Abstract: Provided is a wellbore scraper assembly for use with a wireline. The wellbore scraper assembly, in one example, includes a tubular housing, a plurality of hydraulically deployable scraper features associated with the tubular housing, the plurality of hydraulically deployable scraper features configured to move from a first retracted state to a second radially extended state, and a hydraulic deployment system coupled to the plurality of hydraulically deployable scraper features, the hydraulic deployment system configured to move the plurality of hydraulically deployable scraper features from the first state to the second state.

Abstract: A trocar for preparing pilot holes, tunnels and other spaces within bone includes a piercing tip, a cutting element, and an expansion element for expanding the cutting element radially outwardly with respect to a longitudinal axis of the trocar. The cutting element includes one or more cutting blades. The trocar also includes a hollow shaft. The hollow shaft can include one or more apertures axially and radially aligned with the one or more cutting blades. The expansion element can include an activation rod housed inside the hollow shaft. The one or more cutting blades can be in the form of two opposed cutting blades separated by a gap, the two opposed cutting blades being radially displaceable with respect to the longitudinal axis. The activation rod can include a wedge that partially enters the gap between the two opposed cutting blades to displace the cutting blades to an expanded position.

Abstract: A non-human-entry method for extracting a desired subsurface material such as ore, wherein an access hole is drilled from surface downwardly to the material, a high-pressure fluid injection tool is lowered with or after the drill string to the material and injected outwardly to disaggregate the material and form a cavity, and the material is optionally ground to a desired size by a drill bit or other means to enable suction up production tubing with a carrier fluid to the surface. The injection tool and grinding means are preferably part of an integrated bottom hole assembly at the lowermost end of a drill string, which may include surveying equipment to measure the cavity dimensions at intervals during target material disaggregation to allow fluid injection adjustment to seek to achieve a desired cavity geometry. Deck cementing is optionally employed for ground support.

Abstract: A drill for excavating a bore in the earth includes a steerable primary boring tool, a secondary boring tool and a sensor. The steerable primary boring tool is configured to excavate a primary bore. The secondary boring tool is configured to excavate a plurality of side bores that extend outward from the primary bore at a plurality of azimuthal locations around the primary bore. The sensor is configured to detect a mineral property in the earth adjacent each of the side bores.

Abstract: A downhole tool includes a pressure activated flow switch for selectively actuating and deactuating a device, such as a reaming block. The flow switch is deployed external to the flow bore and includes a flow piston configured to reciprocate between axially opposed open and closed positions such that the device is actuated when the flow piston is in the open position and deactuated when the flow piston is in the closed position. The flow piston is configured to translate from the closed position to the open position when a differential pressure exceeds a predetermined threshold. The flow piston may be further configured to remain in the open position at differential pressures less than the threshold.

Abstract: A downhole tool may include a generally hollow piston having a trigger element extending therefrom, the piston configured to slide along an axial cavity extending through a tubular body of the tool. The trigger element may move from a first position where the trigger engages a support on the body and the piston is fixed, to a second position where the trigger disengages and the piston is released. The tool may also include a generally tubular relief sleeve releasably coupled with the piston using a shear pin, while the trigger element is in the first position, and disposed between the trigger and an extension of the piston, to allow the sleeve to slide between the trigger and the extension after shearing of the pin. The piston, sleeve and pin may be configured to allow the sleeve to release from the piston in response to the shearing of the pin.

Abstract: An undercutting tool for producing transverse grooves in a drilled hole. An upper support and a lower support axially delimit a receiving region of a shank. At least two spreading elements are disposed in the receiving region between the spreading elements and the receiving region. The shank and the supports are disposed so the axial distance between the supports can be reduced by exerting an axial force. The spreading elements each have an oblique upper and lower end face, which each have such an outer geometric shape, extending in a direction not perpendicular to the longitudinal axis and are displaced in substantially opposite radial directions, and the axial force is in each case converted to a radial force in the radial directions.

