Abstract: A free-standing riser system connects a subsea source to a surface structure. The system includes a concentric free-standing riser comprising inner and outer risers defining an annulus there between. A lower end of the riser is fluidly coupled to the subsea source through a lower riser assembly (LRA) and one or more subsea flexible conduits. An upper end of the riser is connected to a buoyancy assembly and the surface structure through an upper riser assembly (URA) and one or more upper flexible conduits, the riser also mechanically connected to a buoyancy assembly that applies upward tension to the riser. The riser may be insulated for flow assurance, either by a flow assurance fluid in the annulus, insulation of the outside of the outer riser, or both. The system may include a hydrate inhibition system and/or a subsea dispersant system. The surface structure may be dynamically positioned.

Abstract: A gooseneck conduit system for use with a telescoping joint of a subsea riser. In one embodiment, a riser telescoping joint includes a tube, and a gooseneck conduit assembly affixed to the tube. The gooseneck conduit assembly includes a plurality of gooseneck conduits and a locking mechanism. The gooseneck conduits extend radially from the tube. The locking mechanism engages a locking pin affixed to the tube to secure the gooseneck conduit assembly to the tube. Each gooseneck conduit couples to an auxiliary fluid line secured to the telescoping joint.

Abstract: An underwater fluid transport apparatus (10) to transport a fluid between a sea bed (12) and the surface (14) of the sea vertically above the sea bed. A riser (20) is connected to a flexible pipe (32) leading to the sea surface (14). A retaining float (24) is installed around the riser in order to maintain the riser (20) in a stretched suspended position between the sea bed (12) and a subsurface region situated between the sea bed and the surface (14) of the sea. The flexible pipe (32) extends in a catenary curve between the riser (20) and the sea surface. An additional float (28) is installed between the riser (20) and the sea surface (14). The riser (20) is attached to the additional float (28) to increase the buoyancy of the riser.

Abstract: An offshore well system for a subsea well. The system includes a floating platform, an external riser and an internal riser nested within the external riser. A external riser tension device tensions the external riser. The drilling system also includes a surface wellhead system that includes a wellhead, a collet, and a flange assembly. The wellhead, collet, and flange assembly are assembled to establish a common bore for receiving the top of the internal riser. A gasket located between the top of the internal riser and an inner shoulder of the flange assembly seals between the wellhead system and the top of the internal riser. The surface wellhead system also retains the internal riser in tension with the wellhead, the internal riser extending above the wellhead into the collet.

Abstract: The present invention relates to an accessory device which comprises a damping sleeve (100), which is coupled to a bend stiffener (4), capable of acting in the anchoring operation of a riser (3) so as to eliminate the need for fuse cables and safety straps, the need to use a team of divers, and to guarantee the implementation of the operation in all sea conditions.

Abstract: A system and method of recovering hydrocarbons located at or above a sea floor of a sea are disclosed. The method includes heating a working fluid at a heater and delivering the working fluid downward into the sea through a first string of a riser to a heat exchanger. The riser has a plurality of strings in a concentric arrangement. The heat exchanger transfers thermal energy from the working fluid to at least hydrocarbons to enable recovery of the hydrocarbons through a second string of the riser. The working fluid returns from the heat exchanger to the heater through a third string of the riser.

Abstract: The present invention pertains to a pipe comprising at least one layer at least comprising, preferably consisting essentially of (or being made of), a tetrafluoroethylene (TFE) copolymer comprising from 0.8% to 2.5% by weight of recurring units derived from at least one perfluorinated alkyl vinyl ether having formula (I) here below: CF2?CF—O—Rf (I) wherein Rf is a linear or branched C3-C5 perfluorinated alkyl group or a linear or branched C3-C12 perfluorinated oxyalkyl group comprising one or more ether oxygen atoms, said TFE copolymer having a melt flow index comprised between 0.5 and 6.0 g/10 min, as measured according to ASTM D1238 at 372° C. under a load of 5 Kg [polymer (F)]. The invention also pertains to use of said pipe in heat exchangers and in downhole operations including drilling operations.

