Abstract: A reamer includes a plurality of cutter pocket holders. The cutter pocket holders are separately manufactured and connected to a body of the reamer. The cutter pocket holders include a plurality of cutter pockets, into which cutting elements may be inserted. A radially rearward cutter pocket holder may include front-loading cutter pockets.

Abstract: A shifting tool includes a body having a longitudinal axis and a structure engaging member supported by the body. The structure engaging member is configured to engage and shift a structure within a tubular. A puncture device is supported by the body. The puncture device is configured to engage a barrier within a flowbore of the tubular in a direction of the longitudinal axis.

Abstract: A fully rotating bias unit for directional drilling rotates at bit speed while providing proportional control of directional response and steering force. The unit also provides added reliability by having increased redundancy (multiple independently controlled actuators). The unit disposed on a drillstring transfers rotation to a drill bit and has a bore communicating fluid from the drillstring to the drill bit. Directors are disposed on the unit to rotate with it. Each of the directors is independently movable between extended and retracted conditions relative to the unit's housing. Actuators of the unit are in fluid communication between the bore and the borehole or some other low pressure. Each actuator is independently operable to direct communicated fluid from the bore to extend a respective one of the directors toward the extended condition.

Abstract: A system includes a retrievable string for use in a completion string of a well, the completion string including an electrical stator. The retrievable string is to be disposed in the completion string, the retrievable string including a rotor for receipt within the electrical stator and to rotate in response to electromagnetic fields generated by the stator, an impeller coupled to the rotor, a housing to surround the impeller, and a recirculation isolator coupled to the housing. The recirculation isolator includes a sealing element and a locking tool, where the sealing element sealingly engages with the completion string, and the locking tool positions the retrievable string in the completion string and detachably couples the retrievable string to the completion string. The locking tool includes a rotational locking feature to engage an indexing receptacle of the completion string.

Abstract: A technique facilitates drilling of deviated boreholes. The technique employs a drilling system which may be disposed along a drill string. The drilling system may be used to drill a straight section of a borehole along a straight borehole axis and to also selectively drill a deviated section of the borehole. The drilling system comprises a housing, a bit shaft rotatably mounted in the housing, and an actuator which may be selectively actuated to shift the bit shaft to another position with respect to the straight borehole axis. The actuator is selectively shiftable between an unbiased mode and a biased mode. In the unbiased mode, the bit shaft axis is in a first position with respect to the straight borehole axis during drilling of the straight section of borehole. The actuator may be selectively shifted to the biased mode in which the bit shaft axis is shifted off axis relative to the straight borehole axis to enable drilling of the desired deviated section of the borehole.

Abstract: A system and method for milling a casing in a wellbore wherein an upper milling portion of a milling system engages a track of a lower guide system of the milling system in order to orient the upper milling portion. The upper milling portion moves along a track from a first position to a second position, where the the upper milling portion is securedly affixed to the lower guide portion. A traveling guide arm is used to move the milling portion along a travel path. A piston on the traveling guide arm is disposed between first and second fluid chambers, with a throughbore in the piston forming a fluid path between the two chambers. An adjustable valve in the throughbore is controlled by a proximity sensor to alter the flow of fluid between the chambers. The sensor monitors the distance between a fixed and moving point of the milling system.

Abstract: A method for estimating a steady state response of a drill string in a borehole includes calculating a first displacement of the drill string in a frequency domain for a first excitation force frequency and a number of multiples of this frequency using an equation of motion of the drill string. The equation of motion has a static force component, an excitation force component, and a non-linear force component with respect to at least one of a deflection and a derivative of the deflection of the drill string. The method further includes: transforming the first displacement from the frequency domain into a time domain; calculating a non-linear force in the time domain; calculating a frequency domain coefficient derived from the calculated non-linear force in the time domain; and calculating a second displacement of the drill string in the frequency domain using the equation of motion and the frequency domain coefficient.

