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: An off-shore structure is installed in a body of water. The body of water extends above a floor, such as a seabed, and has a water surface. A buoyant pontoon and a top structure are provided separately from each other. The top structure has a deck, a plurality of legs that are connected to the deck, and a jacking system for displacing the legs relative to the deck. The pontoon is submerged below the water surface. The submerged pontoon is connected to the floor with tendons. The top structure is aligned above the submerged pontoon connected to the floor. Then, the legs are jacked-down relative to the deck until the legs abut against the submerged pontoon connected to the floor. Subsequently, the jacked-down legs are attached to the submerged pontoon and the deck is jacked-up relative to the pontoon until the deck is standing above the water surface. A number of risers are installed for providing a fluid communication between the floor and the deck after jacking up the deck above the water surface.

Abstract: A system for and method of limiting and controlling the unintended subsurface release of an exploration or production riser system is provided including one or more means for anchoring the riser or casing stack at one or more pre-determined points upon the length of the riser, and/or on the housing of an associated buoyancy chamber or the like, and/or on a particular portion of the riser as dictated by the operational environment, and/or on an anchor portion secured in the sea floor; and a network of restraining members disposed on the anchoring means. A lower anchoring portion includes one or more anchors disposed in communication with a wellhead, or with the sea floor or below the sea floor mud line, or with a well casing portion. A network of restraining members forms an essentially continuous connection from the buoyancy member portion to said bottom anchor portion.

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: Buoyancy unit for use on a riser for sub sea applications, particularly for great depths, with a clamp 11 to be tensioned around the riser 16, and with a tensioning member 18 to damp the clamp 11. Buoyancy bodies 26, 27 are provided to engage with the clamp 11, said clamp 11 having at least one arched element 12-15 providing an annular structure to enclose the riser and to be pressed thereto with a tensioning strap 18. The buoyancy bodies 26, 27 are attached to the arched segments, The clamp 11 is cast from of a concrete material where at least the outer shell or layer is provided to prevent the intrusion of water, the casting of the clamp preferably containing powdered aplite.

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 variable buoyancy subsea running tool for use with subsea transportable devices, such as a tree cap. The buoyancy of the running tool may be varied through fluid or gas displacement in one or more containers. Alternatively, the running tool may be configured with a buoy that has static buoyancy, with the buoyancy of the running tool being varied through the addition of a counterweight. The running tool can be used to install or uninstall a tree cap on a subsea tree. Installation of a tree cap may be actuated by a remotely operated vehicle. Additionally, the running tool may be moved by a remotely operated vehicle and may have additional features such as a position locator device.

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: A high pressure sleeve for a dual bore high pressure riser is provided. The high pressure sleeve is arranged for forming a connection between either the annulus bore and the high pressure sleeve, or for forming a connection between the high pressure sleeve and the production bore. The choice of connection is made by rotation of the sleeve.

Abstract: A subsea riser disconnect assembly 10 may be actuated from a drilling rig DR by axial movement of an upper riser 35 relative to a lower riser 28, for disconnecting the upper riser 35 from the lower riser 28. A subsea riser valve assembly 20 may be actuated from the drilling rig DR by axial movement of the upper riser 35 relative to the lower riser 28, for sealing an interior portion of the lower riser 28 and well bore WB below the subsea riser valve assembly 20. A drill pipe disconnect 30 may be actuated from a drilling rig DR, either onshore or offshore, for disconnecting an upper portion of drill pipe 236 from a lower portion of drill pipe 240. The drill pipe disconnect 30 may be actuatable by hydraulic and/or mechanical forces applied to the drill pipe disconnect 30 from the drilling rig DR. The drill pipe disconnect 30 may be compatible for use with or without the subsea riser disconnect assembly 10 and/or the subsea riser valve assembly 20.

