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 for supporting top tension drilling and production risers on a floating vessel using a tensioner assembly above the water line of the vessel. The method can include attaching at least one hydraulic cylinder on a first end to a first position on a floating vessel and on a second end to a tension frame below the first position. The next step of the method can be forming a fluid connection between the at least one hydraulic cylinder and at least one primary accumulator.

Abstract: A system for controlling gas in a subsea drilling operation is disclosed in one embodiment. The system includes a subsea blow-out preventer, riser coupled to the blow-out preventer, a gas sensor, a controller, and a signal pathway. The gas sensor is configured for placement below the riser and configured to contact wellbore fluids during normal drilling operation. The controller configured to automatically cause manipulation the blow-out preventer based upon information from the gas sensor. The signal pathway couples the gas sensor with the controller.

Abstract: A riser having a riser body having an interior surface, an exterior surface, and two spaced-apart ends, at least one identification assembly on the riser body, the identification assembly having an assembly body and a wave energizable apparatus in the body, the assembly body having an interior surface, an exterior surface, and a channel therethrough in which is positioned part of the riser body, the assembly body releasably secured on the riser body, and the wave energizable apparatus positioned within the assembly body. This abstract is provided to comply with the rules requiring an abstract which will allow a searcher or other reader to quickly ascertain the subject matter of the technical disclosure and is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims, 37 C.F.R. 1.72(b).

Abstract: A line termination assembly for a riser string has a ring adapter mounted to a slip joint and a ring body mounted on top of the ring adapter. The ring adapter radially aligns with the ring body, which forms an inner diameter for receiving the slip joint. The ring body also has a discontinuity for radial access to the inner diameter, such that the ring body is circumferentially discontinuous. The discontinuity defines a chord dimension that exceeds the outer diameter of the slip joint, such that the slip joint may move radially through the discontinuity and into the inner diameter during assembly and disassembly of the system. Fluid bearings and tension rings are mounted to the slip joint and are axially spaced apart from the ring adapter and the ring body.

Abstract: A bend stiffener to surround an end portion of an elongated, essentially cylindrical object, e.g. a flexible pipe or a cable, extending from a subsea installation to a surface vessel, and is connected to an end piece or end flange of the object at a connection to the vessel. A plurality of spaced apart clamp sets, each set has inner, essentially cylindrical clamp surrounding the object and semi-circular longitudinal grooves for receiving spring rods in an outer surface thereof, and outer clamp which in inner surface thereof has longitudinal semi-circular grooves for receiving the spring rods. The spring rods are secured in the end piece or the end flange or an adapted arrangement on the object. Each outer clamp is secured to the respective inner clamp and locks the spring rods relative to the inner clamp and the object.

Abstract: A bend-limiting conduit controls the curvature of a catenary riser extending from the seafloor as it enters the centerwell of a spar-type offshore platform through the keel of the platform. The conduit has a bore dimensioned to receive the riser, and it extends from an upper end constrained within the keel to a lower end disposed below the keel. The conduit has increasing flexibility and weight per unit length from the upper end to the lower end, which results in a lateral load being applied to the riser as it passes through the conduit, thereby causing a gentle and gradual transition in the riser from a curved configuration at the lower end of the conduit, to a straight configuration as it emerges from the upper end of the conduit.

Abstract: The invention relates to a riser pipe section comprising a main tube (2), at least one auxiliary line element (3) arranged substantially parallel to said tube (2), characterized in that the ends of main tube (2) comprise connecting means (8) allowing longitudinal stresses to be transmitted and in that the ends of auxiliary line element (3) comprise linking means (5-6) allowing longitudinal stresses to be transmitted.

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: 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: 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: An apparatus for performing operations on an offshore well includes a subsea wellhead assembly. A riser extends from the subsea wellhead assembly to a surface vessel. A tool connects to a running string and is lowered through the riser into the wellhead assembly for performing operations at the wellhead assembly. A subsea controller is located adjacent the subsea wellhead assembly. The subsea controller controls the operation of the tool. A surface controller is positioned on the surface vessel, and is in communication with the subsea controller via a control line extending downward from the surface controller to the subsea controller. The control line extends downward from the surface controller along an exterior of the riser.