Abstract: A gripper assembly for anchoring a tool within a downhole passage and for possibly assisting movement of the tool within the passage. The gripper assembly includes an elongated mandrel and flexible toes that can be radially displaced to grip onto the surface of the passage. The toes are displaced by the interaction of a driver slidable on the mandrel and a driver interaction element on the toes. In one embodiment, the toes are displaced by the interaction of rollers and ramps that are longitudinally movable with respect to one another. In another embodiment, the toes are displaced by the interaction of toggles that rotate with respect to the toes.

Abstract: A method of lining a wellbore includes deploying a BHA into the wellbore using a conveyance. The BHA includes setting tool, an anchor, and an expandable tubular. The method further includes pressurizing a bore of the setting tool, thereby releasing the anchor from the setting tool. The method further includes pulling the conveyance, thereby: extending the anchor into engagement with a casing of the wellbore, pulling an expander of the setting tool through the expandable tubular, and expanding the tubular into engagement with an open and/or cased portion of the wellbore and retracting the anchor.

Abstract: A system for a drilling and fracturing a wellbore in a single trip includes a drill string, drill bit, and a fluid flow means for delivering fluid through the string and drill bit. The drill bit includes a body with cutting elements, and nozzles between the cutting elements for washing away drilling generated cuttings. A packer on the drill bit selectively seals with an inner surface of the wellbore. Deploying the packer at a designated spot in the wellbore defines a fracturing zone in the wellbore. Closing the nozzles while opening side ports on the body delivers fracturing fluid into the space. A pressurizing system can be included to pressurized the fluid so that pressure in the space overcomes the formation strength and fractures the formation adjacent the enclosed space. The packer can be released, drilling can resume, and fracturing can occur at a different depth in the wellbore.

Abstract: A centraliser (10) for centralising a tubular (12) within a conduit is described. The centraliser comprises a centraliser body, at least one finger (14) pivotally mounted to the body and at least one collar (20), the/each collar being moveable with respect to the at least one finger. Relative movement between the/each collar and the body pivots the at least one finger from a run-in configuration to an extended configuration.

Abstract: A swellable packer with an enhanced sealing ability comprises a tubular body, a swellable element, and a filler ring disposed about the tubular body between the tubular body and the swellable element. The filler ring is formed of a material harder than the swellable element. The filler ring enhances the sealing ability of the swellable packer. Any number of filler rings may be used. The filler ring or rings may be fixed to the tubular body or may be unfixed.

Abstract: A pipe in pipe piston thrust system comprises a plurality of piston assemblies configured to sealingly engage a wellbore, a pump configured to transfer a fluid into the wellbore, and a by-pass disposed between a plurality of annuli formed by the plurality of piston assemblies. The by-pass allows for selective communication of the fluid between the plurality of annuli.

Abstract: An apparatus comprises a support member operable to be disposed within a tubular member that includes a threaded connection with a pin member. The tubular member is coupled to an expansion device that is operable to radially expand the tubular member and a pin catcher that is operable to engage the pin member as the expansion device and pin catcher move axially through the tubular member.

Abstract: Apparatus for drilling and lining a wellbore is described herein. A method of drilling and lining a wellbore is also described herein. A liner hanger is provided, secured in use on a liner. The liner hanger is operable selectively to be set and unset. The liner hanger is adapted to support the liner within an existing casing when set and to release the liner from the casing when unset. A liner hanger setting tool is provided, secured in use on a drill string. The liner hanger setting tool is actuatable selectively to set and unset the liner hanger. The liner hanger setting tool is operable selectively to be activated and deactivated. The liner hanger setting tool is adapted to attach to the liner and/or liner hanger when activated, to support the liner, and to release from the liner and/or liner hanger when deactivated.

Abstract: A gripper assembly for anchoring a tool within a downhole passage and for possibly assisting movement of the tool within the passage. The gripper assembly includes an elongated mandrel and flexible toes that can be radially displaced to grip onto the surface of the passage. The toes are displaced by the interaction of a driver slidable on the mandrel and a driver interaction element on the toes. In one embodiment, the toes are displaced by the interaction of rollers and ramps that are longitudinally movable with respect to one another. In another embodiment, the toes are displaced by the interaction of toggles that rotate with respect to the toes.

