Abstract: A drilling tool (1) for drilling downhole, comprising a drilling head (2) in connection with a first portion (18) of the drilling tool, a driving unit (9) for driving the drilling head and the first portion forward in a longitudinal movement while drilling, and a feed control (19) for controlling the longitudinal movement of the drilling head.

Abstract: A system and a method provide a downhole mechanical energy absorber that protects downhole tools from impact loads and shock loads that occur during run-in contacts, tool drops, perforating blasts, and other impact events. A continuous localized inelastic deformation of a tube is a primary energy absorber in a load limiting design of the downhole mechanical energy absorber.

Abstract: In one embodiment, a downhole assembly includes a motor that is operatively coupled to a transmission, wherein the transmission is operatively coupled to an upper shaft disposed within a housing. The upper shaft is supported by a first radial bearing assembly disposed within the housing. A thrust bearing assembly including a ball bearing disposed between two races is provided. The upper shaft extends through and is supported by the first radial bearing. A distal end of the upper shaft has a first set of mating splines disposed thereon. A lower shaft supported by a second radial bearing assembly is disposed within the housing, wherein the lower shaft has a second set of mating splines disposed thereon. The second set of mating splines are adapted to mate with the first set of mating splines and the lower shaft is telescopically extendable from the upper shaft. A catch is machined on an internal surface of the lower shaft to limit the extent of travel of the lower shaft.

Abstract: A system for opening a window in a casing string (42) positioned in a wellbore (32). The system includes a hydraulic pressure intensifier (116) having a housing and a piston assembly with a differential piston area. The piston assembly is longitudinally shiftable relative to the housing and is initially secured relative thereto to prevent longitudinal movement therebetween. An anchor assembly (114) is operable to longitudinally secure the hydraulic pressure intensifier (116) within the casing string (42). A window opening tool (118) operably associated with the hydraulic pressure intensifier (116) is operably engagable with the casing string (42) such that when the anchor assembly (114) is longitudinally secured within the casing string (42) and the piston assembly is unsecured relative to the housing under hydrostatic pressure, longitudinal movement of the piston assembly transmits a force to the window opening tool (118), thereby opening the window in the casing string (42).

Abstract: A down hole vibration dampener is disclosed that uses a set of polyurethane rings and steel support rings to create a shock absorber within the drill string to reduce the amount of vibration in the drill string. A splined mandrel extends longitudinally within a hollow cylindrical housing. A seal structure present between the exterior of the mandrel and the interior of the housing forms a lubricant receiving chamber. The series of polyurethane and steel rings are located in the lubricant chamber and are compressible longitudinally to absorb vibration and shock loads.

Abstract: An anti-stall tool in an oil well drilling assembly that controls reciprocation of the drill bit by a controller that alters weight-on-bit (WOB) depending upon measured downhole pressure or torque at the downhole motor. The controller receives preset high and low working pressure limits for the downhole motor and keeps the drill bit rotating by maintaining WOB during normal drilling operations, increasing WOB if sensed working pressure indicates that drill bit loading or torque is undesirably low, and reversing WOB by retracting the drill bit if excessive working pressure or torque is sensed.

Abstract: A chuck assembly, an assembly for an earth-boring drill assembly, and a method of retaining a drill bit for an earth-boring drill assembly, the drill assembly including a casing. The assembly includes a drill bit having a generally cylindrical head, a chuck connectable to the casing and operable to support the bit, the chuck having an outer surface with a radially-outwardly extending chuck ridge, an axially-extending first slot being defined in the ridge, a sleeve having an inner surface with a radially-inwardly extending sleeve ridge engageable with the chuck ridge to limit axial movement of the sleeve relative to the chuck, the sleeve having a first lug supported on the inner surface, the first lug being positionable in the first slot to limit relative rotational movement between the sleeve and the chuck. The assembly may also include a retainer assembly provided between the sleeve and the bit.