Abstract: Expandable reamer assemblies include an expandable reamer module and an activation module. An outer tubular body of the activation module is rigidly coupled to a tubular body of the expandable reamer module, and an activation member of the activation module is coupled to a sleeve of the expandable reamer module, the sleeve coupled to at least one blade and configured to move the at least one blade into an extended position. The sleeve moves axially responsive to axial movement of the activation member. Bottom-hole assemblies include an expandable reamer module and an activation module. The activation module is coupled to the expandable reamer module and configured to provide a motive force to the sleeve to move the sleeve opposite a direction of flow of drilling fluid. Methods of using expandable reamer modules include pairing two substantially identical expandable reamer modules and two respective different activation modules.

Abstract: Embodiments of the present invention generally relate to extendable cutting tools for use in a wellbore. In one embodiment, a tool for use in a wellbore includes a tubular body having a bore therethrough, an opening through a wall thereof, and a connector at each longitudinal end thereof; and an arm. The arm is pivotally connected to a first piston and rotationally coupled to the body, is disposed in the opening in a retracted position, and is movable to an extended position where an outer surface of the arm extends outward past an outer surface of the body. The tool further includes the first piston. The first piston is disposed in the body bore, has a bore therethrough, and is operable to move the arm from the retracted position to the extended position in response to fluid pressure in the piston bore exceeding fluid pressure in the opening. The tool further includes a lock operable to retain the first piston in the retracted position; and a second piston operably coupled to the lock.

Abstract: A core barrel assembly having a driven latch mechanism that can lock the core barrel assembly axially and rotationally relative to a drill string. The driven latch mechanism can include a plurality of wedge members positioned on a plurality of driving surfaces. Rotation of the drill string can cause the plurality of wedge members to wedge between an inner diameter of the drill string and the plurality of driving surfaces, thereby rotationally locking the core barrel assembly relative to the drill string. Drilling systems including the driven latch mechanism and methods of using the driven latch mechanism are also described.

Abstract: A method for hardening a portion of the outer surface of a downhole tool body includes friction stirring the vulnerable surface of the tool. Such friction stirring generally includes rotating a friction stir weld tool in contact with the surface until a portion of the tool penetrates the tool. The friction stir weld tool is then translated (while rotating) across a predetermined region of the surface thereby creating a friction stir zone. The friction stir zone is generally considerably harder, and therefore more wear resistant, than the parent material that makes up the tool body. The resulting downhole tool includes at least one surface with a hard friction stir zone.

Abstract: A drill bit comprises a bit body connectable to a drill string at an first end, which bit body is provided with a longitudinal passageway extending from an opening at the first end to a port at a second end. The drill bit further comprises a closure element for closing the passageway, and when the closure element is in a closing position, the closure element is removable. Further, the closure element comprises a first and a second member that are movable relative to each other between an expanded configuration and a collapsed configuration, in which collapsed configuration, the closure element is retractable through the passageway to the first end.

Abstract: A downhole tool and associated methods. The downhole tool includes a body with a throughbore; at least one extendable cutting member; and an actuation member. The actuation member is operatively associated with the extendable cutting member and movable relative to the body to extend the cutting member laterally from the body along an extension axis. The extension axis is offset from a radius of the body.

Abstract: Expandable reamers comprise a housing and at least one blade supported by the housing. The at least one blade is movable between an extended position and a retracted position. The at least one blade is in the retracted position when a travel sleeve is in a first sleeve position and a trigger sleeve is in an unobstructed position. The at least one blade is movable to the extended position when the travel sleeve is in a second sleeve position and the trigger sleeve is in the unobstructed position. The at least one blade is in the retracted position when the travel sleeve is in the second sleeve position and the trigger sleeve is in an obstructed position.

Abstract: A downhole tool comprises a body having a slot therein, a cutting blade mounted within the body and extendible and retractable through the slot such that the outer diameter of the tool can be selectively increased, an actuation member for driving the cutting blade between the retracted and extended positions and a mounting means connecting the blade to the actuation member, said body having a tapered surface along which the blade travels such that as the blade travels along the tapered surface the blade moves radially outwardly with respect to both the body and the mounting means whilst remaining in contact with the tapered surface.

