Abstract: A deep water offshore apparatus for use in oil drilling and production in which an upper buoyant hull of prismatic shape is provided with a passage longitudinally extending through the hull in which risers run down to the sea floor, the bottom of the hull being located at a selected depth dependent upon the wind, wave, and current environment at the well site, which significantly reduces the wave forces acting on the bottom of the hull, a frame structure connected to the hull bottom and extending downwardly and comprising a plurality of vertically arranged bays defined by vertically spaced horizontal water entrapment plates and providing open windows around the periphery of the frame structure, the windows providing transparency to ocean currents and to wave motion in a horizontal direction to reduce drag, the vertical space between the plates corresponding to the width of the bay window, the frame structure being below significant wave action whereby wave action thereat does not contribute to heave motion of

Abstract: A method of setting out long mooring lines that includes the use of both a traction, or drum, winch and a linear winch. An anchoring vessel is provided with supply drums that contain the mooring line, a traction winch, and a linear winch. When the mooring line is lowered or retrieved, the traction winch, is used to maintain tension on the line until a connector approaches the traction winch. The linear winch is then engaged to maintain tension on the line, with the traction winch under low tension, until the connector passes through the linear winch. The traction winch is then reengaged to maintain all the tension on the line and the linear winch is disengaged until the next connector approaches the traction winch.

Abstract: A complete fail signature for an integrated circuit is compared to at least one predicted fail signature generated using a hardware fault simulator to generate fault candidates for the integrated circuit representing the most likely faults present within the tested circuit or device. The complete fail signature may be generated by obtaining physical test data for the integrated circuit derived by testing the integrated circuit using test vectors and comparing the results of the testing with the test results of a flawless integrated circuit to generate a fail signature. Also, the complete fail signature may be generated by compiling the logic of the integrated circuit into binary language suitable for simulation in a hardware fault simulator and compiling the test vectors into binary language suitable for simulation in the hardware fault simulator.

Abstract: An offshore multiple tendon compliant buoyant tower construction for well operations in which a plurality of tendons are arranged in parallel, vertical, closely spaced assembled relation and have top and bottom ends, the bottom ends being connected to a base module at the sea floor, the top ends being connected to a buoyant structure which includes conductor tubes therein for each of said tendons and which serves to restrict bending of the top portion of said tendons to provide a relatively stiff, unbending, noncompliant tendon top portion which extends below the sea surface, the portion of the assembled tendons below the stiff to portion being relatively compliant; the buoyant structure imparting tension to said plurality of assembled tendons at the top ends thereof whereby the tensioned tendons provide lowering of the effective center of gravity of the tower construction below the center of buoyancy and whereby cyclic stresses in the assembled tendons resulting from roll or bending of the tower construction

Abstract: A drilling, production and oil storage caisson for use in deep water offshore well operations in which the caisson has such a deep draft that its bottom end is subject only to minimal excitation forces caused by wave, wind and current acting on the caisson, the caisson including a plurality of oil storage compartments, a plurality of water ballast compartments above said oil storage compartments, a through axial passageway through said compartments; a riser system including a plurality of riser pipes in concentric circular arrangement within the through passageway or center well, each of the riser pipes being supported and tensioned by a buoyant flotation unit connected thereto; a drill string extending axially through said passageway between said riser pipes; and mooring lines connected to the bottom portion of the caisson extending therefrom with relatively low scope of 1:1 or less and providing a small watch circle for anchors for said mooring lines, the mooring lines being tensioned so that the mooring li

Abstract: A jacket tower structure for use in deep water which includes a plurality of tapering jacket sections adapted to be nested, each section including at least three jacket legs. The base and lower jacket sections include cylindrical legs interconnected by box section bracing, the upper jacket sections including cylindrical bracing. The box section bracing is connected to the legs by a unique joint for transmitting stresses to the legs. The box section bracing is floodable for equilizing hydrostatic pressure during and upon installations. Certain transverse box section bracing at ends of adjacent jacket sections include intermediate connection projections for welding during joining of adjacent jacket sections. The cylindrical legs include a plurality of water tight compartments of selected volume, each compartment having one or more check valves for admitting water into the compartments when external water pressure exceeds air pressurization of the compartments.

Abstract: A submerged tubular tower 10 is connected at its lower end 15 to an ocean floor 11 at a site where at least one subsea hydrocarbon well is to be drilled. A riser duct 22 for each well to be drilled extends from an upwardly accessible connection point 20 at the upper end 14 of the tower to the lower end of the tower. The tower is positively buoyant to stand erect in an unguyed manner. The upper end of the tower is located a substantial distance above the ocean floor at a depth sufficiently small to enable wells to be drilled through the riser ducts, through equipment 19 landed on the top of the tower, using floating drilling equipment 12 designed for use in substantially shallower water depths.

