Abstract: What is provided is a method and apparatus wherein a rotating and reciprocating swivel of adjustable stroke length and shearable by ram blow out preventers can be detachably connected to an annular blowout preventer thereby separating the lower wellbore from the riser. In one embodiment the mandrel of the swivel extends through a sleeve/housing. The sleeve/housing has a wiping arrangement of improved configuration that wipes debris from the mandrel, preventing entry of the debris into the sleeve/housing. Ports enable discharge of the removed debris from the area of the sleeve/housing.

Abstract: A transportation apparatus for moving a workover rig includes a first and a second pony substructure. A joist connects the first pony substructure to the second pony substructure. At least one stomper is operably connected to each of the first and second pony substructures for moving the transportation apparatus from a first location to a second location. The first and second pony substructures are configured to receive a vehicle that is configured as a workover rig. A proximal end of a first guide wire attaches to the walking structure, and a distal end of the guide wire attaches to the workover rig to stabilize the workover rig atop the transportation apparatus.

Abstract: What is provided is a method and apparatus wherein a rotating and reciprocating swivel of adjustable stroke length and shearable by ram blow out preventers can be detachably connected to an annular blowout preventer thereby separating the lower wellbore from the riser. In one embodiment the mandrel of the swivel extends through a sleeve/housing. The sleeve/housing has a wiping arrangement of improved configuration that wipes debris from the mandrel, preventing entry of the debris into the sleeve/housing. Ports enable discharge of the removed debris from the area of the sleeve/housing.

Abstract: A lifting elevator includes a first elevator segment having a first plurality of slips, a second elevator segment having a second plurality of slips, and a hinge. The first elevator segment and the second elevator segment each have a swept angle of about 180°, and each of the first plurality of slips and the second plurality of slips includes a die configured to grip an external surface of a pipe.

Abstract: According to one aspect, data identifying a component is received, wherein the component is part of a system associated with a wellhead. A location at which the component is positioned relative to one or more other components is identified. The useful remaining operational life of the component is predicted based on at least an operational parameter specific to the location, and the operational history of the component or one or more components equivalent thereto. According to another aspect, a model representing at least a portion of a proposed system associated with a wellhead is generated, the model comprising a plurality of objects, each of which has a proposed location and represents an existing component. The useful remaining operational life for each object is predicted based on an operational parameter at the corresponding proposed location, and data associated with the respective operational history of the existing component.

Abstract: A dedicated borehole for an ESP or artificial lift mechanism communicates with a sump or wellbore to collect liquids and/or condensate from one or more other bores where there can be laterals into a producing formation. If the ESP or artificial lift mechanism needs to be replaced the dedicated bore with the ESP or artificial lift mechanism can be closed off and the ESP or artificial lift mechanism removed without taking out the main bore or bores connected to the sump or wellbore. Those bores can continue to produce gas as liquids and/or condensate accumulate in the sump, sumps or wellbore. When the ESP or artificial lift mechanism is replaced the liquid can be pumped to surface without interruption of the gas production.

Abstract: Various hoisting systems using multiple hoisting lines in shared block-and-tackle arrangements are provided. In one embodiment, an apparatus includes a hoisting system with multiple hoisting lines wound on a rotatable drum of a drawworks. The hoisting lines are continuous wire ropes that are reeved over a shared crown block and around a shared traveling block in a block-and-tackle arrangement to provide a mechanical advantage. Additional systems, devices, and methods are also disclosed.

Abstract: Various lifting systems are described that use one or more of the following features. A method for setting an adjustable height upper pulley on a tall structure; load transfer from a suspended load to a tall structure; fan-based stabilizer; stabilizer or horizontal load position control mechanism using a closed loop of cable and taction winch for a crane application; crane-based lifting system that uses a closed loop of lifting cable looped around a traction winch; and a stabilizer or horizontal load position control mechanism that does not need a closed loop of cable. Other embodiments are also described and claims. Other embodiments are also described and claimed.

Abstract: An assembly for machine leveling including a plurality of hydraulic cylinders having upper ends adapted for supporting the machine's base, a lower end, a shaft, and a port opening the cylinder; branch conduits having cylinder ends and pump ends, each branch conduit connecting to one of the ports; first shutoff valves connected to the branch conduits for alternatively permitting and resisting fluid flow within the branch conduits; a manifold conduit connected to the branch conduits; a hydraulic pump connected to the manifold conduit and adapted for raising hydraulic pressure within the manifold conduit to a shaft extending pressure; and an electrically modulated variable pressure relief valve connected to the manifold conduit and adapted for raising and lowering the hydraulic pressure.