Abstract: A double-acting compounder is disclosed, comprising: an outer housing; an inner mandrel at least partially disposed telescopically within the outer housing to define a fluid chamber between the inner mandrel and the outer housing, the fluid chamber containing fluid and being sealed at an uphole end and a downhole end; an equalizer between the fluid chamber and an exterior of the outer housing for equalizing pressure; a movable seal assembly disposed within the fluid chamber and having a first end that defines the uphole end or the downhole end of the fluid chamber; the inner mandrel having an outer shoulder for contacting a second end of the movable seal assembly to move the movable seal assembly with the inner mandrel when the inner mandrel moves in a first direction relative to the outer housing to compresses fluid within the fluid chamber; and the outer housing having an inner shoulder for contacting the second end of the movable seal assembly to prevent the movable seal assembly from moving with the inner

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 percussion drilling assembly for boring into the earth is disclosed. The percussion drilling assembly includes a top sub, a casing coupled to the top sub, and a feed tube assembly disposed within the top sub and the casing. The feed tube assembly includes a non-rigid coupling having a throughbore and a tubular body disposed therein. The tubular body is translatable in the radial position and/or rotatable relative to a longitudinal centerline extending through the non-rigid coupling.

Abstract: A system for drilling a lateral hole departing from a main well. The system comprises a motor assembly (415) including a motor (412) to generate a rotating torque, an axial thruster (411) to generate an axial force, a blocking system (410) to fix the motor and the axial thruster downhole. The motor assembly further includes a drive shaft (414) to transmit the rotating torque. The system further comprises a first and second connector (402, 404) for transmitting the rotating torque and the axial force from the motor assembly to a drill string assembly. The first connector is connectable to the drill string assembly so as to transmit the axial force only to the drill pipe (401), and to transmit the rotating torque to a further drive (405) shaft positioned within the drill pipe. The second connector (402) is connectable to the drill string assembly so as to transmit both the axial force and the rotating torque to the drill pipe (401).

Abstract: An anti-stall tool in an oil well drilling assembly that controls reciprocation of the drill bit by a controller that alters weight-on-bit (WOB) depending upon measured downhole pressure or torque. The downhole controller keeps the drill bit rotating by maintaining WOB during normal drilling operations, increasing WOB if sensed working pressure indicates that drill bit loading or torque is undesirably low, and reversing WOB by applying a spring force for retracting the drill bit if excessive working pressure or torque is sensed.

Abstract: An apparatus for mechanically engaging and releasably coupling two tubular members may include a first housing member, a second housing member and a piston member, wherein, in a first position, the first and second housing members are fixed relative to each other by the piston, and wherein, in a second position, the second housing member is rotatable relative to the first housing member. Certain embodiments include matingly engaged axially disposed and axially offset splines. Other embodiments include first and second interlocking mechanisms that are in an opposed relationship to couple first and second tubular members in a fixed position. Some embodiments include a method of reacting a first rotational coupling against a second axial coupling to resist both axial and rotational movement between first and second tubulars. Other embodiments include displacing a moveable member to both axially and rotationally release first and second tubulars.

Abstract: Implementations of the present invention relate generally to methods, systems, and apparatus for absorbing vibration and shock impulses created during drilling operations. In particular, implementations of the present invention include drill-string shock absorbers adapted to absorb longitudinal forces produced during a drilling operation. For example, drill-string shock absorbers in accordance with at least one implementation of the present invention include a generally cylindrical housing having a first end and a second end coupled together by a radially interlocking joint. Such a configuration can reduce mechanical failure and increase the operating life of the shock absorber by transmitting torsional forces directly between the ends of the housing and reducing stresses from being transferred to fastening means securing the first and second ends of the cylindrical housing together.

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: Installation of lines in well tools. A well tool for use in conjunction with a subterranean well includes connectors at opposite ends of the well tool, a line extending between the connectors; at least one threaded connection at a position between the connectors; and an anti-rotation device which permits make-up of the threaded connection without relative rotation between ends of the line. A method of installing a line in a well tool includes the steps of: making-up a threaded connection at a position between end connectors of the well tool; and preventing relative rotation between ends of the line during the threaded connection making-up step, the line extending between the connectors.

Abstract: An anti-surge/reverse thrusting tool for reducing the forces on a drill bit used in subterranean well drilling operations along with methods for drilling wells using a drill string employing the tool. The tool utilizes the pressure differential between drilling fluid flowing through the tool and the fluid located in the well bore annulus proximate the tool to reduce the likelihood of drill bit stall. The tool generally comprises an outer housing and a piston assembly that is axially shiftable relative to the housing.

