Abstract: Disclosed herein are various embodiments of an Annular Pressure Control Diverter designed to be positioned below the conventional blowout preventer stack, and which will be activated during near balanced drilling operations to seal the annulus between the drill pipe and the production casing. Returned drilling fluid and produced fluids are diverted up the annulus between the production casing and intermediate casing and through a well head located below an all-inclusive BOP stack. The Annular Pressure Control Diverter does not rotate, and some embodiments have an elliptical internal cavity which ensures that the elliptical seals cannot rotate. Doors are provided on each side of the Annular Pressure Control Diverter to permit changing of the seal elements. Door locking mechanisms are provided for operator safety.

Abstract: A digital synthesizer is described that comprises: a ramp generator configured to generate a signal of frequency control words, FCW, that describes a desired frequency modulated continuous wave; a digitally controlled oscillator, DCO configured to receive the FCW signal; a feedback loop; and a phase comparator coupled to the ramp generator and configured to compare a phase of the FCW output from the ramp generator and a signal fed back from the DCO via the feedback loop and output a N-bit oscillator control signal. The digital synthesizer comprises a gain circuit coupled to a multiplier located between the ramp generator and the DCO and configured to apply at least one gain from a plurality of selectable gains to the N-bit oscillator control signal that set a selectable loop gain of the digital synthesizer and thereby set a selectable loop bandwidth; and calculate and apply a gain offset dependent upon the selected gain that is adapted when the selected gain is changed.

Abstract: A drill bit for drilling a borehole in earthen formations comprises a bit body including a cone region, a shoulder region, and a gage region. In addition the bit comprises a first primary blade and a second primary blade. Further, the bit comprises a plurality of primary cutter elements mounted to the first primary blade in different radial positions. Still further, the bit comprises a plurality of primary cutter elements mounted to the second primary blade in different radial positions. Moreover, a first primary cutter element of the plurality of primary cutter elements on the first primary blade and a first primary cutter element of the plurality of primary cutter elements on the second primary blade are each positioned in the cone region and are redundant. The shoulder region has a total cutter redundancy percentage that is less than a total cutter redundancy percentage in the cone region.

Abstract: A drill bit includes a bit body comprising at its upper end a connection adapted to connect to a drill string and at its lower end a plurality of journals extending downwardly and radially outward from a longitudinal axis of the bit. A plurality of roller cones are rotatably mounted on the plurality of journals and at least three rows of cutting elements are disposed on each of the plurality of roller cones. The outermost row of the at least three rows of cutting elements has an extension height to diameter ratio greater than a mid row, and the mid row has an extension height to diameter ratio greater than an innermost row.

Abstract: Described herein are roller cone drill bits and modified roller cones for use in drilling subterranean earth formations, and more specifically roller cone drill bits and roller cones having optimized spear point designs and blade orientations on at least one of the roller cones for reduced tracking and/or increased drilling performance during bit use. The roller cone drill bits include a bit body with a longitudinal axis, one or more bit legs depending from the body, and at least one roller cone attached to each of the bit legs and able to rotate with respect to the bit body, wherein at least one of the roller cones includes a spear point at the cone apex having two or more cutting blades, the cutting blades being oriented at a variety of non-equal, asymmetric angles about a central cone axis with respect to each other, such that tracking during drilling using the drill bit is minimized or eliminated.

Abstract: Drilling a sidetrack wellbore out of the side of an existing wellbore utilizing a drillable billet having a path formed in the billet to lead a bi-centered drillbit to kick-out from the wellbore and form a sidetrack wellbore. The bi-centered bit is arranged for the lands of the pilot section to follow the path of the billet while the wings of the ream out a portion of the billet and also ream out the earth to form the full dimension sidetrack wellbore. The bi-centered bit is used to drill the sidetrack wellbore to the target zone so that the entire drilling process extends from the existing wellbore to the target zone without a mandatory withdrawal of the drillstring from the wellbore.

Abstract: A drill bit for drilling a borehole in earthen formations. In an embodiment, the bit comprises a bit body having a bit axis and a bit face. In addition, the bit comprises a pin end extending from the bit body opposite the bit face. Further, the bit comprises a plurality of gage pads extending from the bit body, wherein each gage pad includes a radially outer gage-facing surface. The gage-facing surfaces of the plurality of gage pads define a gage pad circumference that is centered relative to a gage pad axis, the gage pad axis being substantially parallel to the bit axis and offset from the bit axis.

