Abstract: Methods for operating drill strings in a wellbore include providing a drilling apparatus that includes a Kelly drive system for rotating the drill string that includes a bottom hole assembly (BHA) and a Kelly engaged with the Kelly drive system. The BHA includes a hydraulically driven rotating string reamer coupled to the drill string uphole from a drill bit and a near-bit reamer. The hydraulically driven rotating string reamer includes a hydraulic drive operatively coupled to a string reamer. The methods include translating the BHA axially through the wellbore and, while translating the BHA, circulating drilling fluid through the drill string, which causes the hydraulic drive to rotate the string reamer relative to the drill string, drill bit, and near-bit reamer. Rotation of the string reamer by the hydraulic drive reams away imperfections extending radially inward from a wellbore wall of the wellbore.

Abstract: A reversible polycrystalline diamond compact (PDC) bit. The reversible PDC bit includes at least one blade, at least one front cutter disposed on a first side of the at least one blade, and at least one rear cutter disposed on a second side of the at least one blade, wherein the first side is opposite to the second side along a circumferential direction of the reversible PDC bit, wherein rotating the reversible PDC bit in a clockwise direction engages the at least one front cutter to cut into a subterranean formation, and wherein rotating the reversible PDC bit in a counter-clockwise direction engages the at least one rear cutter to cut into the subterranean formation.

Abstract: A drilling system having retractable wings and method of using same. The system includes at least one wing, which can extend from the system once it engages in a casing and abuts against an abutment ring at the bottom end of the casing. When the system starts drilling a hole into the ground, the casing is installed down the hole. In one configuration, the at least one wing is at least partially retracted into the drilling system and locked in this position. In another configuration, the at least one wing extends from the drilling system and locks into an extended position. The system can be connected to a down-the-hole hammer, a top-hammer drilling rod, or any other suitable rock drilling tool/apparatus, and can be used with a single and a dual rotary drilling tool/apparatus.

Abstract: A reamer (1) for underground passageways, comprising: a support housing (3) and a plurality of radially extending cutting wings (11); a plurality of ring segments (13), wherein each ring segment (13) includes an arcuate ring portion (15), wherein the plurality of ring segments (13) are assembled to form a stabilization ring (17) bridging radial outer edges (12) of the plurality of cutting wings (11), wherein the stabilization ring (17) is fastened to at least one of the cutting wings (11) to resist radial movement of the reamer (1).

Abstract: A screw drill bypass valve comprising a valve body, the valve body is internally provided with a first-level valve core and a second-level valve core, a first-level spring is arranged between the first-level valve core and the second-level valve core, a second-level spring is arranged between the second-level valve core and a valve seat, and a rigidity of the second-level spring is greater than that of the first-level spring; the first-level valve core is provided with an inner bypass hole, the valve body is provided with an outer bypass hole, and the inner bypass hole is conducted with the outer bypass hole when a flowing pressure within a fluid channel of drilling fluid disappears; the second-level valve core is provided with an inner diversion hole, the valve body is provided with an outer diversion hole.

Abstract: A method for selecting a bottomhole assembly (BHA) includes inputting BHA parameters, wellbore parameters, and drilling operating parameters, performing a dynamic simulation of a first BHA based on the BHA parameters, wellbore parameters, and drilling operating parameters, and presenting a wellbore quality factor of the first BHA calculated from the dynamic simulation.

Abstract: An over-bit backreamer. The backreamer is configured to be placed over a bit without detaching the bit from a drill string associated with a pilot bore. The backreamer has an internal surface that conforms to a steering surface of the bit. Rotation is transferred from the bit to the backreamer at the internal surface. The backreamer further defines a flange which interacts with a feature, such as a heel, on the bit. The flange and heel form a shoulder which transfers pullback force to the bit. The backreamer comprises a pullback eye that pulls a product pipe back through the borehole.

Abstract: A drilling device for drilling a hole in the ground and/or rock and having in its drilling head a plurality of drilling wing bits arranged at equal distribution with their mutual position being adjustable such that the wing bits are located within a minimum diameter dimension and, on the other hand, adjustable such that they are located to drill a hole with a maximum size diameter and that the drilling device is arranged to pull, during drilling, a protective pipe into the hole at least when drilling the hole in the ground. An outer circumference of the wing bits includes a circumferential groove arranged to receive a ring belonging to a front part of the protective pipe, to an inner surface thereof, when the wing bits are adjusted to a diameter size substantially larger than the minimum diameter dimension in order to pull the protective pipe via the wing bits.

