Abstract: A riser system (202) comprises a riser (204) to be secured between a floating body (206) and a subsea location (209). The riser comprises a composite material formed of at least a matrix and one or more reinforcing elements embedded within the matrix. In use, the riser (204) comprises an upper portion (214) extending from the floating body (206) and having a region arranged to be in tension, a lower portion (216) extending from the subsea location (209) and having a region arranged to be in tension, and an intermediate portion (218) located between the upper and lower portions (214, 216) and having a region arranged to be in compression. A flow-line jumper (302, 402) configured to be secured between two subsea locations, a flow-line jumper arrangement comprising a flow-line jumper (302, 402) and a method of forming a flow-line jumper 302, 402 are also disclosed.

Abstract: A hybrid riser system comprises a lower riser section secured between a lower subsea anchor and an upper buoyant structure, and an upper riser section extending between the lower riser section and a surface or near surface vessel. The lower riser section comprises an elongate support and one or more composite fluid conduits secured to and extending adjacent the elongate support. The composite fluid conduits comprise a composite material formed of at least a matrix and one or more reinforcing elements embedded within the matrix.

Abstract: An installation of bottom-to-surface connections having a plurality of bottom-to-surface connections arranged in a fan from a common floating support. The installation having a first number k of first bottom-to-surface connections, with each first number of connections having a first riser connected to a first undersea pipe tensioned in substantially vertical manner by a first float, and a diving first flexible connection pipe connecting the floating support and first riser. The installation further having a second number m of second bottom-to-surface connection, with each second number of connections having a second rigid pipe connected to a second undersea pipe and tensioned by a second buoyancy element, and a second flexible connection pipe providing the connection between the floating support and the second rigid pipe.

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 riser assembly (400) and method for transporting fluids from a sub-sea location (404) are disclosed. The riser (406) assembly includes a riser comprising at least one segment of flexible pipe; at least one buoyancy element (408) for providing a positive buoyancy to a portion of the riser; and a tethering element (410) for tethering the buoyancy element to a fixed structure (412) and to resist the positive buoyancy of the buoyancy element.

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: Lifting devices for use with drilling risers, where the lifting devices have a plurality of segments, some of which are hinged to facilitate handling and provide multiple shear points between the hinged segments. One embodiment comprises a lifting device for a drilling riser, where the device includes a collar and a lifting lug. The collar has a cylindrical ring with one or more annular ribs connected to corresponding circular edges of the ring. The lifting lug is connected to the collar and the ribs. The collar has a plurality of segments, and at least a first one of the segments is pivotally connected to another one of the segments by a hinge. Each rib may taper smoothly from a smaller thickness at a top edge of the rib to a greater thickness at a base of the rib.

Abstract: The present disclosure relates to a tower comprising a fluid transporting pipe (24) and an element (29) for anchoring a transporting pipe (24) to the bottom (14) of the expanse of water (12), which element is connected to an upstream point (38) of an intermediate section (30) of the pipe. The tower comprises a buoy (26) connected to a downstream point (40) of the intermediate section in order to keep the intermediate section (40) in a substantially vertical configuration. The buoy (26) has a height less than 1.5 times its maximum transverse direction and delimits a first through-passage (78A) in which the intermediate section (30) is fitted. The buoy (26) delimits a second through-passage (78B), separate from the first through-passage (78A), the second through-passage (78B) accepting the upper section (34). The tower (20) comprises a coupling section (32) that couples the connecting upper section (34) to the intermediate section (30).

Abstract: A method includes the positioning of a rising column (22) in a vertical configuration and the total immersion of a buoy for retaining the rising column (22). The method includes the insertion of a male connecting member (62) borne by the buoy in a female connecting member (64) borne by the rising column (22) and the immobilization of the male connecting member (62) in a receiving passage (92) defined by the female connecting member (64). The female connecting member (64) includes at least one surface (98) for guiding the male connecting member (62) towards the receiving passage (92). The insertion step including the guiding of the male connecting member (62) towards the receiving passage (92) by contact with a guiding surface (98) of the female connecting member (64) which has a vertical section diverging away from the receiving passage (92) towards the male connecting member (62).

Abstract: An autonomous junk collecting sleeve for a riser is provided. The sleeve is constructed and arranged to be independently lowered and seated above a subsea tree section and, subsequently, raised and removed independent of the work string. The autonomous junk collecting sleeve includes a first cylindrical structure, a second cylindrical structure concentric to the first cylindrical structure and which are joined together in spatial relation at a bottom end to form an interior J-channel basket. The J-channel basket is operable to collect debris traveling up through the bottom end and over of the second cylindrical structure for deposit therein.