Abstract: In various embodiments, a mining device can include a first housing portion and a second housing portion where relative movement between the first and second housing portions can extend and/or retract a cutting member with respect to the mining device. The mining device can further include a cable which can be mounted to the second housing portion where the cutting member is mounted to the cable and can be radially extended with respect to the first and second housing portions when the second housing portion is moved relative to the first housing portion along an axis. As the cutting member is extended, it can contact the sidewalls of a subterranean shaft to loosen material therefrom.

Abstract: Expandable apparatus include a triggering element comprising an at least partially corrodible composite material. Methods are used to trigger expandable apparatus using such a triggering element and to form such triggering elements for use with expandable apparatus.

Abstract: In one aspect of the present invention an expandable tool for an earth boring system comprises a mandrel comprising a tubular body and an outer diameter, a plurality of blades disposed about the outer diameter, and a slidable sleeve positioned around the outer diameter and capable of manipulating the plurality of blades into collapsed and expanded positions.

Abstract: In one aspect of the present invention, an expandable tool for an earth boring system comprises a mandrel with a sleeve positioned around the outer surface and a blade disposed in a slot formed in the sleeve. The sleeve is also configured to slide along the tubular body. The blade comprises an interior slide groove located on an interior surface and an exterior slide groove located on an exterior surface. A sleeve protrusion is configured to extend into the interior slide groove, while a mandrel protrusion is configured to extend into the exterior slide groove. The blade is configured to shift laterally out of the slot as the sleeve slides axially, wherein the interior and exterior slide grooves are oriented at different angles and as the sleeve slides axially along the length of the mandrel, the slide grooves lock the blade in a pre-determined position through a wedging effect.

Abstract: A cutting device for downhole operations includes a first cutting structure, and a second cutting structure, wherein at least the second cutting structure is selectively presentable for operation. A method of performing a downhole cutting operation comprises running into a well bore a cutting device including a plurality of cutting structures, performing a first cutting operation with a first cutting structure of the cutting device, moving the first cutting structure to selectively present a second cutting structure of the cutting device, and performing a second cutting operation with at least the second cutting structure. The method may further include aligning movable cutting structures of the cutting device to allow the second cutting structure to be selectively presented.

Abstract: The invention is a drilling device for providing a conically shaped cavity in materials primarily used for anchoring systems. The drilling device is comprised of a solid shank for attachment to a drill, a reverse thread section, and a cutting head. The cutting head includes a cutting tip, clean out flutes, extendable cutting blades mounted within an internal chamber of cutting head body, and means for extending the cutting blades. The extendable cutting blades project from the cutting head body radially when the reverse thread section is driven into the internal chamber of the cutting head. The reverse thread section interacts with the means for extending the cutting blades. This may include a pair of cams that are spring biased outwardly. The cams push against the backsides of the extendable cutting blades for driving them from the cutting head body when the drill device is counter rotated.

Abstract: In various embodiments, a mining device can include a first housing portion and a second housing portion where relative movement between the first and second housing portions can extend and/or retract a cutting member with respect to the mining device. The mining device can further include a cable which can be mounted to the second housing portion where the cutting member is mounted to the cable and can be radially extended with respect to the first and second housing portions when the second housing portion is moved relative to the first housing portion along an axis. As the cutting member is extended, it can contact the sidewalls of a subterranean shaft to loosen material therefrom.

Abstract: A method for hardening a portion of the outer surface of a downhole tool body includes friction stirring the vulnerable surface of the tool. Such friction stirring generally includes rotating a friction stir weld tool in contact with the surface until a portion of the tool penetrates the tool. The friction stir weld tool is then translated (while rotating) across a predetermined region of the surface thereby creating a friction stir zone. The friction stir zone is generally considerably harder, and therefore more wear resistant, than the parent material that makes up the tool body. The resulting downhole tool includes at least one surface with a hard friction stir zone.