Abstract: A development and production facility for an offshore oil or gas field is constructed and drilling of wells is performed using a jack-up drilling platform in an improved manner. The facility is composed of a development well platform and a production platform, each of which is composed of a modular prefabricated unitary deck assembly of substantially turn-key completeness and of a prefabricated jacket or leg assembly to which the deck assembly is matable. Crane or derrick barges are used only to position the deck assemblies on the leg or jacket assemblies after the latter assemblies have been placed erect on and secured to the sea floor by use of the jack-up platform. The development well platform is constructed first so that drilling of development wells can be performed from the jack-up platform through the former platform concurrently with the placement and completion of the production platform.

Abstract: A tension-leg offshore platform comprises a positively buoyant, floating upper unit in which an operations platform is supported above an ocean surface by a plurality of spaced vertical columns defining buoyancy chambers. The lower ends of the columns are connected to the ocean floor by a corresponding plurality of tension-leg assemblies. Each tension-leg assembly is comprised of a plurality of positively buoyant tubular members having their lower ends connected securely against upward movement to the ocean floor. The tubular members are of substantially equal length less than the pertinent water depth by an amount adequate to cause their upper ends to be located below the area of significant surface wave action yet substantially above the ocean floor. A separate flexible tension member for each tubular member connects the lower ends of the columns to the upper ends of the corresponding tubular members.

Abstract: A tension leg structure for use with a tension leg platform or the like to interconnect an anchor on the sea floor and platform in which the tension leg structure comprises interconnected buoyant pipe members for transmitting tension forces and for withstanding hydrostatic pressure. Each member has internal watertight bulkheads defining a buoyancy chamber. Tremie pipe extends through the bulkheads of each member and has ends terminating in a slipover coupling provided within a joint interconnecting adjacent tension buoyant members.

Abstract: A pipe construction for utilizing ocean energy including a plurality of toroidal pipe elements stacked one upon the other in coaxial relation to form a cylindrical wall of substantial diameter and length. Sealing means are provided between pipe elements to make leakproof the cylindrical wall, said pipe structure being suspended by a plurality of tension members arranged about the inner circumference of the cylindrical wall. A pipe construction having a circular or a polygonal cross sectional shape and having portions thereof of selected physical characteristics for selected depth of water.

Abstract: A marine riser system is provided which extends between a floating offshore platform and well means in a seabed formation and which has riser end portions connected in novel manner to the floating platform and to wellhead structure at the well hole. Each end portion of the riser is adapted to yield axially, laterally, and rotatively during movement of the riser relative to the platform and to the wellhead structure. Each end portion of the riser is provided with fulcrum or pivot contacts with hawse pipe carried by the platform and with hawse pipe or casing means provided in the wellhead structure. Bending stresses at the riser end portions are reduced at the platform and at the wellhead structure.

Abstract: A means and method to facilitate making a flowline connection between a non-vertically disposed submerged connector means for subsea well operations. A surface vessel carrying a supply of flowline and of tension cable over a subsea well installation lowers one end of the tension cable to anchor the cable adjacent the subsea connector means and after moving away from the subsea installation, a tension control means imparts selected tension to the cable to maintain an approximate catenary curve while flowline is supported from and progressively advanced along the cable to the connector means at the subsea installation. Cable tension is controlled to provide a selected curve of the cable and flowline so that the attitude of the advancing end of the flowline is substantially aligned with the connector means at the subsea installation whereby a flowline connection with subsea pipe installations is effected without or with only minimum assistance from a diver or other subsea robot equipment.

Abstract: A method and apparatus for laying continuous pipe particularly for offshore oil installations and wherein said continuous pipe is pre-formed into flat spirals of pre-selected inner and outer diameters depending upon available handling equipment and arranged in stacks in which each flat spiral is interconnected with the adjacent flat spiral. A stack of flat pipe spirals is positioned on a power driven rotatable pipe spiral carrier mounted on a deck of a pipe laying vessel. Pipe is withdrawn from the stack of spirals by rotating the pipe carrier and moving the pipe through pipe straightening and tensioning means, after which the pipe is fed to suitable pipe laying means for connecting the pipe to subsea installations.

Abstract: An apparatus and method for anchoring an offshore tension leg platform which includes a platform supported above an ocean surface by buoyant supports comprising at least three vertical buoyant support members. Each vertical support member includes a central axial conductor tube for passage of drill pipe adapted to be connected to anchor members carried at the bottom of the vertical support member, the drill pipe providing a for lowering the anchor member, for drilling beneath the anchor member to pin the anchor member in the ocean bottom, and for transfer of ballast from the vertical support member to the anchor member. Each vertical support member includes longitudinally extending anchor line casings spaced from the axial tube to provide passageways for anchor tension lines connected to the anchor and adapted to be tensioned at the upper end of the vertical support member or at the platform.