied with the wear-resistant surface on other gage pads to yield the wear-resistant advantages of previous gage pads.

Abstract: A rolling cone drill bit is provided that has gage inserts on the first row from the bit axis to cut to full gage diameter that have a cutting portion enhanced with a layer of super abrasive material. The gage cutting surface has a center axis that is canted to be more normal to the gage curve such that the its point of contact at gage is away from the thinner portion of the layer of super abrasive material.

Abstract: A method is disclosed comprising the steps of locating, on a surface of a downhole component, a plurality of thermally stable polycrystalline diamond (TSP) bearing elements, and then applying to the surface a settable facing material which bonds to the surface between the bearing elements and embraces the elements to hold them in place. A method in which bearing elements each comprising a body of TSP at least partly surrounded by a layer of less hard material are secured to the surface by welding or brazing part of the surface of each bearing element which comprises said less hard material to said component is also described.

Abstract: A rotary drag bit suitable for directional drilling. The bit includes a bit body from which extend radially-oriented blades carrying PDC cutters. The blades extend to primary gage pads, above which secondary gage pads are either longitudinally spaced or rotationally spaced, or both, defining a gap or discontinuity between the primary and secondary gage pads through which drilling fluid from adjacent junk slots may communicate laterally or circumferentially. Longitudinally leading edges of the secondary gage pads carry cutters for smoothing the sidewall of the borehole. The cutters are preferably configured and oriented so as to provide a relatively aggressive cutting edge to the formation in both longitudinal and rotational directions of bit movement, the cutting edges lying adjacent cutting surfaces preferably disposed at negative rake angles to the formation material of the borehole wall for enhanced durability.

Abstract: A drill bit and method of drilling a subterranean formation are disclosed in which the drill bit is configured with a non-axial gage portion of a bit body. The non-axial gage portion of the bit body presents a peripheral profile which is not parallel to the centerline of the bit body to provide a contact area for engagement of the sidewall of the borehole by at least one cutting element carried by the non-axial gage portion to enlarge the borehole from a first diameter cut by cutting elements on the bit face. The configuration of the drill bit lessens loading on the cutting elements of the drill bit, facilitates maneuverability of the drill bit downhole and enhances steerability of the drill bit.

Abstract: A rotary drill bit suitable for directional drilling. The bit includes a bit body from which extend legs carrying rotatable cutters. The body carries primary gage pads, above which secondary gage pads may be either longitudinally spaced or rotationally spaced, or both. Longitudinally leading edges of the gage pads may carry cutting structure for smoothing the sidewall of the borehole. Cutting structure may likewise be disposed on the trailing ends of the gage pads to provide an up-drill capability to facilitate removal of the bit from the borehole. The gage pads provide enhanced bit stability and reduced side cutting tendencies, as well as reducing lateral loading on the rotatable cutters and associated bearing structure and seals. The invention also has utility in bits not specifically designed for directional drilling.

Abstract: A rotary earth-boring drag bit assembly has a bit body formed of a carbide matrix material. The body has a longitudinal axis and a face on a lower end containing cutters for engaging and cutting a bottom of the borehole. The cutters are carried on fixed blades extending about and radially outwardly of the face. A steel threaded pin member is bonded to an upper end of the body. A steel shank having a threaded receptacle on a lower end secures to the threaded pin member. The steel shank has a threaded pin on an upper end that secures to a drill string. A lower set of gage pads is disposed about a periphery of the body and extends longitudinally away from the face for engaging a sidewall of the borehole. Each of the gage pads is contiguous with and extends from one of the blades. The gage pads are elongated in an axial direction and protrude from the periphery. Slots are located between the gage pads for the flow of drilling fluid and cuttings.

Abstract: A drill bit and method of drilling employing a gage definition region on the bit to relatively gradually and incrementally increase the diameter of the borehole being drilled from a diameter that is cut by fixed face cutters or rolling cone cutters on the bit body to a larger diameter. Preferably, the diameter of the gage definition region defined by cutting structures thereon varies along a longitudinal length of the bit, being smallest nearest the leading end of the bit. In a preferred embodiment, the gage definition region includes a plurality of helically arranged cutting elements disposed around the perimeter of the gage definition region. Such a configuration of cutting elements helps to reduce the loading on, and wear of, each individual cutting element. Thus the effective life of the bit is extended by enhancing its ability to drill the borehole to the gage diameter over a longer interval than may be achieved with conventional bit designs.

Abstract: The invention discloses a single cone earth boring bit which is adapted to be used for boring in oil fields, mining and geological prospecting. The single cone earth boring bit is composed of a bit body (1), gauge blocks (2), active cutting gauge teeth (4), passive gauge teeth (3) and knobby cone (6) etc. On the knobby cone (6), there are inserted wear-resistant teeth intermittently or successively, so as to make the wear resistance of the bit cutting system to be matched with the service life of the bearing. At the same time, gauge blocks (2) are provided on the bit body which may be directly made on or welded to the bit body. On the gauge blocks (2), there are inserted common carbide or wear-resistant active cutting gauge teeth (4) and the passive gauge teeth (3) to enhance the gauge-protecting effect of the bit. Such a single cone earth boring bit can significantly increase the footage of the bit and reduce the cost for drilling.

