Abstract: An improved method to automatically generate one or more useful alternatives to the least-cost point-to-point route on a road network. The method discourages reuse of road sections that have been previously used by inflating the costs associated with these road sections before the recalculation of the search algorithm.

Abstract: Components of and method for making a tube and fitting framework having panel recesses accepting structural panels in a plane tangent to the tubes. The tubes and fittings allow easy assembly of large structures. The panels secured within the panel recesses bear loads imposed on the structure and minimize torque at the fittings. The finished structure is streamlined, with flush junctions of all components. Alternative embodiments include panel recesses in angular or channeled shapes which act to secure the panels to the framework, and other panel securing devices which are externally invisible on the completed structure. Panel securing devices include screws, bolts, studs, pins, adhesives, welding and equivalents. Fittings are secured to tubes by connectors which may engage the interior of the tube in known ways, or by use of O-rings or rubber flanges. Tubes, fittings and panels may be made of any of a wide range of materials including metals, alloys, plastics, rubbers, wood, and composites.

Abstract: A method is disclosed for pipeline leak detection in which a vacuum is maintained in the annulus of a pipe-in-pipe flowline with a vacuum pump having a discharge reservoir which is monitored for the appearance of water and hydrocarbon vapors. In another aspect of the invention pipeline leak detection is accomplished through maintaining a gas at a nominally constant pressure in an annulus of a pipe-in-pipe flowline and monitoring the annulus for pressure increase indicative of water or product intrusion into the annulus.

Abstract: A system for direct electric heating of a subsea pipeline is disclosed in the form of a pipe-in-pipe flowline having an electrically conductive outer carrier pipe and an electrically conductive inner pipe or flowline arranged longitudinally, substantially concentrically within the outer pipe. An annulus is defined between the inner and outer pipes and a pipe insulating joint assembly structurally joins, but electrically insulates, the inner and outer pipes at a first end of the subsea pipeline. A power input provided on the surface facilities is electrically connected across the inner and outer pipes at the first end of the pipeline, and an electrical pathway completes the circuit by connecting the inner and outer pipes at the second end of the pipeline.

Abstract: A method for monitoring a cementing operation is disclosed for predicting whether an effective formation-to-casing seal has been formed across an annulus of a well. In this method a distributed well monitoring system is installed in the annulus of the well before the cement is pumped. Once pumped, the cement is monitored substantially along the annulus. The pressure in the annulus is determined at cement transition and this pressure is compared to the maximum formation pressure as an indication of whether the cement had set to a strength sufficient to maintain an effective formation-to-casing seal across the annulus.

Abstract: A method for reducing VIV is disclosed for a spar platform having a deck, a cylindrical hull having a buoyant tank assembly, a counterweight and an counterweight spacing structure. The overall aspect ratio of the hull is reduced by providing one or more abrupt changes in hull diameter below the waterline.

Abstract: A fairing system is disclosed for protecting a cylindrical marine element from drag and vortex induced vibration. A noncorrosive fairing shroud is rotatably mounted about the cylindrical marine element and defines an annular region between the exterior of the cylindrical marine element and the inside of the fairing shroud and at least one copper element is mounted at the annular region to discourage marine growth at the fairing shroud-cylindrical marine element interface. This enables the fairing to remain free to weathervane to orient most effectively with the current Another aspect of the present invention is a method for protecting a substantially cylindrical marine element from vortex-induced vibration in which a rotatable fairing is installed about the marine element and a marine growth inhibitor is mounted in active communication with the annular interface of the rotatable fairing and the cylindrical marine element.

Abstract: A fairing system is disclosed for protecting multiple, parallel, bundled but separate cylindrical elements deployed in offshore applications. The fairing system deploys a plurality of elongated fairing surface elements foldable about an axis with a connection system joining the elongated edges of the fairing surface elements in a folded manner about the axis. A plurality of thrust bearings are orthogonally connected across the fairing surface elements at each axial end and an axially extending circular rotational surface is defined by the interior of each of the folded fairing surface elements and a transverse edge of the thrust bearings connected thereto. This rotational surface has a diameter which circumscribes the multiple bundled cylindrical elements. A plurality of clamps interconnect the bundled, cylindrical elements and a bearing collar on the axial ends of the clamps is provided to receive the thrust bearings of the axial ends of the fairing elements.

Abstract: A method of providing a tendon guide surface to an installed pile is disclosed in which a tendon foundation guide cone assembly having a tendon guide surface is attached to a lowering unit and lowered to the pile. The tendon foundation guide cone assembly is then attached to the installed pile and released from the lowering unit. A tendon foundation guide cone assembly and a method for securing a tendon to the ocean floor are also disclosed.

Abstract: A method is disclosed for redeploying an offshore platform structure from a first site to a second sight of different water depth in which the connection is released between a subsea jacket base and a plurality of piles which are anchored in the ocean floor at the first site. The offshore platform structure is vertically raised by pumping air into a tank member at the top of the subsea jacket base and the surface tower which is supported upon subsea jacket base is reworked while the jacket base is vertically raised. This operation is less difficult than attempting operations offshore on a horizontally disposed surface tower. The offshore platform structure is transported to the second site and the tank member is ballasted to vertically lower the offshore platform to the second site where it is installed.