Abstract: An earth boring drill bit comprising a milled cutter having rows of teeth hardfacing guides on the cutter. Hardfacing is applied between adjacent teeth hardfacing guides to form a cutting element. The hardfacing may include an annular body with ridges that outwardly project from the body.

Abstract: A hybrid drill bit having both roller cones and fixed blades is disclosed, and a method of drilling. The cutting elements on the fixed blades form a continuous cutting profile from the perimeter of the bit body to the axial center. The roller cone cutting elements overlap with the fixed cutting elements in the nose and shoulder sections of the cutting profile between the axial center and the perimeter. The roller cone cutting elements crush and pre- or partially fracture formation in the confined and highly stressed nose and shoulder sections.

Abstract: A hybrid drill bit having both roller cones and fixed blades is disclosed. The cutting elements on the fixed blades form a continuous cutting profile from the perimeter of the bit body to the axial center. The roller cone cutting elements overlap with the fixed cutting elements in the nose and shoulder sections of the cutting profile between the axial center and the perimeter. The roller cone cutting elements crush and pre-fracture formation in the weak and highly stressed nose and shoulder sections.

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 two-cone drill bit with a hydraulic arrangement that can be used for one or more of the following: cleaning roller cones, impinging on a hole bottom, or inducing a helical flow field. A two-cone drill bit having a bit body formed from two leg sections and two spacing members; methods of manufacturing a two-cone drill bit; and methods of improving hydraulics of a two-cone drill bit are disclosed.

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: A bit having improved dropping tendencies includes a first plurality of cutters in an active region and a second plurality of cutters in a passive region. The second plurality of cutters has unique radial positions with respect to the first plurality of cutters. The first and the second pluralities of cutters also have cutting tips that extend to the primary cutting profile of the bit. A third plurality of cutters is located in the passive region with cutting tips positioned recessed from the primary cutting profile. A forth plurality of cutters is positioned as back up cutters in the active, region and includes cutters positioned in radial locations such that they overlap, when viewed in rotated profile, with cutters in the third plurality of cutters. The fourth plurality of cutters has cutting tips positioned to extend to the primary cutting profile. The cutters on the bit are arranged such that an imbalance force vector exists on the bit when used to drill though earth formation.

Abstract: The harmful effects of tracking are reduced for a drill bit having roller cones with at least one of the outermost rows of active teeth containing one or more teeth having a height that does not extend to the height of at least one of the outermost rows on another roller cone on the bit. The crest on this tooth may have a length in a circumferential direction that is wider than an overall width of the tooth in the outer to inner direction. The invention may be used on any cutter row, not just the outermost row. The design may be used on a different roller cone or row, or more than one cutter row. The anti-tracking feature may be located between the leading and trailing edges of the tooth on one or more roller cones.

Abstract: A two-cone drill bit that exhibits improved stability. In one embodiment, the two-cone drill bit has a first and a second roller cone arranged to have a cone separation angle between about 145 degrees and about 166 degrees. In some embodiments, the two-cone drill bit has a plurality of cutting elements arranged on the roller cones such that a bottom hole coverage greater than about 17 percent is achieved per revolution of the two-cone drill bit.

Abstract: A drill bit having cutting elements disposed on a roller cone surface in a non-linear pattern, wherein at least one of the cutting elements is asymmetrical to its axis of orientation. Also, a method for selecting and adjusting a cutting element orientation based on crater profile geometry which results in increased bottom hole coverage.

Abstract: Roller cone drill bits are provided with cutting elements and cutting structures optimized for efficient drilling of soft and medium formations interspersed with hard stringers. The cutting elements and cutting structures may be satisfactorily used to drill downhole formations with varying amounts of hardness. The cutting elements and cutting structures may also be optimized to reduce tracking and increase wear resistance.

Abstract: A drill bit assembly for direct removal of rock with a rotatable bit assembly (5) that includes a plurality of cutters or choppers (7). According to the invention, an number of cutters (7) are so disposed in relation to each other or the bit assembly (5) that a subsequent cutter (7b), seen in the direction of rotation, will engage an edge created by the action of preceding cutter (7a).