Abstract: An apparatus is disclosed which provides fluid communication between the inner bore and the annular space in a pipe-in-pipe system. Other embodiments disclose an apparatus which provides fluid communication between adjacent segments of the annular space, between the inner bore or the annular space and an external source in a pipe-in-pipe type system. Methods and systems are disclosed utilizing the various apparatus embodiments to transport well fluids in an offshore or onshore hydrocarbon production operation.

Abstract: Disclosed are pipeline systems, methods and apparatus for handling fluids in offshore oil and gas production. The systems disclosed allow subsea functional lines having diameters which differ by more than 2 standard API 5L pipeline diameters to be placed in fluid communication in such a way that the systems are piggable. Pipeline connection terminations are installed to facilitate connection of such functional lines. Such systems offer solutions to problems related to installing subsea pipeline in rough terrain, over subsea canyons and subsea scarps, installing marine risers, and long tiebacks.

Abstract: A riser clamp (20) comprising a first jaw portion (211) and a second jaw portion (212) that can be opened and closed relative to each other. The jaw portions (211/212) each comprise a thermoplastic body (301/302) that can be, for example, injection molded pieces of polyethylene (e.g., HDPE). The jaw portions (211/212) can be connected by a hinge (39) that is integrally formed therewith. The clamp (20) can also include cradles (701/702) and caps (711/712) for holding auxiliary lines.

Abstract: A drilling system includes a derrick installed on a platform of a stationary floating structure. An activity forms a borehole in a sea-bed, and carries out installation of a casing pipe assembly and a BOP assembly in the formed borehole. A BOP trolley forms the BOP assembly together with the activity, and moves while supporting the formed BOP assembly thereon. A slot is formed on a work stand of a moon pool for underwater storage of the BOP assembly so as to extend parallel with the direction of movement of the BOP trolley, and suppresses shaking of risers when the BOP assembly positioned underwater is moved by the BOP trolley and the BOP assembly is moved to an underwater storage position.

Abstract: A tensioner assembly for applying tension to a tubular member, such as a riser, can include an upper latch connected to the tubular member, a platform with a bore, and a plurality of lower latch segments, each having a base that is pivotally connected to the platform. After applying tension to the tubular member, the segments pivot inward to form an annular lower latch ring having an inner diameter less than an outer diameter of the upper latch. The assembly can include a locking mechanism that prevents axial movement of the upper latch, relative to the lower latch ring, after engagement. The upper latch can self-center on the lower latch as it is moved into the latching position.

Abstract: The invention relates to improved metal/composite interfaces, particularly for risers used in offshore oil and gas production to connect a subsea oil well to a surface drilling/production facility. The invention provides a composite hoop structure configured to a bearing surface of a metal groove of metal liner over which axial fibers are laid. The composite hoop structure provides for improved transition of axial, torsional and compressive forces between composite fibers and metal surfaces of the metal liner.

Abstract: Various implementations include a system for introducing upwardly a flexible member into a tubular fixed structure with a sleeve surrounding the flexible member in the region where the flexible member attaches to the tubular fixed structure. The system allows for the flexible member to be drawn upwardly into a bore of the tubular fixed structure. In one implementation, a plurality of locking dogs are attached to and are radially moveable with respect to the sleeve between an inner locking position in which they engage with the flexible member, and an outer release position in which they are disengaged from the flexible member. In addition, a latch ring is disposed on a substantially cylindrical surface so that it may be deflected axially along said surface on contact between the sleeve and tubular fixed structure to permit release of the locking dogs.

Abstract: An umbilical comprising an outer sheath, a core enclosed by the outer sheath and comprising a plurality of helically wound umbilical components, and a tape wound between the outer sheath and the core, wherein the tape comprises a plurality of rigid elements adapted to press into or against the outer sheath and the core when subject to loading. By combining a plurality of rigid elements with a tape, the present invention is able to increase the friction between the core and its outer sheath as part of an existing manufacturing step of adding a final tape or band around the core prior to adding the outer sheath. This particular assists steel tube umbilicals being vertically laid using VLS at deep water depths.

Abstract: A collector for capturing flow discharged from a subsea blowout includes a tubular housing having a containment chamber; a seal connected to the housing; a tubular chimney connected to the housing, having a portion of a subsea connector, and having a diameter less than a diameter of the containment chamber; and a head connected to the housing and the chimney.

