Abstract: An offshore system allows a vessel (12) to sail to a predetermined sea location (14), quickly set up a loading system and start the transfer of hydrocarbons to or from a pipeline (22), and then quickly disconnect and sail away. The vessel is a DP (dynamic positioning) vessel that does not require mooring or anchor lines, so the only apparatus to install is a conduit (30) that can be picked up by the vessel to extend between a stationary pipe end (24) that lies at the sea floor and the vessel. The conduit includes primarily a flexible hose (70) that extends in a sine wave with two loops (80, 82). The conduit includes a rigid reinforced hose section (34) that is pivotally connected to the sea floor. A chain (114) can be provided with a portion of the chain lying on the sea floor, to help the disconnected hose coupling (42D) remain at a stable position above the sea floor.

Abstract: An offshore oil well drilling assembly is provided that includes an offshore platform; and a tension lift frame, which supports a coiled tubing injector and a blow out preventer connected thereto and for further connection to a wellhead, wherein the tension lift frame is a free standing assembly that is supported by the platform.

Abstract: A well intervention system is described which has a riser access drive adapted to be located below a vessel, or a rig, work floor. The riser is tensioned and extends from a subsea wellhead to the access device which, in use, is attached to the riser at the location below the work floor. Embodiments of the invention are described.

Abstract: The current subject matter relates to compliant variable tension risers to connect deep-water subsea wellheads to a single floating platform in wet tree or dry try systems. The variable tension risers allow several subsea wellheads, in water depths from 1220 to 3050 meters, at lateral offsets from one-tenth to twice the depth or more, to tie back to a single floating platform. Also, the current subject matter relates to methods to counter buoyancy and install variable tension risers using a weighted chain ballast line.

Abstract: In an offshore drilling facility, apparatus is disclosed comprising: a drilling floor centralizer for receiving the upper end of a string of drilling riser sections; a moonpool centralizer for receiving another portion of the drilling riser; and at least one roto-track, removably and rotationally carried by at least one of the pin end of one drilling riser section and the box end of the adjacent drilling riser section, for extending the outer diameter of each of the adjacent ends to the outer diameter of the adjacent drilling risers sections intermediate the ends of the drilling riser sections.

Abstract: Systems and methods for controlling movement of an elongated member providing communication between a vessel and a subsea unit are provided. The method can include connecting a positively buoyant member to an elongated member at a first location and connecting a negatively buoyant member to the elongated member at a second location, wherein at least a portion of the negatively buoyant member rests on a seabed when the elongated member is in an operational null position.

Abstract: A riser for connection between a vessel and a fixed connection point on the seabed, in the form of an “L”, where the bottom riser arm is connected to the fixed point (2) on the seabed and the top riser arm (3) is connected to the vessel at the point (4). An elastic element (5) is connected to the bend (6) between the riser's arms and an anchoring point (7) on the seabed.

Abstract: A method and arrangement for well completion and intervention operations where a workover riser 4 projecting from a wellhead 6 and up to a vessel 2 is used, and where the upper portion of the workover riser 4 is designed to be displaced from an upper position to a lowered position favorable for rigging work, where at least the upper displaceable portion of the workover riser 4 essentially follows the heave motion of the vessel 2, whereupon the upper displaceable portion of the workover riser 4 is again raised to its upper position, the workover riser 4 being equipped with a telescoping connection 1.

Abstract: A corrosion-resistant alloy tube is formed and bonded to a pre-machined steel alloy rod to form a riser tensioner cylinder rod. During assembly, an epoxy is injected into an annular space between the tube and rod and then cured. The bonded tube is ground to a desired surface finish prior to installation and utilizes a double seal arrangement that prevents external pressure or corrosive fluids from entering the cured epoxy in the annular space.

Abstract: An arrangement and method for integrating a high pressure riser sleeve from the upper end of a high pressure drilling and workover riser terminated by an upper BOP close to sea level in one end and by a sub-sea blowout preventer BOP or a low riser package LRP close to the seabed in the lower end. The high pressure riser sleeve being installed, connected and integrated to the high pressure drilling and workover riser and extending up to and above the drill floor, inside a low pressure drilling riser slip joint which is connected to the drilling and workover riser. This relates to offshore drilling and well activities preformed from a floating drilling or workover rig or vessel. Operations can be switched from drilling with jointed drillpipe in a conventional manner, into performing underbalanced wireline and/or coiled tubing activities with full well pressure, much more effectively than with prior art.

