Abstract: A drilling tool for drilling a wellbore in a formation includes a drill bit including a plurality of blades and a machined connection disposed on the drill bit. Each of the plurality of blades includes a gauge having a length and an angle. The machined connection is configured to allow attachment of a plurality of machined rings to the plurality of blades. The plurality of machined rings are configured to form the length and the angle of each gauge based on number and type of each machined ring attached. The drill bit is configured to operate in different formations based on the gauge of each of the plurality of blades. The drilling tool is redesigned by removal or addition of one or more of the machined rings based at least in part on a modified length and a modified angle configured in view of a characteristic of the wellbore.

Abstract: A cutting element may include a fluid passage passing through the cutting element. The cutting element may further include a cutting edge and an aperture proximate the cutting edge. The aperture may be coupled to the fluid passage.

Abstract: A bulk material drilling system is described, the drilling system arranged to allow accurate directional control of a drill bit through bulk material via non-mechanical means, while providing real-time feedback on drill bit positioning. A drilling system (22) comprising; a bulk material drill bit (10) having; a sensing portion (18), one or more ports (16) for discharging output energy, the drilling system further comprising; an input portion (30) arranged to detect input parameters from the sensing portion, a controller (32) arranged to control output energy to the port; wherein the controller is further arranged to determine one or more ports to which the output energy is provided; wherein the controller is further arranged to control the discharge of the output energy; wherein the output energy discharge is non-uniformly applied to bulk material; wherein the discharge of the output energy is used to control the drill bit direction.

Abstract: A drill bit comprises a bit body having a longitudinal axis and a blade extending radially outward from the longitudinal axis along a face region and axially along a gauge region. A gauge region includes a gauge feature and first and second recessed regions extending axially above and below the gauge feature, respectively. The gauge feature comprises an outermost surface extending radially beyond outer surfaces of the blade in the recessed regions. A method of drilling a borehole comprises rotating the bit about the longitudinal axis, engaging a formation with cutting elements mounted to the face region, and increasing a lateral force applied substantially perpendicular to the longitudinal axis such that radially outer surfaces in the gauge region engage the formation and such that side cutting exhibited by the bit is initially minimal and substantially constant and subsequently increases in a substantially linear manner with increasing lateral force.

Abstract: A cutting head includes a main body that is attachable to an ice drill shaft at a top side. The main body includes a bottom side that has a bottom peripheral surface. The cutting head includes at least one cutting edge that is disposed on the main body. The cutting edge is configured to perform a cutting operation at the bottom side of the main body. The cutting head includes a cutting rate control pad that is disposed on the bottom side of the main body. The cutting rate control pad extends away from the bottom peripheral surface.

Abstract: Milling systems, tools, and methods include using a mill with secondary attrition system to re-mill cuttings and other debris away from the face of the mill. The secondary attrition system may be located uphole of the mill may be used to stage conditioning and re-sizing of debris. After debris is generated by the mill, the secondary attrition system may re-mill the debris to a finer size before allowing the debris to pass out of the sleeve. The debris may be re-milled by secondary cutting elements while within an annular gap positioned radially between the sleeve and a drive shaft for the mill. The annular gap may have a variable width as a result of a tapered outer surface of the drive shaft and/or a tapered inner surface of the sleeve. The variable width may cause debris to be re-milled into increasingly finer sizes.

Abstract: A downhole-milling-tool method for milling through hard substances, such as barite, found in underground wells, providing a stepped increase of diameters and positioning of carbide cutters and appropriate positioning of fluid ports and channels, to provide removal of cuttings and cooling and lubricating of the cutting head, in turn providing more efficiency and a better rate of penetration (ROP).

Abstract: A downhole milling tool apparatus for use in milling through hard substances, such as barite, found in underground wells, providing a stepped increase of diameters and positioning of carbide cutters and appropriate positioning of fluid ports and channels, to provide removal of cuttings and cooling and lubricating of the cutting head, in turn providing more efficiency and a better rate of penetration (ROP).

Abstract: Methods of forming an earth-boring tool may involve attaching one or more cutting elements to a replaceable cutting structure and positioning the replaceable cutting structure proximate a region of a body of an earth-boring tool that is susceptible to at least one of localized wear and localized impact damage. The replaceable cutting structure may be to the body. Methods of repairing an earth-boring tool may involve bringing a replaceable cutting structure proximate at least one portion of a body of an earth-boring tool exhibiting at least one of localized wear and localized impact damage. The replaceable cutting structure may be attached to the earth-boring tool at the at least one portion.