Abstract: Methods, systems, and program product for monitoring and managing a plurality of marine riser assets are provided. An example of a method includes tracking the subsea deployment and retrieval of each of a plurality of riser joints. This can include deploying the plurality of riser joints from a vessel to form an operationally deployed marine riser string, reading riser joint identification data from a riser joint identification indicator connected to the respective riser joint during the operational deployment thereof, and identifying the respective riser joint being operationally deployed to thereby track the deployment thereof. The method can also include retrieving one or more of the operationally deployed riser joints, reading riser joint identification data from the riser identification indicator of the respective riser joint during retrieval thereof, identifying the respective one or more riser joints being retrieved to thereby track the retrieval thereof.

Abstract: A cap is lowered onto and secured to a subsea member with an external flange, effecting a seal between the external flange and cap. The cap includes a tubular outer body defining a cavity, and a tubular inner body defining a bore, wherein the lower end of the inner body resides within the cavity. The cap also includes a lower engaging member coupled to the outer body that is radially movable between an inward state and an outward state and configured to alternately engage and disengage at least one of a backside of the external flange. Finally, the cap includes an upper engaging member coupled to the outer body and being radially movable independently of the lower engaging member between an inward state and an outward state and configured to engage and disengage the inner body.

Abstract: A connector assembly that can be used to connect a tension ring to a telescoping joint on a riser by using a lower set of hydraulically actuated dogs. A set of hydraulically actuated hang-off dogs on the connector assembly can be used to connect the tension ring to a diverter housing mounted on a rig. To prevent accidental disengagement of the hang-off dogs, a hydraulically actuated lock ring is used to provide a positive stop against the back of the hang-off dogs.

Abstract: The present disclosure provides an improved design for a pull tube sleeved stress joint and associated pull tube for managing stresses on a catenary riser for a floating offshore structure. The pull tube sleeve stress joint includes at least one sleeve surrounding a length of the pull tube with an annular gap between the sleeve and pull tube and a link ring therebetween. For embodiments having a plurality of sleeves, a first sleeve can be spaced by an annular first gap from the pull tube and coupled thereto with a first ring between the pull tube and the first sleeve, and a second sleeve can be spaced by an annular second gap from the first sleeve and coupled thereto with a second ring between the first sleeve and the second sleeve. Both pull tube and sleeves can be made with regular pipe segments welded together with regular girth welds.

Abstract: A bottom-to-surface connection installation of at least two undersea pipes (10a, 10b) resting on the sea bottom, the installation comprising: 1) a first hybrid tower comprising: a) a vertical riser (1a) anchored (3a) to a first base and connected to a said undersea pipe (10a) resting on the sea bottom and having its top end connected to a first sub-surface float (2a); and b) a first connection pipe (4a) preferably a flexible pipe, providing the connection between a floating support (11) and the top end of said riser; and 2) at least one second rigid pipe (1b) rising from the sea bottom on which it rests (10b) or from a second undersea pipe resting on the sea bottom to which its bottom end is connected, said bottom end not being anchored at said first base, up to the sub-surface where its top end is connected to a second float (2b) situated substantially at the same depth as said first float (2a) and fastened to said first float at least respectively a flexible second connection pipe (2b) providing its c

Abstract: An underwater buoy for hanging a duct between a sea bed and the surface, the buoy including a frame and a plurality of modular members mounted in the frame, the modular members extending between their two opposite modular-member ends, the frame including a longitudinal body for receiving the extended tubular duct, and retainers mounted on the body for maintaining the modular members substantially parallel to the body. The retainers include two retaining structures spaced from each other along the body. The retaining structures are maintained in a fixed position relative to each other in order to hold at least one modular member.

Abstract: Systems, computer readable medium, program code, and methods for monitoring and managing a plurality of marine riser assets are provided. An example of a system includes a computer and a computer readable medium containing a program code of instructions that when executed by the computer, cause the computer to perform operations for tracking the subsea deployment and retrieval of each of a plurality of riser joints. The operations can include receiving riser joint identification data from a riser joint identification indicator connected to the respective riser joint during the operational deployment thereof, and identifying the respective riser joint being operationally deployed to thereby track the deployment thereof. The operations can also include receiving riser joint identification data from the riser identification indicator of the respective riser joint during retrieval thereof, and identifying the respective one or more riser joints being retrieved to thereby track the retrieval thereof.