Abstract: Equipment for drilling secant holes (2) includes by an excavating system (3, 14, 4, 16, and 17) and by a guide system (7, 8), both of which are set in the hole (2) being drilled and in a previously made hole (2?). The two systems are fixed with respect to one another in such a way as to define a pre-set distance between centers of the holes; the excavating system includes a motor (3) and a bit (4) connected thereto, and being completely introduced into the borehole.

Abstract: A system for a drilling and fracturing a wellbore in a single trip includes a drill string, drill bit, and a fluid flow means for delivering fluid through the string and drill bit. The drill bit includes a body with cutting elements, and nozzles between the cutting elements for washing away drilling generated cuttings. A packer on the drill bit selectively seals with an inner surface of the wellbore. Deploying the packer at a designated spot in the wellbore defines a fracturing zone in the wellbore. Closing the nozzles while opening side ports on the body delivers fracturing fluid into the space. A pressurizing system can be included to pressurized the fluid so that pressure in the space overcomes the formation strength and fractures the formation adjacent the enclosed space. The packer can be released, drilling can resume, and fracturing can occur at a different depth in the wellbore.

Abstract: A system for use in a subterranean wellbore includes an earth boring bit on a lower end of a drill string, and an inflatable packer system. The packer system includes a pressure activated inlet valve that regulates pressurized fluid from within the drill string to the packer for inflating the packer. The inlet valve opens above a pressure used for drilling and includes a piston and spring disposed in a cylinder; the spring provides a biasing force against the piston and positions the piston between the annulus and an inlet port to the packer. When inflated, the packer extends radially outward from the drill string and into sealing engagement with an inner surface of the wellbore.

Abstract: A crawler system for an earth boring system comprises at least two expandable tools along a common axis and spaced apart from each other along the common axis by a piston cylinder device. The at least two expandable tools comprise a mandrel comprising a tubular body and an outer diameter, a plurality of blades, and a slidable sleeve capable of manipulating the plurality of blades into collapsed and expanded positions. The plurality of blades of one of the at least two expandable tools expand to an expanded position and engage a borehole wall. The piston cylinder device anchors against the engagement between the borehole wall and one of the at least two expandable tools to axially translate the other of the at least two expandable tools.

Abstract: A gripper for use in a downhole tool is provided. The gripper can include an actuator, an engagement assembly, and an expandable assembly. The engagement assembly can comprise a leaf-spring like elongate continuous beam. The expandable assembly can comprise a linkage including a plurality of links. The linkage can be coupled to the actuator such that the actuator expands the expandable assembly which in turn expands the engagement assembly. In operation, during one stage of expansion radial forces are transmitted to the engagement assembly through both interaction of a rolling mechanism on the engagement assembly with the expandable assembly and pressure of the linkage assembly directly on an inner surface of the engagement assembly.

Abstract: A hydraulically powered tractor adapted for advancement through a borehole including an elongate body, aft and forward gripper assemblies, and a valve control assembly housed within the elongate body. The aft and forward gripper assemblies are adapted for selective engagement with the inner surface of the borehole. The valve control assembly includes a gripper control valve for directing pressurized fluid to the aft and forward gripper assemblies. The valve control assembly also includes a propulsion control valve for directing fluid to an aft or forward power chamber for advancing the body relative to the actuated gripper assembly. Aft and forward mechanically actuated valves may be provided for controlling the position of the gripper control valve by detecting and signaling when the body has completed an advancement stroke relative to an actuated gripper assembly.

Abstract: An anchor tool for anchoring a downhole tool within a casing, a well, or any other downhole, hollow space. The tool has a longitudinal tool body with a center axis extending through the tool body in the center of the body, a first recess, a second recess, a third recess, and a fourth recess in the tool body; and a first anchor, a second anchor, a third anchor, and a fourth anchor. The first anchor is provided in the first recess, and so forth, and the anchors are outwards movable in the recesses for anchoring the tool. Each anchor provided in the recesses extends through the tool body transverse to and across the center axis and the anchors and the corresponding recesses are situated in the tool body for providing a symmetrical anchoring of the anchor tool.