Abstract: A system for operation and service of at least one hydrocarbon-producing well and of equipment, which is disposed under water, for further transport of the well stream, where the system comprises at least one pipeline, at least one booster unit, a vessel comprising an anchoring system about which the vessel can rotate or swivel, means for conducting an intervention on subsea equipment, means for communication with and control of the at least one well and other equipment, means for injecting chemicals into the well streams, means for transferring to and inserting pigs in the pipeline, means for production of energy for operation of subsea equipment, means for transferring energy from the means for production of energy to the booster unit and any other subsea equipment.

Abstract: A tensioning apparatus for applying a substantially constant tension to a workover riser (12) includes a first portion (40) adapted to be coupled to a workover riser, a second portion (44) adapted to be coupled to a marine riser (14) and tensioning means (46) for providing relative movement between the first portion and the second portion to, in use, tension the workover riser.

Abstract: Disclosed are compliant variable tension risers (106) to connect deep-water subsea wellheads (102) to a single floating platform (104). The variable tension risers (106) allow several subsea wellheads (102), in water depths from 4,000 to 10,000 feet, at lateral offsets from one-tenth to one-half of the depth, to tie back to a single floating dry tree semi-submersible platform (104).

Abstract: The present invention generally relates to an apparatus and method for compensating a landing string due to movement of a floating rig platform. In one aspect, a compensation system for use with a landing string is provided. The compensation system includes a slip joint member attachable to the landing string, the slip joint member having an upper portion and a lower portion. The compensation system further includes a first lock assembly configured to connect the upper portion of the slip joint member to a floating rig. Additionally, the compensation system includes a second lock assembly configured to connect the lower portion of the slip joint member to a riser disposed below the floating rig. In another aspect, a method for compensating a landing string due to movement of a floating rig is provided.

Abstract: A known deepwater solution for production risers for extracting oil and gas is the SLOR™ riser. The design of the SLOR™ riser is not compatible with large numbers of risers and thus there is a need for a deep water riser that can be deployed in large numbers, for example 20 to 30 risers. The present invention discloses a support frame that can be used to receive a plurality of risers, which can then be connected to a surface vessel.

Abstract: A method and apparatus for determining and reacting to an upper packer failure in a riser slip joint. An upper packer failure is determined by comparing pressures at two points in the upper packer pressure circuit using a differential pressure valve. In the event of a failure of the upper packer, a secondary pressure source is used to energize a lower packer in the riser slip joint.

Abstract: A tensioner anti-rotation device and method that transfers rotational force from an offshore platform deck to a riser in response to waves and currents. The device includes a bracket mounted on the deck, and a rib that transfers force from the deck through the bracket, to the rib, and into the riser such that the tensioners on the riser are not subjected to torque.

Abstract: A heave motion compensator (30, 40, 70, 100, 140, 300) for compensating heave motions comprises a cylinder (41) and a piston (44) delimiting a variable volume fluid chamber (49) in said cylinder (41), wherein said piston (44) can oscillate within said cylinder (41), said piston (44) being provided with a seal (48) frictionally engaging said cylinder. The compensator further includes a motor (65) that causes said seal (48) to revolve relative to said cylinder (41) so as to obtain a dynamic friction regime between the seal (48) and the cylinder (41). In a possible embodiment the motor (65) is arranged to rotate said piston (44), and the seal (48) is mounted on said piston (44) so as to rotate along with said piston (44).

Abstract: A delivery system for downhole use comprising an elongate delivery member, such as a length of wireline cable or coiled tubing, an injector to control the insertion of the delivery member into the well, and a storage device such as a reel to store at least a portion of the delivery member prior to insertion into the well. The system has a motion compensator arranged to compensate for relative motion between the injector and the storage device. The motion compensator optionally is arranged to compensate for relative movement between the injector and the well, and the movement of the motion compensator on the storage device and the motion compensator on the injection head can be coordinated by a motion controller adapted and arranged to measure the movement of the injector and to signal the motion compensator on the storage device to move in accordance with the movement of the injector.