Abstract: This invention relates to a single cone bit with offset axis and composite cones for oil and gas drilling, mining and other subterranean drilling operations. The bit consists of a head body and a cone. The cone section has a shape of composite cones. The outer circumference of the cone is composed of from back face of the cone to top of the cone an extended gage surface, an outer cone surface and a main cone surface. A plurality of cutting elements is mounted onto each cone surface. A head journal at lower end of the head body is for rotatablely connection with the cone. Between the axis of head journal and the axis of the bit, there is an offset value d along rotating direction of the cone. A gage pad is arranged on head body at a location opposite to the offset direction of the head journal. The gage pad is fitted with inserts or hardfaced with wear resistant alloy to prevent bit from whirling and prevent head body from being worn out and to ensure gage protection.

Abstract: A method for evaluating a cutting arrangement for a drill bit includes selecting a cutting element arrangement for the drill bit and calculating a score for the cutting arrangement. This method may be used to evaluate the cutting efficiency of various drill bit designs. In one example, this method is used to calculate a score for an arrangement based on a comparison of an expected bottomhole pattern for the arrangement with a preferred bottomhole pattern. The use of this method has lead to roller cone drill bit designs that exhibit reduce tracking over prior art bits.

Abstract: An earth boring drill bit is constructed having rotatable cutter for forming a borehole in earth. At least one circumferential row of cutting elements is optimized to create overbreak of rock and eliminate tracking, wherein selected pitches have mathematically determined pairs and the absolute difference between the selected pitch and its pair is greater than 10% of the difference between maximum and minimum pitch for that circumferential row. Furthermore, cutting elements are placed along pre-selected generatrices with deviation from said generatrices, which is less than half the maximum pitch of circumferential rows occupied by said cutting element. The present invention eliminates tracking and reduces detrimental axial resonance frequency vibration while reducing cutting element count, including tungsten-carbide inserts, as compared to conventional roller cutter drill bits used for oil, gas and shot hole drilling wells and simultaneously increases footage drilled, drilling speed, and durability.

Abstract: A roller cone drill bit includes a bit body adapted to be coupled to a drill string, a bearing journal depending from the bit body, and a single roller cone rotatably attached to the bearing journal. The single roller cone has a plurality of cutting elements, where at least one of the plurality of cutting elements is formed of an inner region that is at least partially surrounded by an outer region, where the inner region is more abrasive resistant than the outer region. Such an arrangement in a single roller cone bit allows the at least one cutting element to be “self-sharpening.

Abstract: A roller bit is provided having super-abrasive inserts on cutting portions to assure that the bit will maintain cutting efficiency. In the described exemplary bits, the axes of the roller cones are also offset by a significant or “high offset” amount from the central longitudinal axis of the bit, thereby providing for increased shearing and grinding action by the bit. The use of high offset in combination with super-abrasive inserts provides for optimal bit cutting designs which provide increases in ROP while preserving the bit's ability to hold gage and remain durable to achieve acceptable footage. Minimum high offsets and preferred high offsets are described for various bit sizes, designs and nomenclatures, including milled tooth bits and insert-type bits designed for use in soft-through-medium formation hardnesses as well as formations with greater hardnesses.

Abstract: A PLL synthesizer (100) includes a gear-shifting scheme of the PLL loop gain constant, ?. During frequency/phase acquisition, a larger loop gain constant, ?1 is used such that the resulting phase error is within limits. After the frequency/phase gets acquired, the developed phase error, which is a rough indication of the frequency offset is in a steady-state condition. While transitioning into the tracking mode, the DC offset is added to the DCO tuning signal preferably the DC offset is added to the phase error signal and the loop constant is reduced from ?1 to ?2. This scheme provides for hitless operation, while requiring a low dynamic range of the phase detector (101).

Abstract: A method for optimizing drilling performance of a roller cone drill bit is disclosed. The method includes simulating drilling with the bit in a selected earth formation to determine at least one drilling performance parameter. The orientation of at least one non-axisymmetric cutting element on the bit is adjusted and the simulating the drilling and determining the at least one performance parameter are repeated. The adjusting and simulating the drilling are repeated until the at least one performance parameter is determined to be at an optimum value. In one embodiment, the performance parameter includes rate of penetration.