Abstract: Latching device for a drilling device comprising a latching body mountable in an outer tube, an unlatching tube slidably mountable around the latching body, two latches attached to the latching body and pivotable between a deployed position in which the latch cooperates with the outer tube in order to latch the latching body to said outer tube and a retracted position for unlatching the latching body from the outer tube, a piston sliding around the latching body and secured to the unlatching tube, and a compression spring mechanism pressing the piston towards the latches in order to maintain the latches in their deployed position, a pulling force exerted on the unlatching tube compressing the spring mechanism to prevent the piston from pressing against the latches which position themselves in their retracted position.

Abstract: A holding device insertable into a central bore of a drill string component, the central bore having a first diameter along at least part of a central portion of the drill string component and a second diameter proximate ends of the drill string component. The second diameter is lower than the first diameter. The holding device includes an elongated body forming at least partly a housing for a transmission line. The elongated body has transversal dimensions lower than the second diameter. A plurality of arcuate elements are arranged along the elongated body and distinct from and attached to the elongated body. The arcuate elements are elastically bendable so as to be able to move through the second diameter and have a largest chord greater than the first diameter in a free state so as to be able to expand within the first diameter once past the second diameter.

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: 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: A gripper assembly for anchoring a tool within a downhole passage and for possibly assisting movement of the tool within the passage. The gripper assembly includes an elongated mandrel and flexible toes that can be radially displaced to grip onto the surface of the passage. The toes are displaced by the interaction of a driver slidable on the mandrel and a driver interaction element on the toes. In one embodiment, the toes are displaced by the interaction of rollers and ramps that are longitudinally movable with respect to one another. In another embodiment, the toes are displaced by the interaction of toggles that rotate with respect to the toes.

Abstract: An electrically powered and controlled tractor system includes one or more electric gripper assemblies and one or more electric power train assemblies. Power and control signals for the gripper assemblies and power train assemblies can be delivered from a ground surface via a wireline. The gripper assembly employs a motor-activated lead screw and nut combination to expand passage-gripping elements, preferably by pushing the gripping elements radially outward from locations between opposing ends of the gripping elements. A failsafe mechanism can retract the gripping elements during a power interruption. The power train assembly employs a motor-activated lead screw and nut combination to expand and contract two or more telescoping members. The tractor system can include multiple tractor units that each includes one gripper assembly and one power train assembly. A tractor can include one power train assembly and two gripper assemblies.

Abstract: An apparatus for supporting a retrievable downhole component within a drill collar includes a sleeve that is positionable about the downhole component and is mounted within the drill collar. The sleeve is adapted to limit the lateral movement of the downhole component. The sleeve includes a series of fins or is lined with an energy absorbing material which protects the component from shock and vibration while at the same time enables the component to be retrieved should the drill string become stuck in the borehole.

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 method and device for drilling, particularly percussion drilling or rotary percussion drilling a hole in soil or rock material and fixing an anchoring in the hole. To this end, a drilled hole is made by a drill bit mounted on a drill rod. The drill rod, on the rear side facing away from the drilling surface of the drill bit, is surrounded at a distance from the drill bit by an anchoring element whose outside dimension exceeds, at least in part, the circumference of the drilled hole made by the drill bit.

Abstract: Casing bits include an expander for enlarging an inner diameter of expandable casing at least partially disposed within a body of the casing bits. Drilling assemblies include a casing bit attached to an end of expandable casing, and an expander disposed in proximity to the casing bit and a distal end of the expandable casing. Methods of forming casing bits include positioning an expander in proximity to a body of a casing bit. Methods of forming drilling assemblies include positioning an expander in proximity to a body of a casing bit and a distal end of expandable casing, and attaching the casing bit to the end of the expandable casing. Methods of casing a wellbore include one or both of drilling and reaming a wellbore using a casing bit attached to a distal end of expandable casing, and forcing an expander through the expandable casing.

