Abstract: A cutting element for an earth-boring tool. The cutting element comprises a substrate base, and a volume of polycrystalline diamond material on an end of the substrate base. The volume of polycrystalline diamond material comprises a generally conical surface, an apex centered about a longitudinal axis extending through a center of the substrate base, a flat cutting surface extending from a first point at least substantially proximate the apex to a second point on the cutting element more proximate a lateral side surface of the substrate base. Another cutting element is disclosed, as are a method of manufacturing and a method of using such cutting elements.

Abstract: A drill pipe made according to one embodiment includes a number of serially connected tubulars with a communication device placed between the connecting ends of the tubulars, wherein the communication device provides a direct data communication link between the adjoining tubulars.

Abstract: A downhole tool comprises a body, an extendable cutting member operable to cooperate with a hydraulically actuated cam member, and a cam member lock. The lock is configurable to be activated downhole to restrict movement of the cam member relative to the body and prevent extension of the cutting member.

Abstract: A drill bit for drilling a borehole in earthen formations comprises a bit body having a central bit axis, a first end adapted to be connected to a drillstring, and a second end opposite the first end. In addition, the bit comprises a pilot bit extending from the second end of the bit body. Further, the bit comprises a reamer section extending radially from the bit body and axially positioned between the first end of the bit body and the pilot bit. The reamer section comprises a rolling cone cutter rotatably mounted to a journal shaft extending from the bit body. Moreover, the rolling cone cutter has a cone axis of rotation, a backface proximal the bit body, and a nose opposite the backface and distal the bit body.

Abstract: A drill bit has cutting elements with multiple cutting surface geometries that are positioned so that their cutting profiles overlap, but do not completely contain or engulf one another. The different cutting surface geometries and the specific overlap create a zone of high density in the middle regions of the cutting profiles and low density in the periphery, resulting in a cutting profile that becomes sharper with increasing wear. Such an arrangement is more effective and stable as the drill bit encounters hard and abrasive formation materials. Moreover, cutting elements with larger axial volumes may be combined with cutting elements having smaller axial volumes.

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

Abstract: Forming a sequence plan for a machine to travel to a series of specified locations is described. An initial cost table (414) and a pattern of locations (412) is inputted to a Sequential Ordering Problem (SOP) solver (402). The resulting sequence (410) is processed by a motion planner (404) to derive by a motion planning procedure a plan of machine motions through the sequence. A cost table update (408) is performed based on the motion plan, which is then used for another iteration of the SOP solver (402).

Abstract: Disclosed are methods for solution mining of evaporite minerals, such as trona, comprising drilling an access well and at least two lateral boreholes; injecting a fluid; circulating the fluid through the lateral boreholes with a controlled fluid flow; and collecting a pregnant solution. Also disclosed are methods of solution mining that include injecting an aqueous solution into an underground trona cavity at a temperature sufficient to maintain at least a portion of the solution in the cavity in the Wegscheiderite solid phase region; removing aqueous solution from the cavity; and recovering alkaline values from the removed aqueous solution. Also disclosed are methods of solution mining that include injecting an aqueous solution into an underground trona cavity; removing aqueous solution from the cavity, wherein the temperature of the removed aqueous solution is at about the TWA point temperature; and recovering alkaline values from the removed aqueous solution.

Abstract: Techniques for controlling drilling fluid cleaning apparatus that reclaim lost circulation material from spent drilling fluid are disclosed. In one embodiment, a system includes a tank, a density separation device, and a fluid density control system. The tank holds spent drilling fluid containing drilling fluid, lost circulation material, coarse solids and fine solids. The density separation device is coupled to an outlet of the tank. The density separation device provides an overflow stream and an underflow stream. The overflow stream contains less dense material than the underflow stream. The fluid density control system is configured to adjust the density of the spent drilling fluid provided to the density separation device by recirculating a portion of the underflow stream into the tank.

Abstract: The invention relates to an apparatus for a pipe string of a geological drill hole, with a pipe string element and a fluid supply line which is arranged outside the pipe string element, extends along the pipe string element and is connected to a fluid injection device on the pipe string element, by means of which a fluid supplied through the fluid supply line can be introduced into an inner space of the pipe string element. The invention furthermore relates to a pipe string of a geological drill hole, in particular of a geothermal drill hole, a method for operating a geological drilling machine and a method for producing a pipe string for a geological drill hole.