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 hull-to-caisson interface connection assembly accommodates high tension loads between the hull and a caisson of a Spar-type platform, while facilitating angular flexing motion and constraining lateral and axial movement. The interface connection assembly includes an annular bearing shoulder at the top end of caisson, and a laminated bearing assembly mounted in the bottom of the hull and defining a passage through which the upper portion of the caisson passes, so that the caisson shoulder seats against the upper end of the bearing assembly. The bearing assembly includes a laminated structure of alternating steel and elastomeric flex elements, bonded to each other to flex together as a unit, rather than sliding relative to each other. The laminated structure of the bearing assembly supports the vertical tensile loads applied by the weight of the caisson on the hull, while also accommodating the angular loads applied between the caisson and the hull.

Abstract: A subsea lubricator system is disclosed which includes a lubricator tube adapted to be positioned subsea above a subsea well, a pressure control head adapted to be positioned above the lubricator tube, at least one pressure sensor adapted for sensing at least one of a pressure in the subsea well or an ambient seawater pressure proximate the pressure control head, and at least one pump that is adapted to be positioned subsea to inject a lubricant into the pressure control head at a pressure that is greater than the sensed pressure. A method of operating a subsea lubricator system positioned above a subsea well, the lubricator system including a pressure control head, is also disclosed which includes monitoring at least one of a pressure within the well and an ambient seawater pressure proximate the lubricator system, and injecting a lubricant into the pressure control head at a pressure that is greater than the monitored pressure.

Abstract: A riser support system for use in a body of water comprises a buoyant and ballastable support structure and a plurality of substantially vertical and rigid risers each of which is attached to the inside of the support structure at a location below the center of buoyancy of the support structure and below the surface of the body of water. Usually, each riser passes through the inside of a single tube in the support structure. Typically, the riser support system is used to support a plurality of risers and their surface wellheads inside the hull of an offshore platform, usually in such a manner that the axial movement of the risers and support structure is independent of the axial movement of the hull.

Abstract: A multi-tiered self-standing riser system includes one or more intermediate buoyancy chambers configured to provide an upward lifting force on strings of associated riser assemblies. The intermediate chambers have either an open-bottomed or closed container design. The chambers can further include an auxiliary buoyant material designed to either mix with or contain pressurized fluids injected into the chambers. The self-standing riser system further includes a lower riser assembly affixed to a primary well-drilling fixture. The system also includes an upper riser assembly and one or more additional buoyancy chambers disposed in either direct or indirect communication with one another, as well as with drilling, production and exploration equipment as required by associated operations.

Abstract: A universal marine diverter converter (UMDC) housing is clamped or latched to a rotating control device. The UMDC housing assembled with the RCD is inserted into a marine diverter above the water surface to allow conversion between conventional open and non-pressurized mud-return system drilling, and a closed and pressurized mud-return system used in managed pressure or underbalanced drilling.

Abstract: The present invention relates to a method and to a system for limiting vortex-induced vibrations on a riser suspended at one end from a support and subjected to substantially transverse fluid flows. The system comprises suspension means (10) for hanging the riser from the support, which include displacement means for moving the end in a transverse direction in relation to the principal axis of the riser.

Abstract: A tube buoyancy can system for tensioning a top tension riser. In some embodiments, the system includes a tubular can coupled to the top tension riser and a pressurized gas system configured to selectably inject pressurized gas into the tubular can. The tubular can includes an enclosed upper end having at least one closeable opening therethough, an open lower end configured to allow seawater to flow freely into and out of the tubular can, and an inner surface extending therebetween. The inner surface is devoid of structural obstructions which substantially inhibit the free flow of seawater through the lower end. When the opening is open, the tubular can is ballasted by seawater. When the opening is closed and pressurized gas is injected into the tubular can, the tubular can is de-ballasted of seawater.

Abstract: A tieback connector for attaching a riser to a subsea production assembly is provided. The tieback connector includes a main body adapted to be coupled to the subsea production assembly having a central passageway sufficiently large to pass an end of the riser string therein and a connector positioner coupled to the main body, which is adapted to secure the tieback connector around a circumferential surface of a wellhead of the subsea production assembly. The tieback connector further comprises an aligning extension portion defined by a funnel-shaped tip, which aids alignment of the riser terminus during landing of the riser string onto the wellhead. The tieback connector secures the riser to the wellhead.