Abstract: A roller cone drill bit having selected left hand walk is disclosed. The bit includes a bit body adapted to couple to a drill string, and a plurality of legs depending from the bit body. Each leg has a roller cone rotatably mounted thereon. Each cone includes a plurality of cutting elements thereon. At least one cone has a nose point of its profile displaced radially inward with respect to a nose point of the profile of the other cones. A roller cone drill bit having selected right hand walk is also disclosed. The bit include a bit body adapted to couple to a drill string, and a plurality of legs depending from the bit body. Each leg has a roller cone rotatably mounted thereon, each cone including a plurality of cutting elements thereon defining a profile. At least one cone has a nose point of the profile displaced radially outward with respect to a nose point of the profile of the other cones.

Abstract: The invention provides a rock drilling bit with a plurality of cutting teeth raked into the cut of the drilling bit. Such teeth are oriented at an angle of at least about 30 degrees relative to an imaginary line normal to a front surface of the cutting head from which the cutting teeth project. Such an arrangement provides the desired shear cutting force against the rock face while simultaneously reducing the shock and vibration applied to sonde housing and the drill string. The bit according to the invention may further incorporate a rear, frustoconical crushing surface that defines a space or zone crescent-shaped in cross-section that narrows from front to rear, and an improved replacable tooth for use on a rock drilling bit.

Abstract: A method for optimizing drilling performance of a roller cone drill bit is disclosed. The method includes simulating drilling with the bit in a selected earth formation to determine at least one drilling performance parameter. The orientation of at least one non-axisymmetric cutting element on the bit is adjusted and the simulating the drilling and determining the at least one performance parameter are repeated. The adjusting and simulating the drilling are repeated until the at least one performance parameter is determined to be at an optimum value. In one embodiment, the performance parameter includes rate of penetration.

Abstract: One aspect of the invention is a roller cone drill bit including a bit body having three legs depending therefrom, each leg having a journal, a roller cone rotatably mounted on each journal, and each roller cone having a plurality of cutting elements thereon. The cutting elements are arranged in rows on each cone. The rows include at least a gage row and a first row interior of the gage row. The first interior row is staggered with respect to the gage row on each of the three cones. Another aspect of the invention is a roller cone drill bit including a bit body having three legs depending therefrom. Each leg has a journal, a roller cone rotatably mounted on each journal, and each roller cone has a plurality of cutting elements thereon. The cutting elements are arranged in rows on each cone. The rows include at least a gage row and a first row interior of the gage row. The first interior row is staggered with respect to the gage row on at least two of the three cones.

Abstract: A method for optimizing drilling performance of a roller cone drill bit is disclosed. The method includes simulating drilling with the bit in a selected earth formation to determine at least one drilling performance parameter. The orientation of at least one non-axisymmetric cutting element on the bit is adjusted and the simulating the drilling and determining the at least one performance parameter are repeated. The adjusting and simulating the drilling are repeated until the at least one performance parameter is determined to be at an optimum value. In one embodiment, the performance parameter includes rate of penetration.

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 drill bit including a roller cone and fixed cutters positioned external to the roller cone and radially from the bit axis of rotation. The roller cone is located so that a drill diameter of the cone is substantially concentric with an axis of rotation of the bit. The fixed cutters can be made of tungsten carbide, polycrystalline diamond, boron nitride, or any other superhard material. The fixed cutters are positioned to either maintain the hole diameter drilled by the roller cone or to drill a larger diameter hole than the hole drilled by the roller cone. The single roller cone may be located in the center of a multi-cone bit arrangement or in the center of a PDC bit to assist in drilling the center of a wellbore. The single roller cone may be used to form a bi-center bit in combination with a reaming section. The single roller cone may also be located on an independent sub that is removably attached to the bit body.

Abstract: A drill bit for cutting a formation that tends to form ridges comprises: a bit body having a bit axis, a plurality of rolling cone cutters rotatably mounted on the bit body, with each rolling cone cutter having a generally conical surface, a plurality of primary cutter elements extending from one of the cone cutters in a first row, each primary cutter element having an outer side and an inner side, and a plurality of ridge-cutting cutter elements extending from the same cone cutter, the first plurality of ridge-cutting cutter elements being positioned adjacent to the outer side of the first row of primary cutter elements. Each ridge-cutting cutter can be, but is not necessarily, on the same cone cutter as the primary cutter element adjacent to which it cuts, and is preferably positioned on a land or flat adjacent to that primary cutter element.