Abstract: A wearing-point device (22) with a quick-coupling formed from a coupling portion (211) of a wearing-part holder (21) and corresponding attachment portions (223) of the wearing point (22), in which a longitudinal elevation (224) extends with a desired height from a front portion (221) towards the attachment portion (223), sliding surfaces (222, 222?) extending in a downward-sloping manner from the longitudinal center plane of the wearing point (22) in the directions of opposite side edges (228) of the wearing point (22) and forming a downward-sloping rear edge (227) that forms an interface towards the attachment portions (223).

Abstract: A drill bit for a down-the-hole drill hammer is provided that includes a head and a shank extending from the head. The head includes a plurality of non-concentrically or spirally arranged cutting members about its working face. The non-concentric or spiral arrangement of the cutting members in the drill bit and their overlapping cutting paths during rotation of the drill bit reduces the presence of concentric grooves or valleys being cut into the earthen terrain impacted by the bit thereby resulting in more complete cutting coverage.

Abstract: This invention provides a novel nostril gauge system and methods for using the same, which allows the practitioner to measure the size of deformed nostrils resulting from any cause such as from a cleft lip and/or cleft palate, a traumatic injury, an infectious process, a prior surgical intervention, etc. The device allows for the expeditious and accurate measurement of the size/caliber of normal and deformed nostrils before any type of nasal reconstruction intended to correct asymmetric nostril openings (nares). The gauge includes a series of measured and accurately sized gauge steps that are readily used and result in a more precise nostril sizing. The gauge includes a plurality of spines, each having steps thereon correlating to different circumferential sizes. The gauge system is provided with printed size indicia that refers to each gauge step and facilitates the measuring process. In illustrative embodiments, the gauge body defines a loop with a plurality of gauge spines, arranged around its perimeter.

Abstract: The present document describes a drill-bit which achieves both the rigidity and a fast rate of penetration. The drill-bit comprises a cone shaped central portion comprising a plurality of ribs protruding from the central portion and defining a plurality of blades. The blades are curved along a direction of a longitudinal axis of the cone to facilitate insertion into a hole when rotating in a first direction, and exit from the hole when rotating in a second direction opposite the first direction. The drill-bit comprises a plurality of polycrystalline diamond cutters (PDC) on the blades provided in a first position for cutting the hard structure as the drilling-bit rotates in the first direction, and a plurality of up-drill PDC cutters provided in a second position for cleaning the hole as the drill-bit rotate in the second direction to exit the hole.

Abstract: A drill bit having a bit body with a longitudinal axis extending therethrough and a plurality of blades extending from the bit body is disclosed. Each blade has an outer face and at least one side wall. The drill bit has at least one junk slot, wherein each junk slot is defined by the bit body surface and the side walls of adjacent blades. At least one nozzle bore is formed in the bit body, wherein each nozzle bore has an intersecting surface between the bit body surface of a junk slot and an inner surface of the nozzle bore. At least one formation evacuation channel extends through the intersecting surface of at least one of the nozzle bores, wherein each formation evacuation channel has a base surface, and wherein the formation evacuation channel extends partially around the circumference of the nozzle bore.

Abstract: A wellbore conditioning system is disclosed. The system comprises at least one shaft and at least two eccentric unilateral reamers, wherein the unilateral reamers are positioned at a predetermined distance from each other and the unilateral reamers are positioned at a predetermined rotational angle from each other.

Abstract: A fluid cutting head of the type having a plurality of nozzles in a rotatable nozzle assembly for cutting a bore hole in rock. The cutting head has nozzles arranged to be supplied with high pressure drilling fluid, forming jets positioned to cut adjacent rock. The nozzles include one or more generally axially facing pilot nozzles, and one or more generally radially facing reaming nozzles. At least the pilot nozzles include a non-tapering outlet section such that the jet issuing therefrom is of substantially constant cross-section in a zone immediately adjacent the outlet section. The pilot nozzles are located in a leading part of the rotatable nozzle assembly, and have a minimized diameter. The reaming nozzles are located in the following part of the rotatable nozzle assembly. The following part of the rotatable nozzle assembly is formed in a step-wise fashion to keep the reaming nozzles close to the rock face.

Abstract: A milling tool which includes a nose cutting portion, a cutting section having a plurality of hardened cutters and a shaft portion. A wear pad is disposed on the cutting section and shaft portion. Upon the shaft portion, the wear pad extends radially outwardly to an engagement diameter that exceeds the maximum cutting diameter of the cutters.

