Abstract: A method and apparatus for positioning an offshore well substructure on the ocean floor. A substructure having a heigth of 1350 feet and base of 400 feet by 480 feet is subject to significant lateral forces caused by wind, wave, and current forces between the time period of lowering it to the ocean floor and driving piles through its skirt sleeves and into the ocean floor. Mudmats carried by the bottom corners of the substructure have downwardly-extending peripheral walls which penetrate the ocean floor so as to resist any lateral force to which the substructure is subjected. The base of a mudmat is approximately 10,000 square feet and the walls are approximately five feet high. A manifold system carried by each mudmat provides the capability of adjusting the level of the substructure after it has been lowered onto the ocean floor.

Abstract: Operators of submerged remotely operated vehicles (R.O.V.)'s must typically view the subsea environment by use of a submerged television camera carried by the R.O.V. Often no part of the vehicle is visible to the operator to give him a natural indication of the direction in which the camera is facing with respect to the vehicle. The apparatus of the present invention generates an artificial "crosshair" on his television viewing screen representing a selected reference axis of the vehicle. This not only reduces directional disorientation of the operator but also gives him a line of sight, independent of camera direction, which he can use to establish the azimuth of subsea features with respect to the vehicle's compass.

Abstract: An apparatus and method useful in offshore well drilling operations for cleaning the annular space between mudline suspension risers during and after cementing operations to assure that riser backout may be accomplished if a temporary abandonment of a well is to take place. A two-section drive pipe having a quick stab connector between the upper and lower sections of the pipe is provided with ports around the periphery of the lower section and above the mudline. Circulation of fluid down high pressure hoses connected to these ports and up the annulus between the drive pipe and well conductor string within the drive pipe is established using rig pumps located on the deck of the rig. Simultaneously, cement slurry is pumped down the well conductor string to the bottom of the well and up the annulus between the drive pipe and well conductor string.

Abstract: A method of reinforcing a hollow underwater member of an offshore platform which includes drilling and tapping holes at substantially opposite ends of the member, injecting air into the member to determine leak holes, cleaning the outside of the member near the holes, patching the holes on the outside of the member, and injecting grout into the patched member.

Abstract: An apparatus for taking a sample of formation fluid and obtaining temperature and pressure data when the apparatus is lowered into a well casing or pipe string, said apparatus comprising: a sampling device; a gun perforator; two packers, one positioned above and the other positioned below the sampling device; and valves carried by the sampling device.

Abstract: A method and apparatus for abandoning an offshore oil or gas well drilled into the ocean floor having a plurality of concentric strings of pipe having throughbores and spaced to form an annular space between adjacent pipe strings. The invention includes perforating the pipe string with an explosive charge of a size, composition, and velocity so as to only penetrate one pipe string without damaging or penetrating any other pipe string in the well.

Abstract: An apparatus and method for connecting a fluid conduit carried by an ROV to a fluid conduit of a subsea equipment assembly, such as a hydraulically-actuated device, in a non-binding manner. The apparatus includes a vacuum-locking device, such as a hydraulically-actuatable suction lock assembly, which is selectively actuatable to lock or unlock the apparatus with respect to the device of the assembly.

Abstract: A manipulator apparatus carried by a remotely operated vehicle is provided with a suction device capable of gripping underwater objects. The suction portion of the manipulator apparatus utilizes suction chambers isolated from the body of water. When fluid is removed from the suction chambers an appropriately shaped moveable wall moves inwardly thereby forming a suction cavity between the suction device and the object to be moved.The moveable wall may take the form of a rubber-like flexible membrane wall or a piston moveable within the suction portion of the manipulator apparatus.

Abstract: A manipulator apparatus carried by a remotely operated vehicle is provided with a suction device having a flexible membrane wall capable of gripping underwater objects. The suction portion of the manipulator apparatus utilizes expansion chambers isolated from the body of water in combination with the flexible membrane wall which when expanded outward contacts and forms a suction cavity between the manipulator object and the object to be manipulated.

Abstract: A method and apparatus for positioning drilling equipment modules on an offshore platform apparatus which are removeably connected to the platform and adapted to contain equipment associated with the drilling of wells. A major portion of the equipment is secured to and within the modules and is simultaneously removeable with the modules as a unit when drilling operations on the platform apparatus have been completed. The drilling equipment modules are transported to a second location which may be either a jacket positioned on the ocean floor or a storage yard for future use of the modules on another platform. Alternatively, production equipment modules containing previously-installed equipment associated with the production of well fluids and being of a size and arrangement to be interchangeable with drilling equipment modules are subsequently lowered onto the platform apparatus next to the wellhead equipment modules after drilling operations on the platform apparatus have been completed.