Abstract: A communications unit. At least one example includes a platform that has a tower assembly operably coupled thereto such that tower assembly is movable between a horizontally deployed position and a vertically deployed position relative to the platform. The tower assembly includes a plurality of telescoping tower segments that are movably supported relative to each other such that they may be selectively manually deployed between a retracted position and the horizontally deployed position. The unit may further include a locking assembly that is configured to selectively and individually lock each of the plurality of telescoping tower segments in the horizontally deployed position. A deployment assembly operably interfaces with the tower assembly and is configured to selectively move the tower assembly between the horizontally deployed position and the vertically deployed position.

Abstract: A stripper packer for sealing a tubular of a wellsite is provided. The stripper packer includes an extendable housing, a packer, and a sliding window. The extendable housing has a passage therethrough to receive the tubular, and includes a piston operatively connectable between an upper and a lower portion of the extendable housing for selective movement therebetween. The packer is positionable within the extendable housing and sealingly engageable with the tubular. The sliding window is slidably positionable in the passage of the extendable housing and engageable with the packer. The sliding window is movable with the piston in response to pressure whereby the packer is sealable with the tubing.

Abstract: A completion system and method adapted for use in wells having long lateral boreholes includes a mast assembly, a pipe handling mechanism, a pipe arm, a pipe tub, a pump/pit combination skid, a rig carrier, and a control system. The mast assembly can extend in a generally vertical direction, e.g., perpendicular to the rig carrier and/or the earth's surface, such that the rig can be placed directly adjacent to a wellbore, and the top drive or a similar drive system can be engaged with and move along the mast while remaining above the wellbore. The top drive can be engaged with a support fixture that resists torque and rotation during operation. The support fixture can in turn be engaged with the mast to transfer torque forces to the mast while being vertically movable along the mast to enable positioning of the top drive.

Abstract: A control system is configured to actuate a tubular handling tool. The system includes a fluid source and a tubular handling tool having a plurality of piston cylinders and a plurality of slips configured to engage a tubular string. The system also includes a volume synchronizer having a plurality of first chambers in fluid communication with the fluid source, a plurality of second chambers in fluid communication with the piston cylinders, a piston separating each of the first and second chambers, and a rod member connected to each piston. Pressurized fluid supplied to the first chambers simultaneously moves each of the pistons to simultaneously force pressurized fluid out of the second chambers and into the piston cylinders to actuate the slips into engagement with the tubular string.

Abstract: The disclosed invention introduces an efficient lifting mechanism for reciprocating vertically a load system, the load consisting of the aggregate weights of a cargo payload in conjunction with “dead weights” of moving parts of the lifting apparatus. The disclosed invention uses a hydro-pneumatic linear actuator to lift the load and a pressurized accumulator, acting as a force intensifier. The pressurized accumulator, acting as a self-contained stored energy source, provides to the actuator adequate power to lift the “dead weights” plus part of the cargo payload. An external power source provides to the actuator adequate power to lift the remainder of the cargo payload. The disclosed invention saves significant amounts of power and energy in applications in which the “dead weights” are sizable compared to the cargo load. The disclosed invention provides also exceptional means for accurate motion control of the cargo payload.

Abstract: A system and method for monitoring and controlling a snubbing unit having traveling slips and stationary slips are provided. Position sensors are associated with the slips for detecting opened and closed positions of the slips. Load sensors are associated with the slips for detecting load status of the slips. A control system receives input signals from the sensors, and confirms that either the traveling slips or the stationary slips are loaded before releasing or allowing the release the opposing set of slips, when transferring the pipe string load from the one set of slips to the other set of slips.

Abstract: An apparatus and a method are provided for lifting wellbore fluids from a distal section of a wellbore. The apparatus comprises a suction generator connected to a communication line having an open free end that extends into the distal section. The suction generator creates suction to draw fluid from the free end of the communication line up to the proximal section. The suction generator may comprise a piston barrel with a piston disposed therein and the communication line may be a flexible tubing connected to the lower end of the piston barrel. Wellbore fluids can be drawn into the flexible tubing and up the piston barrel, through the piston, by repeated alternating upward and downward movement of the piston.