Abstract: A drill bit comprising: a cutting section comprising gage cutters, wherein in the cutting section is a first end of the bit, and wherein the cutting section has a full gage diameter; a heel section comprising a blade, wherein the heel section is at an end of the drill bit opposite the cutting section, and wherein a diameter of the heel section is a full gage diameter, wherein the blade has a high spiral around the drill bit; and a clearance section between the cutting and heel sections, wherein the clearance section comprises a diameter less than full gage, and wherein clearance section extends from the gage cutters of the cutting section to the blade of the heel section.

Abstract: Reamer bits have cutters with different effective back rake angles. Drilling systems include a pilot bit and a reamer bit, wherein cutters in shoulder regions of the reamer bit have a greater average effective back rake angle than cutters in shoulder regions of the pilot bit. Methods of drilling wellbores include drilling a bore with a pilot bit, and reaming the bore with a reamer bit having cutters in shoulder regions of the reamer bit that have an average effective back rake angle greater than that of cutters in shoulder regions of the pilot bit. Methods of forming drilling systems include attaching pilot and reamer bits to a drill string, and positioning cutters in shoulder regions of the reamer bit to have an average effective back rake angle greater than that of cutters in shoulder regions of the pilot bit.

Abstract: Bottom hole assemblies for cutting windows in wellbore casing comprise a window mill, a first upper mill, a second upper mill, and a third upper mill. The first mill has an outer diameter that is smaller than the outer diameters of the window mill and the second and third upper mills. The first upper mill is disposed above the window mill at a distance measuring approximately twenty to thirty-seven percent of the distance measured from the window mill to the third upper mill. The second upper mill is disposed above the window mill at a distance measuring approximately fifty-five to seventy-five percent of the distance measured from the window mill to the third upper mill. The third upper mill is disposed above the window mill at a distance measuring approximately one-hundred twenty to one-hundred thirty percent of the length of a ramp of a whipstock for guiding the mills.

Abstract: A bi-center drilling tool comprises a main reamer region located eccentrically to an axis of rotation of the tool, and a leading cutting structure located ahead of the main reamer region, in the drilling direction. The leading cutting structure is located so as to apply a side loading to the drilling tool. The side loading is in direction to counter the loading which, in use, is due to the main reamer region being eccentric to the axis of rotation.

Abstract: A rotary drag bit exhibiting enhanced cutting efficiency and extended life is provided. The rotary drag bit comprises a bit body having a face surface, and a plurality of cutters coupled to the face surface of the bit body. The plurality of cutters comprises at least one pilot cutter and a rotationally trailing larger, primary cutter at substantially the same radius and, optionally of slightly less exposure. The pilot cutter is sized and positioned to pre-fracture the formation and perform an initial cut, while the primary cutter removes weakened, remaining formation material along the same rotational path. A method to pre-fracture subterranean formations using a rotary drag bit having a pilot cutter configuration is also provided.

Abstract: A cable guide mechanism configured to be releasably attached to a shaft, which includes a body portion, an indent or groove and a protrusion, characterised in that said indent or groove is located on the opposite side of the body portion to the protrusion, and is dimensioned and configured to releasably retain an inside edge of a first distal end of a loop which is attached to a terminal end of a cable; the protrusion is tapered with its widest section directly opposite the indent or groove; the linear distance between the bottom of the indent or groove and the widest section of the protrusion is sufficiently close to the inside length of the loop that in use the first distal end of the loop cannot climb out of the indent or groove; said shaft is configured to freely rotate co-axially inside the cable guide mechanism.

Abstract: The earth boring bit 10 is designed to bore an angular non-vertical hole into underlying strata. The bit 10 includes a plurality of steeply inclined cutting faces or edges 22 that define a relatively narrow included angle A therebetween. The bit's design ensures that the apex of the bit 10 will contact the surface S and/or other hard strata before the radially outwardly disposed gauge portion of the bit 10. This design reduces or obviates drill chattering or “walking” when the bit 10 is used to drill a hole at an angle that is not vertical relative to the surface or strata S. The bit 10 also includes an interchangeable flow control restrictor that optimizes the velocity of fluid pumped through the bit 10 and thus efficiently flushes debris from the hole as the hole is being drilled.