Abstract: An apparatus energizes a consumer of a pressurized fluid using a high pressure source and a low pressure source. The apparatus may include a fluid circuit in fluid communication with the consumer. The fluid circuit may have a first and a second reservoir. In one arrangement, the fluid circuit may have a flow control device in pressure communication with the first pressure source and the second pressure source, the flow control device being configured to cycle a pressure applied to the first and the second reservoirs using the first pressure source and the second pressure source. In some arrangements, the fluid circuit may include a flow device configured to flow fluid from a second branch to a first branch of the reservoir, and a flow control device in fluid communication with the flow device, the flow control device being configured to cycle a pressure applied to the flow device.

Abstract: A joint connecting a pair of members rotatable about a common axis end to end includes a first member having a threaded end portion and a non-circular exterior surface rearwardly of the threaded end portion, a second member having a threaded socket wherein the threaded end portion of the second member can be engaged, and a non-circular exterior surface, a ground engagement sleeve having a non-circular profile on an inner surface thereof whereby the sleeve can be slidably mounted on the non-circular exterior profiles of the first and second members when such profiles are brought into alignment by rotation of one member relative to the other in a manner effective to pass torque from one member to the other by means of the non-circular profiles, a first pair of alignable holes in the sleeve and first member to receive a fastener to secure the sleeve to the first member and a hole in the second member penetrating the threaded socket and positioned to receive a fastener to secure the second member to a third membe

Abstract: A polycrystalline diamond cutting (PDC) element of a drill bit of a downhole drilling tool is provided. The PDC element having a substrate, a diamond table and at least one pattern. The diamond table has an initial cutting edge along a periphery thereof. The pattern integrally formed within the diamond table. The pattern(s) defining at least one discontinuity about the diamond table that, in operation, selectively breaks away upon impact to create new cutting edges in the diamond table whereby a sharp cutting edge is continuously exposed to a material being cut.

Abstract: A racking board for retaining tubulars is disclosed having a first finger, a second forger positioned generally parallel to the first finger and with a gap between the fingers serving as a storage area for tubulars. A first inflatable member is supported adjacent to the first finger and a second inflatable member is supported adjacent to the second finger, the inflatable members adapted to expand radially into the gap upon inflation so as to capture and retain the tubular. In some embodiments, a single inflatable member in employed to expand into the gap and retain the tubular. A method of racking tubulars is disclosed using elongate, inflatable restraints.

Abstract: A method and a device for the production of a bore with a special shape, for example a bore which deviates from a cylindrical shape or a bore with an undercut. First, a first bore portion is produced using an oscillatingly driven tool, the first bore portion having a shape deviating from a cylinder and having at least one projection projecting from the wall face of the first bore portion towards the bore center. Subsequently, when a bore with an undercut is to be produced, the tool is then at least partially rotated about its longitudinal axis, in order to produce a second bore portion which has a larger cross section than the first bore portion.

Abstract: The invention relates to a drilling device and a drilling method for drilling inside a casing tube, wherein the drilling apparatus has a supporting frame with a fastening means for fixation with respect to the casing tube and a drilling tool, which is driven in a rotating manner via a telescopic rod by means of a drill drive arranged on the supporting frame. An emptying station for attachment to the upper end of the casing tube is provided, wherein the supporting frame of the drilling apparatus can be fastened on the emptying station. For emptying the drilling tool of drill cuttings the emptying station has an unloading means, which is adjustable for receiving the drill cuttings. The unloading means is designed for conveying the drill cuttings away from the emptying station.

Abstract: A drilling method and device is for the execution of diaphragm walls by cutters, (131, 105, 110) carried by a frame (130) supported by suspension and movers (102). A guide hole (200) is formed as far as the depth specified in the design at the center of the panel to be made. Excavation is started with the introduction into the guide hole (200) of a guide element (101) that is fixed with respect to the tool-holder frame and having geometry such as to copy the guide hole along which it slides during excavation. Excavation is carried out as far as the depth specified in the design. The tool is extracted from the excavation and the excavation is filled with concrete and a panel is formed. The method is repeated so as to form adjacent panels.

Abstract: Of the many embodiments provided herein, one embodiment includes a method comprising: providing a drilling fluid comprising: an aqueous fluid; and a surfactant; and drilling a well bore in a subterranean formation comprising an oleaginous fluid using the drilling fluid, wherein the surfactant forms a micelle within the well bore; and removing an oil block in the formation.

