Abstract: A helical bundle of tubes is fabricated with a carousel-type machine, preferably rotating about a vertical axis. Spools of coil tubing are mounted on radial beams extending from a central rotating hub, and are indexed to maintain the axes of the spools in a constant direction. In the preferred vertical rotating axis configuration, the tubes are pulled off the spools by an overhead capstan, and the finished bundle is deposited on a take-up reel. A preferred way of indexing the spools uses chains passing around equal size sprockets attached to the vertical support shafts with at least one of the chains passing around a stationary central sprocket.

Abstract: A diverless and guidelineless method to connect two subsea flowlines by a jumper assembly is provided. Pivotable stabs and fluid connection means are provided on each end of the jumper assembly. The stabs mate into receptacles located on the subsea flowline connections. The flowline is preferably lowered vertically and hinged over while sequentially landing the two pivotable stabs into their respective stab receptacles.

Abstract: A method and apparatus is described for installing an export production riser on an offshore production platform that moves in response to ocean waves, wind and currents. The riser is provided with a catenary shape between the near vertical connection on the platform and the horizontal position on the seafloor. The upper end of the riser is maintained at a nominal inclination from the vertical to control excessive bending stresses in the riser. A flexible joint is provided at the upper end of the riser to allow rotational movement between the riser and platform as the platform moves.

Abstract: A pipeline breakaway mechanism is provided which includes an elbow in a pipeline and two clamps holding the pipeline to a structure such as a platform or another pipeline. When a strong pull is exerted on the pipeline, the pipeline is bent until it buckles around the first clamp; the first clamp then fails at a preset load, causing the pipe to bend around the second clamp and causing the previously formed buckle to straighten. This buckling and straightening of pipe causes the pipe wall to fracture at a load much smaller than its tensile strength.

Abstract: The present invention pertains to a pipeline having a deliberate weak link to relieve a large tension load, said weak link being a pipe loop in said pipeline of sufficient weakness to fail prior to reaching said large tension load.

Abstract: A heave compensating support system is disclosed for positioning a subsea work package. The present invention provides a subsurface buoy with a lift line connected to the subsea work package and a compensating lift line having a catenary loop below its connection to the subsurface buoy on one end and connected to a surface vessel on the other end, whereby the heave compensating support system elements cooperate to establish a natural frequency for the suspended subsea work package which materially differs from the average wave frequency acting upon the surface vessel.

Abstract: Riser clamps are installed onto fixed or compliant offshore platforms by a diverless technique. Each riser clamp is rigidly or hingedly attached to a heavy tapered wedge. Mating tapered receptacles are built into the platform, preferably at various levels along a corner leg. Only one lift line is utilized which may be either a drill string or wire rope, and one remotely operated vehicle (ROV) for observation, to lower and stab each riser clamp into one of the tapered receptacles on the platform.

Abstract: A flowline bundle is twisted or braided into a permanent rope-like helical configuration, prior to laying the flowline bundle offshore by the reel method.Apparatus for forming the helical flowline bundle includes a pipe twist head and a series of pipe tumblers alternating with intermediate pipe supports, which apparatus rotates and translates part of a flowline bundle while simply translating the other part.

Abstract: A flowline bundle is twisted or braided into a permanent rope-like helical configuration, prior to laying the flowline bundle offshore by the reel method. Apparatus for forming the helical flowline bundle includes a pipe twist head and a series of pipe tumblers alternating with intermediate pipe supports, which apparatus rotates and translates part of a flowline bundle while simply translating the other part.

Abstract: A method and apparatus are provided for positioning and securing a seismic float alongside a tow vessel, utilizing a docking cone to secure one end of the float and to raise that end of the float above the water, thereby submersing the other end of the float beneath the water, and thereby damping out movements of the float with wave action. Having so positioned and secured the float, a saddle or other attachment means may then be lowered onto the float for retrieval of the float to onboard the tow vessel.

Abstract: A method and apparatus are provided for constructing a deep essentially horizontal borehole in the earth, as for the installation of a pipeline in Arctic offshore waters. This directional drilling technique eliminates exposure of an Arctic offshore pipeline to ice gouging and minimizes the hazards associated with unstable permafrost. Means are provided for gripping inside a borehole in order to apply thrust to a drill bit utilized to drill the borehole which is to contain the pipeline.

Abstract: A method and apparatus is presented for connecting a flexible conduit bundle from a subsea wellhead to a floating platform. Movement of the floating platform relative to the subsea wellhead is compensated for by arranging the conduit bundle to be suspended in a catenary manner between the wellhead and the floating platform. The catenary form of the conduit bundle is maintained by bending the circuit around anchor blocks located a selective distance from the subsea wellhead.

