Abstract: Catenary hoses are installed individually between a floating production platform and a submerged riser buoy. During installation the hose end to be installed on the submerged riser buoy is linked with a remotely controlled handling tool which is lowered onto the buoy and which subsequently pulls an end of the hose into a hose receptor on the buoy. The hose is similarly connected to the platform by use of another remotely controlled handling tool.

Abstract: Tubular marine riser sections are formed by a wound or woven filament-resin matrix tubular body having a modulus of elasticity in tension of about 27,000,000 psi or greater utilizing carbon or boron for the filament material. The riser sections may be provided with end couplings secured to the tubular body for forming a riser system wherein the tensile strength or load bearing capacity of each section and its hydrostatic collapse resistance may be selectively determined by its position in the riser system. The riser sections may be provided with cylindrical collapse resisting ribs defining spaced buoyancy chambers filled with low density material contained by an outer shell formed of a glass or aramid fiber-resin matrix composite having a lower modulus of elasticity in tension than the primary load bearing tubular member. An inner abrasion and fluid impervious sleeve is disposed within the tubular body but is not bonded thereto.

Abstract: A buoyancy system for a tension leg platform tether 10 or other element extending a significant vertical distance through a body of water. A series of bulkheads 25 divide the interior of the tether 10 into individual buoyancy cells 31. A central access tube 32 extends along the central axis of the tether 10, passing through a sealed penetration in each bulkhead 25. A series of cascade conduits 42 are provided the lower portion of each buoyancy cell 31 in fluid communication with the buoyancy cell 31 immediately above. A tool 82 is provided for injecting air into a selected buoyancy cell 31. As air is injected, water exists through the central access tube 32 until the buoyancy cell 32 is emptied of water, at which point air passes through the cascade conduit 42 into the adjacent upper buoyancy cell. The tool 82 can also be used to selectively flood individual buoyancy cells 31.

Abstract: A pressure balanced tether buoyancy system 12 useful for reducing the load imposed on a tension leg offshore platform 24 by the tethers 10 securing it to the ocean bottom. The tether 10 has tubular tether walls 11 defining a central cavity 15 isolated from the surrounding seawater. A series of bulkheads 25 extend laterally across the interior of the tether 10, dividing it into a series of individual buoyancy cells 31. Each bulkhead 25 is provided with a differential pressure valve 34 establishing selective fluid communication between the two buoyancy cells 31 separated by the bulkhead 25. Preferably, each differential pressure valve 34 is adapted to open in response to a differential pressure across the bulkhead 25 exceeding the differential hydrostatic existing across the vertical distance separating adjacent bulkheads 25. This permits a pressure gradient to be established interior to the tether 10 approximating that of the seawater in which the tether 10 is located.

Abstract: A marine riser safety valve is disclosed which, when placed in series with a deep water marine riser string, prevents collapse of riser pipe when inadvertent gas influx replaces the drilling fluid column. A cylindrical body is provided having a depression formed therein with at least one diaphragm port from the central bore of the body through the wall of the depression. A valve port is provided axially from the depression. A cylindrical member including a cylindrical diaphragm and a valve sleeve are joined end-to-end. The cylindrical member is disposed about the exterior of the body with the elastomeric diaphragm covering the depression and the valve sleeve covering the valve port. When a differential pressure develops across the wall of the diaphragm of a predetermined threshold, the diaphragm constricts into the body depression and moves the valve sleeve axially, opening the valve port to permit sea water influx.

Abstract: A device is provided for lightening an undersea production riser having a central tube surrounded by peripheral stringers. Foamed resin collars are stacked on the central tube. They have a central opening for passing the central tube therethrough and channels disposed concentrically for passing the peripheral lines therethrough. The wall of the central channel is lined with a reinforced material and it has a conical shape for fitting the part of the lining projecting from the end of the collar into the central channel of the adjacent collar. Centering of the collars is provided by two half shells made from metal sheet bearing on the central tube and on the wall of the central channel.

Abstract: Production from a subsea wellhead to a floating production facility may be realized with the use of a substantially neutrally buoyant flexible production riser which includes biasing means for shaping the riser in an oriented broad arc. The broad arc configuration permits the use of wireline well service tools through the riser system.

Abstract: An apparatus and method for transferring a fluid, such as oil, between a fluid conveying line and a ship. The apparatus includes a transfer unit anchored at the bottom of the sea and attached to the fluid conveying line, and a coupling device which is brought into the ship together with the transfer unit so that connections can be made to the coupling device at a weather resistant location within the ship. Fluid is transferred between the fluid conveying line and the ship via the transfer unit and coupling device.

Abstract: A deep draft oil well drilling platform having a large hollow body is shaped, designed, and ballasted to have a substantial portion thereof submerged under the surface of the ocean a sufficient distance to be substantially unaffected by surface waves and weather. The body contains an oil well drilling rig and all supplies, equipment, and materials normally necessary to drill an oil well, with such rig, equipment, and the like positioned well below the surface of the water.