Abstract: An electrically powered and controlled tractor system includes one or more electric gripper assemblies and one or more electric power train assemblies. Power and control signals for the gripper assemblies and power train assemblies can be delivered from a ground surface via a wireline. The gripper assembly employs a motor-activated lead screw and nut combination to expand passage-gripping elements, preferably by pushing the gripping elements radially outward from locations between opposing ends of the gripping elements. A failsafe mechanism can retract the gripping elements during a power interruption. The power train assembly employs a motor-activated lead screw and nut combination to expand and contract two ore more telescoping members. The tractor system can include multiple tractor units that each includes one gripper assembly and one power train assembly. A tractor can include one power train assembly and two gripper assemblies.

Abstract: The present invention generally relates to methods and systems for mitigating trouble zones in a wellbore in a preferred pressure condition and completing the wellbore in the preferred pressure condition. In one aspect, a method of reinforcing a wellbore is provided. The method includes locating a valve member within the wellbore for opening and closing the wellbore. The method further includes establishing a preferred pressure condition within the wellbore and closing the valve member. The method also includes locating a tubular string having an expandable portion in the wellbore and opening the valve member. Additionally, the method includes moving the expandable portion through the opened valve member and expanding the expandable portion in the wellbore at a location below the valve member. In another aspect, a method of forming a wellbore is provided. In yet another aspect, a system for drilling a wellbore is provided.

Abstract: A technique that is usable with a well includes running a motor into the well and actuating the motor to turn a drill bit. The motor is used to pump well fluid from the well.

Abstract: A gripper for use in a downhole tool is provided. The gripper can include an actuator, a toe assembly, and an expandable assembly. The toe assembly can be a leaf-spring like elongate continuous beam. The expandable assembly can be a linkage including a plurality of links. The linkage is coupled to the actuator such that the actuator expands the expandable assembly which in turn expands the toe assembly. In operation, during one stage of expansion radial forces are transmitted to the toe through both interaction of a rolling mechanism on the toe with the expandable assembly and pressure of the linkage assembly directly on an inner surface of the toe.

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: The invention relates to a method and device for drilling, particularly percussion or rotary percussion drilling, a hole in soil or rock material and for producing an anchoring. According to the invention, a drill bit (2) fastened to drilling rods (3) makes a drilled hole (1). A number of, in particular, wedge-shaped spreading elements (7) oriented contrary to the direction of drilling (6) are provided in a part joined to the drill bit (2). These spreading elements can be introduced into the wall of the drilled hole (1) after the drilled hole (1) is completed whereby making it possible to obtain a secure anchoring immediately after the drilled hole (1) has been completed.

Abstract: The present invention relates to a device for controlling the Blow out preventer (BOP) used in well drilling operations comprising: BOP control unit, master control panel connected to the BOP unit for acquisition of data and processing the said data, comprising an input module, an output module and analog I/P module; a plurality of slave panels connected to master panel through the connecting means comprising input module, output module for controlling the BOP control unit; wherein the said slave panel is a programmable logic controller(PLC) for controlling BOP control unit.

Abstract: The invention relates to a method and device for drilling, particularly percussion drilling or rotary percussion drilling a hole in soil or rock material and fixing an anchoring in the hole. To this end, a drilled hole is made by a drill bit (3) mounted on a drill rod (2). According to the invention, the drill rod (2), on the rear side facing away from the drilling surface (5) of the drill bit (3), is surrounded at a distance from the drill bit (3) by an anchoring element (4) whose outside dimension exceeds, at least in part, the circumference of the drilled hole made by the drill bit (3) whereby enabling a constructively easier and more reliable securing of the anchoring inside the drilled hole.

Abstract: Methods and apparatus to apply axial force to a packer in a downhole tool are described. In one described example, an apparatus to apply an axial force to an inflatable packer associated with a downhole tool includes a sleeve slidingly coupled to a body of the downhole tool and an end of the packer. An inner portion of the sleeve is sealed against the body of the downhole tool to form a chamber, and the chamber is fluidly coupled to a pump associated with the downhole tool to receive a pressurized fluid to cause the sleeve to apply an axial force to the packer.

