Abstract: A section mill having a tubular mill body is attached to a carrier pipe string such as a coiled tubing string. A translatable elongated tubular piston mandrel is positioned within the mill body to receive a flow of fluid from a central fluid bore in the carrier pipe string. The tubular piston mandrel has attached upper and lower pistons respectively positioned within upper and lower piston chambers in the mill body. The pistons move the piston mandrel vertically upward and downward in response to fluid pressure generated by fluid from the tubular piston mandrel. Longitudinally adjustable plungers are attached to the tubular piston mandrel. Cutter shoes are mounted to the adjustable plunger by pivotally attached yoke links. The yoke links and cutter shoes pivot radially inward and outward by upward and downward movement of the tubular piston mandrel and the attached adjustable plungers.

Abstract: A downhole sealing apparatus having a sealing assembly with one or more seal elements configured to engage a bore wall or bore-lining tubular wall to seal an annulus between the apparatus and the wall or tubular wall. A bypass arrangement is configured to provide selective bypass of the sealing assembly and the sealing apparatus is reconfigurable between a first configuration permitting bypass of the sealing assembly and a second configuration in which the bypass arrangement prevents or restricts bypass of the sealing assembly. A downhole method provides the downhole sealing apparatus within a bore hole, with the downhole sealing apparatus reconfigured from the first configuration in which the bypass arrangement permits bypass of the sealing assembly to a second configuration in which the bypass arrangement prevents or restricts bypass of the sealing assembly.

Abstract: A pipe rehabilitation system and/or robot can be used inside a pipe to measure characteristics of branch conduits, install plugs into branch conduits before the pipe is lined with a liner, remove portions of plugs and liners after lining to restore fluid communication between the pipe and branch conduits, and/or install fittings into the branch conduits to connect the liner to the branch conduits. A probe can measure characteristics of a branch conduit. A tool can install plugs and/or fittings into the branch conduits. A linkage can connect a tool to a robotic tractor so that the connected elements can navigate through a main pipe. A visualization system can aid in aligning a robot with a branch conduit. Height-adjustable braces can support robotic tools in a pipe. A plug can include integrated locating features and/or movable parts that enable expanding the plug to seal with the branch conduit.

Abstract: A method for decommissioning a heavy water reactor facility includes: opening an upper part of the calandria vault; inserting a support device into an inner part of the calandria vault through the upper part of the calandria vault to support the main shell of the calandria; cutting between the main shell and the sub-shell of the calandria by inserting a cutting device into the inner part of the calandria vault through the upper part of the calandria vault; and drawing out the main shell of the calandria to the outside of the calandria vault by moving the support device from the inner part of the calandria vault to the outside through the upper part.

Abstract: An apparatus for cutting and/or milling of tubulars in a wellbore, especially using coiled tubing. An elongated main body has a longitudinal bore, with a piston slidably positioned in the bore. The piston is connected to one or more operating arms which are rotatably connected to the main body. The connection between the piston and the operating arms may be a pinned connection or a geared connection, both of which provide for a positive connection between the piston and the operating arms. Cutter bases are connected to the cutter arms, with a number of cutters mounted to the cutter bases. Fluid flow down the coiled tubing and through the main body bore pushes the piston downwardly, opening the operating arms and cutter bases and permitting the apparatus to be pulled up into the lower end of a tubular string for cutting and/or milling.

Abstract: An anchor for securing a well tool can include a longitudinally extending central axis, an outwardly extendable grip member, and a mechanical linkage including multiple pivotably connected links. The links pivot relative to each other in a plane laterally offset from the central axis. A method of anchoring a well tool can include flowing a fluid through an anchor connected to the well tool, thereby outwardly extending a grip member into contact with a well surface, and applying a tensile force to the anchor, thereby increasingly biasing the grip member against the well surface and securing the well tool relative to the well surface. A method of anchoring a tubing cutter in a tubular string can include applying a tensile force from an anchor to the tubular string, and cutting the tubular string while the tensile force is applied from the anchor to the tubular string.

Abstract: A single trip casing cutting and pulling assembly which includes a casing spear (12), a mud motor (16) and a casing cutter (18), wherein a valve (14) is located between the casing spear (12) and the mud motor (16). The casing spear is operated by fluid flow from surface and the valve (14) prevents operation of the casing cutter (18) until the casing spear (12) is set and casing cutting is required. A method is described for cutting and pulling casing which does not require any rotation of the drill string to operate any part of the casing cutting and pulling assembly. An embodiment is described which includes retrieving the seal assembly (48) on the same trip. Further embodiments describe performing an integrity test and a circulation test on the same trip with the option of making further cuts at shallower depths on the same trip until a section of cut casing can be recovered.