Abstract: A riser system and method including a bore submerged surface package of valves, a cross over assembly with a high pressure-low pressure connector connected to the bore submerged surface package of valves, a high pressure insert, and a telescoping flow tube. The riser system also include a high pressure bore subsea stack, a low pressure slip joint, a tension ring, a flex joint, a diverter, a mandrel capable of interfacing with the high pressure-low pressure connector, a high pressure mandrel crossover and at least one high pressure insert riser joint, a high pressure-low pressure latch, a telescoping flow tube telescopic conduit, at least one telescoping flow tube latch, a telescoping flow tube low pressure flex joint, a telescoping flow tube main housing, or a rotating control device.

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: The device described herein combines a subsea wellhead and a tree mandrel into a single piece. The wellhead includes a tree valve block having an upper and lower section. The lower valve block section is integral with the wellhead and includes access between the production line and the tubing annulus to the main bore of the wellhead.

Abstract: Systems and methods for stabilizing a riser or similar object against motion can include engaging two or more cylinder apparatus to the object. Communication of fluid between cylinder apparatus, responsive to a force on the object, can limit movement of the object, such as through extension or retraction of pistons within the cylinders. The cylinder apparatus can include internal channels that can accommodate coiled tubing, slickline, wireline, and similar conduits or devices, enabling operations to be performed through the cylinders, independent of their position.

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: An offshore drilling riser joint has a central riser pipe, a number of auxiliary lines mounted around it, and a buoyancy module assembly of a buoyant material. A pair of upper thrust sleeves slide over two of the auxiliary lines, each of the upper thrust sleeves having a flange in contact with an upper end of the buoyancy module assembly. Each of the upper thrust sleeves transfer upward thrust imposed by the buoyancy module assembly to an upper support flange mounted to the central riser pipe. A pair of lower thrust sleeves slide over two of the auxiliary lines. Each lower thrust sleeve has a lower thrust flange that is engaged by a lower end of the buoyancy module assembly. Each of the lower thrust sleeves transfer weight of the buoyancy module assembly while out of water to a lower support flange mounted to the central riser pipe.

Abstract: The disclosure relates to an assembly including a supporting buoy and an anchoring assembly (28) comprising a base (100) attached to the bed (12) of the expanse of water. The assembly comprises a flexible anchoring line (30) connecting the anchoring assembly (28) to the supporting buoy (26). The anchoring line (30) comprises a lower section (84) made of chain links (92). The anchoring assembly (28) comprises a device (110) for guiding the lower section (84). The lower section (84) is movably mounted in the guide device (110) relative to the base (100), between an extended configuration and a contracted configuration, and a locking member (114) which can be released from the anchor line (30) on the anchoring assembly (28).

Abstract: A marine riser includes one or more buoyancy modules running along a length of the marine riser, wherein the one or more buoyancy modules are molded such that an umbilical may be secured along a length of the one or more buoyancy modules.

Abstract: Disclosed is a riser tower structure including a plurality of elongate objects. The riser tower structure is provided with blocks, preferably of buoyant material, along at least part of its length. The blocks provide the riser tower with a substantially circular cross-sectional profile, wherein one or more strakes are provided on the outside of the blocks. The strakes in a main embodiment are helical. Also disclosed is a corresponding method of constructing such a riser tower structure.

Abstract: An undersea installation for transporting hydrocarbons between a seabed and a surface and to a method for installing same. The installation includes a tubular undersea pipeline, a float and a coupling device. The undersea pipeline has a rising part, a connecting part and an intermediate portion. The coupling device includes a first longitudinal part and a second part connected in a coupling region of the first part. The coupling region of the first longitudinal part and the float being configured to be connected together. The first part is configured to pivot about the coupling region while bending the intermediate portion when the rising part is unwound and tilts towards the seabed.

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: Methods, systems, and program product for monitoring and managing a plurality of marine riser assets are provided. An example of a method includes tracking the subsea deployment and retrieval of each of a plurality of riser joints. This can include deploying the plurality of riser joints from a vessel to form an operationally deployed marine riser string, reading riser joint identification data from a riser joint identification indicator connected to the respective riser joint during the operational deployment thereof, and identifying the respective riser joint being operationally deployed to thereby track the deployment thereof. The method can also include retrieving one or more of the operationally deployed riser joints, reading riser joint identification data from the riser identification indicator of the respective riser joint during retrieval thereof, identifying the respective one or more riser joints being retrieved to thereby track the retrieval thereof.

Abstract: The present invention is directed a rotating flow control diverter having a riser adapter. The riser adapter allows the rotating flow control diverter to be positioned in a riser string below the drilling platform. The rotating flow control diverter has two flanged connections that connect to the flanged connections of riser pipe such that the rotating flow control diverter becomes an integral part of the riser string. The rotating flow control device has means to circulate lubricating fluid in the bearing assembly without the need for external feed lines.