Abstract: In various embodiments, a mining device can include a first housing portion and a second housing portion where relative movement between the first and second housing portions can extend and/or retract a cutting member with respect to the mining device. The mining device can further include a cable which can be mounted to the second housing portion where the cutting member is mounted to the cable and can be radially extended with respect to the first and second housing portions when the second housing portion is moved relative to the first housing portion along an axis. As the cutting member is extended, it can contact the sidewalls of a subterranean shaft to loosen material therefrom.

Abstract: A secondary cutting structure for sure in a drilling assembly, the secondary cutting structure including a tubular body and a block, extendable from the tubular body, the block including a first arrangement of cutting elements disposed on a first blade and a second arrangement of cutting elements disposed on a second blade, wherein the second arrangement is a modified redundant arrangement. Also, a secondary cutting structure for use in a drilling assembly, the secondary cutting structure including a leading blade disposed on a first block and a trailing blade disposed on the first block adjacent the leading blade. Additionally, the secondary cutting structure includes a unique blade disposed on a second block, wherein a gage portion of at least one of the blades has a length between 30% and 45% of a total blade length.

Abstract: A communication tool apparatus is described which is adapted to provide selective communication of control fluid through a downhole tool, such as a safety valve. The downhole safety valve is a tubing retrievable subsurface safety valve (“TRSSSV”). The communication tool may be run downhole and within the TRSSSV. Once within the TRSSSV, the communication tool apparatus activates a cutting device within the TRSSSV such that communication of control fluid through the TRSSSV is possible. A replacement safety valve run on a wireline may then be inserted into the TRSSSV and be operated via the control fluid line, as a new communication path created by the communication tool described herein. A method of using the communication tool apparatus is also described.

Abstract: A methodology and apparatus for cutting shape(s) or profile(s) through well tubular(s), or for completely circumferentially severing through multiple tubulars, including all tubing, pipe, casing, liners, cement, other material encountered in tubular annuli. This rigless apparatus utilizes a computer-controlled, downhole robotic three-axis rotary mill to effectively generate a shape(s) or profile(s) through, or to completely sever in a 360 degree horizontal plane wells with multiple, nested strings of tubulars whether the tubulars are concentrically aligned or eccentrically aligned. This is useful for well abandonment and decommissioning where complete severance is necessitated and explosives are prohibited, or in situations requiring a precise window or other shape to be cut through a single tubular or plurality of tubulars.

Abstract: In various embodiments, a mining device can include a first housing portion and a second housing portion where relative movement between the first and second housing portions can extend and/or retract a cutting member with respect to the mining device. The mining device can further include a cable which can be mounted to the second housing portion where the cutting member is mounted to the cable and can be radially extended with respect to the first and second housing portions when the second housing portion is moved relative to the first housing portion along an axis. As the cutting member is extended, it can contact the sidewalls of a subterranean shaft to loosen material therefrom.

Abstract: An expandable underreamer apparatus disposed on a distal end of a drillstring and configured to drill a formation includes a substantially tubular main body adjacent a cutting head, the main body providing at least one axial recess configured to receive an arm assembly, and the arm assembly configured to translate between a retracted position and an extended position. The apparatus further includes a plurality of cutting elements disposed on the arm assembly, and a plurality of wear indicators imbedded in at least one arm assembly and positioned behind the cutting elements with respect to a direction of rotation of the arm assembly, wherein the wear indicators are configured to provide an increased torque to the drillstring upon contacting the formation.

Abstract: A cutting device for downhole operations comprises a first cutting structure, and a second cutting structure, wherein at least the second cutting structure is selectively presentable for operation. A method of performing a downhole cutting operation comprises running into a well bore a cutting device comprising a plurality of cutting structures, performing a first cutting operation with a first cutting structure of the cutting device, selectively presenting a second cutting structure of the cutting device, and performing a second cutting operation with at least the second cutting structure. The method may further comprise aligning the cutting device to allow the second cutting structure to be selectively presented.