Abstract: Force-dampening arrangement (100) for dampening forces between two interconnectable parts in a tube string, of which interconnectable parts a lower part (101) is connected to the upper end of a string element (105, 3a) extending into a subsea well (5) and an upper part (103) is suspended from a floating surface installation (1) through at least one suspension element (3b) extending up to said surface installation. The force-dampening arrangement (100) is connected to the tube string above a string-portion (3a) extending into said subsea well, and below at least a portion of said suspension element (3b). The force dampening arrangement (100) exhibits an upper and lower section (109, 111) that are vertically movable in relation to each other, thereby yielding for impact forces between said interconnectable upper and lower parts (103, 101) resulting from vertical heave movement of said portion of suspension elements (3b) moving vertically in respect of the string element (3a).

Abstract: Modular stress joints usable to compensate for forces applied to a subsea riser or other structure include a base member and one or more additional members. Members having desired lengths can be selected such that the sum of the length of the base member and additional members defines a desired total length. Members having desired wall thicknesses can be selected such that a combination of the wall thicknesses of the base member and each additional member defines an overall wall thickness or stiffness. The total length, overall wall thickness, or both correspond to expected forces applied to the subsea riser or structure, such that the stress joint is adapted to compensate for the forces and prevent damage. The number or length of members used and their thickness or other characteristics can be varied to provide multiple lengths and stiffnesses, such that the stress joint is modular and reconfigurable.

Abstract: Disclosed herein is a guide frame (10) for location at one or more points along the length of a riser tower structure (112,114). The riser tower structure is of a type that has an upper end supported at a depth below the sea surface and has a central core (200) with one or more conduits (220) arranged therearound extending from the seabed toward the surface. In use, the guide frame guides the conduit (s) relative to the central core, said guide frame (10) being attachable to said riser tower structure non-continuously (40,50), thereby not becoming an integral part of said riser tower structure. Also disclosed is a riser tower comprising such guide frames.

Abstract: A riser configuration having a rigid riser portion and a flexible riser portion. The riser configuration also includes a subsea buoy across which the riser portions are connected. Buoyancy means are mounted on the flexible riser portion.

Abstract: A subsea communication system is used to communicate between a position that is proximal to a surface of the sea and an apparatus of the seabed. The subsea communication system includes an umbilicalless communication system.

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: An offshore universal riser system. A riser system includes a valve module which selectively permits and prevents fluid flow through a flow passage extending longitudinally through a riser string. An anchoring device releasably secures the valve module in the flow passage. A method of constructing a riser system includes the steps of installing the valve module in the flow passage, and installing at least one annular seal module in the flow passage. The annular seal module is operative to prevent fluid flow through an annular space between the riser string and a tubular string positioned in the flow passage. Drilling methods include injecting relatively low density fluid compositions into the annular space, and selectively varying a restriction to flow through a subsea choke in a drilling fluid return line. The riser string, including housings for the various modules and external control systems, is dimensioned for installation through a rotary table.

Abstract: A riser pipe section (4) is disclose for offshore well drilling operations comprising a main tube element (6) having as an extension a male connector element (10) and a female connector element (9) comprising a first series of tenons. At least one auxiliary tube element (7) is secured to the male connector element (10) and to the female connector element (9) so that the main tube element (6) and the auxiliary tube element (7) jointly transmit tensile stresses between the male connector element (10) and the female connector element (9). A locking ring is mounted on the male connector element and the ring comprises a second series of tenons.

Abstract: An offshore universal riser system may include a valve module which selectively permits and prevents fluid flow through a flow passage extending longitudinally through a riser string. An anchoring device may releasably secure the valve module in the passage. A method of constructing a riser system may include the steps of installing the valve module in the passage, and installing at least one annular seal module in the passage. The annular seal module may prevent fluid flow through an annular space between the riser string and a tubular string positioned in the passage. Drilling methods may include injecting relatively low density fluid compositions into the annular space, and selectively varying a restriction to flow through a subsea choke in a drilling fluid return line. The riser string, including housings for the various modules and external control systems, may be dimensioned for installation through a rotary table.