Abstract: Disclosed are methods to counter buoyancy and install variable tension risers using a weighted chain ballast line. An example of an apparatus used in conjunction with the embodiments includes compliant variable tension risers to connect deep-water subsea wellheads to a single floating platform. The variable tension risers allow several subsea wellheads, in water depths from 4,000 to 10,000 feet, at lateral offsets from one-tenth to one-half of the depth, to tie back to a single floating dry tree semi-submersible platform.

Abstract: A subsea communication system includes addressable nodes in a wellbore and addressable nodes on a floor, where the nodes in the wellbore and on the floor are able to communicate wirelessly with each other, such as through a formation.

Abstract: A heave compensation system that facilitates the transfer of pipe between a floating platform and a snubbing jack. The heave compensation system includes a first end connected to the floating platform and a second end in connection with a traveling slip assembly of the snubbing jack, the heave compensation system is operable between a disengaged position and an engaged position. When the heave compensation system is in the disengaged position the traveling slip assembly moves separate and independent from the movement of the floating platform, and when the heave compensation system is in the engaged position the traveling slip assembly is locked in a constant position relative to the floating platform.

Abstract: A system and method of establishing an offshore exploration and production system is disclosed, in which a well casing is disposed in communication with an adjustable buoyancy chamber and a well hole bored into the floor of a body of water. A lower connecting member joins the well casing and the chamber, and an upper connecting member joins, the adjustable buoyancy chamber and a well terminal member. The chamber's adjustable buoyancy enables an operator to vary the height or depth of the well terminal member, and to vary the vertical tension imparted to drilling and production strings throughout exploration and production operations. Also disclosed is a system and method of adjusting the height or depth of a wellhead while associated vertical and lateral forces remain approximately constant. A variety of well isolation members, lateral stabilizers and anchoring means, as well as several methods of practicing the invention, are also disclosed.

Abstract: The present invention relates to a heave compensator for a riser, particularly a working riser (9), comprising a telescopic connection (10) with a first chamber (60) which is in fluid connection with the interior of the riser and a second chamber (62) which is connected with a source of pressure fluid. By varying the pressure in the second chamber in response to the movements of the platform, the telescopic connection can be arranged to move in correspondence with the platform's movements, thereby permitting access to the riser during working operations.

Abstract: A heave compensation system to enable the transfer of tubulars between a floating platform and a snubbing jack. The heave compensation system includes a first end connected to the floating platform and a second end in connection with a traveling slip assembly of the snubbing jack, the heave compensation system is operable between a disengaged position and an engaged position. When the heave compensation system is in the disengaged position the traveling slip assembly moves separate and independent from the movement of the floating platform, and when the heave compensation system is in the engaged position the traveling slip assembly is locked in a constant position relative to the floating platform.

Abstract: A system for interconnecting a floating rig and a riser assembly includes a rotating control device permitting pressurization of the riser assembly; and a sliding joint connected to the rotating control device, the sliding joint being longitudinally extendable and compressible while the riser assembly is pressurized. Another system includes a sliding joint including more than two telescoping sleeves, and the sliding joint being longitudinally extendable and compressible while the riser assembly is pressurized at the surface. An apparatus includes a sliding joint with multiple sets of telescoping sleeves, each set including at least two of the sleeves. Another apparatus includes a sliding joint with multiple radially overlapping seal assemblies.

Abstract: There is disclosed a tubing support assembly for supporting tubing utilised in the oil and gas exploration and production industry, a vessel including such a tubing support assembly, and a method of deploying such tubing from a vessel. In one embodiment, a tubing support assembly (12) is disclosed which includes a tubing support in the form of a tension frame (20) that receives and supports tubing such as a casing riser (14) to be deployed from a drillship (10). The tension frame (20) is movable relative to a deck (22) of the drillship (10) and can be located below a level of the deck (22), to facilitate deployment of the tubing (14) from the drillship (10) to a seabed (37).

Abstract: Disclosed are compliant variable tension risers (106) to connect deep-water subsea wellheads (102) to a single floating platform (104) in wet tree or dry try systems. The variable tension risers (106) allow several subsea wellheads (102), in water depths from 1220 to 3050 meters, at lateral offsets from one-tenth to twice the depth or more, to tie back to a single floating platform (104). Also disclosed are methods to counter buoyancy and install variable tension risers using a weighted chain ballast line (228, 230).