Abstract: A downhole tool (10?) comprises a body (12?) having a longitudinal axis and a body through-bore (14?), a slot (34?) communicating the outside of the body with the body through-bore. A sleeve actuator (30?) mandrel also has a bore and is selectively axially slidable in the body through-bore. A hollow bar (36?) is slidable with a radial component in the slot. At least two levers (210), each pivoted to the mandrel (about a first axis perpendicular the longitudinal axis) extend into the hollow bar and are pivoted thereto (about a second axis parallel the first axis). The levers lie in an actuation plane perpendicular the first and second axes and containing the slot. The levers are disposed at an inclined angle with respect to the longitudinal axis so that longitudinal motion of the mandrel translates into radial movement of the bar.

Abstract: A communication tool apparatus is described which is adapted to provide selective communication of control fluid through a downhole device such as a safety valve. The downhole safety valve is a tubing retrievable subsurface safety valve (“TRSSSV”). The communication tool may be run downhole and within the TRSSSV. Once within the TRSSSV, the communication tool apparatus activates a cutting device within the TRSSSV such that communication of control fluid through the TRSSSV is possible. A replacement safety valve run on a wireline may then be inserted into the TRSSSV and be operated via the control fluid line, as a new communication path created by the communication tool described herein. A method of using the communication tool apparatus is also described.

Abstract: In accordance with an embodiment of the present invention, a drilling tool includes a tubular body defining a longitudinal axial cavity extending therethrough and defining at least one cutter element recess. The drilling tool also includes a cutter element at least partially disposed within the at least one cutter element recess and includes at least first and second cutting arms at least substantially disposed within the cutter element recess in a retracted position. The first and second cutting arms are operable to move from the retracted position to an extended position in which the first and second cutting arms extend at least partially beyond a periphery of the tubular body. The first and second cutting arms and the tubular body enclose a space when the first and second cutting arms are in the extended position.

Abstract: An expandable drilling apparatus is deployed upon a distal end of a drillstring and includes a cutting head and a substantially tubular main body adjacent the cutting head providing a plurality of axial recesses configured to receive arm assemblies configured to translate between a retracted and an extended position. A flow switch actuates the arm assemblies when a drilling fluid pressure exceeds an activation value and the drilling apparatus includes a biasing member to reset the arm assemblies when the drilling fluid pressure falls below a reset value.

Abstract: A downhole perforator assembly (10) for establishing communication between the interior of a tubular string (18) and a surrounding annulus (24) includes a downhole power unit (100) having a power unit housing (150) and a moveable shaft (130) and a downhole perforator (260) having a perforator housing (262), a mandrel (278) slidably positioned within the perforator housing (262) and a penetrator (288) radially outwardly extendable from the perforator housing (262). The power unit housing (150) is operably associated with the perforator housing (262) and the moveable shaft (130) operably associated with the mandrel (278) such that when the downhole power unit (100) is activated and the moveable shaft (130) is longitudinally shifted relative to the power unit housing (150), the mandrel (278) is longitudinally shifted relative to the perforator housing (262) and at least a portion of the penetrator (288) is extended radially outwardly from the perforator housing (262).

Abstract: An expandable downhole tool such as an under-reamer or a stabiliser comprises a mandrel mounted for linear slidable movement relative to a main body. A fixed guide takes the form of a spline bar is disposed in an axial recess and is restrained from movement longitudinally and laterally. To retain the spline bar in position, lock blocks are provided and can be bolted to a surrounding housing of the main body in which axial recess is formed, by means of lock pins. The longitudinally slidable mandrel has two axially spaced cut-out recesses, into which can be received the lower ends of travel blocks. Cutter block has obliquely outwardly extending guide ways which are slidably mounted on similarly shaped slide ramps projecting outwardly from the spline bar. Upon increase of hydraulic pressure from below the tool, the mandrel is urged to the left against its spring biasing from the deactivated position to take up an axially displaced position.