Abstract: A method and apparatus for drilling a subterranean formation or material utilizing a drilling apparatus which includes a drill string having a leading end and a trailing end and having a bottom hole assembly connected with the leading end. The bottom hole assembly includes a drill bit and an externally threaded screw section. In operation, the drill bit is rotated, forming material cuttings and an opening in the subterranean formation, and the threaded screw section is rotated within the opening, forming a helical groove in the subterranean formation.

Abstract: A bottom hole assembly including a pilot bit for initially forming an unconfined inner sidewall of a wellbore and a reamer tool above the pilot bit and comprising a first cutter ring to expand the unconfined inner sidewall, and a second cutter ring located above and outwardly of the first cutter ring to expand the unconfined inner sidewall as expanded by the first cutter ring. The reamer tool may further comprise a third cutter ring located above and outwardly of the second cutter ring to expand the unconfined inner sidewall as expanded by the second cutter ring. The first cutter ring may be located on a first roller cone, the second cutter ring may be located on a second roller cone, and the third cutter ring may be located on a third roller cone.

Abstract: A drilling tool for drilling a wellbore that includes at least a reaming section and a pilot conditioning section. The pilot conditioning section then includes at least one pilot conditioning blade having at least one cutting element formed of an impregnated matrix material. An outermost extent of the at least one cutting element from a central axis of the tool body is at least half of a pilot hole diameter.

Abstract: A rotary drag bit exhibiting enhanced cutting efficiency and extended life is provided. The rotary drag bit comprises a bit body having a face surface, and a plurality of cutters coupled to the face surface of the bit body. The plurality of cutters comprises at least one pilot cutter and a rotationally trailing larger, primary cutter at substantially the same radius and, optionally of slightly less exposure. The pilot cutter is sized and positioned to pre-fracture the formation and perform an initial cut, while the primary cutter removes weakened, remaining formation material along the same rotational path. A method to pre-fracture subterranean formations using a rotary drag bit having a pilot cutter configuration is also provided.

Abstract: A system, apparatuses and methods for anchoring are provided. The system includes two-stage drill bit and a method of anchoring into a two-stage hole drilled by the drill bit. The apparatus of the instant invention includes a two-stage drill bit for drilling a pilot hole for a common nail into a material such as concrete, stone, masonry or cementuous or other materials. The method of the instant invention includes the steps of drilling a first hole within a material to which an object is to be anchored, drilling a second hole concentric with the first hole, and placing an anchor within the holes.

Abstract: A reaming tool including a body adapted to couple to a drill string at both axial ends thereof, the body including a plurality of reaming blades affixed at azimuthally spaced apart locations around the circumference of the body, wherein selected ones of the plurality of reaming blades including at least one cutter attached at a selected position and orientation. Additionally, a pilot hole conditioning section including a plurality of azimuthally spaced apart pilot blades affixed to the body longitudinally ahead of the reaming blades. Furthermore, at least one of the reaming blades formed as a single structure with an azimuthally corresponding pilot blade.

Abstract: A reaming tool that includes a body having reaming blades affixed thereto. The reaming blades each have at least one cutter attached thereto at a selected position and orientation. The plurality of reaming blades includes at least one radially most extensive reaming blade. The reaming tool further includes a pilot blade azimuthally spaced apart from the at least one radially most extensive reaming blade. The pilot blade is affixed to the body longitudinally ahead of the at least one radially most extensive reaming blade.

Abstract: A downhole tool that functions as an underreamer or as a stabilizer in an underreamed borehole. The tool includes one or more moveable arms disposed within a body having a flowbore therethrough in fluid communication with the wellbore annulus. The tool alternates between collapsed and expanded positions in response to differential fluid pressure between the flowbore and the wellbore annulus. In one embodiment, the tool moves automatically in response to differential pressure. In a second embodiment, the tool must be selectively actuated before it is moveable. The tool may include borehole engaging pads that comprise cutting structures or wear structures or both, depending upon the function of the tool.

Abstract: A drill out bi-center bit and a method for using the same are provided that offer the ability to drill out cement and casing shoes, and increased stability. The bi-center bit includes a bit body having a first end operable to be coupled with a drill string, a second end including a pilot section, and an eccentric reamer section intermediate the first and second ends. A first plurality of cutter assemblies is disposed upon the exterior surface of the pilot section, while a second plurality of cutter assemblies is disposed upon the reamer section. A plurality of recessed cutter assemblies is also disposed upon the pilot section, such that the recessed cutter assemblies are located within a radius beginning at a central axis of the pilot section and terminating at a central axis of the reamer section and are recessed with respect to a lower surface of the pilot.