Abstract: A well servicing system includes a frame adapted to mount to a pipe handling system that includes a hanger adapted to guide a load coupled to a cable towards a wellhead, where the load exerts at least a portion of a tensile force on the cable; and a winch including a drum and a brake. The brake is adapted to control rotational motion of the drum to spool a portion of the cable over the drum and set the drum to substantially prevent rotational motion of the drum. The well servicing system also includes a hydraulic piston-cylinder coupled to a sheave. The piston is adapted to stroke into or out of the cylinder when the tensile force exceeds a desired load when the drum is set to substantially prevent rotational motion to spool the cable from the drum.

Abstract: A system and method for axially displacing a portion of coiled tubing into and/or out of a wellbore so that the coiled tubing does not incur a fatigue cycle during such axial displacement, such as, but not limited to a translation system located between the wellhead and the injector head base to axially displace the injector head and, therefore, the gripped coiled tubing, away from and toward, the wellhead.

Abstract: A support structure for use on a rig floor and for supporting a unit used to manipulate tubular components through a wellhead comprises a support plate adapted to securely mount the support structure to said unit, a passage in the support plate of sufficient diameter to allow tubular components to pass therethrough, a plurality of rig engaging members and at least one tensile member mount. The unit used to manipulate tubular components through a wellhead may be a compact snubbing unit or may be a push/pull unit. The support structure may further comprise a worker platform to support a worker above the rig floor. Various push/pull system embodiments.

Abstract: The disclosed invention introduces an efficient lifting mechanism for reciprocating vertically a load system, the load consisting of the aggregate weights of a cargo payload in conjunction with “dead weights” of moving parts of the lifting apparatus. The disclosed invention uses a hydro-pneumatic linear actuator to lift the load and a pressurized accumulator, acting as a force intensifier. The pressurized accumulator, acting as a self-contained stored energy source, provides to the actuator adequate power to lift the “dead weights” plus part of the cargo payload. An external power source provides to the actuator adequate power to lift the remainder of the cargo payload. The disclosed invention saves significant amounts of power and energy in applications in which the “dead weights” are sizable compared to the cargo load. The disclosed invention provides also exceptional means for accurate motion control of the cargo payload.

Abstract: A hydraulic workover rig including a base structure, a derrick extending from the base structure, a hydraulic lift cylinder connected to the upper end of the derrick, a lower slip assembly connected to the base structure, an upper slip assembly, and at least two snub cylinders connected to the base and the upper slip assembly. A distal end of a piston rod of the lift cylinder is connectable to a pipe string extendable through the upper and lower slip assemblies such that both a lifting force and a snubbing force may be applied simultaneously to the pipe string.

Abstract: A drilling rig with top drive assembly consisting of a traveling block housing, sheaves, with axles connected to a pair of links supporting a top drive, and a compressible extendable airbag as a thread compensator for running tubulars into a wellbore, making up tubulars, or breaking tubulars out of a wellbore.

Abstract: A wellbore tubular handling system and method for moving tubulars into a wellhead. The wellbore tubular handling system includes a service rig including a transport chassis, a mast pivotally connected to the transport chassis and moveable between a storage position and an erected position and a block supported on the mast; an upper snubbing unit pivotally connected to the mast, the upper snubbing unit including a first driving ram and a second driving ram, each including a mounted end and an outboard end, each of the first driving ram and the second driving ram being connected at the pivotal connection to the mast adjacent their mounted ends and a travelling snubbing slip assembly mounted to the outboard ends of the first driving ram and the second driving ram and being drivable toward and away from the mounted ends by the first driving ram and the second driving ram; and a stationary snubbing slip assembly configured for connection to the wellhead.

Abstract: A hydraulic lubricator assembly includes a spool for enclosing a downhole tool, wherein the spool comprises an upper end and a lower end. The hydraulic lubricator assembly further includes a pressure isolation connector attached to the upper end of the spool, wherein the pressure isolation connector includes a lower packing gland and an upper packing gland. A hydraulic assembly is positioned above the pressure isolation connector, wherein the hydraulic assembly comprises a rod connected to the downhole tool, and wherein the hydraulic assembly lowers the downhole tool into the wellbore.

Abstract: In one embodiment, a tubular gripping assembly for use with a top drive to handle a tubular includes a tubular gripping tool having a mandrel and gripping elements operatively coupled to the mandrel; and a link assembly attached to the mandrel, wherein a load of the link assembly is transferred to the mandrel. In another embodiment, the tubular gripping assembly includes a swivel having selectively actuatable seals. In yet another embodiment, the tubular gripping assembly includes a thread compensator to facilitate tubular make-up. In yet another embodiment, the tubular gripping assembly includes a wedge lock release apparatus to facilitate the release of gripping elements from the tubular.