Abstract: A roller bit is provided having super-abrasive inserts on cutting portions to assure that the bit will maintain cutting efficiency. In the described exemplary bits, the axes of the roller cones are also offset by a significant or “high offset” amount from the central longitudinal axis of the bit, thereby providing for increased shearing and grinding action by the bit. The use of high offset in combination with super-abrasive inserts provides for optimal bit cutting designs which provide increases in ROP while preserving the bit's ability to hold gage and remain durable to achieve acceptable footage. Minimum high offsets and preferred high offsets are described for various bit sizes, designs and nomenclatures, including milled tooth bits and insert-type bits designed for use in soft-through-medium formation hardnesses as well as formations with greater hardnesses.

Abstract: A roller cone drill bit in which the orientations of the teeth are varied within a single row, and/or between the heel row of one cone and the heel row of another cone, to prevent tracking.

Abstract: The invention is directed to a roller cone drill for drilling earth formations. The drill bit includes a bit body and a plurality of roller cones attached to the bit body and able to rotate with respect to the bit body. The drill bit further includes a plurality of teeth disposed on each of the roller cones such that the number of teeth on each cone differs by two or fewer from the number of teeth on each of the other cones. In one preferred embodiment, the drill bit includes three roller cones. In another preferred embodiment, the teeth of the bit are arranged on each cone so that teeth on adjacent cones intermesh between the cones. In another preferred embodiment, the drill bit includes a first cone, a second cone, and a third cone, and the number of teeth on each of the cones is 17, 16, and 18, respectively.

Abstract: An earth-boring bit for removing rock and earthen formation while being rotated includes a generally circular bit body. A plurality of saddle members are mounted to the bit body, each saddle member supporting and receiving a journal member. A cutter shell is rotatably mounted on bearings disposed on each journal member. A kerf ring is releasably secured to each cutter shell. Each kerf ring includes at least two kerfs circumferentially disposed around the rings, each kerf having a longitudinal axis and a pair of opposing sides that converge to define a crest for receiving inserts for disintegration of formation material. The kerfs are oriented on the kerf ring such that the longitudinal axes of the inserts diverge as the kerfs extend radially outward from the kerf ring. The inserts embedded in each kerf are generally flush with the sides of the kerf and protrude from the crest.

Abstract: An earth-boring bit for drilling a borehole comprises a bit body having a bit axis, at least two rolling cone cutters rotatably mounted on the bit body, a plurality of inner row cutter elements positioned on at least one cone cutter in a first inner row, a plurality of gage-cutting cutter elements positioned in a first fanned-gage row on a first one of the one cutters, and a plurality of gage-cutting cutter elements positioned in a second fanned-gage row on a second one of the one cutters, wherein the gage-cutting cutter elements on the bit define a gage curve and cutter elements in the first fanned-gage row and the second fanned-gage row contact the gage curve at different points. In one embodiment, each cutter element has an extension, and the extensions of the uppermost fanned-gage row cutter element and the first inner row cutter element define a step distance such that the ratio of the step distance to the extension of the first inner row cutter element is greater than 0.5.

Abstract: A roller bit is provided having super-abrasive inserts on cutting portions to assure that the bit will maintain cutting efficiency. In the described exemplary bits, the axes of the roller cones are also offset by a significant or “high offset” amount from the central longitudinal axis of the bit, thereby providing for increased shearing and grinding action by the bit. The use of high offset in combination with super-abrasive inserts provides for optimal bit cutting designs which provide increases in ROP while preserving the bit's ability to hold gage and remain durable to achieve acceptable footage. Minimum high offsets and preferred high offsets are described for various bit sizes, designs and nomenclatures, including milled tooth bits and insert-type bits designed for use in soft-through-medium formation hardnesses as well as formations with greater hardnesses.

Abstract: This invention relates to a roller bit applying for the oil, natural gas, mine and geological drilling, and more particularly relates to a kind of roller bit with the parallel inlayed compacts, it includes head and cone, the compact land and the teeth-groove are arranged on the cone, the difference is that there are 2 to 3 compacts having the cylindrical body being arranged on the top of the base teeth along the teeth direction. The cutting performance of the present invention is similar to that of the oblate compacts, and, by utilizing the conventional cylindrical compacts, it is not only easy to process and with low manufacturing cost, but the bit can effectively drill through the stringered earth formation with both hard and soft formation and thus better economic benefit from drilling the stringered formation can be obtained.