Abstract: The present invention relates to apparatus for retaining at least one umbilical in relation to a string. The apparatus (30) comprises a body (32), first (38) and second members (40) and first (50, 52) and second fasteners. The body and the first member are movable in relation to each other between a first disposition, in which the body and the first member define a first bore (34) between them for accommodating a string, and a second disposition, in which the body and the first member are spaced apart from each other such that the string can be received in or removed from the first bore.

Abstract: A connector device for kill- and choke lines between a riser and a floating drilling platform includes a slip joint on top of the riser including an outer barrel, a kill- and choke manifold arranged on the platform and provided with flexible kill- and choke hoses to the slip joint's outer barrel, and wherein the slip joint's outer barrel is provided with a horizontally directed kill- and choke-manifold.

Abstract: A riser system for transporting slurry from the seabed to the sea surface. The riser system comprises a first and second riser, a slurry pump system (17) to transport slurry up one of the risers, and a waste water pump system (107) to return waste water down one of the risers. The slurry pump system and the waste water pump system are selectively connectable to each of the risers to allow each riser to be either a slurry riser (1) or a waste water riser (2). With this arrangement, if a slurry riser develops a leak partway along its length the waste water riser can be converted into a slurry riser such that operation can continue.

Abstract: An apparatus for use with a subsea well and comprising an upper riser part, a lower riser part, and a weak link coupling the upper and lower riser parts together; and a mechanism coupled between the upper and lower riser parts for damping recoil of the upper riser part following a breaking of the weak link, damping resulting from a plastic deformation of a component or components of the mechanism occurring as the upper and lower riser parts separate.

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: The offshore drilling system comprises a floating drilling vessel 1, a well drilled in the sea bottom 2, a tubular riser extending the well up to the floating vessel, well sealing elements fastened to the end of the riser at the level of floating vessel 1. The riser comprises tubular elements 12 connected to one another by connectors 13 designed to withstand the internal pressure of the well. Tubulars 12 comprise a metallic tubular body hooped by windings of fibers coated with a polymer matrix. The riser comprises several sections, each section consisting of tube elements whose hoop stress is determined as a function of the depth at which the section lies and of the mechanical strength of said metallic tubular body.

Abstract: A gooseneck conduit system for use with a telescoping joint of a subsea riser. In one embodiment, a riser telescoping joint includes a tube and a gooseneck conduit assembly affixed to the tube. The gooseneck conduit assembly includes a gooseneck conduit extending radially from the tube, and a tenon projecting from a rear face of the gooseneck conduit. The width of the tenon increases with distance from the rear face. The riser telescoping joint also includes a mortise channel extending along the length of the tube. The mortise channel is interlocks with the tenon and laterally secures the gooseneck conduit assembly to the tube.

Abstract: An adjustable riser suspension system for suspending a riser under tension including a riser hanger, a mating sleeve rotationally coupled to the riser hanger, a ratchet-latch sleeve located inside the mating sleeve with an external profile configured to engage an internal profile of the mating sleeve and an internal profile configured to engage an externally threaded face of the riser. The riser hanger and mating sleeve are configured to move downward relative to the riser such that the mating sleeve fits over at least a portion of the riser, causing the ratchet-latch device to ratchet over the external threads of the riser. The mating sleeve is configured to rotate relative to the riser, causing the internal and external profiles of ratchet-latch device to lock the riser and the mating sleeve to prevent movement of the riser relative to the mating sleeve.

Abstract: A system compensates for heave-induced pressure fluctuations on a floating rig when a drill string or tubular is lifted off bottom and suspended on the rig, such as when tubular connections are made during NIPD, tripping, cementing operations or when a kick is circulated out during conventional drilling. In one embodiment, a pressure relief valve or adjustable choke allows the movement of fluid from the riser when the tubular moves down, and a pump with a pressure regulator moves fluid to the riser when the tubular moves up. The system also compensates for heave induced pressure fluctuations on a floating rig when a riser telescoping joint located below an RCD is moving between its retracted and extended positions while drilling.

Abstract: Apparatus and a method are disclosed for venting gas from an annulus region of a flexible pipe. The method includes the steps of depressurising a bore region of a flexible pipe and via at least one vent flow fluid communication path, venting gas from an annulus region of the flexible pipe into the bore region.