Abstract: A method and apparatus for conducting earth borehole operations comprising a CT system comprising a first carrier with a reel of CT and a CT injector, a second carrier comprising a top drive rig having a mast, and a lifter operative to move the CT injector from the first carrier to an operative or near operative position with respect to the mast on the second carrier.

Abstract: A hydraulic workover rig including a base structure, a derrick extending from the base structure, a hydraulic lift cylinder connected to the upper end of the derrick, a lower slip assembly connected to the base structure, an upper slip assembly, and at least two snub cylinders connected to the base and the upper slip assembly. A distal end of a piston rod of the lift cylinder is connectable to a pipe string extendable through the upper and lower slip assemblies such that both a lifting force and a snubbing force may be applied simultaneously to the pipe string.

Abstract: A snubbing apparatus for moving well tubing through a blowout preventer including a support frame, a standing tubular engaging assembly, a pair of linear actuators, and a traveling tubular engaging assembly. The actuators have a cylinder and a rod, and the cylinder has an upper end and a lower end. The cylinders are connected to the support frame in a diametrically opposing relationship to one another and with the lower ends of the cylinders extending downwardly beyond the lower end of the support frame and spaced apart from one another a distance sufficient so that the lower ends of the cylinders are positioned on opposing sides of the blowout preventer when the support frame is connected to the blowout preventer.

Abstract: Methods and apparatus for connecting a tubular to a tubular string are provided. In one embodiment, an apparatus suitable for engaging, compensating, and connecting a tubular includes one or more compensating pistons, an engaging assembly for engaging a tubular, and a connector for connecting the engaging assembly to the one or more compensating pistons while allowing for rotation of the tubular relative to the compensation pistons.

Abstract: A subsurface lubricator facilitates well completion, re-completion and workover while increasing safety and reducing expense. The subsurface lubricator includes a bi-directional packoff tool on its bottom end. Short hydraulic cylinders lubricate the subsurface lubricator into the well until the bi-directional packoff tool is in a top end of a casing of the well. High pressure fluid pumped through a side port of a wellhead of the well lubricates the subsurface lubricator into the well.

Abstract: A snubbing apparatus for moving well tubing through a blowout preventer including a support frame, a standing tubular engaging assembly, a pair of linear actuators, and a traveling tubular engaging assembly. The actuators have a cylinder and a rod, and the cylinder has an upper end and a lower end. The cylinders are connected to the support frame in a diametrically opposing relationship to one another and with the lower ends of the cylinders extending downwardly beyond the lower end of the support frame and spaced apart from one another a distance sufficient so that the lower ends of the cylinders are positioned on opposing sides of the blowout preventer when the support frame is connected to the blowout preventer.

Abstract: A snubbing jack includes a first telescopic member and a second telescopic member. A stationary plate and a movable plate are affixed to the telescopic members. The movable plate moves away from the stationary plate upon expansion of the telescopic member and moves toward the stationary plate upon contraction of the telescopic members. An intermediate plate is removably secured between the stationary plate and the movable plate.

Abstract: An apparatus for pumping fluids from a well having a production tubing extending from a wellhead of the well downhole to a downhole location. A pump having a pump barrel connected to a bottom of the production tubing, and a plunger reciprocable within the pump barrel for lifting fluid from the bottom of the well up through the production tubing and to the wellhead as the plunger upstrokes, and for filling the barrel below the plunger as the plunger upstrokes. A sealed housing attached to the wellhead with the production tubing in fluid communication with the interior of the sealed housing. A cable drum positioned within the interior of the sealed housing. A prime mover operably connected to the cable drum for rotating the cable drum and a cable wound on the cable drum for winding and unwinding by rotating the cable drum. The cable extending downwardly through the production tubing and attached to the plunger.

Abstract: A subsurface lubricator facilitates well completion, re-completion and workover while increasing safety and reducing expense. The subsurface lubricator includes a bi-directional packoff tool on its bottom end. Short hydraulic cylinders lubricate the subsurface lubricator into the well until the bi-directional packoff tool is in a top end of a casing of the well. High pressure fluid pumped through a side port of a wellhead of the well lubricates the subsurface lubricator into the well.

Abstract: A method and apparatus for removing tubulars from a wellbore is disclosed. A lifting member grips the tubular and applies a lifting force. The lifting force is then transferred to a first surface. The lifting member is monitored and when the capacity of the first surface is reached a force transfer assembly is activated. The force transfer assembly transfers the lifting load between the first surface and a second surface. The lifting member and force transfer assembly are then adjusted to maximize the amount of lifting force applied to the tubular.