Abstract: Flexible hang-off arrangement is provided for a catenary riser suspended from an offshore or inshore platform, which includes floating or fixed platforms, vessels or/and buoys. The bending loads in the top segments of the said riser are reduced by incorporating a pivot at the riser hang-off. Pressure containing welded, bolted, rolled or swaged pipe spools transfer fluids, including hydrocarbons between the riser and the platform. Along significant spool lengths the tangents to the center lines of said spools are orthogonal to and offset from the tangent to the center line of the riser at the hang-off. The said pressure containing spools include arbitrary looped, spiral and helicoidal designs that are subject to torsion.

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: An arrangement and method for controlling and regulating bottom hole pressure in a well during subsea drilling in deep water involves adjustment of a liquid/gas interface level in a high pressure drilling riser up or down to change the slope and offset of the pressure gradient in the well. The arrangement may include a surface BOP and gas bleeding outlet at the upper end of the drilling riser, a lower BOP with a by-pass line, and an outlet at a depth below the water surface that is connected to a pumping system with a flow return conduit running back to a drilling vessel or platform.

Abstract: The invention relates to a riser pipe section comprising a main tube (2), at least one auxiliary line element (3) substantially parallel to said main tube (2) and at least two fastening means (7, 8) that connect the ends of said element (3) to main tube (2). The section is characterized in that fastening means (7, 8) allow longitudinal stresses to be transmitted from said element (3) to main tube (2) and in that at least one of fastening means (7, 8) allows at least a rotating motion of said element (3) in relation to said main tube (2), the rotating motion following an axis perpendicular to the plane passing through axis (4) of the main tube and through the axis of auxiliary line element (3).

Abstract: A method for servicing a component of a riser system, such as a flexible joint is disclosed. The riser system may be supported in a support apparatus such that the flexible joint and an adjoining section of riser are detached to allow for inspection, servicing, repair, and/or replacement of the flexible joint or various subcomponents thereof. An apparatus is also disclosed for supporting the flexible joint during servicing.

Abstract: A curvature limiter for a hydrocarbon transferring subsea system comprising a flexible tubular member through which an intermediate portion of the flexible hydrocarbon pipe passes. The flexible tubular member comprises a plurality of successive substantially cylindrical sections which are hingedly mounted with respect to each other. At a predetermined maximum displacement thereof the tubular member defining a mean plane in such a way that the flexible tubular member forms a mean curvature having the predetermined curvature radius on said mean plane.

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: Flexible riser, comprising a length of a flexible pipe with an upper end, a bend restrictor and a termination for hanging up on a vessel, a floating installation or a platform, distinguished in that the bend restrictor in the upper end is connected to an adapter pipe extending from a lower end at the bend restrictor to an upper end, to an end coupling to which the upper ends of both the flexible pipe and the adapter pipe are fastened, the flexible riser extending through the bend restrictor and the adapter pipe and the end connection comprising a means for hanging up at deck level of the vessel, the installation or the platform. Method for pulling-in and banging up of the flexible riser.

Abstract: A free standing riser system includes a riser, a subsea intervention unit, and an umbilical line. The riser includes interconnected joints linked to one another, a lower-end of the riser being coupled to a wellhead and an upper-end of the riser enclosed in a buoy assembly, including a terminal, the riser being maintained in an erect, substantially vertical position. The subsea intervention unit is provided above the riser, and includes three connections: one connection to the terminal of the riser, one connection to a flexible jumper that is connected to a FPU, and one connection that provides a vertical conveyance to an intervention rig.

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 present invention relates to a bottom-to-surface connection device comprising at least one undersea pipe or riser (1, 1a-1b) capable of including a single float (2, 21-27), said float being connected at its bottom end to a junction device (8) creating a leaktight flexible joint between the bottom end of the float (2) and said riser (1a), the connection device being characterized in that said junction device (8) is interposed between and secured to a bottom portion (1a) of the riser going down to the sea bottom and a top portion of the riser passing through said float and rising to the surface, said junction device (8) comprising at least one first laminated abutment in the form of a body of revolution having a plurality of elastomer layers defining surfaces of revolution that are frustoconical in shape or ellipsoidal in section.

Abstract: A method and device for use in the replacing of liquid in a riser (12) of the kind used in the recovery of petroleum offshore, wherein the riser (12) forms a connection between a wellhead (4) on or above the sea floor (6) and a drilling vessel (1), and wherein a body (30), which is arranged to keep the liquids separate, is displaced longitudinally of the riser (12).