Abstract: A buoyancy assembly for mounting on a pipe such as a marine riser having service lines, such as choke and kill lines extending therealong, the assembly including discontinuous clamping band members shaped to encompass the pipe and having brackets disposed to join the ends of the band members and tighten their grip on the pipe when bolts joining the band members to the brackets are tightened, the brackets having opposed walls extending outwardly therefrom and supporting cradles to receive and clamp the service lines, and the assembly including arcuate flotation modules of syntactic foam shaped to lie against the riser pipe and removably occupy the spaces between the service lines and form a generally cylindrical outer contour, the modules being held in place against the pipe by tensioning belts each comprising a strap anchored to the adjacent brackets and being tensioned by a tension bar gripping an end of a strap and bolted by tensioning bolts to a link which is pivotally connected to the adjacent bracket.

Abstract: The invention relates to an elongated buoyant arm mounted below the water line of a drilling vessel. The arm is of variable buoyancy and is attached to a drilling riser extending between the drilling vessel and the sea bottom to maintain tension on the riser.

Abstract: A method and apparatus is disclosed for a marine production riser system. The system includes a series of housing sections linked to form a vertical riser column. The integrity of the riser column is maintained by guidelines extending in tension between a subsea installation and a surface vessel. Each housing section has a plurality of passages extending therethrough. Fluid-handling lines retained within the passages are isolated from current forces by the housing sections. To utilize the invention, the nonbuoyant housing sections are positioned between the guidelines, are loosely banded to the guidelines, and are lowered to form the riser column. Fluid-handling lines are threaded through axially-coinciding passages located in each housing section and continuous throughout the riser column. The fluid-handling lines are connected at the sea floor and surface vessel to complete a fluid carrying system.

Abstract: A riser connects a stationary submerged structure such as an offshore oil well head with a caisson of positive buoyancy anchored to the water bottom. The riser comprises continuous guide means extending from the caisson to a certain distance above the submerged structure and housing, with a clearance from the bottom transfer lines connecting said structure to the caisson, and holding means joining together said guide means and at least one anchoring line of the caisson.

Abstract: A marine riser system for a petroleum production platform or other structure includes a central support column extending from a subsea manifold vertically upward to a connection with a riser tensioner assembly mounted on a floating platform. The central support column includes one or more vertically spaced levels of radially extending arms which are pivotally connected to the central support column and are held in generally horizontally projecting positions by individual hydraulic cylinder actuators. Each of the support arms is adapted to be connected to a riser conduit and to apply a predetermined upward tension to the conduit whereby the entire riser system is maintained under a predetermined tension with respect to the support column and to permit motion of the platform structure under varying sea conditions. The riser system includes a plurality of vertically spaced apart guide funnels supported on sets of foldable arms.

Abstract: A buoyancy system for large scale underwater risers is provided, comprising a plurality of canisters. Each of the canisters extends partially around the circumference of a riser--usually, two canisters and the support structure surround a riser--and a plurality of canisters is associated with each riser section. Air is injected into the lowermost canister or canisters, at a pressure sufficient to displace the contained water within the canister; and when the water level within a canister is lowered sufficiently that a port in a cross connected tube is uncovered, the compressed air enters the tube and travels upwardly to the next canister above, where the unwatering sequence is repeated. Because very great depth can be accommodated--3,000 meters or more--provision is made for reflooding the canisters in the event of an emergency. Additionally, because of pneumatic considerations, different configurations of cross tube are provided for installation in the canisters at varying depths.

Abstract: A marine compliant riser system is provided for attaching a flexible flowline to a buoyed conduit riser section. The improved system includes a releasable yoke assembly for receiving flexible flowline with a means for holding flexible flowline termination.Quick-disconnect yoke attachment means support and lock the yoke assembly onto horizontal buoy-mounted support means. A fail-safe release means is provided for pulling an unreleased yoke attachment away from the support arm in the event of an opposite end release.The system is particularly adapted for emergency disconnect of a subsea wellhead or production gathering system from a floating vessel.

Abstract: An improved facility, for the drilling and production of hydrocarbon deposits located in a deep sea bed, includes a central structural column having a bottom end secured to a submarine base mounted on the sea bed and a top end secured to a subsea buoy. A plurality of peripheral tubular conduits are located around the central structural column and connected thereto by a guide device which permits the peripheral tubular amendments to move relative thereto and positions the peripheral tubular conduits in parallel with the central structural column.

Abstract: A marine compliant riser system connects a subsea hydrocarbon source to a floating surface facility through a lower multi-conduit riser section to a submerged buoy section located below a turbulent water zone and a flexible flowline. Fluid connection is established between corresponding lower riser conduits and the surface facility by a plurality of flexible conduits. Connection assembly means connects individual upwardly-directed flexible conduits with corresponding upwardly-directed lower riser conduits in fluid flow relationship. A yoke assembly mounted on the buoy section, includes beam means for holding a plurality of spaced apart flexible conduit terminations, with each of the flexible conduits being connected individually in catenary arrangement between the yoke assembly and the surface facility. The flexible conduits are attached to the surface facility in compact, non-linear array and to the yoke assembly in substantially linear array.