Abstract: A roller cone bi-center bit for economically drilling an enlarged borehole below casing in earth formation is provided. The bi-center bit includes a rolling cone cutter or other appropriate cutter to enlarge a pilot bore also made by rolling cone or other type of cutters. The bit comprises a single-diameter body with a recess to accommodate the trailing cutter which enlarges the pilot bore. The bi-center bit may also provide the ability to change out the cutters efficiently in the field. The cutters are oriented to enhance drilling out the cement plug at the bottom of the casing. The cone cutter may be also be mounted on segments which are designed to be easily removed for replacement or adjustment in position in the field.

Abstract: A rotary drill bit for penetrating earth strata wherein the drill bit includes a drill bit body that has an axial forward end. The drill bit body has a hard insert, which is preferably monolithic, that is affixed to the drill bit body at the axial forward end thereof. The hard insert presents at least three discrete leading cutting edges for cutting the earth strata. Each cutting edge is stepped.

Abstract: An apparatus and method for removing cuttings in a deviated borehole using drilling fluids. The apparatus includes a pipe string and a bottom hole assembly having a down hole motor and bit for drilling the borehole. The pipe string has one end attached to the bottom hole assembly and does not rotate during drilling. The apparatus and methods raise at least a portion of the pipe string in the deviated borehole to remove cuttings from underneath the pipe string portion.

Abstract: A screw form anchor device (10) intended for screwed penetration into a host material. The anchor device (10) includes a body (11) having a manipulating end (12) and a distal end (13). A screw thread (22) is formed by a plurality of tapering angular helix thread forms (22a) which extend from the distal end. Each angular helix thread form (22a) has an outward facing surface (24) and, relative to the distal end, a downward facing surface (25). In the preferred form an emergent helix thread (26) commences from a point distant from the distal end (13). This emergent helix thread (26) extends toward the manipulating end (12) of the body (11).

Abstract: A hole opener including a tool body having upper and lower ends. The upper and lower ends may be coupled to adjacent drilling tools. At least two blades are formed on the tool body and are arranged so that the hole opener is positioned concentric with a wellbore, and cuffing elements are located on the blades. The at least two blades and the cutting elements are arranged to increase a diameter of a previously drilled wellbore.

Abstract: The hole-opener is designed so that it can be disassembled in the field to replace worn cones or to enlarge the effective diameter of the tool. It comprises: a tubular drive sub, which connects at its front end with a rotating drill string which is being pulled along a pilot hole; a sleeve which slides over the rear portion of the drive sub; and a retainer sub which is connected with the rear end of the drive sub. The drive sub has external protruding bars which engage slots formed in the forward end of the sleeve, for limiting forward movement of the sleeve and locking the drive sub and sleeve together so that they rotate as a unit. The retainer sub has a radial shoulder which abuts the rear end of the sleeve to lock it in place. The retainer sub also transmits axial pull from the drive sub to the sleeve. The sleeve carries rotary cutting elements which are pulled and rotated to cut formation and enlarge the pilot hole.

Abstract: A method and apparatus for reaming or enlarging a borehole with the ability to drill cement, cement float equipment, and debris out of a casing without substantial damage to the casing interior or the reaming apparatus. The reaming apparatus also provides enhanced protection from contact with the casing wall for selected structural features and elements thereof.

Abstract: A bi-center drill bit is disclosed which includes a bit body having pilot blades and reaming blades distributed azimuthally around the body. The blades have cutting elements disposed thereon at selected positions. The body and blades define a longitudinal axis of the bit and a pass-through axis of the bit. In one aspect, selected ones of the pilot blades include thereon, longitudinally between the pilot blades and the reaming blades, a pilot hole conditioning section including gage faces. The gage faces define a diameter intermediate a pilot hole diameter and a pass-through diameter defined, respectively, by the pilot blades and the reaming blades.

Abstract: A hole opener including a tool body having upper and lower ends. The upper and lower ends may be coupled to adjacent drilling tools. At least two blades are formed on the tool body and are arranged so that the hole opener is positioned concentric with a wellbore, and cutting elements are located on the blades. The at least two blades and the cutting elements are arranged to increase a diameter of a previously drilled wellbore.