Abstract: An improved drill bit for directional drilling includes a housing or headpiece having means at a rear end thereof for mounting the bit on a trailing component of a drill head, and passages for ejection of drilling fluid into a borehole. A first axle is mounted to extend forwardly from a front end of the housing, and a first roller is rotatably mounted on the first axle. The first roller has cutting projections such as carbide studs thereon and extends outside of the outer diameter of the housing by a distance which defines the size of the borehole when the drill bit is rotated over 360 degrees. A second axle is mounted to extend from the front end of the housing, and a second roller is rotatably mounted on the second axle at a position offset from the first axle. The second roller extends slightly outside of the outer diameter of the housing, but by a distance less than the distance the first roller extends outside of the housing.

Abstract: A drill bit that is arranged to change the direction of drilling. A cone head is rotatably mounted on a shank portion extending from an elongate housing. When the housing is rotated, the cone head generates a concave hole. When a change in direction is required, the housing is rotated a few degrees in one direction and then counter-rotated in the opposite direction. This generates a partial but redirected pilot hole that is also substantially concave in configuration. Continued full rotation causes the drill bit to follow the partial pilot hole in the new direction.

Abstract: The invention provides an improved apparatus for directional boring and in particular an improved system for boring through hard and rocky substrates frequently encountered when boring under obstacles such as roadways. According to one aspect of the invention, a directional drilling apparatus includes a drilling head having a front face angled relative to the lengthwise axis of the tool and configured for steering the drilling apparatus, a housing having an internal chamber for mounting an electronic locating device therein rearwardly of the drilling head for transmitting a signal indicating the orientation of the angled face of the drilling head, and a joint at which the drilling head is removably mounted to the housing of the locating device.

Abstract: A drill bit for cutting a formation that tends to form ridges comprises: a bit body having a bit axis, a plurality of rolling cone cutters rotatably mounted on the bit body, with each rolling cone cutter having a generally conical surface, a plurality of primary cutter elements extending from one of the cone cutters in a first row, each primary cutter element having an outer side and an inner side, and a plurality of ridge-cutting cutter elements extending from the same cone cutter, the first plurality of ridge-cutting cutter elements being positioned adjacent to the outer side of the first row of primary cutter elements. Each ridge-cutting cutter can be, but is not necessarily, on the same cone cutter as the primary cutter element adjacent to which it cuts, and is preferably positioned on a land or flat adjacent to that primary cutter element.

Abstract: A one cone drill bit is equipped with multiple jet flow guiding grooves along the cone. The multiple grooves connects to a circular groove axially centered on the nose end portion of the cone. The circular groove sweep the cuttings and mud flow across the drilled face and up the well borehole.

Abstract: A novel and improved roller cone drill bit and method of design are disclosed. A roller cone drill bit for drilling through subterranean formations having an upper connection for attachment to a drill string, and a plurality cutting structures rotatably mounted on arms extending downward from the connection. A number of teeth are located in generally concentric rows on each cutting structure. The actual trajectory by which the teeth engage the formation is mathematically determined. A straight-line trajectory is calculated based on the actual trajectory. The teeth are positioned in the cutting structures such each tooth having a designed engagement surface is oriented perpendicular to the calculated straight-line trajectory.

Abstract: Directional boring bits (1100, 1200) are disclosed which have at least one roller cone (1202, 1104) and also each define a deflecting surface (1104) for deflecting the boring bit when the bit is advanced without rotation. The borehole can be curved by pushing the bit forward without rotation.

Abstract: A directional boring machine equipped with a boring head comprising a blade assembly. The blade assembly may comprise a plurality of blades with deflecting surfaces. Alternately, the blade assembly has a single, stepped or serrated blade. The serrated blade assembly has a planar blade which is tapered in thickness and width from its base to its forward end. The forward end has teeth cut away on the backside to provide a recess or relief space for cuttings during the drilling process. A relief space or slot also is provided between the front two teeth for the same purpose. The blade is divided into two halves, and the halves are offset so that each of the teeth on each half provides a separate cutting point. The blade is angled in an upward direction relative to the base of the blade assembly to improve penetration and cutting actions. The blade assembly in combination with the boring head body provides exceptional cutting performance in a variety of soils and rock.

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.