Abstract: A tension mooring system for a floating structure such as a drilling or production platform having a plurality of permanent mooring lines extending upwardly from a plurality of bottom anchors and terminating below the water level and having buoys connected to the upper ends thereof with sufficient buoyancy to maintain the upper end of the mooring lines in a generally vertical posture, replaceable mooring lines connecting from the buoys to the floating structure, the upper position of the permanent mooring lines being preselected to be below a highly corrosive area of the air-sea interface, and a pulling mechanism on the replaceable mooring lines to impart a preselected tension to the mooring lines, the bottom anchors being pre-positioned by drilling and cementing or driving piling through templates.

Abstract: The invention relates to an offshore, gravity base, jack-up platform comprising a deck, a gravity base and one or more legs interconnecting the deck and base. The gravity base comprises a generally polygonal shaped, monolithic hull structure with reaction members extending downwardly from the hull to penetrate the waterbed and react to vertical and lateral loads imposed upon the platform while maintaining the gravity hull in a posture elevated above the surface of the waterbed.A method aspect of the invention includes the steps of towing a gravity base, jack-up platform, as a unit, to a preselected offshore site floating upon the gravity hull. During the towing operation, the deck is mounted adjacent the gravity base with a leg or legs projecting through the deck. At a preselected offshore station ballast is added to the gravity base and the platform descends slightly to a posture where the platform is buoyantly supported by the deck.

Abstract: The invention relates to an offshore platform operable for use in Arctic locations where prolonged ice conditions may be encountered. The platform includes a lower barge hull having an exterior configuration in the general shape of a rectangular frustum and being operable to be fixed relative to a desired seabed site. The lateral side walls of the barge hull are heated for facilitating movement of contiguous sea ice upwardly relative to the barge side walls to fail the ice in bending as it advances toward the barge hull. A deck is positioned above the lower barge hull and is supported by a first and second column at an elevation whereby the lower surface of the deck will be above and out of contact with sea ice passing over the hull. The deck is positioned relative to the barge hull in a posture such that at least a portion of the deck extends beyond an imaginary vertical plane projecting upwardly from at least one longitudinal edge of the upper surface of the barge hull.

Abstract: The invention relates to a jack-up platform locking apparatus. The subject locking apparatus includes a frame operable to be securely connected to a deck of the platform and a lock unit having at least one tooth for engaging a compatibly configured surface upon a vertically adjustable platform leg. Hydraulic motor means are provided for vertically adjusting the lock with respect to the deck and leg. An additional hydraulic motor is provided for horizontally actuating or deactuating the lock with respect to the platform leg. The invention further includes a mechanical assembly for vertically securing an engaged lock with respect to the platform deck. A reaction wedge member is provided for horizontally securing the lock in firm engagement with the leg of the offshore platform.

Abstract: A riser for production of oil and gas in a marine location with the riser connected to the casing supported at the mud line of a body of water and extending upward in the water to a tension moored floating structure. The riser includes a flexible joint near its connection to the casing and is supported at its upper end from the floating structure and is also supported from the floating structure at a point between 50 and 175 feet below the water level. A production string extends upwardly from the producing zone through the casing, the flexible joint and the riser to the floating structure and wellhead equipment is supported on such riser. Centralizers are provided for the production string with the centralizer immediately above the flexible joint being between 35 to 65% of the total distance between such centralizer and the centralizer positioned immediately below the flexible joint.

Abstract: A floating vessel having a crane for lifting heavy weights comprises tanks having relatively large openings below the water-line which openings can be closed in a substantially water-tight manner to vary the shape of at least that part of the vessel which is below the water-line.

Abstract: A bottom-supported vessel from which subaqueous operations may be performed. The vessel includes a platform and a mat, both of which are configured to permit the platform to nest within the mat while the vessel is floating. The mat is submersible and is adapted to be buried into the soil beneath the ocean floor to provide support for the platform. Legs extend from the mat to the platform and support the platform when the mat is buried. A method of placing a bottom-supported vessel in position for performing subaqueous operations.

Abstract: An arctic drilling barge to perform offshore activities in the shallow water, fast ice regions of the arctic seas. Optimal ice interaction is obtained by shaping the hull of the barge in the form of an upright frustum. Ice which does adhere to the barge is detached and melted by circulating fluid through a plurality of interior hull compartments next to the hull sidewalls of the barge.