Abstract: An offshore oil well platform assembly is provided that includes a jacking frame, which supports a coiled tubing injector, which in turn is connected to a wellhead during a coiled tubing operation; and a compensation system. The compensation system includes a force measurement system which measures forces applied to the wellhead; a force delivery system, which provides a compensating force to counteract at least a portion of the measured forces on the wellhead; and a control system which receives signals from the force measurement system indicative of the measured forces, and operates the force delivery system based on the measured forces.

Abstract: A system for installing sub-surface fluid transport tubing and pressure testing coupling seals in a vertically oriented geothermal heating/cooling system installation, and particularly in a direct exchange system installation, includes providing an elevated containment area, that has a confined space opening, supported by extensions/poles, within which opening an upper portion of the fluid transport tubing segment, to be installed within the borehole, can be positioned and contained. The system further includes pressure testing above-ground segmental coupling seals, by using moderate gas pressure applied via temporary gas hose and plug connections to respective ends of the operatively connected fluid transport line set.

Abstract: A tensioning device (15) for a riser (5) connecting a subsea borehole (7) with a floating installation (1) on the surface of the sea (11), where the tensioning device (15) is provided with telescoping tubes (27, 27?) and also several evenly spaced hydraulic cylinders (31, 31?) arranged in a peripherally encircling manner and mainly in the longitudinal direction of the riser, and where the tension in the riser is exerted through hydraulic pressure in said cylinder (31, 31?), the tensioning device (15) consisting of two successive, interconnected telescopic tensioning units (23, 25), the tensioning units (23, 25) being designed separately to maintain a prescribed tension in the riser (5).

Abstract: The method of preventing over tension to an umbilical wrapped on the spool of an offshore reel when the umbilical is unexpectedly pulled from the spool on the reel, comprising providing a main disk, mounting the main disk on the spool of the reel with a slip connection which will slip at a desired force, connecting motor power for the reel to the main disk, connecting brakes to the main disk, such that when tension from the umbilical exceeds a desired force, the slip connection will slip and prevent the umbilical from being subjected to tension higher than the desired amount.

Abstract: A jacking frame for an oil well offshore platform is provided that includes a support structure; a coiled tubing injector supported by the support structure and having a longitudinal axis; and a centralizer attached to the support structure, which moves a wellhead of the platform into alignment with the longitudinal axis of the coiled tubing injector.

Abstract: The invention is directed to a tensioner for providing linear and angular movement of a drilling or production facility relative to a conduit or riser secured to the tensioner and to the wellhead in offshore operations. The tensioner compensates for vessel motion induced by wave action and heave and maintains a variable tension to the riser string alleviating the potential for compression and thus buckling or failure of the riser string. The tensioner of the present invention preferably includes at least one top load plate that facilitates easy and quick installation and removal of the tensioner from the rig floor of the vessel or platform. The tensioner also facilitates the placement of at least one piece of equipment disposed within the area formed by the tensioning cylinders. The tensioner may also include one or more pieces of equipment, e.g., a rotary table, integrally formed with the tensioner to further increase the ease and speed of installation and removal of the tensioner from the rig floor.

Abstract: A slip joint for a riser between a well and a floating petroleum installation, for example an oil platform. The slip joint includes, an outer pipe and an inner pipe, the pipes arranged to enable telescopic movement relative to one another in order to compensate for a change in distance between the sea bottom and the platform. The inner pipe is connected to a piston, the piston being operable in response to hydraulic pressure for inflicting a tensile force on riser. The outer diameter of the inner pipe is adapted to the diameter of outer pipe so as to form an annulus between the pipes. The piston is fixedly connected to inner pipe at or close to a downwardly directed end thereof, the annulus and the piston being subjected to hydraulic pressure. A protective sleeve is provided below the piston, which is slippingly arranged within outer pipe.