Abstract: A guide for use in connecting a riser pipe to a subsea riser base comprises a guide post and an expanding mandrel actuable by hydraulic pressure applied through a cable having hydraulic hoses in its core to lock the mandrel in a subsea riser base. The guide post is provided with buoyancy means to reduce its effective weight in water to enable it to be manipulated and manoeuvred by a remote controlled vehicle or diver.

Abstract: A flexible pipe comprising a first set of stress bearing elements extending substantially the whole length of the pipe, for accommodating maximum hoop stress resulting from flow of pressurized fluid through the pipe, and a second set of stress bearing elements extending substantially the whole length of the pipe for accommodating longitudinal stress resulting from a flow of pressurized fluid through the pipe.

Abstract: A piping or conduit system in which conduits to receive flow lines or flexible pipe can be connected end to end to form a riser assembly, and thereafter, the flow lines can be inserted through individual conduits of the assembly. The section contains a low density foam to impart essentially zero negative and positive buoyancy, and the foam is filled into areas surrounding the individual conduits of the sections. Suitable reinforcing and tension stress resisting elements are provided so that each section is essentially self sustaining.

Abstract: A method for drilling wellbores from an offshore platform to penetrate a subterranean formation using a combination of surface drilling techniques and subsea drilling techniques to achieve an improved effectiveness by avoiding the necessity for large conduits communicating the ocean floor and the offshore platform.

Abstract: System for the remote control, the maintenance or the fluid injection for a submerged satellite well head comprising a platform equipped with equipment usable for the remote control, maintenance or fluid injection for the well head and located substantially perpendicular to the well head, at least one pipeline connecting the platform to the well head, a control device located on the well head or in the immediate vicinity of the latter, and at least one remote control line connecting the platform to the remote control device, wherein the platform is on the surface and the pipeline is connected to the platform by a connector and to the well head by a spherical articulation equipped with a flexible joint.

Abstract: An assembly for mooring a submarine conduit to a pipeline or a fixed structure such as a storage tank. The assembly comprises a mooring head, a fixed mooring frame and a movable mooring arm. The mooring head is fixed to the end of the conduit to be connected. The mooring arm is mounted on the fixed mooring frame and is effective to receive the mooring head. The mooring arm is displaceable in a horizontal plane on the mooring frame. An end of the pipeline to which the conduit is to be connected is located on the rotational axis of the mooring arm. A junction pipe connects the end of the conduit to the end of the fixed pipeline. A cable attached to the mooring head passes through the mooring arm and is attached to a winch on the surface for drawing the mooring head into engagement with the mooring arm.

Abstract: An offshore marine structure for drilling wells into the ocean floor including a floating vessel which carries the necessary drilling equipment. A riser which extends from the vessel to a well head at the ocean floor, encloses a drill string and permits circulation of the drilling mud and fluids. The riser is comprised of at least two detachably connectable segments, one of which can be moved with the floating vessel, while the other remains buoyantly in place until such time as the two segments are reconnected.

Abstract: A method for handling pipe for drilling and well operations. The pieces of pipe to be used are connected together in a string above the surface of the medium, such as the earth or the seabed, into which they will be inserted. The pieces are connected so that the string lies in a substantially horizontal plane prior to insertion. The resulting string is then moved by a prime mover which moves in the horizontal plane. The string is moved into the medium at an angle near the horizontal. By employing suitable supports pre-assembled long length strings can be tested, inserted, and manipulated. Similarly, a complete string or large section thereof can be removed from a point of insertion such as a well bore without the necessity of disconnecting each separate member from the string. This method also accommodates the handling of single pieces of pipe.

Abstract: Diclosed is a connecting assembly for communicating between a first location and a second location lower than the first location, with the two locations separated by a fluid body. A first tube extending between the two locations generally encloses a second tube, and the annular area between adjacent surfaces of the two tubes is sealed toward the second location. The buoyancy of the assembly is selectively controlled by selectively controlling the quantity and density of fluid in the area between the tubes. In an embodiment shown, a marine drilling facility is joined to an underwater well site by a riser with a liner set and sealed therein, and gas-lift pumping is used in controlling buoyancy. In a method, a riser is set between an underwater well site and a marine well operating facility. A first segment of the well may be drilled through the riser. Casing is cemented in the well, and a liner is sealed at its bottom end to the riser.

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 marine drilling riser is provided with a plurality of buoyancy cans having fail safe dump valves operative to vent compressed gas from the buoyancy cans and thereby cause rapid loss of buoyancy.

Abstract: A novel casing torque hanger means for supporting the upper end of a string of casing from the upper end of a riser pipe which is supported by a floating vessel such as a Vertically Moored Platform. It includes a cylindrical member having a torque resistant spool below a casing hanger bowl. The casing string to be supported is provided with a casinghead mandrel at its upper end for engaging said torque resistant spool.