Abstract: Earth-boring tools include a body, at least one first blade extending outward from the body, and at least one second blade extending outward from the body. The at least one first blade includes an upper surface, a first gage region having a first longitudinal length, and a recess extending at least partially into the at least one first blade from the upper surface. The at least one second blade includes a second gage region having a second, greater longitudinal length. Additional earth-boring tools include first blades having first gage regions of a first longitudinal length and second blades having second gage regions of a second, greater longitudinal length. An upper external surface is tapered radially outward in a longitudinally upward direction relative to a central axis of the earth-boring tool. Methods including forming such first and second blades and removing material from the first blades to form recesses.

Abstract: A reamer device that uses polycrystalline diamond compact (PDC) cutting elements mounted to the reamer blades. The device includes a body that defines a cutting face, a gage region and an extended end, and includes multiple blades disposed along the gage region of the body. Each of the multiple blades multiple planar surfaces, and a plurality of cutting elements positioned along the length of each of the multiple blades. The cutting elements disposed along second and third planar surfaces of each blade being slightly offset from the other blades such that in application the rotating multiple blades cause an upwardly spiraling effect.

Abstract: A coring tool may comprise a core bit, and the core bit may comprise at least one cutting structure extending from adjacent an inner bore of the core bit to an outer gage of the core bit. A drill plug may be configured to close the inner bore of the core bit, and the drill plug may comprise at least one cutting structure. An indexing device may be disposed between the drill plug and the core bit. The indexing device may be configured to maintain a predetermined angular relationship between the core bit and the drill plug. The at least one cutting structure of the core bit and the at least one cutting structure of the drill plug may form a substantially continuous cutting structure at the predetermined angular relationship. Related methods of drilling with a coring tool.

Abstract: The present invention provides a hard-rock core barrel roller cutter assembly, which comprises a roller cutter and a saddle. The roller cutter comprises a base portion for operating, and a connecting portion integrated with the base portion and detachably connected to the saddle. The connecting portion has a butted oblique plane, and a width of the connecting portion is gradually increased from one end adjacent to the base portion to another end far away from the base portion. A fixing block is detachably connected to the saddle, and the fixing block has a pressure slope which matches with the butted oblique plane. A width of the fixing block is gradually decreased from one end adjacent to the base portion to another end far away from the base portion, and the saddle is muff-jointed out of the connecting portion and the fixing block.

Abstract: A method of forming a wellbore is disclosed. An inner string and an outer string are conveyed downhole. The inner string is attached to the outer string at a first location and the wellbore is formed. The inner stringy is attached to the outer string at a second location us hole of the first location and an annulus between the outer string and the wellbore is cemented without retrieving the inner string from the wellbore.

Abstract: The expandable tools disclosed herein may be used as an underreamer to enlarge a borehole, or may be used to stabilize a drilling system in a previously underreamed borehole or in a borehole that is being underreamed while drilling progresses. At least one moveable arm, which translates between a collapsed and expanded position in response to a differential pressure between the axial flowbore and the wellbore, includes a borehole-engaging surface with cutting elements and at least one nozzle to direct a fluid across the borehole-engaging surface. Flow directing elements on the external surface of the tool may be used to decrease the flow area in an annulus between the tool and the wellbore and directs fluid flow in the annulus toward the borehole-engaging surface.

Abstract: The present invention provides apparatus and methods for controlled steering. One embodiment of the invention provides a bit body comprising a trailing end, a pilot section, and a reaming section. The trailing end is adapted to be detachably secured to a drill string. The pilot section is located on a leading, opposite end of the bit body. The reaming section is located intermediate to the leading and trailing ends. The pilot section comprises at least one steering device for steering the pilot section of the bit body, thereby steering the entire bit body. Another embodiment of the invention provides a wellsite system comprising a drill string; a kelly coupled to the drill string; and a bit body as described above. Another embodiment of the invention provides a method of drilling a curved borehole in a subsurface formation.

Abstract: A drill bit having a bit body intermediate a shank and a working face having at least one cutting insert. A bore is formed in the working face co-axial within an axis of rotation of the drill bit. A jack element is retained within the bore by a retaining element that intrudes a diameter of the bore.