Abstract: A rotary drag bit being suitable for directional drilling. The bit includes a bit body from which extend radially-oriented blades carrying PDC cutters. The blades extend to primary gage pads, above which secondary gage pads are either longitudinally spaced or rotationally spaced, or both, defining a gap or discontinuity between the primary and secondary gage pads through which drilling fluid from adjacent junk slots may communicate laterally or circumferentially. Longitudinally leading edges of the secondary gage pads may carry cutters for smoothing the sidewall of the borehole. The tandem primary and secondary gage pads provide enhanced bit stability and reduced side cutting tendencies. The discontinuities between the primary and secondary gage pads enhance fluid flow from the bit face to the borehole annulus above the bit, promoting formation cuttings removal. The tandem gage arrangement also has utility in conventional bits not designed specifically for directional drilling.

Abstract: A rotary drag bit being suitable for directional drilling. The bit includes a bit body from which extend radially-oriented blades carrying PDC cutters. The blades extend to primary gage pads, above which secondary gage pads are either longitudinally spaced or rotationally spaced, or both, defining a gap or discontinuity between the primary and secondary gage pads through which drilling fluid from adjacent junk slots may communicate laterally or circumferentially. Longitudinally leading edges of the secondary gage pads carry cutters for smoothing the sidewall of the borehole. The tandem primary and secondary gage pads provide enhanced bit stability and reduced side cutting tendencies. The discontinuities between the primary and secondary gage pads enhance fluid flow from the bit face to the borehole annulus above the bit, promoting formation cuttings removal. The tandem gage arrangement also has utility in conventional bits not designed specifically for directional drilling.

Abstract: An anti-whirl rotary drag bit including one or more cutters, wear knots or other support structures disposed on the flank of a bit profile in a normally cutter-devoid region of the profile adjacent the gage of the bit in the circumferential segment of the gage used as a bearing zone for the bit to ride against the side of the bore hole. Such flank cutters or other structures reduce wear of the bearing zone but, due to their placement, do not come into play except under certain drilling situations such as reaming or high rates of penetration wherein whirl tendencies resulting from cutting forces are not as pronounced.

Abstract: A rotary drag bit including a gage design which facilitates steerability while preventing lateral displacement of the bit and attendant ledging of the borehole wall, and reams and conditions the borehole wall as the bit advances through the formation. The bit includes an elongated gage section comprised of a plurality of circumferentially spaced gage pads, each including mutually longitudinally displaced gage pad segments of varying lateral aggressiveness, or tendency to cut formation material under application of load.

Abstract: A method and apparatus for reaming or enlarging a borehole using a bi-center bit with a stability-enhanced design. The cutters on the pilot bit section of the bi-center bit are placed and oriented to generate a lateral force vector longitudinally offset from, but substantially radially aligned with, the much larger lateral force vector generated by the reamer bit section. These two aligned force vectors thus tend to press the bit in the same lateral direction (which moves relative to the borehole sidewall as the bit rotates) along its entire longitudinal extent so that a single circumferential area of the pilot bit section gage rides against the sidewall of the pilot borehole, resulting in a reduced tendency for the bit to cock or tilt with respect to the axis of the borehole.

Abstract: An earth-boring bit has a bit body that is threaded at one end for connection into a drill string. At least one cantilevered bearing shaft depends inwardly and downwardly from the bit body. A cutter is mounted for rotation on each bearing shaft and includes a plurality of cutting elements arranged in generally circumferential rows. At least one wear-resistant element is secured to the bit body between the lower end of the bit body and the threaded end, the wear-resistant element being elongate or generally oblong in cross-section.

Abstract: An anti-whirl rotary drag bit including one or more cutters, wear knots or other support structures disposed on the flank of a bit profile in a normally cutter-devoid region of the profile adjacent the gage of the bit in the circumferential segment of the gage used as a bearing zone for the bit to ride against the side of the bore hole. Such flank cutters or other structures reduce wear of the bearing zone but, due to their placement, do not come into play except under certain drilling situations such as reaming or high rates of penetration wherein whirl tendencies resulting from cutting forces are not as pronounced.

Abstract: A wear assembly for attachment to a protective sleeve for a drill bit sub wherein the wear assembly includes an elongate wear bar which has an interior surface for attachment to the protective sleeve. The wear bar also has an exterior surface. The wear bar further contains a slot opening at the exterior surface. The slot contains at least one hard insert affixed therein by brazing.

Abstract: A drill includes support pads for supporting and guiding the drill in the drill hole. The support pads are formed as parallelepiped-shaped cemented carbide bodies which each have two wing-shaped protrusions on their longitudinal sides. In a corresponding way, the drill head of the drill includes recesses with two bulged parts on the long sides. This gives the support pad a determined axial position and strengthens the support pad at the weakening caused by the central hole. Further, the support pad can be turned half a revolution if one of its ends becomes damaged since the end spaces do not have to function as abutment surfaces.