Abstract: A method and apparatus is set forth in the present invention for supporting the weight of a marine riser by use of a passive tensioning system which utilizes a buoyant member located upon the upper end of the riser. The member has a vertical slot defined through its side such that the riser may access the member from a lateral direction. Such lateral access of the riser to the member allows these buoyant members to be changed from beneath the riser when maintenance and/or inspection is required on a particular member.Since the riser need only to move laterally to access any member, and the riser may be temporarily supported at the surface by other means, the lower end of the riser does not need to be disconnected from subsea equipment when maintenance and/or inspection operations are required on a buoyant member. Well operations do not need to be interrupted, therefore, during buoyant member maintenance operations.

Abstract: An apparatus for perforating the casing wall of a well and producing the well. The apparatus makes use of a dual flow connector having two downwardly-directed ports and carried by a pipe string which is in fluid communication with the upper end thereof. A gun perforator is removably connected to the connector and depends therefrom for closing one port of the connector while a screen is secured to the connector and depends therefrom for closing the other port of the connector.

Abstract: The present invention is directed to a pressurized fluid accumulator adapted to be connected to a subsea valve actuator on a drilling wellhead assembly, prior to lowering the combined assembly to the ocean floor.The apparatus of the present invention consists of a pressure compensated piston located in a first hydraulic cylinder. Movement of this piston causes pressurized hydraulic fluid to be delivered in sufficient volume to activate a subsea hydraulically-activated valve.The first piston is connected to and driven by a second piston contained in a second hydraulic cylinder. Charging and accumulation of pressurized hydraulic fluid in the first cylinder causes a nearly absolute vacuum to be developed under the second piston. The pressure differential between this vacuum and the prevailing sea pressure is used to move the first piston during delivery of the hydraulic fluid to the actuator of the hydraulically activated valve.

Abstract: An oil storage barge having a concave bottom is adapted to be anchored over a subsea well or pipeline that is leaking oil. Flexible skirts extend to the ocean floor, and oil that is trapped under the barge may be stored in the barge or then transferred to another vessel.

Abstract: Method and apparatus for use in a floating vessel subjected to wave action, used to determine the proper vessel heading so that the longitudinal axis of the vessel will be positioned parallel to the direction of oncoming waves, thereby reducing the risk of capsizing of the vessel. The apparatus comprises a mass elastically suspended from a portion of the vessel structure. Observation of the direction of rotation of the mass allows the helmsman to determine what direction to steer the vessel so that the vessel remains headed into the waves.

Abstract: An improved floodwater for oil recovery comprises seawater which is free of undesirable proportions of bacteria, solids and oxygen, has a pH at least near, but not more than, about 9.5, and contains a minor amount of ammonium and nitrite ions and, optionally, surfactant, effective for increasing its capability of displacing oil.

Abstract: A method and apparatus are described for the installation and removal of a ring gasket from a ring gasket retainer assembly which forms a part of an underwater wellhead connection. A buoyant ring gasket installation tool, tethered to an underwater vehicle, carries the gasket to the wellhead connection. Due to the buoyancy of the installation tool it floats above the underwater vehicle. By proper placement of the tool beneath an opening defined upwardly through the wellhead connection the tool may float the ring gasket upwardly through the opening and position the ring gasket properly with respect to the ring gasket retainer assembly, which may then be actuated to retain the gasket within the underwater wellhead connection.

Abstract: A method and apparatus are described for the installation and removal of a ring gasket from an underwater wellhead connection. The ring gasket is carried by a ring gasket installation tool from the surface to the underwater wellhead connection by a self-propelled underwater vehicle. Final placement of the ring gasket may be accomplished by selective manipulation of the ring gasket installation tool by the underwater vehicle or by a cable attached to the tool.

Abstract: A hydraulic connection apparatus for use by divers or an underwater vehicle is disclosed which allows pressurized hydraulic fluid to be supplied to hydraulically-actuated devices carried upon subsea equipment. A pressurized fluid source carried by the underwater vehicle is placed in fluid communication with the hydraulically-actuated devices by the connection apparatus. The connection apparatus comprises a buoyant device that is allowed to float upwardly into a receptacle carried by a portion of the subsea equipment. Co-operating hydraulic connection elements carried by the buoyant device and the receptacle provide a pressure tight seal between the device and the receptacle. Pressurized hydraulic fluid then flows from the buoyant device and through the receptacle to the hydraulically-actuated devices carried upon the subsea equipment.

Abstract: An anchored submerged marine structure commonly referred to as a well template is located at the bottom of a body of water and used in the directional drilling of underwater wells. The well template carries curved well conductors, each conductor capable of deviating well drilling equipment passed through the conductor so that each well may reach reservoirs located a further distance away from the template. The template's upper surface is formed to aid in the installation of the well conductor through the template.