Abstract: An apparatus for drilling a hole in the ground has a hammer drill installed at a bottom of a rod assembled in multi-stages at support structure on the ground. The hammer drill has a pilot hammer drill and a reamer hammer drill coupled to each other through a key structure formed in the vertical direction so as to allow simultaneous rotations and up-and-down movements relative to each other.

Abstract: A subterranean support-bolt drilling assembly has a drill bit rotatable about a central axis and including at least one cutting edge. The drilling assembly also includes a spacer coupled to a rearward end of the drill bit. A reamer member is coupled to a rearward end of the spacer, the reamer member having at least one cutting element, the at least one cutting element having a cutting edge that extends radially beyond an outer peripheral portion of the drill bit relative to the central axis. A subterranean support-bolt drill bit includes a bit body and at least one cutting element coupled to the bit body. The support-bolt drill bit has a central pilot extending from the bit body in an axially forward direction. The cutting edge of the at least one cutting element extends radially beyond the central pilot relative to a central axis of the drill bit.

Abstract: In one aspect of the present invention, a steering assembly for downhole directional drilling comprises an outer bit comprising a bore and an outer cutting area and in inner bit comprising an inner cutting area and connected to a shaft that is disposed within the bore. At least one biasing mechanism is disposed around the shaft. At least one fluid channel is disposed within the outer bit and redirects fluid to the at least one biasing mechanism causing the at least one biasing mechanism to push the shaft and alter an axis of the inner bit with respect to an axis of the outer bit.

Abstract: The invention relates to a drill for realizing a partially tapered bore hole in a soil covering a hardpan layer. The drill comprises a rotatable drivable unit that is provided with a carrying structure and a multiple number of cutting elements carried by the carrying structure. The multiple number of cutting elements are arranged along a line extending substantially radially and outwardly from a central axis of the rotatable drivable unit. Further, lower ends of cutting elements in a radial inner section are mainly positioned in a plane transversely to the rotation axis of the rotatable drivable unit. Lower ends of cutting elements in a radial outer section are mainly positioned in a downwardly tapered surface having a symmetry axis coinciding with the rotation axis of the rotatable drivable unit. The lower ends of the cutting elements may subscribe, during rotation, a truncated cone surface.

Abstract: Drill assembly for making a hole into a soil or rock which arrangement comprises a pilot bit (10) drilling the middle part of the hole and a ring bit (1) drilling the outer circle of the hole in which case in the drilling situation the ring bit (1) is adjusted around the pilot bit (10) and rotary movement and drilling impacts are directed from the pilot bit (10) to the ring bit (1) with the help of the mentioned surfaces (4-6);(7-9),(15, 16) adjusted between the bits and conveying power and that the ring bit (1) can be removed around the pilot bit (10) and can be installed to it and that further a coupling ring (2) belongs around the ring bit (1) in order to join a casing pipe, which can be pulled to the drilled hole, to the ring bit (1) with the help of the mentioned coupling ring. The coupling ring.

Abstract: A bottom hole assembly to directionally drill a subterranean formation includes a drill bit, a stabilizer assembly located proximate to and behind the drill bit, a drilling assembly comprising a drive mechanism and a directional mechanism, and a flex housing integral with the drilling assembly.

Abstract: Methods, systems, and tool assemblies for distributing weight between a bit and a reamer device are disclosed. For example, at least one of the drill bit and the reamer may be configured to selectively distribute a weight-on-bit between the drill bit and the reamer, such as within a predetermined range. Additionally, methods of drilling wellbores may include selectively distributing a weight-on-bit applied to a bottom hole assembly between a drill bit and a reamer of the bottom hole assembly. Also, a reamer may be configured to exhibit a first maximum rate-of-penetration into a relatively hard formation, and a drill bit may be configured to exhibit a second maximum rate-of-penetration into a relatively soft formation that is less than the first maximum rate-of-penetration.

Abstract: A reamer bit for use in earth boring operations comprising a body, four cutter mounts, rolling cutters on each mount, and cutting elements disposed on each cutter arranged so adjacent cutting swaths formed by the bit are created by cutting elements on cones of oppositely disposed cutter mounts. The swaths are generally curvilinear, wherein the outermost swaths are formed by cutting element rows on the outer portion of the cutters. The reamer bit can further comprise a pilot bit.