Abstract: An offshore oil production system, comprising a structure in a body of water, having a portion extending above a surface of the body of water; a wellhead located at a boom of the body of water; a riser extending from the wellhead to the portion extending above the surface; a primary wellbore extending into a subsea formation beneath the body of water; and at least two secondary wellbores extending further into the subsea formation beneath the body of water and beneath the primary wellbore.

Abstract: A containment valve assembly using the upcoming pressures to control the flow of oil/gas through a riser pipe with a stop flow plug positioned within the valve housing that has an outer surface shaped to fit within and against the riser pipe, and an inner socket cavity having a conical nose receiver portion with a relief vent allowing the oil/gas to escape through the valve assembly, when desired. The stop flow plug is shaped to fit within the inner socket cavity and moves between an open position and a closed position, wherein the stop flow plug fits securely against the conical nose receiver portion, sealing the relief vent. At the top of the valve, a nut will lock the stop flow plug to the close out plate for additional stoppage. A second embodiment adds a heavy duty insert to supplement the sealing pressure, when needed. Electronic monitors convey data remotely.

Abstract: An inertia transition terminal pipe element having a main rigid pipe element including at one of its ends an inertia transition piece that is constituted by at least one and preferably a plurality “n” of coaxial reinforcing pipe elements placed coaxially around the main pipe element, each reinforcing pipe element presenting an inside diameter greater than the outside diameter of the main pipe element. The various main and reinforcing pipe elements each being positioned with one end situated at the same level along the axis of symmetry of the pipe elements, and each reinforcing pipe element presenting a length that is less than the height of the main pipe element. The annular gap between the various pipe elements being filled with a solid filler material. A rigid undersea pipe is also disclosed including at at least one of its ends, an inertia transition pipe element.

Abstract: A method for maintaining wellbore pressure includes reducing flow rate of a drilling fluid pump fluidly connected to a drill pipe in the wellbore. Flow out of the well is enabled into a first auxiliary line associated with a drilling riser. A seal around the drill pipe is closed. Fluid is pumped down a second auxiliary line at a rate selected to maintain a specific pressure in the wellbore. Drilling fluid flow through the drill pipe is stopped.

Abstract: A riser assembly and method of producing a riser assembly for transporting fluids from a sub-sea location is disclosed. The assembly includes a riser comprising at least one segment of flexible pipe, the riser having a first end for connection to a floating facility and a further end;at least one buoyancy element for enabling a portion of the riser to form a hog bend configuration and an adjacent portion of the riser to form a sag bend configuration; and a weight element provided between the first end of the riser and the at least one buoyancy element, such that in an initial deployment position, the weight element is provided at least partially in the sag bend portion of the riser.

Abstract: Adapters for inclusion on the lower end of a completion/work-over riser includes a flow loop in fluid communication with a production flow loop hub and a production bore to facilitate testing and calibration of a subsea multi-phase flow meter during completion operations. The flow loop can be in fluid communication with one or more flow loop isolation valves, one or more production bore isolation valves, one or more annulus bore isolation valves, or one or more cross-over valves. In addition, a pressure/temperature sensor can also be included in the adapter. The adapters disclosed herein permit production fluid to flow through the subsea multi-phase flow meter while the riser is still attached to the subsea Christmas tree and before production operations have begun.

Abstract: A fluid recovery system is provided. In one embodiment, the fluid recovery system includes a telescoping joint of a marine riser having an inner barrel and an outer barrel configured to extend and retract with respect to one another when installed as part of the marine riser. A drip pan is coupled to the outer barrel to enable the drip pan to catch fluid, such as drilling mud, leaking from the telescoping joint between the inner barrel and the outer barrel. In this embodiment, the fluid recovery system also includes a pump and a return conduit that are coupled to enable the pump to pump caught fluid from the drip pan back into the telescoping joint via the return conduit. Additional systems, devices, and methods are also disclosed.