Abstract: A system for damping vibration in a drill string can include a magnetorheological fluid valve assembly having a supply of a magnetorheological fluid, a first member, and a second member capable of moving in relation to first member in response to vibration of the drill bit. The first and second members define a first and a second chamber for holding the fluid. Fluid can flow between the first and second chambers in response to the movement of the second member in relation to the first member. The valve assembly can also include a coil for inducing a magnetic field that alters the resistance of the magnetorheological fluid to flow between the first and second chambers, thereby increasing the damping provided by the valve.

Abstract: A cutting element for a drag-type earth-boring drill bit includes a cutting table with a face including a region that is configured to cut into a formation at a positive back rake angle and to direct formation cuttings, or chips, that have been cut from the earth formation toward the hydraulics of the drill bit. Drill bits may include one or more cutting elements that have been configured in this manner. Such a drill bit may also include a wear pad for limiting the depth to which a cutting element penetrates a surface of a bore hole in an earth formation. Such a wear pad may have a substantially constant thickness.

Abstract: Cutting elements for downhole cutting tools comprise a top surface having a cutting surface portion and a cutting profile disposed across the top surface. The cutting elements comprise first and second longitudinal side surfaces and first and second lateral side surfaces, each having a respective cross-section. The cutting profile can be disposed on the cutting surface either asymmetrically or symmetrically. Asymmetrical disposition permits two cutting elements to be arranged facing each other to cover a center point of a cutting tool. The cutting edge of asymmetrical or symmetrically disposed cutting profiles can have a shape that facilitates self-sharpening during cutting.

Abstract: A cutter retention method which uses brazed material placed in cutter pockets and cutter pocket grooves or recesses to allow braze material between the cutters and cutter pockets and in said grooves and overlapping onto the top of the cutters to better retain the cutters in the cutting bore hole tool apparatus for enhanced cutter retention and extended drilling or boring time of drill bits, underreamers, section mills hole openers, casing cutters or other down hole tools used in bore hole drilling and completion operations.

Abstract: Downhole cutting tools such as blade mills comprise a body having a first end for connection with a rotating component of a drill string and a cutting end for rotation in unison with the body. The cutting end comprises at least two blades, each of the at least two blades comprising a front sidewall surface, a back sidewall surface, an inner end, an outer end, and at least one beveled portion disposed along the front sidewall surface toward the inner end of each of the at least two blades. At least one of the beveled portions comprise at least one cutting element disposed thereon that is disposed across a center point of the face of the cutting end to provide for cutting away an object disposed in a wellbore to occur across a center point of the cutting end.

Abstract: In one aspect, an apparatus for use in a wellbore is provided that in one embodiment includes a drill bit having a bit body that is susceptible to corrosion when the drill bit is utilized in wellbore, an anode placed at a selected location on the bit body, a cathode associated with the bit body and a power source configured to provide electrical power to the anode to complete an electrical circuit between the anode and the bit body, wherein the supply of the electrical power to the anode arrests corrosion of the bit body when the drill bit is in the wellbore.

Abstract: An expandable reamer apparatus and methods for reaming a borehole are disclosed, including at least one laterally movable blade carried by a tubular body selectively positioned at an inward position and an expanded position. The at least one laterally movable blade, held inwardly by at least one blade-biasing element, may be forced outwardly by drilling fluid selectively allowed to communicate therewith or by at least one intermediate piston element. For example, an actuation sleeve may allow communication of drilling fluid with the at least one laterally movable blade in response to an actuation device being deployed within the drilling fluid. Alternatively, a chamber in communication with an intermediate piston element in structural communication with the at least one laterally movable blade may be pressurized by way of a movable sleeve, a downhole turbine, or a pump.

Abstract: A system and method for maintaining continuous flow through a drill string during drill pipe connection includes establishing drilling fluid flow axially through the length of a tubular sub attached to the top of a drill string. The sub is then engaged with a collar disposed at least partially around the perimeter of the sub so as to define an exterior flow path along the exterior of the sub. Radial flow is then initiated into the sub through said collar and along said exterior flow path. Axial flow is then terminated through the length of the tubular sub while maintaining radial flow into the sub. A pipe joint is then attached to the top of the tubular sub, axial flow is reestablished through the length of the tubular sub, radial flow is terminated into the sub, and the collar is disengaged from the sub.