Abstract: A cushion sub 10 including an input portion 130 for receiving drive from a drive means, and an output portion 60 for transmitting the drive to a drill string. One of the input portion 130 and the output portion 60 including one or more guides 70. The other of the input portion 130 and the output 60 portion being engaged with the one or more guides 70 for transmitting the drive and arranged for relative reciprocating sliding movement along the one or more guides 70 between a first and a second limit of movements. At least one of the one or more guides 70 including a shoulder 500 adjacent at least one of and between the first and the second limit of movement to minimise adverse step formation as the at least one guide 70 wears. One of the input portion 130 and the output portion 60 may define a cylinder 20, 50 including first end wall 40 and second endwall 50. The guides 70 might be formed by drive pins 70. The drive pins 70 may be press fitted to the first endwall 40.

Abstract: A dynamic damper for installation in a drill string (1), the purpose of which damper is to reduce the risk of jamming the drill bit (5), thereby avoiding damages in the event of unwanted extreme oscillations and rotational speed of the drill string caused by uncontrolled release of torsional energy in the drill string when the drill string suddenly breaks free of the jam. For this purpose, the damper is constructed from an outer and an inner string section (11) and (12), supported concentrically and interconnected through a helical threaded connection (10), so that relative rotation between the sections caused by torque (8) will give an axial movement that lifts and loosens the drill bit from the bottom of the hole in critical jamming situations. The spring (9) maintains the outer string section in an axial position against the shoulder (22). A hydraulic damping effect on the axial movements is achieved by oil volumes (16) and (17) being interconnected through narrow bores (18).

Abstract: A system and method for drilling a well bore with an under-balanced hydrostatic pressure. The system comprises a tubular containing a first port and wherein a well bore annulus is formed between the well bore and the tubular member, and a compression member disposed about the outer portion of the tubular member, the compression member having extending therefrom an internal sliding mandrel, and wherein the internal sliding mandrel contains a second port. The system further comprises an external sliding sleeve operatively associated with the internal sliding mandrel, wherein the external sliding sleeve containing a third port, and wherein in a closed position the first, second and third port are misaligned and in an open position the first, second and third port are aligned. The system also includes a compressible seal disposed about the external sliding sleeve and in contact with the internal sliding mandrel, the compressible seal responsive to a longitudinal weight transferred to the compression member.

Abstract: A downhole releasable swivel joint comprises a mandrel and a housing. A resilently deformable retaining device maintains the components in the illustrated first relative axial position until downward movement of the housing is stopped and a sufficient load is applied to the mandrel to overcome the retaining force of the retaining device whereupon the mandrel is able to move downwardly relative to the housing to adopt a second relative axial position. Apertures are provided in the wall of the mandrel and apertures are provided in the wall of the housing. When the mandrel is in the illustrated first relative axial position the apertures and are isolated from each other by a seal. When the mandrel is in the second relative axial position the apertures communicate with each other to permit flow from the interior of the mandrel to the exterior of the housing.

Abstract: An axial bearing includes a first piston and a second piston. Axial contact surfaces between the pistons are arranged in the same pressure space. The same pressure fluid fed to the axial bearing acts on the contact surfaces and on working pressure surfaces of the pistons. A rock drilling machine is also provided with such an axial bearing.

Abstract: A telescoping sub (50) for mining operations and the like. The telescoping sub (50) includes a rotor (94) portion coupleadle to the rotary head of a drilling rig, and a stator (74) portion that is coupleable to a drill rod. The rotor (94) portion is slideadly coupled to the stator (74) portion and is moveable with respect thereto between an extended position and a retracted position. With the telescoping sub (50) in the retracted position, the drilling rig is operated to drill to a first depth. The drilling rig is then operated to move the rotor (94) portion to the extended position, and the drilling rig is operated to drill to a second depth that is greater than the first depth.

Abstract: Apparatus and methods for forming an underground passageway and simultaneously laying therein a conduit or other elongate components comprises a rotary drill member coupled to a rotary and axially movable drill stem. The coupling is one which virtually automatically enables the drill stem to be coupled to and uncoupled from the drill member and comprises interlocking driving lugs carried by the drill stem and the drill member. The driving lugs are sandwiched between telescoped portions of the drill member and the drill stem and thereby are reinforced by such portions of the drill stem and the drill member in such manner as to preclude movement of the driving lugs in both radially inward and radially outward directions.