Abstract: A wellbore system includes method of cutting a casing in a wellbore. A string is disposed in the casing, the string including a cutting tool and an activation sub coupled to the cutting tool. The cutting tool includes a ball seat and a cutter. The activation sub includes a control piston disposed therein. The control piston has a ball at an end thereof. The control piston is configured to move within the activation sub to engage the ball to the ball seat when a flow rate of a fluid through the control piston is above a flow rate activation threshold, wherein engaging the ball to the ball seat creates a pressure differential across the ball seat that moves the ball seat to extend the cutter from the cutting tool.

Abstract: A cutting head assembly uses multiple cutting heads directing ultra-high pressure fluid in different directions towards an inner surface of a pipe to be cut in order to complete a full cut of the pipe while rotating or revolving the multiple cutting heads less than 360 degrees relative to central axis. The ultra-high pressure fluid mixes with abrasive inside fittings on or near each of the nozzles to further assist with cutting through the pipe. Some cutting head assemblies have two nozzles, while other cutting head assemblies have three or four nozzles.

Abstract: A sacrificial shroud is disposed over a packing element of a downhole packer to provide isolation from incompatible wellbore fluids and to minimize a tendency for swabbing or packer preset due to fluid flow past the packing element during run-in, thereby allowing for faster run-in speeds. The shroud may be depletive or consumable, such as by dissolution into a wellbore fluid or by melting at a predetermined downhole thermodynamic condition. The shroud may take the form of a sleeve or an applied coating.

Abstract: A method of cutting a tubular includes providing a rotatable cutting tool in the tubular, the cutting tool having a blade with a cutting structure thereon; extending the blade relative to the cutting tool; rotating the cutting tool relative to the tubular; guiding the cutting structure into contact with the tubular; cutting the tubular using the blade; and limiting extension of the blade.

Abstract: A pulling grip assembly and methods, systems, and apparatuses for constructing the pulling grip assembly are disclosed. The pulling grip assembly can include a pulling grip. The pulling grip can include an elongated body portion and a lug portion. The lug portion can include a blind hole for receiving an assembly including a hollow fastening member and a pulling cable retained within the hollow fastening member.

Abstract: A cutting assembly is housed within a main body. The cutting assembly includes a rotary blade mounted vertically within the main body. A blade motor is coupled to the rotary blade. The blade motor is configured to rotate the rotary blade with sufficient speed and torque to cut through a wellbore tubular. The blade motor is supported by a blade motor mount. A lead screw is coupled to the blade motor mount. The lead screw is rotatable to control a vertical position of the rotary blade. A lead screw motor is rotably coupled to the lead screw. The lead screw motor is configured to rotate the lead screw to adjust the vertical position of the rotary blade. A guide is located within the main body. The guide includes a profile that controls a horizontal position of the blade based on the vertical position of the rotary blade.

Abstract: An earth-boring tool may include a plurality of blades extending axially and radially from a body. A first plurality of cutting elements may be disposed along rotationally leading faces of the plurality of blades. A pocket may be formed within a blade, and the pocket may extend angularly into the blade from a rotationally leading face of the blade within a shoulder region of the blade. A second plurality of cutting elements may be disposed within the at least one pocket. A rotational pathway of at least one cutting element of the second plurality of cutting elements may at least partially overlaps with another rotational pathway of at least one cutting element of the first plurality of cutting elements.

Abstract: A motorized release device for a downhole device includes one or more dogs disposed within a guide of the downhole device. The one or more dogs may move radially within the guide relative to a central axis of the motorized release device, such that the one or more dogs may move between an engaged position and a disengaged position. The motorized release device also includes a cam that is rotatable about the central axis, such that the cam may move between a locked position and an unlocked position. The cam may block the one or more dogs from moving to the disengaged position while the cam is in the locked position. The motorized release device may also include an electronics board. The electronics board may attach to a motor that rotates the cam between the locked position and the unlocked position.

Abstract: A casing mill for downhole casing milling has multiple elongated cutter bases hingedly connected to a main body by a plurality of positioning arms. An operating mechanism within the main body of the casing mill, actuated by fluid flow, moves the cutter bases to an extended position. Multiple cutters fixed to the cutter bases are then positioned to engage a casing end surface. Preferably, the cutters are arranged in vertically spaced apart rows, such that when one row is worn out in the milling process a visual indication is seen at the surface, as the casing mill drops to the next row of cutters.