Abstract: Drilling a well to total depth without tripping the bit out of the hole despite encountering a troublesome zone is made possible by using a memory based composite material delivered with the drill pipe or advanced over it, as needed. The material can be activated as a troublesome zone is encountered and assumes as former configuration that places it in sealing relation to the troublesome zone in the bore hole while spacing it from the drill pipe so as to allow resumption of drilling with the troublesome zone isolated.

Abstract: A gripping element for incorporation into a track of a downhole tractor. The gripping element may be configured with an arcuate or curved surface in order to roughly match the arcuate nature of a well through which the downhole tractor is advanced. Due to the matching arcuate surfaces of the gripping element and the wall of the well, problems associated with uneven wear on the tracks may be avoided. Furthermore, damage to the well wall may be minimized as a result of the substantially matching surfaces of the well wall and the track made up of such gripping elements. Additionally, the gripping element may be made up of primarily a monolithic body in order to avoid challenges presented by some segmented body configurations.

Abstract: A zone isolating and testing apparatus comprising an isolation tool and a downhole flow control means and a method of using such apparatus. The zone isolating and testing apparatus is particularly useful for testing zones during reverse circulation drilling using concentric drill string such as concentric drill pipe or concentric coiled tubing. The isolation tool of the zone isolating and testing apparatus comprises an expandable packer means and is adapted to connect to concentric drill string near the drilling means and be in fluid communication with the concentric drill string. The downhole flow control means of the zone isolating and testing apparatus comprises at least two valves, one for closing off the annular conduit between the inner tube and outer tube of the concentric drill string and the other for closing off the inner conduit of the inner tube.

Abstract: A method and device for boring a hole in soil or rock material and for forming an anchoring are disclosed. A borehole is formed by inserting a drill bit, and tensioning elements coupled to the drill bit are introduced into the borehole. After completion, the boring rods are detached from the drill bit and removed. The boring rods are provided with a hollow space in its longitudinal direction to introduce a hardenable fluid into the borehole. Anchoring or fixing elements for anchoring on the borehole's inner wall are provided on the drill bit at the end opposite the drilling surface and/or on the tensioning elements. The tensioning elements are subjected to a turning or twisting whereby shortening their effective length for tensioning or centering so that a centering and an optionally temporary tensioning of the tensioning elements can be effected before the hardenable material completely hardens.

Abstract: A gripper assembly for anchoring a tool within a downhole passage and for possibly assisting movement of the tool within the passage. The gripper assembly includes an elongated mandrel and flexible toes that can be radially displaced to grip onto the surface of the passage. The toes are displaced by the interaction of a driver slidable on the mandrel and a driver interaction element on the toes. In one embodiment, the toes are displaced by the interaction of rollers and ramps that are longitudinally movable with respect to one another. In another embodiment, the toes are displaced by the interaction of toggles that rotate with respect to the toes.

Abstract: A well bore tool with a torsional resistant slip mechanism for resisting axial and torsional forces comprising a mandrel, a plurality of slips disposed about the circumference of the mandrel. The slips include a plurality of inserts oriented to resist axial forces and torsional forces. The tool also comprises a setting means adjacent each to slip for radially expanding and setting said slips.

Abstract: A steering tool for use in a well bore is disclosed. The tool includes at least one extendable and retractable blade deployed thereon. The blade is elastically spring biased radially inwards towards the tool such that upon removal of an actuating force, the blade retracts. In exemplary embodiments, the blade includes at least one spring-like, elastically deformable member disposed to elastically spring bias the blade. The spring-like member may include first and second elongated leg portions located on opposing sides of a sprung hairpin portion. Tools embodying this invention may be advantageous for small diameter applications.

Abstract: A gripper assembly for anchoring a tool within a downhole passage and for possibly assisting movement of the tool within the passage. The gripper assembly includes an elongated mandrel and flexible toes that can be radially displaced to grip onto the surface of the passage. The toes are displaced by the interaction of a driver slidable on the mandrel and a driver interaction element on the toes. In one embodiment, the toes are displaced by the interaction of rollers and ramps that are longitudinally movable with respect to one another. In another embodiment, the toes are displaced by the interaction of toggles that rotate with respect to the toes.