Abstract: The present invention includes a nontwisted composite tether comprising one or more composite rods encased in a jacket and a method for manufacturing same. A portion of the rods may be bundled into one or more strands, provided however that the rods comprising the strands are not twisted into twisted strands in the assembled nontwisted tether. Such untwisted strands, if any, additionally are not twisted relative to each other. Temporary and/or permanent buoyancy may be to the tether. The present invention includes methods for preparing, transporting, and installing a composite tether on a floating platform. The tether, preferably assembled at a waterfront, is launched into the water and towed to an offshore installation site, where the tether is upended and connected via a bottom end connector on the tether to an anchor foundation in the seabed and connected a top end connector on the tether to the floating platform.

Abstract: A method of manufacturing a composite riser section with a liner assembly comprises holding the liner assembly in a horizontal position, bowing the liner assembly upward, and winding resin impregnated fibers about the liner assembly to form a structural composite overwrap. Another method of manufacturing a composite riser with a liner assembly comprises holding the liner assembly in a horizontal position between two supports, and winding resin impregnated fibers about the liner assembly to form a structural composite overwrap. A system for manufacturing a composite riser section with a liner assembly having a longitudinal axis comprises a first support and a second support that hold the liner assembly in a horizontal position therebetween, and a plurality of rollers that rotate the liner assembly about the longitudinal axis.

Abstract: An integrity monitoring system for monitoring degradation in a composite riser string. The system includes composite riser structures incorporating strain and vibration sensors to measure changes in the stiffness strain on a first orientation and on a second orientation. The system can also include monitoring modules attached to each individual riser and devices to transfer the data from the monitoring module to the surface controller. Additionally, the monitor system can provide for an alarm when predetermined warning limits are exceeded.

Abstract: A composite collapse riser especially useful for deep water mineral, oil and gas exploration and production. The riser has a core with a metal liner and metal composite interfaces at each end. A reinforcing layer of dry fiber laminate, composite material or combination thereof is placed over the metal liner. Over the reinforcing layer is a shear ply layer, and over the shear ply layer is an outer main layer of composite material.

Abstract: The present invention discloses multiple sealing systems for composite risers and methods of preventing interior fluid leakage to the outside of composite risers. Single or multiple elastomeric seals are formed between an elastomer applied in single or multiple grooves provided circumferentially along the outer surface of a metal to composite interface (MCI) of a liner assembly of the composite riser and an elastomeric shear ply provided on the outside of the liner assembly. The elastomeric seals and a seal between the MCI and the liner of the liner assembly provide a multiple sealing system for the composite riser to prevent leakage of interior fluids. In the event that the integrity of the seal between the MCI and liner fails or the integrity of the liner is compromised, the elastomeric seals would prevent leakage of the fluid to the outside of the composite riser.

Abstract: The present invention discloses redundant sealing systems for composite risers having metal liner assemblies and methods of preventing interior fluid leakage to the outside of composite risers. An elastomeric seal is formed between an elastomeric tip provided on the end of a metal to composite interface (MCI) of the liner assembly and an elastomeric shear ply provided over the liner assembly. The elastomeric seal and a mechanical seal between the MCI and a transition ring which secures the liner to the MCI, provides a dual sealing system for the composite riser to prevent leakage of interior fluids. In the event that the integrity of the mechanical seal or the integrity of the liner is compromised, the elastomeric seal would prevent leakage of the fluid to the outside of the composite riser.

Abstract: The present invention provides methods and apparatus for mooring a tension leg platform. The platform is positioned over an anchor means attached to the ocean floor. A plurality of guidelines or cables, attached to the anchor means, are called to the surface by means of acoustic recall buoys which are attached to a free end of the guide cables. The guide cables are then connected to the floating platform. Tension legs, each including a plurality of tubular leg elements threaded at each end, with threaded couplings connecting adjacent leg elements, are then lowered from the floating platform. Guide means connected between the tension legs and the guide cables direct the tension legs toward the anchor means on the ocean floor. A hydraulically actuated wellhead connector is connected to a lower end of the tension leg. The wellhead connector engages a wellhead body attached to the anchor means, and is locked thereto upon the sending of a hydraulic signal to the wellhead connector.