Abstract: In one aspect of the invention a rotary mine roof drilling apparatus has an arm attached to and intermediate a drill bit and a platform. The apparatus also has a thrusting mechanism adapted to push the drill bit into a mine roof. The drill bit has a bit body intermediate a shank and a working surface. The working surface has a cutting element with a carbide substrate bonded to a diamond working end with a pointed geometry; and the diamond working end has a 0.050-0.200 inch apex radius.

Abstract: In one aspect of the present invention, a drill bit assembly for downhole drilling comprises an outer bit comprising a central axis and an outer cutting area and an inner bit disposed within the outer bit and comprising an inner cutting area. The outer bit comprises a first plurality of cutting elements and the inner bit comprises a second plurality of cutting elements wherein an average distance of each cutting element in the first plurality to the central axis forms a first moment arm and an average distance of each cutting element in the second plurality to the central axis forms a second moment arm. A ratio of the inner cutting area to the outer cutting area is substantially equal to a ratio of the outer moment arm to the inner moment arm.

Abstract: A drill bit made according to one embodiment includes a first member including one of a magnet and a coil, and a second member that moves relative to the first member, the second member including the other of the magnet and the coil, wherein the relative motion causes the generation of an electrical charge in the coil.

Abstract: A wet drill bit assembly and a dry drill bit assembly for cutting a borehole in the earth strata of a mine wherein the borehole has a reduced dimension interior region and an enlarged dimension exterior region. The wet drill bit assembly includes an axial forward spade-style cutting member, which has a spade hard cutting member with a first transverse cutting dimension, and an axially spaced apart axial rearward reamer cutting member, which has a hard insert with a second transverse cutting dimension, which is greater than the first transverse cutting dimension. The dry drill bit assembly includes an axial forward cutting member, which has an axial forward hard cutting insert with a first transverse cutting dimension, and an axially spaced apart axial rearward hard cutting insert that has a second transverse cutting dimension which is greater than the first transverse cutting dimension. An elongate sleeve is adapted to receive cutting debris from the operation of the axial forward hard cutting insert.

Abstract: A drilling apparatus which includes a drill bit attachable to the drilling end of a drill string, the drill bit including a bit body being attached to a shank and having a working face with at least one cutting element. The drilling apparatus also includes a jack element positioned within a bore of the bit body having a working tip substantially protruding from the working face, and which jack element is also adapted to move with respect to the bit body. One or more position feedback sensors are positioned proximate the jack element and are adapted to detect the axial and/or angular position of the jack element with respect to the bit body.

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 directional drilling system comprises a main drill bit 24 rotatable about a main bit axis 26, a pilot drill bit 34 rotatable about a pilot bit axis 36 substantially parallel to the main bit axis 26, and adjustment means 28 for adjusting the position of the pilot bit axis 36 relative to the main bit axis 26.

Abstract: A drill bit assembly comprising a bit body connectable to a tubular drill string, and provided with a longitudinal passageway for an operating tool; an externally removable closure element for closing the passageway for the operating tool; and a passage tool attached to or connectable to the closure element in its closing position, wherein the passage tool comprises a lower part to which the closure element is attached or connectable, which lower part is arranged so that it can be moved out of the bit body together with the closure element, and an upper tubular part which is arranged so that it can be moved along the passageway in the bit body, the upper tubular part forming a passage with a downstream opening for the operating tool when the lower part of the passage tool has been moved out of the bit body.

Abstract: A system and method for boring a hole in rock with a digger derrick; which utilizes a hollow stem auger, a kelly bar, and a core barrel with a top support member with a hole therein for receiving the kelly bar with a detachable central pilot bit thereon which is translatable up and down with respect to the core barrel as the kelly bar and auger are manipulated. The kelly bar is selectively positionable with respect to the auger so as to allow the ability to retract the pilot bit inward into the core barrel and to shorten the separation between the pilot bit and the auger.

Abstract: A drilling assembly comprises a drill bit that includes a bit body intermediate a working face and a shank. An indenting member adapted to guide the drill bit protrudes from the working face. A flexible portion is disposed above the bit body.