Abstract: A cap is lowered onto and secured to a subsea member with an external flange, effecting a seal between the external flange and cap. The cap includes a tubular outer body defining a cavity, and a tubular inner body defining a bore, wherein the lower end of the inner body resides within the cavity. The cap also includes a lower engaging member coupled to the outer body that is radially movable between an inward state and an outward state and configured to alternately engage and disengage at least one of a backside of the external flange. Finally, the cap includes an upper engaging member coupled to the outer body and being radially movable independently of the lower engaging member between an inward state and an outward state and configured to engage and disengage the inner body.

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 specialized conduit 10 of undetermined length with an emergency disconnecting flange or coupling 9B as well as lower flared fittings and O-rings at the lower end of specialized conduit: a) for sealing conduit to wellhead casing liner and b) cleaning wellhead casing liner during entry and said specialized conduit has an upper reinforced tapered shroud over the specialized conduit that when inserted into wellhead casing liner creates a tight metal to metal seal and said specialized conduit tip is reinforced with a machined stainless steel nose piece and upper end of specialized conduit is fitted or formed with coupling or bolt flange to attach to a new LMRP, creating a Lower Emergency Marine Riser (LEMR) to insert into a wellhead for rapid replacement of defective BOP creating immediate and uninterrupted well production and simultaneous containment.

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

Abstract: Methods and apparatus for installing deepwater completions and performing well intervention from a vessel that can perform other duties while not running completions or performing interventions. The system for installing deepwater completions and performing well intervention may comprise a surface pipe handling and deployment package including a horizontally operated rig that may also be operated in a slanted mode. Deepwater completions may be deployed from the vessel via a buoyant horizontal riser (BHR), which may be supported by a submerged buoyant tensioning system (BTS). In this manner, the cost of performing completion or intervention operations may be significantly reduced compared to such operations run from a drilling rig.

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 invention relates to a hydrocarbon exploration system, comprising a first vessel (1) having a turret (3) around which the vessel can weathervane, the turret being moored to the sea bed (4), and a second vessel (7) connected with at least one riser (12) to a subsea well (5), the first vessel (1) being connected to the second vessel via a fluid transfer duct (20) comprising a first end section (23) attached to the turret of the first vessel (1), a substantially horizontal mid section (24), and a second end section (22) attached at or near the second vessel (7), the second vessel (7) weighing between 2,000 and 15,000 ton its base being attached to the sea bed via taut tendons (9), the weight exerted by the fluid transfer duct (20) on the second vessel being below 1,000 ton, a power generator being situated on the first vessel (1), power being transferred from the power generator via an electrical swivel on the first vessel.

Abstract: An apparatus and method for providing a controllable supply of fluid, and optionally power and/or communication signals, to a subsea equipment are provided. The fluid may be a water-based fluid, oil-based fluid, or chemicals. The apparatus includes a reservoir disposed on a seabed for storing a supply of fluid for delivery to the subsea well equipment. A subsea pumping device is configured to receive the fluid from the reservoir, pressurize the fluid, and deliver the pressurized fluid to an accumulator of a hydraulic power unit disposed on the seabed. The hydraulic power unit can store the pressurized fluid and control an output of the pressurized fluid to the subsea well equipment, thereby providing a subsea fluid source for the subsea equipment.

Abstract: The method of providing flotation modules on subsea drilling riser joints comprising providing flotation modules as a full circle, installing said flotation modules sequentially onto the end of the central pipe of said drilling riser joints in a desired orientation, providing passageways through said flotation modules which extend from one end of said subsea drilling riser joints to the other end of said drilling riser joints.

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 system comprising a surface installation in position above a plurality of subsea wells disposed within the watch circle of the surface installation. A plurality of flowlines directly couple at least one of the plurality of subsea wells to the surface installation. A control station, a hydraulic power unit, and an injection unit are disposed on the surface installation. A distribution body is disposed on the seafloor and is coupled to each of the control station, hydraulic power unit, and the injection unit via one or more umbilicals. A first wellhead component is disposed on one of the subsea wells and is coupled to the distribution body via one or more flying leads that provide electrical, hydraulic, and fluid communication. A second wellhead component is disposed on another one of the subsea wells and coupled to the distribution body via one or more flying leads that provide electrical, hydraulic, and fluid communication.

Abstract: A riser system including: at least one riser for extending from infrastructure on a sea bed and each riser having a riser termination; an end support restrained above and relative to the sea bed and having attachment means to couple each riser termination for storage and decouple each riser termination for coupling to a floating vessel; and an intermediate support supporting an intermediate portion of the riser to define a catenary bend between the intermediate support and the riser termination device.