Abstract: A mobile-unit station dedicated to pipe cutting is provided.

Abstract: A method of cutting a tubular includes disposing a rotatable cutter assembly in the tubular, the cutter assembly including a blade having a cutting portion; engaging the tubular using a trailing cutting structure of the cutting portion; engaging the tubular using an intermediate cutting structure of the cutting portion; forming a window in the tubular; and longitudinally extending the window using a leading cutting structure of the cutting portion. A rotatable blade includes a blade body extendable from a retracted position; and a cutting portion on the blade body having: a trailing cutting structure configured to engage the tubular, an intermediate cutting structure configured to engage the tubular while the trailing cutting structure engages the tubular, a leading cutting structure configured to engage an exposed wall thickness of the tubular; and an integral stabilizer disposed on at least a portion of an outer surface of the blade body.

Abstract: In some aspects, a cutting tool is provided. The cutting tool can include a mandrel, a sleeve, and first and second cutting elements. The mandrel can include first and second protrusions positioned at respective first and second lengths along the mandrel. The sleeve can at least partially surround the mandrel. Each of the first and second cutting elements can move from a respective position within the sleeve to a respective position at least partially protruding from the sleeve in response to a respective force exerted by a respective one of the first and second protrusions.

Abstract: Method and apparatus for deploying at least one repeatable signal to empirically measure cement bonding before and after operating a tool string assembly comprising a selectively arrangeable tool assembly of a downhole drive tool usable for operating a downhole placement tool with shaft and axial displacement member extendable and retractable therefrom to radially deploy and operate at least one conduit and downhole coupling tool for placing cement and at least one inner conduit proximally concentrically within a surrounding bore, wherein said drive coupling tool is further usable for transmitting or receiving, through a conductance well element into a memory tool, to measure cement bonding about said surrounding bore before and after concentrically cleaning and coupling cement to at least one conduit and surrounding bore.

Abstract: A casing mill for downhole casing milling has multiple elongated cutter bases hingedly connected to a main body by a plurality of positioning arms. An operating mechanism within the main body of the casing mill, actuated by fluid flow, moves the cutter bases to an extended position. Multiple cutters fixed to the cutter bases are then positioned to engage a casing end surface. Preferably, the cutters are arranged in vertically spaced apart rows, such that when one row is worn out in the milling process a visual indication is seen at the surface, as the casing mill drops to the next row of cutters.

Abstract: A downhole tool that includes a cutter and jacking system and methods of using such a tool to remove a portion of casing or tubing from a wellbore. The tool may include an upper slip and a lower slip configured to selectively engage casing of a wellbore. A cutter and an extendable section may be positioned between the upper and lower slips. The cutter may be used to cut casing into an upper portion and a lower portion and the extendable section may be used to increase a distance between the upper and lower slips that moves the upper portion of the casing and the lower portion of the casing away from each other. The extendable section may be hydraulically actuated to move the upper portion of the casing away from the lower portion of the casing. The cutter may be an abrasive jet configured to cut the casing.

Abstract: A cutting element includes a front face and leading face extending between a first and second sides. A leading cutting edge is located at an intersection of the front face and the leading face, and an undulating back-up cutting edge is formed in the front face and extends from the first side to the second side, and defines a leading surface and a trailing surface. A method includes cutting with a tool having a blade coupled to a tool body, and a cutting element coupled to a forward surface of the blade. The cutting element has a leading cutting edge formed at an intersection of front and leading faces, and an undulating back-up cutting edge formed in the front face and defining leading and trailing surfaces. The leading cutting edge of the cutting element contacts and cuts a work piece.

Abstract: A system and method facilitate sidetracking by eliminating one or more trips downhole. A sidetracking system includes a whipstock assembly and a stinger assembly. The stinger assembly has a running/stinger assembly which extends at least partially through the whipstock assembly. The running/stinger assembly is designed for disconnection from the whipstock assembly after delivery downhole. After disconnecting the stinger assembly, the sidetracking system enables delivery of cement slurry down through the stinger assembly to form a cement plug at a desired location.

Abstract: A shaped charge casing cutter is constructed with the cutter explosive formed into radial section modules aligned in a toroidal cavity between a pair of housing plates. The center sections of the plates are contiguously aligned with opposite parallel surfaces of a center disc. The plate rims are offset from respective center disc planes in opposite directions from each other to form a toroidal cavity. The toroidal cavity is enclosed by a circumferential belt secured to said plate rims. V-grooved shaped charge explosive in the form of multiple pi sections is distributed about the cavity to intimately contact a pair of frusto-conical liners.