Abstract: Drilling apparatus comprises: a body; a pilot hole-drilling assembly (14) mounted to the body for drilling a pilot hole of a first diameter; and a hole-opening assembly (16) mounted to the body for opening the pilot hole to a larger second diameter. The apparatus is configured such that the pilot hole-drilling assembly (14) will drill at a faster rate than the hole-opening assembly (16) for a given unit loading. As the pilot hole-drilling assembly (14) has the capability to drill at a faster rate than the hole-opening assembly (16), the pilot hole-drilling assembly will tend to experience relatively low weight-on-bit (WOB). The pilot hole-drilling assembly (14) will thus tend to maintain a vertical orientation. The hole-opening assembly (16) will follow the path of the pilot hole, while opening the hole to the required diameter.

Abstract: A drill bit has an axis of rotation and a working face with a plurality of blades extending outwardly from a bit body. The blades form, in part, an inverted conical region, and a plurality of cutters with a cutting surface is arrayed along the blades. A jack element is coaxial with the axis of rotation and extends within the inverted conical region within a range defined by the cutting surface of at least one cutter.

Abstract: A completion arrangement and methods of using the completion arrangement are described herein. The completion section includes a completion section and impacting formations. The completion section is arranged to be coupled to production tubing, and has means to allow hydrocarbons to pass therein from reservoir rock in which the wellbore is formed. The impacting formations are drivingly moveable relative to the wellbore. The means being arranged to serve as flushing portals, whereby drilling fluid introduced into the production tubing is arranged to flow via the means into a space between the production tubing and the wellbore, and circulate in the space and the impacting formations. One, or both, of the drilling fluid circulating in the space and the impacting formations are arranged to remove obstructing material and formations from the wellbore for return to surface by way of the space, during insertion of the completion arrangement into the wellbore.

Abstract: A casing bit, which may comprise a composite structure, for drilling a casing section into a subterranean formation, and which may include a portion configured to be drilled therethrough. Cutting elements and methods of use may be included. Adhesive, solder, electrically disbonding material, and braze affixation of a cutting element may be included. Differing abrasive material amount, characteristics, and size of cutting elements may be included. Telescoping casing sections and bits may be included. Embodiments may include: at least one gage section extending from the nose portion, at least one rotationally trailing groove formed in at least one of the plurality of blades, a movable blade, a leading face comprising superabrasive material, at least one of a drilling fluid nozzle and a sleeve, grooves for preferential failure, at least one rolling cone affixed to the nose portion, at least one sensor, discrete cutting element retention structures, and percussion inserts.

Abstract: A casing bit, which may comprise a composite structure, for drilling a casing section into a subterranean formation, and which may include a portion configured to be drilled therethrough. Cutting elements and methods of use may be included. Adhesive, solder, electrically disbonding material, and braze affixation of a cutting element may be included. Differing abrasive material amount, characteristics, and size of cutting elements may be included. Telescoping casing sections and bits may be included. Embodiments may include: at least one gage section extending from the nose portion, at least one rotationally trailing groove formed in at least one of the plurality of blades, a movable blade, a leading face comprising superabrasive material, at least one of a drilling fluid nozzle and a sleeve, grooves for preferential failure, at least one rolling cone affixed to the nose portion, at least one sensor, discrete cutting element retention structures, and percussion inserts.

Abstract: A casing bit, which may comprise a composite structure, for drilling a casing section into a subterranean formation, and which may include a portion configured to be drilled therethrough. Cutting elements and methods of use may be included. Adhesive, solder, electrically disbonding material, and braze affixation of a cutting element may be included. Differing abrasive material amount, characteristics, and size of cutting elements may be included. Telescoping casing sections and bits may be included. Embodiments may include: at least one gage section extending from the nose portion, at least one rotationally trailing groove formed in at least one of the plurality of blades, a movable blade, a leading face comprising superabrasive material, at least one of a drilling fluid nozzle and a sleeve, grooves for preferential failure, at least one rolling cone affixed to the nose portion, at least one sensor, discrete cutting element retention structures, and percussion inserts.