Abstract: The present invention relates generally to offshore drilling and production operations, and, more particularly, to marine drilling workover/intervention tensioning and compensating devices and methodologies. A heave compensated hydraulic workover device and/or system is provided comprising a hydraulic tensioning cylinder system disposed beneath a rig floor and adapted to be connected at a mandrel to the rig floor through a rotary table disposed in the rig floor. The heave compensated hydraulic workover device and/or system also comprises a well intervention apparatus disposed at least partially within the hydraulic tensioning cylinder system beneath the rig floor, the well intervention apparatus capable of being used in conjunction with at least one of a well, a wellhead, a blow-out pressure system, a jointed tubular, a pipe, and a drilling string.

Abstract: A handling device for well intervention, the handling device being releasably connected, in an operative position, to a riser and to a heave compensator which is arranged to maintain a prescribed tensioning of the riser. The handling device comprising: a lower riser securing device; a substantially vertical tensioning frame provided with at least two parallel guides; a jacking table provided with an upper riser securing device; at least one tension-resistant connection between the tensioning frame and the heave compensator located thereabove; the jacking table being movably connected to the at least two parallel guides, at least one of the at least two parallel guides including lifting screws for moving the jacking table along the guides in their, in the position of use, vertical extent, and the jacking table including hydraulic cylinders for moving the upper riser securing device in a horizontal direction along at least one axis of movement.

Abstract: An offshore oil well assembly is provided that includes a floating vessel and a coiled tubing injector supported on the floating vessel. A coiled tubing string is movable by the injector into and out of a wellbore. The assembly also includes at least one measurement device which, either directly or indirectly, measures a heave induced acceleration of the injector; and a control system which receives a signal from the measurement device indicating the heave induced acceleration of the injector, and transmits a command signal which causes a counteracting acceleration to be applied to the coiled tubing, wherein the counteracting acceleration is opposite to the heave induced acceleration experienced by the injector.

Abstract: A running tool for deployment from a base such as a vessel for installing a component at an underwater facility such as a hydrocarbon extraction well includes a carriage which is lowered from the base. The carriage releasably retains the component. A compensator is located between the carriage and the base for compensating for relative motion between the underwater facility and the base.

Abstract: An apparatus and method for protecting against the problems associated with heave of a floating drilling rig are disclosed. The disclosed invention is a unique inline compensator in which a plurality of cylinders housed within a tubular housing and a plurality of low pressure and high pressure accumulators function together to provide a system for compensating for heave in the event a primary heave compensation system fails or becomes inoperative. The typical inline compensator of the present invention utilizes a plurality of hydraulic cylinders that act in opposite directions and that have different piston areas such that the piston rods of the cylinders are extended or retracted at different pressure levels to account for heave. The typical inline compensator of the present invention is self-contained and compact enough to fit in the limited space available on a floating drilling structure. Further, a pair of inline compensators of the present invention can be utilized with coiled tubing operations.

Abstract: The present invention relates generally to offshore drilling and production operations, and, more particularly, to marine drilling workover/intervention tensioning and compensating devices and methodologies. A heave compensated hydraulic workover device and/or system is provided comprising a hydraulic tensioning cylinder system disposed beneath a rig floor and adapted to be connected at a mandrel to the rig floor through a rotary table disposed in the rig floor. The heave compensated hydraulic workover device and/or system also comprises a well intervention apparatus disposed at least partially within the hydraulic tensioning cylinder system beneath the rig floor, the well intervention apparatus capable of being used in conjunction with at least one of a well, a wellhead, a blow-out pressure system, a jointed tubular, a pipe, and a drilling string.

Abstract: A motion compensator is used on a floating vessel servicing a subsea well. The motion compensator includes a first frame assembly adapted to be connected to a cable extending from a lifting structure. When connected to the cable, the first frame assembly extends longitudinally along an axis substantially parallel with that of the cable. The motion compensator also includes a second frame assembly connected to the first frame assembly. The second frame assembly overlaps a longitudinal portion of the first frame assembly. The first and second frame assemblies are moveable relative to each other and define an expanded position and a contracted position. The motion compensator further includes a piston assembly positioned between the first and second frame assemblies. The piston assembly has a piston chamber and a piston that slidingly engages the piston chamber when the first and second rod assemblies move relative to each other.

Abstract: Disclosed are compliant variable tension risers (106) to connect deep-water subsea wellheads (102) to a single floating platform (104). The variable tension risers (106) allow several subsea well-heads (102), in water depths from 4,000 to 10,000 feet, at lateral offsets from one-tenth to one-half of the depth, to tie back to a single floating dry tree semi-submersible platform (104). Also disclosed are methods to counter buoyancy and install variable tension risers using a weighted chain ballast line (228, 230).