Abstract: An apparatus and method for characterizing a subsurface formation is provided. The apparatus includes a tool body, a probe assembly carried by the tool body for sealing off a region of the borehole wall, an actuator for moving the probe assembly between a retracted position for conveyance of the tool body and a deployed position for sealing off a region of the borehole wall and a perforator extending through the probe assembly for penetrating a portion of the sealed-off region of the borehole wall. The tool may be provided with first and second drilling shafts with bits for penetrating various surfaces. The method involves sealing off a region of a wall of an open borehole penetrating the formation, creating a perforation through a portion of the sealed-off region of the borehole wall and testing the formation.

Abstract: An apparatus for bursting pipe is preferably adapted to receive rotational energy from the inner member of a dual-member drill string. In a preferred embodiment, a plurality of pipe-bursting members, driven by the interconnected inner members, cut or burst a subterranean pipe. In another preferred embodiment, a plurality of screw drives move the pipe-bursting members between an expanded position and a retracted position in response to rotation of the interconnected inner members.

Abstract: A borehole reamer which may be deployed to a desired depth in an existing uncased borehole or below existing casing and used to substantially expand the diameter of the borehole. The diameter may be expanded by an amount that ranges from a fraction to a multiple of the original diameter of the borehole. In this fashion, geological formations containing oil, gas or groundwater which were previously uneconomical to produce may be worked into a condition of economical production. In a preferred embodiment, the borehole reamer is formed as an elongated assembly having an outside diameter which is sized to fit within a diameter of a conventional borehole. The assembly is preferably attached to drill pipe and lowered into a borehole to an appropriate depth corresponding to a pay zone of interest. A lower portion of the assembly, which is located at the deeper depth in the borehole, is constructed in the form of a bellows which functions as a pilot/anchor for the assembly.

Abstract: Drilling apparatus, such as an underreamer (20) comprises a generally cylindrical tubular body (22) and two cutting blades (26, 27) pivotally mounted to the body and movable between a retracted position and an extended position. Each cutting blade has a retracted position minimum gauge cutting portion (36) and an extended position maximum gauge cutting portion (35), with the blades in the extended position the gauge cutting portions (35) extending axially and being located in a transverse plane on or forward of the blade pivot axis.

Abstract: The present invention generally relates to downhole tools. More particularly, the invention relates to a locking mechanism for use on a downhole tool. A flow actuated locking mechanism is provided for a downhole tool that includes an annular, two-position sleeve having an unlocked position and a locked position. A pin assembly within the tool is used to retain the sleeve in the locked position. In one aspect of the invention, the locking mechanism is used on a reaming tool with extendable cutters that are extendable from the body of the tool to increase the diameter of the tool and aid in forming a wellbore therearound. The locking mechanism prevents the cutters from collapsing or closing as the reamer is moved axially in the wellbore.

Abstract: An underreamer for forming a cavity within a well bore includes a housing adapted to be rotatably disposed within the well bore and a piston slidably coupled to the housing. The underreamer also includes a first cutter having a first end and a second end. The first end of the first cutter is pivotally coupled to the housing. The underreamer further includes a second cutter having a first end and a second end. The first end of the second cutter is coupled to the piston. The second end of the first cutter is coupled to the second cutter such that an axial force applied to the piston is operable to slide the piston relative to the housing and extend the second end of the second cutter radially outward relative to the housing from a retracted position to form the cavity when the housing is rotated relative to the well bore.

Abstract: An underreamer for forming a cavity from within a well bore includes a housing adapted to be disposed within the well bore. The underreamer includes an actuator partially slidably positioned in the housing. The actuator comprises a first portion and a second portion. A cross-sectional area of the second portion is larger than a cross-sectional area of the first portion. The underreamer includes at least one cutter set, wherein each cutter set has a first end and a second end. The first end of each cutter set is pivotally coupled to the housing. The second end of each cutter set is pivotally coupled to a connector. An axial force applied to the actuator is operable to slide the actuator relative to the housing causing the second portion of the actuator to contact each cutter set and extend each cutter set radially outward relative to the housing from a retracted position to a first position. The actuator may also include a stop member proximate an end of the actuator.