Abstract: A subsurface lubricator facilitates well completion, re-completion and workover while increasing safety and reducing expense. The subsurface lubricator includes telescopic hydraulic cylinders to lubricate a lubricator tube into the well. For very long tool strings, extension rods and stay rods are used to extend a reach of the telescopic hydraulic cylinders.

Abstract: A method for restraining tubular members during well servicing. A first step involves monitoring a velocity of tubular members as they are withdrawn from a well. A second step involves activating a tubing restrainer when the velocity of the tubular members exceeds a predetermined threshold.

Abstract: A mobile snubbing system and method of operation transports a snubbing unit to a wellhead on a mobile platform. The snubbing unit is supported by a frame pivotable about a wellhead end of the platform for aligning the snubbing unit with the wellhead. A pipe handler boom is operable between a platform position for loading and off-loading tubulars at an open side of the platform and a second snubbing position for loading and off-loading tubulars at the top end of the snubbing unit. The boom can be telescopic for extending to the top of the snubbing unit and can be automated after learning tubular manipulation at the wellhead. Pipe racks can be deployable from the open side of the platform and an indexer and kicker in the platform enables loading and off-loading tubulars at the pipe handler.

Abstract: A method and device for preventing a pipe string (5) clampingly arranged in a slips (2) from slipping out of the slips (2) in the event of the pipe string (5) slipping in the slips (2), wherein a pipe clamp (22) is clamped, preferably hydraulically, onto the pipe string (5) at a position above the slips (2) and maintained in the clamped state for essentially as long as the pipe string (5) is held by the slips (2), the pipe clamp (22), in the event of the pipe string (5) slipping in the slips (2), being displaced together with the pipe string (5) until the pipe clamp/tong (22) stops against the wedges (16) of the slips (2).

Abstract: A casing running tool comprising an integral elevation module and make-up/torque module. In accordance with one aspect or the invention, the tool is adapted to automatically engage a collared end of a tubular structure such as a casing string segment. The integral make-up/torque module is actuated by hydraulic control lines to exert compression force upon the outer diameter of a tubular, such as a casing string segment. This compression force is sufficient to enable torque to be applied to the tubular without slippage. In one embodiment, the make-up/torque module comprises an outer body carrying a plurality of hydraulically-actuable pistons, such that the tool is actuable from the rig floor to grasp the tubular with sufficient force that rotational force (torque) supplied via a drive motor in a top-drive rig. In accordance with another embodiment, the multifunction tool further includes an internal ball valve assembly for selectively allowing or restricting fluid flow through the tool.

Abstract: An apparatus for controlling vertical movement of a tubular within a wellhead includes an anchor spool connected atop the wellhead, and a detachable superstructure supporting the tubular. The anchor spool provides connectors for detachably connecting bottom ends of at least two piston cylinders of the detachable superstructure. The tubular may be a landing joint or a high-pressure mandrel of either a well stimulation tool, or a well isolation tool. The apparatus provides unobstructed access to a top end of the tubular. The anchor spool includes an elongated sidewall and an axial passage through which a tubing hanger can be reciprocated. The height of the sidewall permits the apparatus to be used for landing/removing a tubing string even if the anchor spool is mounted directly to a blowout preventer (BOP).

Abstract: A tool for use in wells to maintain a tubed pipe filled with drilling fluid supplied by a well and to circulate the fluid through a well-pipe space, the tool facilitating sliding of tubes and producing cementation of the space. The tool can be intercalated with drilling equipment between a block and a pipe elevating arrangement for tubes that are gradually coupled to make up the casing pipe. The tool is placed between amelas extending from a rig support to adjacent the pipe elevating arrangement, the tool including a support array for positioning the tool in the drilling equipment, a positioning dynamic array to move the tool upward and downward to mate the tool on, and decouple it from, a tube, and a packaging array to, during the matings, establish a hermetic, self-adjustable elastic seal for the passage of well fluid to the inside of the tube.

Abstract: Methods and apparatus for drilling with a top drive system. In one aspect, the apparatus provides a tubular gripping member for use with a top drive to handle a tubular comprising a housing operatively connected to the top drive and a plurality of gripping elements radially disposed in the housing for engaging the tubular, wherein moving the housing relative to the plurality of gripping elements causes the plurality of gripping elements to engage the tubular.