Abstract: A suspension device (14) for suspending an oil pipe on an underwater float (12) between a seabed and a sea surface and a method for installing such a device. The device (14) includes two hitching members (16,18) that respectively comprise a connection end (22, 22) and an attachment end (24, 24). The hitching members are respectively attached to the float (12) and to the coupling end (10) of the pipe by the fastener thereof while the connection ends (24, 24) are connected by connectors (20, 20). The connection end (22, 22) of each hitching member (16, 18) comprises two hooks (44, 46, 44, 46). The connectors include two independent links (20) for parallel adjustment so as to connect, two by two, the hooks (44, 46, 44?, 46?) of the two hitching members (16, 18).

Abstract: The system includes a containment housing with an open bottom which is configured to fit over an undersea oil well pipe which is spilling oil, the housing being lockable to a platform or ring surrounding the oil well pipe or positionable on the sea floor. A pipe is positioned internal of the housing into which the oil well pipe can be fitted, the vertical pipe being directed to or connectable to an evacuation pipe which extends to the surface of the sea, through which the oil from the well moves by means of an evacuation pump. The oil is pumped at a rate approximately at least as great as the rate of the oil spill. An infusion line and associated pump is connected to the chamber for pumping mud and/or cement and/or concrete into the chamber to stop and seal the spill and to ensure the housing remains positioned over the oil spill well pipe.

Abstract: Disclosed are methods, systems and apparatus for circulating fluid within the annulus of a flexible pipe used in a riser in an offshore hydrocarbon production facility. Fluid, such corrosion inhibitors, can be introduced into the annulus by pumping fluid from a storage tank located on a platform or vessel into tubes within the annulus. Use of the system to flow the fluid through the annulus can prevent or reduce corrosion of the steel members within the annulus and increase the fatigue life of the riser.

Abstract: A rotating flow control device, and more particularly a rotating control flow device for use inside a riser assembly during offshore drilling activities. The rotating flow control device has a stationary housing adapted to mount between the interconnected ends of riser pipe. The bearing assembly of the rotating flow control device is entirely contained within the riser pipe and maybe remotely detached and removed from the stationary housing. The rotating flow control device may be positioned in the riser such that it effectively isolates the riser slip joint from pressurized well bore returns.

Abstract: A method is described for connecting a flexible upper riser part to a lower riser part via an upper riser assembly supporting a lower riser termination. The method includes securing a cable linkage to a riser connector at the lower end of the flexible upper riser part. The method includes operating a winching means on the upper riser assembly to wind in the cable linkage and draw the riser connector into a docking position on the upper riser assembly. Then coupling the riser connector to the lower riser termination occurs. A corresponding method of disconnecting the flexible riser part is also described, as well as a method of mounting the winching mechanism on a submerged landing platform.

Abstract: A riser pipe for drilling an offshore well comprises a main tube extending the well up to a floating support, an auxiliary line being arranged parallel to main tube (4a, 4b). The auxiliary line comprises tubular sections (7a, 7b) made of steel and assembled end to end with a sliding fit by means of a tubular end part (25). According to the invention, a material, a titanium alloy for example, having an elastic limit at least 25% higher than that of the steel tubular sections (7a, 7b), is selected to manufacture said end part (25), and the end part as well as the end of said sections are dimensioned by taking account of the elastic limit of said material so as to reduce the sealing section of the end part.

Abstract: A structural health monitoring system for a marine composite riser string is provided. Each riser pipe section includes a cylindrical form having an axis and also a carbon epoxy matrix. A sensor is associated with (e.g., embedded in) and substantially circumscribes the riser pipe section. The sensor includes a PolyVinyliDene Fluoride laminate and electrodes (e.g., conductive silver ink coating) so that the sensor generates electricity at the electrodes responsive to mechanical stresses and strains of the riser section, including vibrations. The system can also include a data acquisition system and digital signal analyzer to analyze signals responsive to the generated electricity at the electrodes of sensors and to provide health monitoring and damage detection for the marine riser pipe string, including impact damage and fatigue crack initiation.

Abstract: A riser clamp (20) comprising a first jaw portion (211) and a second jaw portion (212) that can be opened and closed relative to each other. The jaw portions (211/212) each comprise a thermoplastic body (301/302) that can be, for example, injection molded pieces of polyethylene (e.g., HDPE). The jaw portions (211/212) can be connected by a hinge (39) that is integrally formed therewith. The clamp (20) can also include cradles (701/702) and caps (711/712) for holding auxiliary lines.