Abstract: A lock holds a movable member in position to a stationary member. The set position of the tool is held while being configured to release with the capability of being reset in the same trip to lock a set position of the tool in the same or a new location.

Abstract: A downhole tool includes a radial expansion assembly deployed about, and configured to rotate substantially freely with respect to, a tool mandrel. The expansion assembly includes at least one stabilizer block configured to extend radially outward from the mandrel into contact with a wellbore casing string. When deployed between uphole and downhole cones, the stabilizer block includes a plurality of angled splines configured to engage corresponding splines on the cones. Relative axial motion between the stabilizer block and the cones causes a corresponding radial extension or retraction of the stabilizer block.

Abstract: A method of abandoning a borehole includes, running a tool into the borehole, cutting a casing with a first portion of the tool, reaming the borehole in an area where the casing has been cut with a second portion of the tool, disconnecting a drillstring from the tool, and cementing the borehole through the drillstring.

Abstract: A coiled tubing cutter assembly comprises a housing configured to be inserted in a length of coiled tubing. The housing forms a main bore and a first pathway through which cutting fluid can flow through the housing and be directed to impinge against an inner surface of the coiled tubing over which the housing is positioned so as to cut the coiled tubing. A sleeve is positioned in the main bore. The sleeve is movable between a first position and a second position within the main bore. The sleeve is configured so as to block the first pathway when in the first position and to allow cutting fluid to pass through the first pathway in the second position. A method of cutting coiled tubing is also disclosed.

Abstract: There is described a device for machining apparatus arranged for machining of a portion of a casing positioned in a wellbore, wherein a return fluid conduit extends from the machining apparatus in a direction toward a deposit area arranged in the wellbore. Also described is a method for machining of a portion of a casing positioned in a wellbore, wherein the method comprises the steps of: arranging a return fluid conduit between a machining apparatus and a deposit area or an area connected to the deposit area, providing a particle carrying liquid flow (M) in a direction from the machining apparatus and toward the deposit area, during the machining of the casing leading metal shavings into the liquid flow (M), and directing the liquid flow (M) into the return fluid conduit, as the metal shavings are held back and deposited in the wellbore.

Abstract: A tool is run in with a bottom hole assembly that includes a seal and support within the tubing where a fish is to be milled. A ported sub allows pressurized fluid pumped from the surface to enter the bottom hole assembly above the sealed support location and to be directed to set an anchor and to a fluid driven motor such as a progressive cavity motor that is in turn connected milling tool at the rotor of the progressive cavity motor. The fluid exiting the stator goes through a debris removal device and can return to the surface through an annulus around the production tubing. A telescoping joint allows the mill to axially progress with a force applied to the fish generated by a tractor or a stack of Belleville washers.

Abstract: Devices and methods for deploying perforating guns through a wellhead production assembly and into a wellbore. In particular embodiments, the invention provides devices and methods for deploying multiple perforating guns through a wellhead production assembly. In the event that the perforating gun assembly is dropped into the wellhead production assembly, a safety clamp will land upon a landing profile within a deployment riser, preventing the perforating gun assembly from falling into the wellbore.

Abstract: A cut-and-pull spear is configured to obtain multiple grips in a tubular to be cut in tension. A lock feature holds the set position of the slips and seal. The lock can be defeated with an axial force that retracts a spring-loaded dog, and the lock can be reset to the run-in position, with the slips and seal retracted, so that the assembly can be repositioned in the same trip for another cut. A cam surface prevents setting the slips and seal until the spear is relocated to the next desired cut location or removed from the wellbore. The lock can be defeated with picking up or with a pressuring up on a dropped ball for an emergency release. A surface signal of the release is provided by a stack of disc springs that have to be compressed to release the lock.

Abstract: A wellbore casing cutting tool, having multiple blades which rotate outwardly by a fluid operated mechanism, has multiple cutters on each blade. The cutters are preferably positioned on the blades such that the lowermost cutting edges of multiple cutters all bear on the surface of the casing being cut. The cutters are preferably made with a metal base, covered with hardened cutting material such as tungsten carbide or hardened cutting buttons. The metal wears away as cutting progresses, continually exposing fresh cutting surfaces. The multiple cutters permit cutting of long windows in casing walls, and the structure of the cutters results in relatively short metal cuttings, rather than long metal cuttings which can ball up downhole.