Abstract: An earth boring bit for boring a hole having a predetermined depth into the earth. The earth boring bit includes a cylindrical drum for being mounted for rotation on the end of a boom of a mobile machine and connected to and rotated by a power supply mounted on the boom. The drum includes an exterior for defining the diameter of the hole being bored and an interior adapted for receiving upturned earth therein as the hole is being bored. A plate is carried by the drum adjacent a lower end thereof for movement between a closed position for cooperating with the interior of the drum for retaining the upturned earth therein and an open position for dispensing the upturned earth out of the interior of the drum at a predetermined location away from the hole being bored. A cutting member is carried on the plate for cutting the earth in a progressive slice and directing the earth into the drum, thereby boring the hole into the earth.

Abstract: The invention is directed to a bi-center drilling tool adapted to fit within and drill through a casing shoe without damage to the surrounding casing. In one embodiment, the tool comprises a bit body having a proximal and a distal end where the distal end defines a pilot bit and an intermediate reamer section, where each the pilot and reamer sections define a bit face including primary and secondary cutting blades and cutting elements disposed on said blades. In this embodiment, the cutting or wear elements disposed on the one or more cutting blades which extend to or are proximate to the pass-through gauge define a selected angle between the line of contact on the cutting or wear elements and the material to be drilled.

Abstract: A reaming tool which includes a body having reaming blades affixed thereto at azimuthally spaced apart locations around a circumference of the body is shown and described. The reaming blades each have at least one cutter attached thereto at selected positions and orientations on each of the blades to minimize a net lateral force developed by the reaming tool. The tool includes a pilot hole conditioning section having a plurality of azimuthally spaced apart pilot blades affixed to the body longitudinally ahead of the reaming blades.

Abstract: An earth boring bit for boring a hole having a predetermined depth into the earth. The earth boring bit includes a cylindrical drum for being mounted for rotation on the end of a boom of a mobile machine and connected to and rotated by a power supply mounted on the boom. The drum includes an exterior for defining the diameter of the hole being bored and an interior adapted for receiving upturned earth therein as the hole is being bored. A plate is mounted in the drum adjacent a lower end thereof for movement between a closed position for cooperating with the interior of the drum for retaining the upturned earth therein and an open position for dispensing the upturned earth out of the interior of the drum at a predetermined location away from the hole being bored. At least one cutting member is carried on the plate for cutting the earth in a progressive slice and directing the earth into the drum, thereby boring the hole into the earth.

Abstract: A method and apparatus for reaming or enlarging a borehole with the ability to drill cement, cement float equipment, and debris out of a casing without substantial damage to the casing interior or the reaming apparatus. The reaming apparatus also provides enhanced protection from contact with the casing wall for selected structural features and elements thereof.

Abstract: A rotary displacement piling equipment for boring a hole within the soil includes a rotary displacement bit, driving rod members connected to the bit, a casing surrounding the driving rod member, and a casing adapter having a lower end provided with a cylindrical collar for co-operating with the upper part of the casing for keeping in line the casing with respect to the driving rod member and with an horizontal thrust face for applying a thrust at the upper end of the casing, the driving rod member passing through the casing adapter. The equipment may also include a rotary drive box co-operating with the driving rod member for rotating the driving rod means and provided with connecting member to be connected to the upper end of the casing adapter, and vertical supporting and guiding member for supporting and vertically guiding the rotary drive box.

Abstract: A bi-center drill bit includes pilot and reaming blades affixed to a body at azimuthally spaced locations. The blades have PDC cutters attached at selected positions. In one aspect, the pilot blades form a section having length along the bit axis less than about 80 percent of a diameter of the section. In another aspect, selected pilot blades and corresponding reaming blades are formed into single spiral structures. In another aspect, shapes and positions of the blades and inserts are selected so that lateral forces exerted by the reaming and the pilot sections are balanced as a single structure. Lateral forces are preferably balanced to within 10 percent of the total axial force on the bit. In another aspect, the center of mass of the bit is located less than about 2.5 percent of the diameter of the bit from the axis of rotation. In another aspect, jets are disposed in the reaming section oriented so that their axes are within about 30 degrees of normal to the axis of the bit.

Abstract: A drill bit for use in horizontal boring includes a bit body with a central axis of rotation including a forwardmost pilot section, a reaming section rearwardly of the pilot section including a forwardly inclined arcuate steering surface and a plurality of gauge cutting teeth disposed rearwardly of the pilot section in opposed relationship to the inclined steering section, the gauge teeth extending farther from the central axis in a radial direction than the steering section such the arcuate steering section lies entirely within a circular profile corresponding to the path of the gauge teeth when the bit is rotated 360° and a coupling section at a rear end portion of the body configured for attachments to an adjacent component of the drill sting.