Abstract: A system for damping vibration in a drill string can include a valve assembly having a supply of a 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 or a valve for varying a resistance of the fluid to flow between the first and second chambers.

Abstract: An apparatus for lowering wireline into a well. The apparatus comprises a sleeve having a first and second end, wherein the first end contains a first plurality of wedges and the second end contains a second plurality of wedges. The apparatus further includes an upper mandrel having a third plurality of wedges that are configured to engage the first plurality of wedges and a first cap configured to engage the upper mandrel, wherein the first cap contains a first and second passage, and wherein the first passage is configured to receive the wireline. The apparatus further comprises a lower mandrel having a fourth plurality of wedges that engage with the second plurality of wedges, and a second cap configured to engage the lower mandrel, wherein the second cap contains an opening that has the lower mandrel disposed there through.

Abstract: A method and apparatus for allowing a downhole drill string to be stuck at one location and continue to rotate above the stuck section. The apparatus provides a method for collapsing the stuck subassembly by reducing its outside diameter. Simultaneous with the subassembly collapse, a jarring action is initiated from within the drill string to further loosen the stuck sections. At the same time drilling fluid inside the string is allowed to circulate outside the string through a circulation sub. The fluid is forced around the stuck subassembly further increasing the likelihood that the subassembly will be freed.

Abstract: A drilling assembly (2) comprises upper (4) and lower (6) drill strings with a fluid passage (80) therethrough for distributing fluid to a bottom hole assembly (10). The upper drill string (4) has an upper end (11) connectable to a drilling apparatus (13) and fluid source (16) and a lower end (18) with an attached casing expander unit (20) that communicates the fluid passage (80) of the upper (4) and lower (6) drill strings. An upper end (22) of the lower drill string (6) is formed from a casing string (24) telescoped over the casing expander unit. A constriction (31) connects the casing string (24) with the rest of the lower drill string (6). A flow restriction device (35) in the lower drill string acts to control fluid flow through the fluid passage.

Abstract: A rotatable drilling shoe attachable to a section of casing that allows for drilling and casing of a well bore in a single trip. The drilling shoe includes a fixed section and a rotatable section that has a drillable bit attached thereto. The drilling shoe further includes a mechanism for inhibiting rotation of the rotatable section after the casing is cemented into place so that the drillable bit can be drilled out by a subsequent drilling operation.

Abstract: In one aspect of the present invention a drill bit assembly comprises a body portion intermediate a shank portion and a working portion. The working portion has at least one cutting element. The body portion has at least a portion of a reactive jackleg apparatus which has a chamber at least partially disposed within the body portion and a shaft movably disposed within the chamber, the shaft having at least a proximal end and a distal end. The chamber also has an opening proximate the working portion of the assembly.

Abstract: A system for damping vibration in a drill string can include a valve assembly having a supply of a 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 or a valve for varying a resistance of the fluid to flow between the first and second chambers.

Abstract: A drilling device for producing undercut holes. The drilling device includes a drilling tool having an axis of rotation and a cutting portion arranged such that the cutting portion drills a hole with a longitudinal axis that is radially offset with respect to said axis of rotation and a centering device operable to apply a lateral force to said drilling tool for moving said axis of rotation towards said longitudinal axis to cause said cutting portion to form an undercut in a said hole.

Abstract: A well string assembly includes an upper tubular well string part having upper and lower ends between which there is formed a passageway, a lower well string part having upper and lower ends, which lower end is spaced apart from the lower end of the upper well string part and may include a drill bit. An auxiliary tool is arranged such that it can be passed along the passageway. It comprises an operating means for manipulating the well string interconnection means so as to disconnect the lower well string part from the upper well string part. The auxiliary tool can be passed, after disconnecting the upper and lower well string parts, through an opening at the lower end of the upper well string part, so as to reach a position in which at least part of the auxiliary tool is not radially surrounded by a part of the well string.

Abstract: An apparatus for handling tubular goods which includes an elongate tubular body having a peripheral sidewall and opposed ends. The peripheral sidewall has a plurality of axial slots arranged circumferentially around the tubular body parallel to an axis of the tubular body. An articulating coupling protrudes from at least one of the opposed ends. The articulated coupling includes an insert positioned within the tubular body with radial pins that engage the slots, the pins being axially movable along the slots. A gripping assembly is provided at one of the opposed ends for engaging a tubular good.