Abstract: Devices and methods for the enhanced assembly and disassembly of offshore marine risers through the use of a combination of passive and active buoyancy elements in a marine riser. Methods for assembling passive buoyancy joints comprise providing disc handling devices capable of simultaneously manipulating a plurality of buoyancy discs capable of nesting and interlocking with one another. The combination of passive and active buoyancy elements along with a near surface disconnect package allow for quicker upper riser recovery especially in the event of an approaching tropical storm.

Abstract: An improved subsea riser for use in oil and gas drilling applications having a cylindrical floatation member adapted for attachment to a blow out preventer. The member may be configured with a plurality of generally evenly spaced dimples, indentations or protrusions about the circumference of the member to provide more streamlined water flow around the riser reducing turbulence and oscillations of the riser. The dimples, indentations or protrusions may be arranged in several ways including icosahedral, dodecahedral, octahedral and other polyhedral configurations.

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: An apparatus for reducing the load applied to a rig. The rig is positioned over a well, with the well having a tubular string disposed therein. A landing string is connected to the tubular string such as casing, production and/or testing assemblies. The apparatus comprises a floatation module attached to the landing string and a clamp for clamping the floatation module onto the landing string. In one embodiment, the floatation module comprises a tubular sleeve having a buoyant material applied thereto. The tubular sleeve includes slots. The clamp may contain a set of dies adapted to engage the slots of the tubular sleeve. A method of landing a work string into a sub-sea well head from a floating drilling rig is also disclosed, wherein a marine riser connects the rig to the sub-sea well head.

Abstract: In one embodiment, the present invention relates to a riser apparatus for use in offshore drilling for oil or other fossil fuels, the riser apparatus comprising: a plurality of riser sections coupled serially end-to-end, wherein each of the riser sections comprises: a tube having a first end and a second end; a first flanged that is mechanically joined to the first end of the tube; a second flanged that is mechanically joined to the second end of the tube; wherein the tube is constructed of an aluminum alloy; and wherein the flanges are constructed of the aluminum alloy; and wherein the riser apparatus has a length of approximately 1,500 meters or greater.

Abstract: A buoyancy system includes a plurality of buoyancy joints distributed along a riser system. Each joint can include a riser pipe, an external frame disposed around a riser and a vessel, and a buoyant cladding disposed between the vessel and the frame.

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: The invention provides a marine riser apparatus (1) for use in the production of hydrocarbons from offshore wells and an associated method of installation of the apparatus at sea. The riser tower comprises rigid pipelines arranged in a riser tower bundle (2) and extending from a wellhead on the seabed (4) to a point below the sea surface where they are connected to flexible jumpers (3) which extend from the tower structure to connect the tower structure to a surface vessel or platform (5). The riser apparatus further comprises a buoyancy device (7) attached to the riser tower bundle, such that the buoyancy device is located above and exerts a buoyancy force on the riser tower, the buoyancy module also supporting an intermediate section of at least one of the jumpers.

Abstract: A system, program product, and method for monitoring and managing a plurality of marine riser assets is provided.

Abstract: A retrievable tree cap for use on a subsea tree having a concentric bore. The tree cap may be installed and retrieved using a remotely operated vehicle. Hydraulic pressure may be used to lock the tree cap onto the subsea tree and to set the tree cap seals. The tree cap is locked onto the subsea tree before setting the seals within the concentric bore. The tree cap includes a locking means that may engage a profile within the subsea tree regardless of the radial orientation of the tree cap. The tree cap may be used to hydraulically isolate an annulus bore from the production bore of the subsea tree. The tree cap may provide for the injection of a corrosion inhibitor within a cavity of the tree cap and may also provide for the removal of water trapped between the tree cap and the subsea tree.

Abstract: A riser monitoring assembly is provided to monitor and manage a riser extending between subsea well equipment and a floating vessel. A riser measurement instrument module is connected adjacent a selected portion of the riser provides dynamic orientation data for the selected portion of the riser. A computer having a memory associated therewith and riser system analyzing management software stored thereon is in communication with the riser measurement module to process data received therefrom. The riser monitoring assembly can utilize real-time orientation data for the selected portion of the riser to analyze the riser dynamic behavior, to determine a model of the real-time structure of the riser, to determine and manage the existence of vortex induced vibration, to determine and manage riser stress levels, to manage riser inspection and riser maintenance, and to supplement determination and management of the position of the vessel.