Abstract: A riser connector connects the upper portion of a riser (12) having a latching enlargement (32) to a receptacle (14) on a vessel (16), so the riser upper end (22) can connect to a fluid coupling (42) leading to a conduit (40) on the vessel. A double-click mechanism (88), with parts on the enlargement and on the receptacle, turns a load ring on the enlargement to latch the enlargement in place when it is lifted to an upper position and lowered to a latched position, and releases it by again lifting and lowering. A cable coupling (24) is temporarily mounted on the top of the riser to enable the riser to be lifted by a cable (26), the cable coupling being later removed to connect the riser upper end to the fluid coupling on the vessel.

Abstract: Apparatus for heating and lagging at least one main undersea pipe for conveying a flow of hot effluent. The apparatus includes a covering of thermally insulating material surrounding the main pipe(s), and covered by a leaktight outer protective casing and an internal chamber coaxial with the outer casing. The insulating covering surrounds the internal chamber in an annular space between the outer casing and the internal chamber. The main pipe is contained inside an internal chamber that is preferably cylindrical in shape. A heat-transfer fluid having a maintained temperature surrounds the main pipe contained inside the internal chamber and is circulated inside the internal chamber.

Abstract: Method for drilling and lining a well wherein at least one liner (1, 2, 32) with a larger external diameter than the substantial part of a drilling riser (10) is pre-installed at a point below the substantial part of the drilling riser (10). A bore hole section (21) is drilled after the drilling riser (10) has been installed, the bore hole section having a larger diameter than the at least one pre-installed liner (1, 2, 32). The at least one pre-installed liner (1, 2, 32) is subsequently lowered into the bore hole section (21, 22). A drilling and liner system for implementing the method is also described.

Abstract: Methods and apparatus for flowing a subsea well. The method comprises the steps of: supplying a multi-phase medium from a subsea tree 18 to a removable separator package 10; separating the multi-phase flow into one or more phases at the desired pressures, the pressures being controlled by one or more pressure control devices 51, 67, 71, 75, 76, 77, 78, 79 on one or more outlets from the separator package 10; and analysing each of the one or more phases to determine the amount and quality of products produced by the well.

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 fairing for the reduction of vortex-induced vibration and the minimization of drag about a substantially cylindrical element immersed in a fluid medium. The fairing also eliminates the galloping phenomenon typically associated with a teardrop-shaped fairing. The fairing having a U-shaped cylindrical shell with opposing edges defining a longitudinal gap and parallel fins extending outwardly from the opposing edges of the shell, the parallel fins being positioned so as to reduce vortex-induced vibration, minimize drag and to eliminate the galloping phenomenon on the cylindrical element.

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 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 method performing an operation in a subsea wellhead assembly through a riser extending between the wellhead assembly and a surface platform includes the step of connecting a surface blowout preventer to an upper portion of the riser. Then a tool is connected to a string of conduit. A control line is then connected to the tool, extended alongside the conduit. The tool and control line are lowered through the blowout preventer and riser. The method also includes the step of mounting a slick joint to an upper end of the conduit when the tool is near the wellhead assembly. The control line is then linked through the slick joint and extends to the surface platform. The method also includes the step of communicating with the tool via the control line and performing an operation in the wellhead assembly with the tool.

Abstract: A water intake riser that can be suspended from a vessel having a riser connected to a riser hanger, which riser hanger includes a first tubular element, a second tubular element to which the riser is connected, a flexible load transfer element joining the tubular elements, and a hose of which the ends are secured to the adjacent ends of the tubular elements.

Abstract: A well treating composition containing a polysaccharide-based water-superabsorbent material has particularly applicability as a thermal insulating, fracturing or acid stimulation fluid. The water-superabsorbent material is capable of absorbing, at a minimum, its own weight. Particularly effective are biodegradable materials containing guar gum and carrageenan. The composition may further contain a crosslinking agent, brine and/or a viscosifying polymer or a gelling agent. As an oil-based fluid, the crosslinking agent is absorbed onto the water-superabsorbent material and serves to effectively delay crosslinking.

Abstract: A flowline is described for producing hydrocarbons from a subsea well that is comprised of a substantially neutrally buoyant tubular composite umbilical. The flowline may possess electrical heating apparatus within the tubular walls of the tubular composite umbilical to prevent waxes and hydrates from forming within the flowline and blocking the flowline. The electrical heating apparatus is comprised of at least one electrical conductor disposed within the tubular walls of the composite umbilical that conducts electrical current that is used to heat the tubular composite umbilical. The tubular composite umbilical that contains any produced hydrocarbons is substantially neutrally buoyant in the sea water adjacent to the subsea well. Positively neutrally buoyant tubular composite umbilical flowlines are also described.