Abstract: Drill bits for subterranean drilling comprising a bit body including at least one blade that includes a blade face comprising a contact zone and a sweep zone are disclosed. In particular, drill bits including at least one blade that extends at least partially over a nose region of the bit body, a shoulder region of the bit body and a gage region of the bit body and that include a sweep zone that rotationally trails the contact zone with respect to a direction of intended bit rotation about a longitudinal axis of the bit body and include a contact zone that defines a range of about 90% to about 30% of the blade face surface area is disclosed. Additionally, drill bits comprising a sweep zone located at least partially within a gage region are disclosed. Also, methods of off-center drilling and methods of manufacturing drill bits are disclosed.

Abstract: A downhole tool string, comprising a tool string bore and a drill bit located at the bottom of the tool string. The drill bit comprises a body intermediate a shank and a working surface. The working surface may comprise a substantially coaxial rotationally isolated jack element with a portion of the jack element extending out of an opening formed in the working surface to engage a subterranean formation. The tool string may comprise a driving mechanism adapted to rotate the jack. The clutch assembly disposed within the tool string bore may comprise a first end in communication with the jack element and second end in communication with the driving mechanism.

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: An apparatus for cutting a wellbore includes a motor with a stator and a rotor. The rotor includes an output shaft connected to a cutting structure to drive the cutting structure in use. The stator and rotor are spaced radially outwardly of the axis of the rotor such that at least one of the stator and the rotor has an access bore that extends through the motor to a position adjacent the cutting structure and through which a further object can pass without obstruction from the stator and rotor. The further object includes a further cutting structure. The motor workings are radially outward of the output shaft and the further cutting structure so as not to obstruct passage of the further cutting structure toward the cutting structure, such that the motor workings do not require drilling or removal to allow the further cutting structure access to the cutting structure.

Abstract: An expandable reamer apparatus and methods for reaming a borehole, wherein a laterally movable blade carried by a tubular body may be selectively positioned at an inward position and an expanded position. The laterally movable blade, held inwardly by blade-biasing elements, may be forced outwardly by drilling fluid selectively allowed to communicate therewith by way of an actuation sleeve disposed within the tubular body. Alternatively, a separation element may transmit force or pressure from the drilling fluid to the movable blade. Further, a chamber in communication with the movable blade may be pressurized by way of a downhole turbine or pump. A ridged seal wiper, compensator, movable bearing pad, fixed bearing pad preceding the movable blade, or adjustable spacer element to alter expanded blade position may be included within the expandable reamer. In addition, a drilling fluid pressure response indicating an operational characteristic of the expandable reamer may be generated.

Abstract: Well pressure control is integrated in real time with geomechanics determinations made during drilling. A well drilling method includes updating determinations of properties of a formation surrounding a wellbore in real time as the wellbore is being drilled; and controlling wellbore pressure in real time as the wellbore is being drilled, in response to the updated determinations of the formation properties. Another well drilling method includes obtaining sensor measurements in a well drilling system in real time as a wellbore is being drilled; transmitting the sensor measurements to a control system in real time; the control system determining in real time properties of a formation surrounding the wellbore based on the sensor measurements, and the control system transmitting in real time a pressure setpoint to a controller; and the controller controlling operation of at least one flow control device, thereby influencing a well pressure toward the pressure setpoint.

Abstract: Device for performing deep drillings, especially geothermal, may include a surface base, a borehole in a geological formation, filled with fluid, and a robotic multi-functional underground drilling platform, which contains especially a block (2) for crushing rock (1), a block for continuous formation of casing profile, a block of casing as transfer and transport infrastructure, a block (16) of transport container, a control and communication block (39), an energy block (4), a block of operating transport containers, and a block of removing and loading rock (1) from the place of crushing. The block (2) for rock crushing may be interconnected with block of removing and loading rock (1) from the place of crushing by means of water channels, ensuring removal of the crushed rock 107. The block of removing and loading rock (1) from the place of crushing may be interconnected with block (16) of transport container by means of water channels.