Abstract: A buoyancy system includes a plurality of buoyancy joints distributed along a riser system. Each joint can include a riser pipe, an external frame disposed around a riser and a vessel, and a buoyant cladding disposed between the vessel and the frame.

Abstract: A shallow water riser extending between a seabed connection and a floating support connection and of a length through the shallow water to be in wave form with at least one and, as illustrated, two wave areas in contact with the seabed. A protective sheath optionally surrounds the riser at the contact regions with the seabed. The upraised wave portions are supported by float elements.

Abstract: An inner tubular member of a subsea wellhead assembly carries a locking member that moves between a locked and unlocked positions lands within an outer tubular member having a grooved profile in its bore. The inner tubular member joins to a portion of the conductor casing extending from a low pressure wellhead housing above the mudline of the seafloor. In the locked position, the locking member engages the grooved profile on the outer tubular member to connect the outer tubular member and inner tubular member. The inner tubular member also carries a hydraulically actuated, axially moveable locking sleeve that slidingly engages the locking member to move the locking member between the locked and unlocked positions. An ROV supplies hydraulic fluid through an ROV port to actuate the locking sleeve.

Abstract: Systems for implementing methods for generating platform location sets comprising selecting a set of platform locations; determining additional platform locations to add to the set of platform locations; validating the additional platform locations, and determining an optimum location for each platform location in the set of platform locations.

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 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: A technique for guiding a riser in an offshore environment. The technique utilizes a keel guide that permits the passage of connectors or other components therethrough. A bushing is mounted within the keel guide to guide the relative linear motion of the riser assembly through the keel guide.

Abstract: A buoyancy module comprises a multi-layer outer protective shell that has an exterior surface and an interior surface. A first layer of foam buoyancy material is located adjacent to the interior surface. A second layer of foam buoyancy material that includes macrospheres and syntactic foam is surrounded by the first layer of foam buoyancy material. The multi-layer outer protective shell can include a layer of fiberglass backed by a fibrous plastic liner. In this embodiment, the layer of fiberglass provides the exterior surface of the multi-layer outer protective shell, while the fibrous plastic liner provides the interior surface of the protective shell. The second layer of foam buoyancy material can be a precast material. The precast material can include for example macrospheres and syntactic foam. The first layer of foam buoyancy material is preferably a stronger layer than the second layer of foam buoyancy material.

Abstract: The invention relates to a marine riser tower having a plurality of rigid metallic conduits bundled together with a metallic tubular core. The conduits may include production lines for hydrocarbons, water injection lines, and/or gas lift lines. A production line or gas lift line is located within the core, while the water injection line is located outside the core.

Abstract: A floating offshore platform, of the type having a buoyancy can disposed within a support structure, includes a can guide assembly that has at least two compliant compression pads that are configured and arranged to provide a non-linear load-versus-deflection characteristic in response to impact loads generated by the impact of the can against the guide assembly. At least one of the compression pads is substantially stiffer (less compliant) than the other pad. The pads are arranged so that the relatively soft pad absorbs the impact load before the relatively stiff pad is engaged. In one embodiment, first, second, and third compression pads are arranged vertically, the upper and lower pads being softer (more compliant) than the middle pad. In another embodiment, a first, relatively soft, compression pad coaxially surrounds a second, relatively stiff compression pad.

Abstract: There is provided a buoyancy system for a structure having at least one component being substantially stationary with respect to the bottom of a water covered area. The system comprises a set of buoyancy modules of engineered materials to apply an identified amount of buoyancy. The set of buoyancy modules is attached to the structure at a set of buoyancy load transfer locations. The set of buoyancy modules comprises layers of the engineered materials. The engineered materials comprise a substantially reinforced axial layer, a substantially reinforced hoop layer; and a leak prevention layer.