Abstract: A mobile snubbing system and method of operation transports a snubbing unit to a wellhead on a mobile platform. The snubbing unit is supported by a frame pivotable about a wellhead end of the platform for aligning the snubbing unit with the wellhead. A pipe handler boom is operable between a platform position for loading and off-loading tubulars at an open side of the platform and a second snubbing position for loading and off-loading tubulars at the top end of the snubbing unit. The boom can be telescopic for extending to the top of the snubbing unit and can be automated after learning tubular manipulation at the wellhead. Pipe racks can be deployable from the open side of the platform and an indexer and kicker in the platform enables loading and off-loading tubulars at the pipe handler.

Abstract: The present invention relates to subterranean cementing operations, and more particularly to an apparatus useful in loading cementing plugs and darts into tubulars, and methods of using such apparatus in subterranean cementing operations. An example of a method of the present invention is a method of placing a compressible object having a cross-section within a tubular, including the steps of: reducing the cross-section of the compressible object; placing the compressible object with the reduced cross-section in a tubular; and releasing the compressible object within the tubular. Another example of a method of the present invention is a method of reducing the radial cross-section of a compressible object. Other examples of apparatus of the present invention include apparatus for placing a compressible object into a tubular.

Abstract: A control line guide and manipulating arm can protect and guide one or more control lines which are desired to be attached and lowered into a wellbore with a tubular string. The control lines may be moved toward a tubular string, can be clamped to the tubular string, and the tubular string and control lines may be lowered into the wellbore. When the elevator reaches a predetermined position, the spider slips are preferably set. To protect the control lines, the control lines are moved in a substantially radial direction outward from the tubular string. The spider slips are closed only after the control lines are retained outward. After another tubular joint is connected to the tubular string and the elevator grips the tubular string, the spider slips are preferably released. For easier attachment, of the control lines to the tubular string, the control lines are moved in a substantially radial direction toward the tubular string.

Abstract: An apparatus for controlling vertical movement of a tubular within a wellhead includes an anchor spool connected atop the wellhead, and a detachable superstructure supporting the tubular. The anchor spool provides connectors for detachably connecting bottom ends of at least two piston cylinders of the detachable superstructure. The tubular may be a landing joint or a high-pressure mandrel of either a well stimulation tool, or a well isolation tool. The apparatus provides unobstructed access to a top end of the tubular. The anchor spool includes an elongated sidewall and an axial passage through which a tubing hanger can be reciprocated. The height of the sidewall permits the apparatus to be used for landing/removing a tubing string even if the anchor spool is mounted directly to a blowout preventer (BOP).

Abstract: A tubing injector for injecting tubing (4) into a pipeline or bore or the like comprises: an annular piston for moving the tubing (4); a collet for gripping the tubing on movement of the piston in an injecting direction, the collet (14) and the tubing being movable with the piston, and the collet being releasable from the tubing (4) on movement of the piston in another direction, and a ratchet collet for preventing the tubing from being ejected.

Abstract: Drilling rig apparatus for connecting and disconnecting well pipe at a drilling rig. A remotely controlled power wrench assembly is mounted on a remotely controlled lifting mechanism attached to a base spaced about the well axis on the rig floor. The wrench assembly includes upper and lower wrenches carried by the lifting mechanism. The wrench assembly includes a lower wrench for gripping a lower box coupling of a drill pipe section at the well center. An upper wrench is provided for torquing and spinning an upper pin coupling into or out of threaded engagement with the lower box coupling. A manipulator is pivotably carried on a rod supported from the wrench assembly. The manipulator captures a drill pipe section and transfers the drill pipe section between the well axis and a position at the side of the wrench assembly. A slot is provided between frame members of the base for placement of a power slip manipulator for setting and releasing slips in the rotary table.

Abstract: A snubbing unit for running and retrieving a string of tubing into a well under pressure selectively operates in a stand alone mode and a rig assist mode. The unit has a lower frame for mounting during the stand alone mode on a snubber blowout preventer. Stationary weight supporting slips and snubbing slips are carried by the lower frame during the stand alone mode. The unit has four hydraulic cylinders with weight supporting slips and snubbing slips carried by a traveling base plate on the piston rods. A stationary base plate is mounted between the lower frame and the traveling base plate. A spacer tube is connected to and between the lower frame and the stationary base plate in the stand alone mode. In the rig assist mode, the lower frame along with the stationary weight supporting slips and the spacer tube are removed to enable a rig blowout preventer to connect to the stationary base plate.