Abstract: An underreamer (5) is formed from a tubular body (10) having a longitudinal bore therethrough, and providing an integral piston actuator (20) responsive to hydraulic pressure to move cutters (40) into engagement with the well bore and springs (60) to resist premature engagement of the cutter arms (40) and to return the cutters (40) to the body upon conclusion of the underreaming job. Skewed longitudinal grooves (45) are formed in the tubular body thereby permitting the flowpath through the underreamer to provide substantially the same inner diameter throughout the tool (5).

Abstract: A drill for drilling wide diameter and high depth holes in the soil including a base machine (1) having a rotary (2) that is equipped with a clamp (9) and, by means of translation cylinders (8), rotates and axially moves a series of drill stem (7) having a tool (6) at the free end thereof, includes: an hydraulic joint (3) linked to the rotary (2); at least a winch (4) linked to the hydraulic joint (3) and provided with at least a wire rope (18); a carrier canister (5) slidely connected with the stem (7) between the rotary (2) and the tool (6) by means of at least the wire rope (18); at least a winch (4), a wire rope (18), a carrier canister (5) are rotated together with the stem (7) of the rotary (2) in correspondence of an operating condition of the drill.

Abstract: A downhole tool (10) for mounting on a drill string comprises: a mandrel (16); a body (18) axially movably mounted on the mandrel; and radially extendable members, such as stabiliser blades or cutters (30), mounted in the body and being operatively associated with the mandrel such that relative axial movement of the mandrel and body induces radial movement of the members. Application of axial tension to the tool produces axial movement of the body relative to the mandrel, tending to retract the members from an extended configuration. The mandrel may be arranged to draw the members inwardly to permit positive retraction of the members from an extended configuration. Further, the body may define a channel (32) and the mandrel and the members include an arrangement (38, 39, 40, 42) for maintaining a desired orientation of the members relative to the body channel.

Abstract: Drilling apparatus, such as an underreamer (20) comprises a generally cylindrical tubular body (22) and two cutting blades (26, 27) pivotally mounted to the body and movable between a retracted position and an extended position. Each cutting blade has a retracted position minimum gauge cutting portion (36) and an extended position maximum gauge cutting portion (35), with the blades in the extended position the gauge cutting portions (35) extending axially and being located in a transverse plane on or forward of the blade pivot axis.

Abstract: An underreamer for forming a cavity within a well bore may include a housing rotatably disposed within the well bore. The underreamer may also include an actuation rod slidably positioned in the housing. The underreamer may further include a plurality of cutter sets nested together around the actuation rod while the cutter sets are in a retracted position where each cutter set is pivotally coupled to the housing and the actuation rod. The cutter sets are also pivotally coupled together. An axial force applied to the actuation rod operates to slide the actuation rod relative to the housing and extend the cutter sets radially outward relative to the housing to form the cavity when the housing is rotated.

Abstract: A tool for expanding a hole size while drilling tool is disclosed. The tool utilizes a mechanically actuated mandrel and extendable cutting lugs designed in a configuration with fewer moving parts than previous designs. The cutting lugs have multiple cutting elements attached. The cutting lugs are driven between two cylindrical diameter surfaces to achieve a large differential between the retracted and extended positions of the tool, and to provide sufficient stability to allow the tool to be used in the extended position while drilling forward. The lugs are internally assembled and tapered to closely match the slots in the body of the tool for additional stability and to prevent complete passage through the tool for prevention of catastrophic failure. The tool has a locking mechanism to allow the tool to remain in the extended position when the weight is removed from the tool.

Abstract: There is provided a new and useful coring assembly for mounting on the end of a drill string and comprising a core barrel; abrading means on at least a part of the core barrel; a reaming collar mounted about a lower section of the core barrel and selectable between a first condition in which the collar is rotatable with the barrel and a second condition in which the collar is rotatable relative to and slidable longitudinally relative to the core barrel; a housing suspended from the core barrel; a deflection crank extending between the housing and the core barrel; and means within the housing for transferring power from a power source to the crank for selectively rotating the crank for moving the core barrel between a first position in which the core barrel and the housing are aligned and a second position in which the barrel and the housing are not aligned.