Abstract: Method intended for automatic control of an underwater pipe for connecting the lower end of the pipe to a wellhead, wherein the following stages are carried out: Stage 1: determining a mathematical model expressing the position of the lower end of the pipe as a function of the position of the upper end of the pipe, Stage 2: determining a reference path leading to the wellhead, Stage 3: from the mathematical model determined in stage 1, determining control laws allowing to control the path of the lower end of the pipe, Stage 4: applying determined motions to the upper end of the pipe so that the position of the lower end is as close as possible to the reference path determined in stage 2.

Abstract: A subsea well system has a flowline jumper that extends between components on the sea floor. The jumper has connectors on each end for connecting to the two components and has a curved portion. At least a portion of the jumper is buoyant to cause it to assume a vertical arcuate configuration when installed. One end of the jumper has a connector that has a mandrel that guides into a mating socket formed on the end of an arm. The arm is mounted to a ring that can be rotated to various orientations.

Abstract: A subsea riser disconnect assembly 10 may be actuated from a drilling rig DR by axial movement of an upper riser 35 relative to a lower riser 28, for disconnecting the upper riser 35 from the lower riser 28. A subsea riser valve assembly 20 may be actuated from the drilling rig DR by axial movement of the upper riser 35 relative to the lower riser 28, for sealing an interior portion of the lower riser 28 and well bore WB below the subsea riser valve assembly 20. A drill pipe disconnect 30 may be actuated from a drilling rig DR, either onshore or offshore, for disconnecting an upper portion of drill pipe 236 from a lower portion of drill pipe 240. The drill pipe disconnect 30 may be actuatable by hydraulic and/or mechanical forces applied to the drill pipe disconnect 30 from the drilling rig DR. The drill pipe disconnect 30 may be compatible for use with or without the subsea riser disconnect assembly 10 and/or the subsea riser valve assembly 20.

Abstract: A bottom-to-surface connection installation for an undersea pipe. The installation comprises a vertical riser having its bottom end connected to an undersea pipe on the sea bed, and having a float at its top end, and a pipe connecting a floating support at the top end of the vertical riser. The connection between the riser bottom end and the undersea pipe is via an anchor system having a base on the sea bed. The base holds and guides junction elements between the bottom end of the riser and the end of the lower end of the undersea pipe. The junction elements comprise a rigid pipe element presenting an angled bend and a pipe coupling element which are fixed to a moving support of the base. The junction elements are fixed to the moving support and are free to move only in translation in a single longitudinal direction.

Abstract: A method for controlling drag and vortex induced vibration in a substantially cylindrical element by providing an ultra-smooth surface about the cylindrical element. The system for controlling drag and vortex induced vibration utilizes a substantially cylindrical marine element having an ultra-smooth effective surface.

Abstract: Expandable and contractible buoyancy modules are assembled to the risers of a deepwater exploration spar or other offshore structure to provide an upwardly directed buoyancy force to offset at least a portion of the weight of the riser. The buoyancy modules have a fabricated pressure tight expandable and contractible envelope composed of rubber or rubber-like material which is mounted onto a tubular member having a central passage for receiving the riser to be supported. The tubular member projects beyond the respective upper and lower ends of the envelope and defines upper and lower riser joint connectors and buoyancy module travel stops which secure the buoyancy module to the riser and provide for force transmission from the buoyancy module to selected locations along the length of the riser or to the upper end of the riser.

Abstract: A frame and system for adding buoyancy to a riser used in connection with floating platforms is provided which, in some example embodiments, includes a stem attached to multiple supports which include flanges arranged to take impact and abrasion loads off an internal buoyancy module. An air management system is also provided.

Abstract: The invention is an insulation material which comprises a silicon based matrix and a plurality of non-metallic beads supported in the matrix. In one embodiment of the invention, the matrix comprises a platinum cured, addition cured silicon material and the beads comprise a mean diameter of less than about 60 microns and an isostatic strength of at least about 10,000 psi. The insulation material may be used in conjunction with subsea oil and gas production equipment, such as pipelines, wellheads and christmas trees.

Abstract: A frame and system for adding buoyancy to a riser used in connection with floating platforms is provided which, in some example embodiments, includes a stem attached to multiple supports which include flanges arranged to take impact and abrasion loads off an internal buoyancy module. An air management system is also provided.