Abstract: The present invention is directed to novel methods and apparatus for the design, installation, use, recovery, and reuse of a Self Supporting Riser (SSR) for wells that are not under a platform. The SSR of the present invention uses standardized joints that can be recovered, potentially warehoused, and recombined in different configurations for different purposes or locations. Emphasis is on methods and apparatus that use relatively small vessels subject to high motions in the installation, use and recovery of the SSR. The SSR is adapted for high current and/or deep water applications for purposes of downhole well intervention and subsea equipment installation. In contrast to the apparatus and processes of the prior art, this invention addresses a comprehensive system design.

Abstract: A downhole deployment system comprises a spoolable tubular member (76) adapted to be coupled to a subsea assembly and to extend to surface level. The deployment system also comprises a spoolable support member (96) adapted to extend through the spoolable tubular member (76) and into a wellbore. The spoolable tubular member (76) may define a conduit between the subsea assembly and the surface and the spoolable support member (96) may be utilised to extend through this defined conduit and into a wellbore, for example to deploy a tool into a wellbore, to engage a downhole tool or other object, for example for activation, retrieval or the like.

Abstract: A substantially cylindrical buoyancy module for a marine riser includes a plurality of buoyancy elements separated along at least one helical separation plane.

Abstract: The invention discloses a subsea device comprising a can, a string of risers, a blowout preventer and a string of tie-back pipes. The blowout preventer is installed on the can. The top of risers is connected to a rig and its bottom is mounted on the blowout preventer. The upper of tie-back pipes is fixed to the can. The lower of tie-back pipes is mounted to a wellhead in the seabed by a subsea wellhead apparatus and connected to the casings for collecting oil/gas stored in formations by the subsea wellhead apparatus. A passage communicating the blowout preventer with tie-back pipe is jointed on the can. A pipeline, transporting oil/gas, mud and cuttings in drilling process, is divided into two sections, both tie-back pipes and casings, by the wellhead apparatus settled on seabed, thereby ensuring security of the rig in the drilling process and stronger operability of entire production system.

Abstract: The present invention relates to overpressure protection systems and methods for use on a production system for transferring hydrocarbons from a well on the seafloor to a vessel floating on the surface of the sea. The production system includes a subsea well in fluid communication with a turret buoy through a production flowline and riser system. The turret buoy is capable of connecting to a swivel located on a floating vessel. The overpressure protection device is positioned upstream of the swivel, to prevent overpressure of the production swivel and downstream components located on the floating vessel. The device may include one or more shut down valves, one or more sensors, an actuator assembly, and a control processor.

Abstract: A marine riser system for transferring fluid between a well on the seafloor and a vessel floating on the surface of the sea. The riser system has a turret buoy capable of connecting to a floating vessel; two or more hybrid risers, each of the hybrid risers having a vertical riser, a riser buoy attached to the upper portion of the vertical riser and a flexible jumper connecting the riser buoy to the turret buoy, and wherein the hybrid risers are secured to the seafloor. A flowline may connect a lower portion of each of the vertical risers to a subsea manifold, which interconnects the flowline and a subsea well. The subsea manifold is capable of controlling the flow to or from a subsea well. The hybrid risers are positioned about the turret buoy so that the turret buoy is horizontally balanced while disconnected from a vessel. In another embodiment, the marine riser system is capable of directing a fluid from the floating vessel to a subsea export flowline.

Abstract: The present invention relates to overpressure protection systems and methods for use on a production system for transferring hydrocarbons from a well on the seafloor to a vessel floating on the surface of the sea. The production system includes a subsea well in fluid communication with a turret buoy through a production flowline and riser system. The turret buoy is capable of connecting to a swivel located on a floating vessel. The overpressure protection device is positioned upstream of the swivel, to prevent overpressure of the production swivel and downstream components located on the floating vessel. The device may include one or more shut down valves, one or more sensors, an actuator assembly, and a control processor. Each shut down valve and sensor is coupled to a production flowline. Each of the sensors is capable of generating a signal based upon a pressure sensed within the production flowline. The actuator assembly is connected to each of the shut down valves for operating the shut down valves.

Abstract: An improved subsea manifold system that is capable of being used in an early production system for producing hydrocarbons from a plurality of wells from a common riser system. The subsea manifold is able to control the fluid from a multiple of subsea wet-tree wells while at the same time giving the operator the option to isolate production from a single subsea well for production evaluation. The subsea manifold also includes a pigging loop which enables efficient pigging of the flowline(s) of the early production system.