Abstract: An improved platform for performing subaqueous operations in ice conditions. A substructure on the platform supports the equipment for performing the subaqueous operation and straddles an aperture through the platform. Means are secured to the underside of the substructure for presenting a relatively low coefficient of friction or low lateral resistance between the underside of the substructure and the face of the platform. Locomotion means are associated with substructure for moving the substructure laterally over the face of the platform relative to the aperture whereby the equipment for performing the subaqueous operations may remain over the wellhead in spite of certain magnitudes of lateral movement of the platform responsive to the ice conditions.

Abstract: Subsea cable apparatus adapted to extend from a floating structure to a subsea wellhead apparatus or stack with a marine riser pipe extending from the floating structure to the subsea wellhead, such apparatus including a cable supported on the floating structure, by a multiple roller sheave with an integral load cell for measuring tension in the cable, a clamp on the riser pipe adapted to engage the cable to support it, the cable between the clamp and the floating structure forming a free catenary loop, means for engaging and disengaging said clamp on said cable, remote, diverless means for disconnecting said clamp from said riser pipe, a telescoping connection in the lower end of said cable to absorb the shock of landing control pod attached to the lower end of the cable on the pod receptacle on the subsea wellhead apparatus and to compensate for relative movement between the cable and the subsea wellhead stack, a pod connector on the lower end of the cable, a mating pod receptacle connector on the subsea we

Abstract: An improved floating structure suitable for use as a floating drilling platform, production platform or other moored floating structure having a vertical tension mooring system with a plurality of anchors, ballasting and deballasting means, and a plurality of mooring lines connecting each anchor to the floating platform, the anchors having a total buoyancy to support the entire weight of the structure so that in transit a minimum structure is below the water, and to minimize surge or sway having a mooring line pretension to displacement ratio in the range from 0.05 to 0.3, having an anchor weight in the range from 0.10 to 0.45 of the anchor displacement and 0.10 to 0.60 of the platform displacement and an anchor displacement in the range from 1.05 to 1.30 times the platform displacement.

Abstract: Method and apparatus for determining on board a heaving drilling vessel, the flow rate of drilling fluid flowing from a well hole and into a telescoping marine riser connecting the well hole with the vessel. A measuring apparatus is associated with a drilling fluid return conduit of the riser in such a position that the measuring apparatus and the portion of the conduit between the measuring apparatus and the riser are at all times filled with drilling fluid. The measuring apparatus generates a first signal proportioned to the flow rate of drilling fluid flowing therethrough, measures the drilling fluid level in the riser and generates a second signal proportional to the change in volume of the drilling fluid contained therein above the point at which the conduit intersects the riser. The telescoping movement of the riser is measured and a third signal is generated proportional to the change in volume of the flow path provided by the riser between the well hole and said point.

Abstract: A system for emergency release of a ship from its mooring cables is disclosed wherein pressurized actuating fluid stored in accumulators may be selectively released to actuate fluid powered cutters to sever the mooring cables. In its preferred form the system includes fire inerting apparatus adapted to operate in conjunction with the cable cutters to provide a fire inert atmosphere and thereby eliminate the possibility of fire or explosion resulting from sparks generated during the cutting operation. The system is remote controlled and operates on a power source independent from the ship's normal power. This abstract is neither intended to define the invention of the application, which of course is measured by the claims, nor is it intended to be limiting as to the scope of the invention in any way.

Abstract: A multi-passage ball joint assembly for connecting a riser or similar pipe to a well pipe therebelow and adapted primarily for use in underwater installations. The ball member of the joint assembly has a main longitudinal bore or passage through which well operations may be conducted and additionally is formed with at least one other passage for conducting fluid therethrough. The housing of the joint assembly includes passageways which are in communication with the bore and passages extending through the ball member in all positions of said ball member relative to the housing whereby fluid may be conducted downwardly through the ball joint for actuating devices therebelow or for other purposes. This abstract is neither intended to define the invention of the application which, of course, is measured by the claims, nor is it intended to be limiting as to the scope of the invention in any way.