Abstract: The invention relates to a telescopable boring rod mechanism with at least two mutually displaceable Kelly rods, which are equipped with means for transmitting a torque to the adjacent Kelly rod. At least one of the Kelly rods is constructed from at least two rod segments, which are made from a different material.

Abstract: A damping apparatus and method for a drillstring comprising a bit comprising providing to the drillstring a damping mechanism comprising magnetorheological fluid and generating an electromagnetic field affecting the magnetorheological fluid in response to changing ambient conditions encountered by the bit.

Abstract: The present invention generally provides a downhole tool with an improved means of transmitting data to and from the tool through the use of wired pipe capable of transmitting a signal and/or power between the surface of the well and any components in a drill string. In one aspect, a downhole tool includes a body, and a mandrel disposed in the body and movable in relation to the body. A conducive wire runs the length of the body and permits signals and/or power to be transmitted though the body as the tool changes its length.

Abstract: An adjustable down-hole tool, for example a drill-string stabiliser (10), comprises a body (12) having a through bore (16). A mandrel (18) is rotationally fixed but axially movable in the body, the mandrel being movable by fluid pressure in the tool against the action of a first return spring (44) between a first, activated position and a second deactivated position. A sleeve (66) is between shoulders (68, 69) on the body and mandrel. Castellations (18a,b, 69a,b) are on the mandrel and facing edge or edges of the sleeve so that, when the castellations are in phase the mandrel is prevented from travelling from said first to second position and when they are out of phase they interdigitate and the mandrel is not prevented from travelling from said first to second position. A control piston (36) is slidable in the mandrel, being movable by fluid pressure in the tool against the action of a second return spring (50).

Abstract: A locking swivel apparatus is provided. The locking swivel includes an upper body portion having a counter bore about a cylindrical axis and a mandrel receivable in the counter bore. The apparatus further includes a locking arrangement, including at least one replaceable gear member, disposed to engage with the upper body portion and the mandrel. The locking arrangement is further disposed to selectively couple and decouple the upper body portion and the mandrel, such selective coupling and decoupling disposed to correspondingly constrain and allow relative rotation of the upper body portion and the mandrel about the cylindrical axis. Embodiments of the locking swivel include two replaceable gears disposed to selectively engage and disengage one another.

Abstract: Apparatus and methods for integrating transmission cable into the body of selected downhole tools, such as drilling jars, having variable or changing lengths. A wired downhole-drilling tool is disclosed in one embodiment of the invention as including a housing and a mandrel insertable into the housing. A coiled cable is enclosed within the housing and has a first end connected to the housing and a second end connected to the mandrel. The coiled cable is configured to stretch and shorten in accordance with axial movement between the housing and the mandrel. A clamp is used to fix the coiled cable with respect to the housing, the mandrel, or both, to accommodate a change of tension in the coiled cable.

Abstract: A telescoping rig with an upper mast telescopingly received within a lower mast. A torque carrier is formed of an upper part suspended within the upper mast and a lower part attached to the lower mast. The lower part may be secured to the upper part when the rig is in operational position, and is movable to allow the upper mast to move into a telescoped position within the lower mast. The rig is readied for transport by disconnecting upper and lower parts of a torque carrier, moving the lower torque carrier laterally within the lower mast to allow the upper mast to telescope within the lower mast; and telescoping the upper mast within the lower mast.

Abstract: Subsea controlled milling apparatus and methods. In a described embodiment, a method of controlling displacement of a cutting device conveyed on a tubular string in a subterranean well includes the steps of: interconnecting an apparatus in the tubular string, the apparatus including an axial advancement device and an anchoring device; actuating the anchoring device to anchor the apparatus in the well; applying a pressure differential to the advancement device, thereby displacing the cutting device relative to the apparatus; and operating the cutting device to cut a structure in the well.

Abstract: A locking swivel apparatus is provided. The locking swivel includes an upper body portion having a counter bore about a cylindrical axis, a mandrel receivable in the counter bore, and a lower cap member threadably engaged with the upper body portion. The apparatus further includes an internal locking arrangement configured to selectively couple and decouple the upper body portion and the mandrel. The selective coupling and decoupling is disposed to correspondingly constrain and allow relative rotation of the upper body portion and the mandrel about the cylindrical axis. The apparatus still further includes a supplemental internal locking mechanism configured, upon engagement, to selectively constrain the upper body portion and the mandrel from reciprocating along the cylindrical axis. The engagement of the supplemental locking mechanism is operable to secure the upper body portion and the mandrel in a coupled position.