Abstract: A thermal insulating packer fluid contains water and/or brine, a crosslinkable viscosifying polymer, a crosslinking agent and an optional set retarder. The composition is capable of inhibiting unwanted heat loss from production tubing or uncontrolled heat transfer to outer annuli. The viscosity of the composition is such as to reduce the convection flow velocity within the annulus.

Abstract: The riser assembly is plugged adjacent its bottom end either as it is made up or after full makeup or anywhere in between. A heavy fluid is either added to the riser string as it is made up or delivered into the string after makeup to displace seawater or other fluids that may have been in the riser as it is assembled. The floating rig can be secured over the subsea well head and the riser now full of heavy fluid is less prone to be displaced by wave action and preferably simply dangles straight down so that the connection to the subsea wellhead can be simply accomplished. The effect of wave action is minimized or eliminated when deciding placement of the floating rig with respect to the wellhead. Repositioning of the rig takes less effort and is needed less frequently.

Abstract: A connector for connecting sections of drilling riser pipe wherein a first riser contains a pin assembly with an external first grooved profile and a second riser contains a housing assembly. An internal split pivoting latch segment assembly carried by the housing assembly contains a second grooved profile adapted to mate to the first grooved profile and a split actuation ring movably carried by the housing assembly forces the second grooved profile of the latch segment assembly into engagement with the first grooved profile of the pin assembly. A plurality of retraction links engage an upper edge of the latch segment assembly to disengage the second grooved profile of the latch segment assembly from the first grooved profile of the pin assembly if the risers are to be disconnected.

Abstract: A drilling system for drilling subsea wellbores includes a tubing-conveyed drill bit that passes through a subsea wellhead. Surface supplied drilling fluid flows through the tubing, discharges at the drill bit, returns to the wellhead through a wellbore annulus, and flows to the surface via a riser extending from the wellhead. A flow restriction device positioned in the riser restricts the flow of the returning fluid while an active fluid device controllably discharges fluid from a location below to just above the flow restriction device in the riser, thereby controlling bottomhole pressure and equivalent circulating density (“ECD”). Alternatively, the fluid is discharged into a separate return line thereby providing dual gradient drilling while controlling bottomhole pressure and ECD. A controller controls the energy and thus the speed of the pump in response to downhole measurement(s) to maintain the ECD at a predetermined value or within a predetermined range.

Abstract: An arrangement and a method to control and regulate the bottom hole pressure in a well during subsea drilling at deep waters: The method involves adjustment of a liquid/gas interface level in a drilling riser up or down. The arrangement comprises a high pressure drilling riser and a surface BOP at the upper end of the drilling riser. The surface BOP havs a gas bleeding outlet. The riser also comprises a BOP, with a by-pass line. The drilling riser has an outlet at a depth below the water surface, and the outlet is connected to a pumping system with a flow return conduit running back to a drilling vessel/platform.

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: A well production and multi-purpose intervention access hub for flowing fluids from multiple wells to a host facility through a flowline. The hub comprises a production header module and a flowline header module configured for fluid communication with the flowline. The production header module and the flowline header module connect to form a hub bore that is in fluid communication with the flowline and extends through the utility interface. A utility module may connect with the hub for fluid communication and mechanical tool intervention access with the hub bore. The hub comprises valves for isolating the fluid communication between a well the hub bore from the fluid communication between another well and the hub bore. The valves also allow fluid communication between an isolated well and the utility module upon connection of the utility module to the hub.

Abstract: A protective element for a riser segment, including an elongated buffer body, at least one foot connected with the buffer body, the at least one foot being provided with an engagement part arranged to engage on a main pipe of a riser segment, the distance between the engagement part of the foot and the buffer body being such that in a mounted condition the part of the buffer body located farthest from the main pipe is located farther from the main pipe than auxiliary pipe elements arranged on the main pipe.

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 undersea pipe of the riser type providing a connection between a floating support and the sea bottom. The riser has a rigid pipe of the catenary type extending from the floating support to a point of contact with the sea bottom. The catenary riser comprises a lower pipe portion terminating at the point of contact. The apparent weight per unit length in water of the lower pipe portion being at least 25% less than that of the remainder of the pipe constituting the catenary riser.

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.