Abstract: A device for tensioning and relieving production tubing (49) extending from a subsea hydrocarbon well (107) up through a riser (63) to a floating installation (87), a continuous production tubing extension (85) passing through a telescopic unit (67) in the upper part of the riser (63), preferably extending above a production deck (89) on the floating installation (87), where the production tubing (49) is provided with a tubing tensioner unit (1) below and in the proximity of the lower end of the telescopic unit (67).

Abstract: An offshore hydrocarbon production system includes a vessel (12) with a turret (16), and a fluid swivel (50) on the turret that is connected to risers (41–43) that extend to the sea floor (26), wherein a drilling/workover rig (60) on the vessel can lower tubing (65) toward the sea floor without danger that the tubing will wrap about the risers when the hull weathervanes. The rig is mounted on the turret. Pipes (54) that extend from the rotatable part of the fluid swivel to fittings (55) on the hull (14), are supported on a gantry (80) that is fixed to the hull and having a gantry middle portion (106) that extends over the turret. The gantry middle portion extends higher than the top (88) of the rig.

Abstract: A deflectable in-line swivel that permits axial deflection of a tubular string is presented. The in-line swivel is preferably constructed as a ball and socket design whereby the ball of a swivel mandrel is permitted to articulate within a socket of a retainer sub. The system preferably includes a thrust bearing to allow the tensile loads to be carried across the swivel.

Abstract: An apparatus for supporting a structure on a platform. The platform may be a floating platform. The apparatus comprises a base frame, wherein the base frame has a first bracket and a second bracket attached thereto. The apparatus further includes a x-axis frame having a first pivot point and a second pivot point. The apparatus further comprises a z-axis frame having a third pivot point and a fourth pivot point. A sliding frame assembly is operatively positioned within the z-axis frame, and wherein the sliding frame assembly has a plurality of rods for connecting with an injector head. The apparatus may further include a motion restriction system that restricts movement of the x-axis frame and the z-axis frame. The sliding frame assembly comprises a sliding pad for lateral movement. A method for compensating for the movement of a floating platform having a riser extending therefrom is also disclosed.

Abstract: A riser for conveying fluids from a subsea location to a surface vessel comprises an upper section which is located in a confining conduit, said upper section being allowed to deform elastically into a helical configuration against the inside of the confining conduit when subjected to axial compression. The riser further comprises a main section extending below the confining conduit to said subsea location. The riser also comprises a buoyancy arrangement which keeps the main section in tension. This arrangement allows the Christmas tree to be supported directly on the deck of the surface structure and allows the surface structure to support the weight of the tree as well as the tubing which is hung off from the tree.

Abstract: An offshore riserless drilling system drills a subsea borehole from a platform and through a cased borehole. The system comprises a lightweight drill string suspending a bottomhole assembly and extending from the platform downwardly through a depth of water into the cased borehole; a first limiter limiting the range of motion of the drill string adjacent the platform; and a second limiter limiting the range of motion of the drill string adjacent the cased borehole. The preferred methods include lowering a bottomhole assembly suspended on a lightweight drill string from a platform through a depth of water; limiting the bend radius of the drill string adjacent the platform; guiding the bottomhole assembly into a cased borehole; limiting the bend radius of the drill string adjacent the cased borehole; maintaining the bottomhole assembly in the cased borehole, and drilling the subsea borehole.

Abstract: A closed system drill string compensator having a hydraulic fluid accumulator, at least one air pressure vessel, and a piston and a piston rod slidably engaged within a cylinder. The drill string compensator provides tensioning force for supporting a drill string and permits the drilling vessel to remain connected to the drill string during ocean level changes caused by wave action or ocean heave. In one embodiment, the accumulator surrounds the cylinder and at least one air pressure vessel is radially disposed around the accumulator and the cylinder. In another embodiment, the accumulator surrounds the cylinder and includes two ports, one port for permitting fluid communication between the cylinder and the accumulator and a second port for permitting fluid communication between the accumulator and the air pressure vessel, the first port including a shut-off valve disposed therein. Methods of compensating a drill string are also disclosed.