Abstract: A cut and pull spear is configured to obtain multiple grips in a tubular to be cut under tension. The slips are set mechanically with the aid of drag blocks to hold a portion of the assembly while a mandrel is manipulated. An annular seal is set in conjunction with the slips to provide well control during the cut. An internal bypass around the seal can be in the open position to allow circulation during the cut. The bypass can be closed to control a well kick with mechanical manipulation as the seal remains set. If the tubular will not release after an initial cut, the spear can be triggered to release and be reset at another location. The mandrel is open to circulation while the slips and seal are set and the cut is being made. Cuttings are filtered before entering the bypass to keep the cuttings out of the blowout preventers.

Abstract: A cut and pull spear is configured to obtain multiple grips in a tubular to be cut under tension. The slips are set mechanically with the aid of drag blocks to hold a portion of the assembly while a mandrel is manipulated. An annular seal is set in conjunction with the slips to provide well control during the cut. An internal bypass around the seal can be in the open position to allow circulation during the cut. The bypass can be closed to control a well kick with mechanical manipulation as the seal remains set. If the tubular will not release after an initial cut, the spear can be triggered to release and be reset at another location. The mandrel is open to circulation while the slips and seal are set and the cut is being made. Cuttings are filtered before entering the bypass to keep the cuttings out of the blowout preventers.

Abstract: A cut and pull spear is configured to obtain multiple grips in a tubular to be cut under tension. The slips are set mechanically with the aid of drag blocks to hold a portion of the assembly while a mandrel is manipulated. An annular seal is set in conjunction with the slips to provide well control during the cut. An internal bypass around the seal can be in the open position to allow circulation during the cut. The bypass can be closed to control a well kick with mechanical manipulation as the seal remains set. If the tubular will not release after an initial cut, the spear can be triggered to release and be reset at another location. The mandrel is open to circulation while the slips and seal are set and the cut is being made. Cuttings are filtered before entering the bypass to keep the cuttings out of the blowout preventers.

Abstract: A grapple device is secured to a mill to allow relative rotation between them. The grapple has an outward bias to allow it to grip the packer bore or an extension from the packer. The mandrel has a wedge adjacent its lower end and torque fingers that fit between grapple segments when relative longitudinal movement occurs between the mandrel and the grapple assembly. The grapple assembly has a left hand thread so that it comes out of the packer if the mandrel engages the grapple assembly in a manner for tandem rotation. The torque fingers on the wedge on the mandrel support the grapple fingers over their length as rotation to the right removes the grapple assembly from the packer bore. Reverse circulation takes away the cuttings into the mill bore where they are separated from the reverse circulating fluid.

Abstract: Tools and methods for cutting multiple, co-extending casings in oil and gas wells. The tools comprise a cylindrical body and first and second sets of cutting blades. Each set of cutting blades is mounted to the body for actuation from a retracted, run-in position to an extended, cutting position. The cylindrical body is rotated and the first set of cutting blades is actuated to cut the co-extending casings within a first sweep diameter. The second set of cutting blades then is actuated to cut the co-extending casings beyond the first sweep diameter and within a second sweep diameter.

Abstract: A packoff device is disclosed for sealing an annulus within a wellbore, and for bypassing the sealed annulus. The packoff device may include a mandrel having a bore formed axially therethrough and first and second ports extending radially from the bore. A sealing element that extends radially-outwardly from the mandrel may be positioned axially between the first and second ports, and may create a seal within an annulus between the mandrel and a casing, to isolate a portion of the annulus above the sealing element from a portion below the sealing element. A sleeve within the bore may, with the mandrel, form a channel providing fluid communication between the first and second ports. The sleeve may be movable between open and closed states. The first and second ports may be unobstructed by the sleeve in the open state, one or more may be obstructed in the closed state.

Abstract: A window milling system can include a window mill having selectively retractable and extendable blades, and a whipstock assembly having a receptacle therein, the window mill being secured relative to the whipstock assembly the blades are received in the receptacle. A method of cutting a window through a wellbore lining can include cutting through the lining with a window mill, then retracting blades of the window mill, and then outwardly extending the blades in a whipstock assembly, thereby securing the whipstock assembly to the window mill. A window mill can include multiple blades adapted for cutting through a wellbore lining, the blades being outwardly extendable relative to a body of the window mill in a well. Another method of cutting a window through a wellbore lining can include a window mill drilling a wellbore outward a substantial distance from the window after the window mill cutting through the lining.