Abstract: A method is disclosed for reducing NOx pollutants in the combustion of hydrocarbon fuels in a two stage burner. A first stage of combustion is established and maintained passing a stream of combustion air and first stage products of combustion down a centerline of the burner to a second stage downstream therefrom. This second stage is established by arranging an array of fuel tips around the first stage burner, each fuel tip having a fuel jet with a nominal trajectory angled toward the burner centerline and an inert gas jet placed between the burner and the fuel jet which is angled to cross the trajectory of the fuel jet. Fuel is injected into the second stage of the burner through the fuel jet and the inert gas, e.g. steam, is injected through the inert gas jet such that it influences the trajectory of the fuel to a modified fuel trajectory which is moved away from the centerline of the burner.

Abstract: A parasite mooring system is disclosed for restraining a compliant platform with respect to an auxiliary vessel. The parasite mooring system includes a parasite mooring line, a platform termination securing the parasite mooring line to the compliant platform; and a grip securing the parasite mooring line to a mooring line of the auxiliary vessel passing beyond the compliant platform. Another aspect of the present invention is a method for conducting offshore well operations in which a semisubmersible vessel is brought adjacent a compliant platform such that at least one mooring line of the semisubmersible vessel extends past the compliant platform and a parasite mooring line from the compliant platform is connected to the mooring line of the semisubmersible vessel.

Abstract: A compliant tower is disclosed having a foundation connected to a wide-bodied compliant framework with a plurality of vertically extending legs a minimum of horizontal bracing. The compliant framework is configured to maintain a substantially wide, open riser suspension corridor. A topside facility is supported by the compliant framework and a plurality of freely suspended production risers extend through the riser suspension corridor from the vicinity of the topside facility to communicate with the reservoir. These production risers are spaced to provide clearance to prevent riser interference in response to normal flexure of the compliant tower and normal environmental loads on the risers. A riser support assembly is configured to accomodate relative motion between the risers and the topside facility, supporting the production risers in tension near their upper ends to provide the principal load transfer between the riser and the compliant framework.

Abstract: An offshore platform structure is disclosed for temporarily using a jack-up rig for well operations in deepwater applications having a bottom founded jacket base which supports a surface tower which extends above the ocean surface and a subsea rig support interface which is adapted to support the jack-up rig for well operations. At least one selectively buoyant rig support buoyancy tank connected to the rig support interface whereby a portion of the temporary load on the jacket base in supporting the jack-up rig for drilling operations may be alleviated.

Abstract: A tendon cluster array is disclosed for tethering a superstructure of a tension leg platform to an ocean floor in which a plurality of tendons are anchored to the ocean floor at their lower ends with a substantially planar, horizontally disposed tendon bracket receiving the upper ends. A tendon bracket connection pivotally secures the tendon bracket to a downwardly disposed surface of the superstructure.

Abstract: The present invention is a deepwater compliant platform that has enhanced dynamic characteristics by virtue of its wide stance, eliminates conventional conductor drivepipe guides and supporting framework, and reduces the net material requirements with a substantially open interior permitted in the absence of the conductor guides. This utilizes the wide body stance to accommodate a wide riser suspension corridor through the open interior thereby allowing suspended risers to be spaced apart sufficiently to avoid interference in response to normal tower motions.

Abstract: A tension leg caisson is disclosed for supporting surface facilities on a deck for conducting hydrocarbon recovery operations in deepwater location applications. The tension leg caisson has an elongated, buoyant central vertical column or caisson with a plurality of outrigger pontoons. A plurality of tendons are connected on one end to the outrigger pontoons at a location which is spaced apart from the vertical. The other end is anchored to the ocean floor. Another aspect of the invention is a method of improving the dynamic response of a buoyant central caisson type platform.

Abstract: A dual string high pressure riser system is disclosed for use in drilling a deepwater well through a subsea wellhead. An outer riser extends from the surface and sealingly engages the wellhead and an inner riser extends from the surface downwardly, concentrically through the outer riser to communicate with the well. A surface BOP provides well control at the top of the dual high pressure riser. In another aspect of the present invention, a method is disclosed for conducting deepwater drilling operations in which a surface BOP and a lightweight outer riser are installed in communication with a subsea wellhead and a first interval is drilled through the outer riser. Casing is run through the outer riser into the first interval, cemented within the borehole and sealed at wellhead.

Abstract: A tension leg tripod is disclosed for supporting surface facilities on a deck for conducting hydrocarbon recovery operations in deepwater location applications. The tension leg tripod has an elongated, buoyant central vertical column or caisson with three outrigger pontoons. Three tendons are grouped in tendon cluster arrays, each being connected on one end to the outrigger pontoons at a location which is spaced apart from the vertical. The other end of the tendons are anchored to the ocean floor.