Abstract: A shock absorbing apparatus and method includes a shaft travelling north and south within a tube. The tube is positioned south of a sucker rod. The shaft has a piston head coupled at a south end thereof, which piston head is received in an area of reduced diameter with the shaft. North pores and south pores permit the movement of fluid into and out of the interior of the tube, in response to the northward/southward movement of the piston head. Fluid entering through the pores provides a shock absorbing effect on both the upstroke and the downstroke. The shock absorbing effect on the upstroke can be rapidly eliminated and an upward shock force generated, through the shearing of a shear pin that maintains a bushing in position on the shaft, restricting northward travel of the piston head.

Abstract: Method and apparatus for drilling a well bore in a hydrocarbon formation using concentric drill string having an inner pipe and an outer pipe defining an annulus there between. A drilling means such as an air hammer or a rotary drill bit and driving system is provide at the lower end of the concentric drill string and drilling medium is delivered through the annulus or inner pipe for operating the drilling means to form a borehole. Drilling medium, drilling cutting and hydrocarbon are removed from the well bore by extracting the drilling medium, drilling cutting and hydrocarbon through the other of the annulus or inner pipe.

Abstract: The invention relates to a telescopable boring rod mechanism with at least two mutually displaceable Kelly rods, which are equipped with means for transmitting a torque to the adjacent Kelly rod. At least one of the Kelly rods is constructed from at least two rod segments, which are made from a different material.

Abstract: An adjustable down-hole tool, for example a drill-string stabiliser (10), comprises a body (12) having a through bore (16). A mandrel (18) is rotationally fixed but axially movable in the body, the mandrel being movable by fluid pressure in the tool against the action of a first return spring (44) between a first, activated position and a second deactivated position. A sleeve (66) is between shoulders (68, 69) on the body and mandrel. Castellations (18a,b, 69a,b) are on the mandrel and facing edge or edges of the sleeve so that, when the castellations are in phase the mandrel is prevented from travelling from said first to second position and when they are out of phase they interdigitate and the mandrel is not prevented from travelling from said first to second position. A control piston (36) is slidable in the mandrel, being movable by fluid pressure in the tool against the action of a second return spring (50).

Abstract: A locking swivel apparatus is provided. The locking swivel includes an upper body portion having a counter bore about a cylindrical axis, a mandrel receivable in the counter bore, and a lower cap member threadably engaged with the upper body portion. The apparatus further includes an internal locking arrangement configured to selectively couple and decouple the upper body portion and the mandrel. The selective coupling and decoupling is disposed to correspondingly constrain and allow relative rotation of the upper body portion and the mandrel about the cylindrical axis. The apparatus still further includes a supplemental internal locking mechanism configured, upon engagement, to selectively constrain the upper body portion and the mandrel from reciprocating along the cylindrical axis. The engagement of the supplemental locking mechanism is operable to secure the upper body portion and the mandrel in a coupled position.

Abstract: A locking swivel apparatus is provided. The locking swivel includes an upper body portion having a counter bore about a cylindrical axis and a mandrel receivable in the counter bore. The apparatus further includes a locking arrangement, including at least one replaceable gear member, disposed to engage with the upper body portion and the mandrel. The locking arrangement is further disposed to selectively couple and decouple the upper body portion and the mandrel, such selective coupling and decoupling disposed to correspondingly constrain and allow relative rotation of the upper body portion and the mandrel about the cylindrical axis. Embodiments of the locking swivel include two replaceable gears disposed to selectively engage and disengage one another.

Abstract: A downhole tool for generating a longitudinal mechanical load. In one embodiment, a downhole hammer is disclosed which is activated by applying a load on the hammer and supplying pressurizing fluid to the hammer. The hammer includes a shuttle valve and piston that are moveable between first and further position, seal faces of the shuttle valve and piston being released when the valve and the piston are in their respective further positions, to allow fluid flow through the tool. When the seal is releasing, the piston impacts a remainder of the tool to generate mechanical load. The mechanical load is cyclical by repeated movements of the shuttle valve and piston.