Abstract: An ultra-high pressure (UHP) cutting device for insertion into a wellbore for cutting the casing of the wellbore from within the wellbore is provided. The cutting device comprises a UHP hose connector for connection with a UHP hose in communication with a fluid source; a rotatable UHP tube with a top end in fluid communication with the UHP hose connector and a bottom end opposite the top end; a rotating means in operational communication with the UHP tube for rotating the UHP tube during operation of the cutting device; and a cutter head in fluid communication with the bottom end of the UHP tube.

Abstract: An apparatus for abrasive jet cutting comprises an abrasive jet perforating tool coupled rotatably to a tubing string and a horizontal indexing tool coupled connectably to the perforating tool. A tubing swivel, an extension tool with protective sleeve, and an anchor may also be used. A method for abrasive jet cutting comprises determining well parameters for a well; assembling, according to the well parameters, the apparatus for abrasive jet perforating; and using the perforating tool to perforate tubular members in the well. A horizontal indexing tool is used to rotate the perforating tool and the perforating tool is used to cut tubular members in the well. An extension tool with a protective sleeve is used to protect the apparatus. A tubing swivel may be used to allow the perforating tool to rotate freely and an anchor may be used to prevent the perforating tool from moving vertically.

Abstract: Devices and methods for cleaning or removing cuttings from a cut as cutting is being performed.

Abstract: Devices and methods for cutting a workpiece. A cutter is provided with a fluid jet generator that creates and projects a jet of fluid proximate the cut being made in a workpiece.

Abstract: Tools and methods for cutting multiple, co-extending casings in oil and gas wells are provided. The tools comprise a cylindrical body and first and second sets of cutting blades. Each set of cutting blades is mounted to the body for actuation from a retracted, run-in position to an extended, cutting position. The cylindrical body is rotated and the first set of cutting blades is actuated to cut the co-extending casings within a first sweep diameter. The second set of cutting blades then is actuated to cut the co-extending casings beyond the first sweep diameter and within a second sweep diameter.

Abstract: The present invention generally relates to methods and apparatus for subsea well intervention operations, including retrieval of a wellhead from a subsea well. In one aspect, a method of performing an operation in a subsea well is provided. The method comprising the step of positioning a tool proximate a subsea wellhead. The tool has at least one grip member and the tool is attached to a downhole assembly. The method also comprising the step of clamping the tool to the subsea wellhead by moving the at least one grip member into engagement with a profile on the subsea wellhead. The method further comprising the step of applying an upward force to the tool thereby enhancing the grip between the grip member and the profile on the subsea wellhead. Additionally, the method comprising the step of performing the operation in the subsea well by utilizing the downhole assembly.

Abstract: A section mill for removing a portion of a casing in a wellbore. The section mill may include a body having a first end portion, a second end portion, and a bore formed axially therethrough. A plurality of blades may be coupled to the body. Each of the blades may have a first end portion and a second end portion. The first end portion of each blade may be coupled to the body via a hinge pin, and the second end portion of each blade may have a cutting surface formed thereon. A seat may be formed within the bore. The blades may be adapted to actuate from an inactive position to an active position in response to an impediment forming a seal against the seat.

Abstract: The present invention relates to a downhole driving unit (11) for insertion into a well, comprising a driving unit housing (51), a hydraulic motor comprising a hydraulic motor housing (93), the hydraulic motor comprising a cam ring (24), a wheel assembly (90) comprising a stationary part (91) and a rotational part, the stationary part (92) being connected with the driving unit housing and a rotatably connected with a rotational part, the stationary part and the rotational part constituting the hydraulic motor housing, said hydraulic motor comprising a rotatable section (84) connected with the rotational part, the cam ring being connected with or forming part of the stationary part of the wheel assembly, the rotational part comprising a wheel ring (99), where in a bearing (36) is arranged between the cam ring and the wheel ring. The present invention also relates to a downhole system comprising the driving unit and to use of such driving unit.

Abstract: The present invention relates to a downhole driving unit (11) for insertion into a well, comprising a driving unit housing (51), a hydraulic motor (23) comprising a hydraulic motor housing (93), a wheel assembly (90) comprising a stationary part (91) and a rotational part (92), the stationary part being connected with the driving unit housing and being rotatably connected with a rotational part, the wheel assembly comprising a wheel ring (99) for contacting an inner wall in the well and connected with or forming part of the rotations part. The wheel assembly further comprises the hydraullic motor (23) so that the stationary part and the rotational part constitute the hydraulic motor housing, the hydraulic motor comprising a rotatable section (84) connected with the rotational part for rotating part of the wheel assembly.