Abstract: Taught is an auger having a working head (15), a ratcheting T-handle (50), and a shaft (20) attached there between forming a hand-powered ratcheting auger for drilling holes near the ground surface. Shaft (20) may include one or more lengths of extension shaft parts to control the length of the shaft. Working head (15) contains a drill-bit (14), semi-circular non-planar cutting blades (12), a working head shaft part (22), with the drill-bit and cutting blades fixedly attached to the working head shaft part and shaft part (22) detachably attached to shaft (20). The auger may also include an air induction unit 66 including an air-receiving opening in the T-shaped handle; an air-line 60 positioned within a hollow of the shaft connecting the air-receiving opening with air exhaust openings so as a jet of the air can blow out of said auger to break up and blow away the drilling detritus.

Abstract: An apparatus for drilling a wellbore (10) is disclosed, the apparatus comprising a lowermost pilot drill bit (16) having a diameter less than that of the diameter of wellbore (12) drilled by the apparatus, above which is a reamer, having an adjustable drill diameter from a first diameter less than that of the pilot drill to a second diameter greater than that of the pilot drill, above which is a body portion (24) having a lower diameter less than that of the pilot drill and an upper diameter greater than that of the pilot' drill but less than the second diameter of the reamer.

Abstract: A method of forming a supported subterranean well bore in which, in one disclosed embodiment, a first drill bit is mounted on a first string of casing tubulars via a steerable tool, and the drill bit is used to form a first bore. Upon reaching the required depth the casing string is cemented in place to support the formed bore and a second drill bit is mounted on a second casing string and is inserted into the first casing string. The second drill bit is used to drill through the wall of the first casing string and proceed to form a second, deeper bore. Once the second drill bit has reached the required depth, the second casing string is cemented in place to support the second bore.

Abstract: A directional drilling apparatus include a first cutter that substantially cuts a wellbore bottom along a first axis and a second cutter that cuts the wellbore bottom along a second axis different from the first axis. The second cutter may extend an adjustable amount out of the first cutter. In another embodiment, a pilot string may connect the second cutter to the first cutter.

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: A drilling tool has a body with a main drilling region and a pilot drilling region, eccentric to the main drilling region. The main drilling region has main blades and the pilot drilling region has pilot blades. The main drilling region has a main pass-through diameter, centered upon a first axis, one of the main blades extending to the main pass-through diameter, the pilot region having a pilot gauge diameter, centered upon a second axis of rotation at least one of the pilot blades extending to the pilot gauge diameter, wherein part of a circle of diameter equal to the pilot gauge diameter and centered upon the second axis of rotation extends outside of a circle of diameter equal to the main pass-through diameter and centered upon the first axis.

Abstract: A particle impact drilling system and method are described. In several exemplary embodiments, the system and method may be a part of, and/or used with, an apparatus or system, methods, to excavate a subterranean formation. The system can including, for example, removing near-borehole damage, casing, window milling, fishing, drilling with casing, under reaming, coring, perforating, effective circulatory density management, assisted annular flow, and directional control. Embodiments of associated systems and methods are also included.

Abstract: A casing bit, which may comprise a composite structure, for drilling a casing section into a subterranean formation, and which may include a portion configured to be drilled therethrough, is disclosed. Cutting elements and methods of use are disclosed. Adhesive, solder, electrically disbonding material, and braze affixation of a cutting element are disclosed. Differing abrasive material amount, characteristics, and size of cutting elements are disclosed. Telescoping casing sections and bits are disclosed. Aspects and embodiments are disclosed including: at least one gage section extending from a nose portion, at least one rotationally trailing groove formed in at least one of the plurality of blades, a movable blade, a leading face comprising superabrasive material, at least one of a drilling fluid nozzle and a sleeve, grooves for preferential failure, at least one rolling cone affixed to the nose portion, at least one sensor, discrete cutting element retention structures, and percussion inserts.

Abstract: A reamer for subterranean wellbores may include a composite framework, which may include one or more high strength stems, each having one or more reamer bodies coupled thereto. The body may include a plurality of plates coupled together and may include additional components formed integrally therewith or coupled thereto. A method of forming a reaming tool may include forming a high strength stem and a reamer body and coupling the body to the stem. A method of using the reaming tool may include coupling one or more bodies in a drill string and reaming a wellbore.

Abstract: The drilling of a casing bit and any other equipment in the casing with another casing bit where at least two casing bits of different diameter and having associated casing sections may be assembled to form a drilling assembly for drilling subterranean formations, the at least two casing bits and casing sections are arranged in a telescoping relationship.