Abstract: A rotary drilling apparatus and method for drilling subterranean formations, including a body being provided with at least one cutter thereon exhibiting reduced, or limited, exposure to the formation, so as to control the depth-of-cut of the at least one cutter, so as to control the volume of formation material cut per rotation of the drilling apparatus, as well as to control the amount of torque experienced by the drilling apparatus and an optionally associated bottomhole assembly regardless of the effective weight-on-bit are all disclosed. The exterior of the drilling apparatus may include a plurality of blade structures carrying at least one such cutter thereon and including a sufficient amount of bearing surface area to contact the formation so as to generally distribute an additional weight applied to the drilling apparatus against the bottom of the borehole without exceeding the compressive strength of the formation rock.

Abstract: The present invention relates methods and apparatus for lining a wellbore. In one aspect, a drilling assembly having an earth removal member and a wellbore lining conduit is manipulated to advance into the earth. The drilling assembly includes a first fluid flow path and a second fluid flow path. Fluid is flowed through the first fluid flow path, and at least a portion of which may return through the second fluid flow path. In one embodiment, the drilling assembly is provided with a third fluid flow path. After drilling has been completed, wellbore lining conduit may be cemented in the wellbore.

Abstract: The present invention provides drilling assembles and methods that are especially useful for a bottom hole drilling assembly for drilling/reaming/ or other operations related to drilling a borehole through an earth formation. In one embodiment, the drilling assembly utilizes standard drill collars which are modified to accept force transfer sections. In another embodiment, the drilling assembly comprises a tension inducing sub which creates a force that may be used to place the bottom hole assembly or portions thereof in tension. In another embodiment, a reaming assembly is held in tension to provide a stiffer reaming assembly.

Abstract: A system for pumping fluid (e.g., but not limited to, drilling fluid), the system having pump apparatus; including a plurality of removable pump modules; and, in certain aspects, removable valve cartridges for such modules.

Abstract: Disclosed is a novel autonomous excavating apparatus capable of solving conventional problems. The autonomous excavating apparatus comprises an apparatus body including a lower body 101 formed in a cylindrical shape and combined with a conical-shaped lower end, and a spiral blade 102 provided on an outer peripheral surface of the lower body 101 in the form of a right-handed screw. The lower body 101 has an internal space provided with a wheel 103 which has a rotary shaft 104 rotatably supported relative to the lower body 101 through bearings 105, 106. A motor 108 is fixed to the lower body 101 at a position above the wheel 103, and an output shaft of the motor is coaxially connected to the rotary shaft 104. Thus, the motor 108 can drivingly rotate the wheel 103 relative to the lower body 101.

Abstract: A method and apparatus for down-the-hole drilling. The drilling is carried out by a drilling device including a casing and a drilling unit. The drilling head includes a first drill for drilling a center hole, a second drill for reaming the center hole and a flushing flow arrangement including a first flusher for leading a flushing medium onto a drilling surface and a second flusher for returning of the flushing medium and drilling waste inside the casing. The first drill is removably coupled with the second drill to enable removal thereof from the hole. The casing is arranged to be drawn into a hole to be drilled by the drilling unit. The flushing medium is brought onto the drilling surface and returned therefrom by axially directed flow arrangements disposed in a cross-section view on an outer periphery of the first drill and/or in an inner periphery of the second drill.

Abstract: An electronically activated tool (50) comprising a tool body, cutter blocks and sensors with means for attachment to a drilling support and rotation so as to permit the simultaneous underreaming and measurement of the diameter of a wellbore (especially in oil and gas drilling) characterized by a means of activation using an electronic signal sent by mud-pulse, fibre-optics, wireless transmission or other means which may also communicate commands and receive data from the underreamer during drilling, at least one radially extendable cutter block (62) incorporating positional sensors adapted to measure the relative position of the cutter block to the tool, at least one calliper means (76) to measure wellbore diameter, all of which are inter-linked by a means of communication using receivers, sensors and microprocessors and a system that optimizes underreaming or expansion (22) by simultaneously comparing and correlating wellbore diameter data (22) and underreaming parameters in real-time or in memory.

Abstract: Methods and systems for storing kinetic energy in a fluid-base power circuit. A regenerative control valve manifold diverts fluid flow from a hydraulic device performing a first operation into an accumulator. The accumulator stores a fluid volume sufficient to perform a second operation. The regenerative control valve manifold connects the accumulator to the power circuit providing a fluid flow and charge pressure sufficient to perform the second operation.

Abstract: Job monitoring methods and apparatus for logging-while-drilling equipment are disclosed. A disclosed example method includes obtaining a fluid associated with an underground geological formation, analyzing the fluid with one or more sensors to form respective ones of sensor outputs, identifying a downhole scenario associated with the fluid based on the sensor outputs, the identifying being performed while the sensors are within the underground geological formation, and selecting a telemetry frame type based on the identified downhole scenario.