Abstract: The present invention provides a method and apparatus for connecting a flowline to a subsea structure. A riser and flowline connection tool are deployed downwardly to the subsea structure and a flowline terminal head, which is at the end of the flowline, is pulled to the flowline connection tool by means of a pullcable. Then the flowline terminal head is secured to the subsea structure and the flowline connection tool is recovered to the surface. The flowline terminal head consists of a connector hub with clamping surface to which the flowline is welded, and a flexible carrier pipe of interlocking metallic rings into which the end of the flowline is inserted. The carrier pipe limits the curvature of the flowline as the terminal head is bent into alignment with a flowline receptacle of the subsea structure. The flowline terminal head may include buoyant encircling rings which keep it free of difficult terrain in the vicinity of the subsea structure.

Abstract: The present invention provides a method and apparatus for connecting a flowline to a subsea structure. A riser and flowline connection tool are deployed downwardly to the subsea structure and a flowline terminal head, which is at the end of the flowline, is pulled to the flowline connection tool by means of a pullcable. Then the flowline terminal head is secured to the subsea structure and the flowline connection tool is recovered to the surface. The flowline terminal head consists of a connector hub with clamping surface to which the flowline is welded, and a flexible carrier pipe of interlocking metallic rings into which the end of the flowline is inserted. The carrier pipe limits the curvature of the flowline as the terminal head is bent into alignment with a flowline receptacle of the subsea structure. The flowline terminal head may include buoyant encircling rings which keep it free of difficult terrain in the vicinity of the subsea structure.

Abstract: Method and apparatus for use in drilling a well from a floating vessel by means of a riser which connects the vessel's drilling equipment to a wellhead assembly adjacent the ocean floor. Braking apparatus is provided which is capable of arresting the vertical motions of the drilling riser and of securing the upper end of the riser to the vessel whenever the riser is disconnected from the wellhead.

Abstract: Apparatus for use in drilling a well from a floating vessel by means of a riser which connects the vessel's drilling equipment to a wellhead assembly adjacent the ocean floor. The riser is capable of being disconnected from the wellhead assembly and having the motion of its upper end arrested and subsequently secured to the vessel. The present riser braking clamp apparatus comprises braking elements integrally carried by the telescoping joint located at the upper end of the riser. Actuation of these braking elements prevents further telescopic movement of the telescopic joint, thereby preventing movement of the riser upper elements relative to the vessel.

Abstract: A hollow curved auger is provided for simultaneously laying and trenching a pipeline, as from the surface of an ice-covered body of water. The pipeline passes through the auger which comprises rotary teeth encircling the pipeline and turning in opposed directions. The depth and direction of pipeline trenching and burial are controlled by varying the longitudinal force in the pipe and rotational orientation of the auger.

Abstract: The present invention provides a method and apparatus for connecting a flowline to a subsea structure. A riser and flowline connection tool are deployed downwardly to the subsea structure and a flowline terminal head, which is at the end of the flowline, is pulled to the flowline connection tool by means of a pullcable. Then the flowline terminal head is secured to the subsea structure and the flowline connection tool is recovered to the surface. The flowline terminal head consists of a connector hub to which the flowline is welded, a curved carrier pipe into which the end of the flowline is inserted, a bullnose to which the pullcable is attached, and a dovetail tenon which engages a dovetail receptacle to secure the terminal head to the subsea structure. The flowline terminal head may include buoyancy which keeps it free of difficult terrain in the vicinity of the subsea structure.

Abstract: A method and apparatus are provided for connecting an offshore pipeline or flowline bundle to a deepwater subsea structure and then laying away from the structure. The pipeline or flowline bundle is deployed from a pipelay vessel while connected via a pullcable to a riser deployed from a drilling ship to make a connection with the subsea structure. The connection operation is facilitated by a remotely operated connection tool deployed at the end of the riser, which contains a winch for hauling in the pullcable, as well as other mechanisms for securing the pipeline or flowline bundle to the subsea structure.

Abstract: A method and apparatus are provided for laying an offshore pipeline or flowline bundle to a deepwater subsea structure. The pipeline or flowline bundle is laid along a prescribed path, preferably U-shape, such that a pullhead at the terminus of the pipeline or flowline bundle falls just short of the subsea structure. A pull-in tool connected to the pipeline or flowline bundle by a short length of pull cable is then landed on and latched to the subsea structure, and the pipeline or flowline bundle is pulled up to the subsea structure by the pull-in tool and pull cable.