Abstract: The present invention discloses embodiments of a drilled underground gaseous storage system. The embodiments of the present invention comprise storage tubes inserted below the surface of the ground for the storage of gases. The embodiments of the present invention may be used to store gaseous hydrogen. In addition, the embodiments of the present invention many be used to store other gases such as compressed natural gas.

Abstract: A braking device for drilling operations in a borehole includes a brake retainer having a plurality of brake connector openings defined therein, a body member having a tapered surface having a first diameter and a second diameter, the second diameter being larger than the first diameter, at least one brake element positioned at least partially between the brake retainer and the body member and in communication with the tapered surface and at least one of the brake connector openings, and a bias member configured to exert a biasing force on the body member to move the body member toward the brake retainer to move the brake element from contact with the first diameter of the tapered surface toward contact with the second diameter.

Abstract: A rotary drill bit having blades with gage pads disposed on exterior portions thereof to improve steerability of the rotary drill bit during formation of a directional wellbore without sacrifice of lateral stability. One or more of the gage pads may include radially tapered exterior portions and/or cut out portions to assist with reducing wear of the associated gage pad. For some applications, a rotary drill bit may be formed having blades with gage pads having a relatively uniform exterior surface. Hard facing material and/or buttons may be disposed on exterior portions of the gage pad to form a radially tapered portion to improve steerability, reduce wear of the gage pad and/or improve ability of the rotary drill to form a wellbore having a generally uniform inside diameter, particularly during directional drilling of the wellbore.

Abstract: Expandable reamer tools include an outer body, a fluid passageway extending through the outer body, and at least one blade configured to slide relative to the outer body between a refracted position and an expanded position in a direction oriented at an acute angle of less than ninety degrees (90°) to a longitudinal axis of the outer body. In some embodiments, the tools may include a moveable inner sleeve member configured to selectively allow hydraulic fluid pressure within the fluid passageway to act directly on the at least one blade. Methods for enlarging a borehole using such expandable reamer tools and methods for removing such expandable reamer tools from a borehole are also disclosed.

Abstract: A Polycrystalline Diamond Compact (PDC) cutter for a rotary drill bit is provided with an integrated sensor and circuitry for making measurements of a property of a fluid in the borehole and/or an operating condition of the drill bit. A method of manufacture of the PDC cutter and the rotary drill bit is discussed.

Abstract: Methods of forming a polycrystalline diamond compact for use in an earth-boring tool include forming a body of polycrystalline diamond material including a first material disposed in interstitial spaces between inter-bonded diamond crystals in the body, removing the first material from interstitial spaces in a portion of the body, selecting a second material promoting a higher rate of degradation of the polycrystalline diamond compact than the first material under similar elevated temperature conditions and providing the second material in interstitial spaces in the portion of the body. Methods of drilling include engaging at least one cutter with a formation and wearing a second region of polycrystalline diamond material comprising a second material faster than the first region of polycrystalline diamond material comprising a first material. Polycrystalline diamond compacts and earth-boring tools including such compacts are also disclosed.

Abstract: An expandable reamer apparatus and methods for reaming a borehole are disclosed, including at least one laterally movable blade carried by a tubular body selectively positioned at an inward position and an expanded position. The at least one laterally movable blade, held inwardly by at least one blade-biasing element, may be forced outwardly by drilling fluid selectively allowed to communicate therewith or by at least one intermediate piston element. For example, an actuation sleeve may allow communication of drilling fluid with the at least one laterally movable blade in response to an actuation device being deployed within the drilling fluid. Alternatively, a chamber in communication with an intermediate piston element in structural communication with the at least one laterally movable blade may be pressurized by way of a movable sleeve, a downhole turbine, or a pump.

Abstract: The present invention relates methods and apparatus for lining a wellbore. In one aspect, a drilling assembly having an earth removal member and a wellbore lining conduit is manipulated to advance into the earth. The drilling assembly includes a first fluid flow path and a second fluid flow path. Fluid is flowed through the first fluid flow path, and at least a portion of which may return through the second fluid flow path. In one embodiment, the drilling assembly is provided with a third fluid flow path. After drilling has been completed, wellbore lining conduit may be cemented in the wellbore.