Abstract: A flexible connection apparatus is disclosed for accommodating relative movement between a compliant offshore structure and the sea floor. The compliant offshore structure supports a fluid-carrying system which conveys fluids between the sea floor and the structure. The fluid-carrying system includes a riser and a helical flowline. The lower end of the riser is connected to the sea floor. The first end of the helical flowline is connected to the upper end of the riser and the second end of the helical flowline is connected to the structure. As the compliant offshore structure is displaced from its vertical equilibrium position due to loading forces induced by wind, waves, and ocean currents, the helical flowline elastically flexes through torsional deflection to accommodate such movement. In a preferred embodiment of the apparatus, a wellhead is connected between the riser and the helical flowline such that the centerline of the helical flowline is substantially vertical.

Abstract: The invention pertains to motion compensators and compensator systems, particularly adapted for disposition between an offshore platform and a riser or conductor pipe. Each compensator includes a cylinder with a piston reciprocably mounted therein, the piston rod protruding from one end of the cylinder. That one end of the cylinder is directed toward and connected to either the platform or the riser pipe, with its other end being directed toward the other of those two bodies. Link rods are independently connected to the protruding part of the piston rod and extend longitudinally toward said other end of the cylinder for connection to said other of the two bodies. A compressible fluid is disposed between the piston and said other end of the cylinder to resist movement of the piston toward said other end and thereby resist movement of the platform and the riser pipe away from each other.

Abstract: A buoyant riser system for use in a deep water offshore drilling environment is anchored by a system of compliant guys below the active weather zone of the sea. A controllably buoyant housing of the system is submerged at a depth that is readily accessible to divers and includes a blow-out preventer (BOP) from which a suspended sub-riser leads to a well bore to which the sub-riser is coupled. Above the housing, a riser suspended from a floating drill rig is coupled to the BOP thereby communicating the drill rig directly with the well bore for drilling and well completion operations.

Abstract: This invention involves a modification of the prior art subsea drilling system in which a carousel is positioned on a central post surrounded by a coaxial circular array of well slots and is adapted to be rotated by drill pipe through conventional means, from the floating platform. The carousel utilizes a fixed support platform spaced from the axis of rotation a distance equal to the radius of the array of well slots. The platform has its own well slot and a bearing concentric with the well slot. A well slot platform, or support post platform, is journaled in this bearing and supports a plurality of guide posts on a circle centered at the axis of the well slot. The support posts support cables hanging from the drilling vessel, which are used to guide the drill bit down from the surface to the carousel well slot. The carousel is adapted to revolve while supported by circular rails concentric with the central guide post.

Abstract: A subsea template is installed by a method which includes the steps of securing the template in a position beneath the deck of a semi-submersible drilling vessel, moving the semi-submersible drilling vessel to an appropriate offshore site and subsequently lowering the template from the semi-submersible to the sea bed. In addition, at least three anchorage templates may be loaded onto one or both of the pontoons of the semi-submersible drilling vessel at its original position and are subsequently lowered from the pontoons to their respective locations on the sea bed after the semi-submersible has moved to the offshore site.

Abstract: An improved system for anchoring a floating vessel which is anchored only by parallel and essentially vertical conduits. The anchoring load is carried by units of concentric pipes including an outer riser pipe and inner strings of casing. Drilling wells and/or production of oil and gas or like operations are conducted through these casings. The tension of the inner casing string is transmitted to the floating vessel through the upper end of the outer riser pipe. The system prevents excessive buildup of stresses in the upper end of the inner casing due to the bending caused by excursions caused by the waves, the wind and the current.

Abstract: A method and apparatus for remotely establishing an underwater well under conditions of great water depth including a drilling guide structure located on the floor of the body of water; a single handling and guiding string extending upwardly from the drilling guide structure and maintained in tension by an elongated buoy; a series of drilling guide arm units, flowline guide arm units and wellhead guide arm units to be lowered down the string, oriented relative to desired well positions and then retrieved once the wells have been drilled and the wellheads and flowlines secured in place; and a production gathering assembly to be lowered down the string, oriented relative to the wellheads and flowlines, and then coupled to these wellheads and flowlines.

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 support and connecting system for a multiline riser which joins a floating platform to a subsea well is shown including a support housing which mounts upon the floating platform for disconnectably mounting a termination housing to which a plurality of lines are connected. The termination housing is also connected to the platform by a cable tensioning system which adjusts the tension within its connecting cables. A termination head fits within the termination housing and connects, through a termination riser adapter, to the uppermost riser of a riser run that communicates between the platform and the subsea well. The arrangement permits the riser run to engage the floating platform during assembly and recovery of the risers. In the event of a storm or other need for emergency disconnection, the riser run may be withdrawn from the termination housing and hung off or recoved without disconnecting the lines.

Abstract: A production riser assembly for producing oil to a floating platform includes a central riser (22) and a plurality of production risers (34) annularly spaced around the central riser. The central riser has a flexible joint (26) with a hydraulic connector (82) therebelow. Each production riser has a flexible hose (47) at its lower end which is connectable to flowline subs (46) located in spaced relation from the central riser connector. Hydraulically operated connectors (45) are located at the bottom end of each flexible pipe, and each riser is independently tensioned.

Abstract: This relates to drilling in water from a platform or vessel using a riser pipe. An inverted funnel skirt or cone is placed over slots cut in the wall of a riser pipe a short distance above its lower end. The apex end of the cone is welded to the riser pipe above the slots and drill cuttings pass through the slots and fall to the seafloor. Another embodiment includes an "L" shaped diverter flowline welded to the periphery of each hole in the riser pipe with one leg of the "L" extending a short distance below the hole.

Abstract: A drilling riser between a subsea wellhead and a floating platform has a slip joint in its upper end. A chamber is formed within the slip joint and supplied fluid pressure to develop a tensioning force on the upper end of the riser as the floating platform cycles vertically under the influence of heave and tidal forces.

Abstract: A well support system is provided including a tubular riser connecting a subsea well to a surface platform. A flexible elastomeric mounting column is providing for supporting the tubular riser from the surface platform. A first support structure supports the lower end of the flexible mounting column from the surface platform. A second support structure supports the tubular riser from an upper end of the flexible mounting column, so that a weight of the tubular riser is supported in compression by the flexible mounting column. The flexible mounting column provides a substantially constant supporting force over a range of compressed displacement corresponding to a range of expected relative movement between the riser and the platform. The flexible mounting column is preloaded in compression to within its constant force output range.

Abstract: Method and apparatus are described to reduce the tension required on a riser pipe used in offshore drilling between a floating vessel and a subsea wellhead. Heavy drilling fluid is circulated down a drill pipe and up the annulus between the drill pipe and the borehole wall to a point just above a subsea wellhead. From this point, a separate drilling fluid return conduit extends to the floating vessel. Means are provided to maintain a constant level of an interface between the heavy returning drilling fluid and the lightweight fluid which can be confined within the riser pipe.

Abstract: An apparatus and method for offshore well operations in which a tension leg platform, a multiwell template means, and a riser system are arranged to provide: effective use of the advantages of a tension leg platform, a simplified riser design, and a novel template design which minimizes orientation problems of well equipment at the sea floor. A multiwell template means in which the template frame includes a latch ring member for each well to cooperate with a retrievable guide line base frame having releasable latch members whereby angular or radial orientation of the guide line base frame is not required with respect to the template frame. A retrievable guide line base frame having alignment means thereon and guide posts with guide lines attached thereto.

Abstract: A method and apparatus is disclosed for determining the flow rate of drilling fluid flowing from a subaqueous well. The invention may also be used to determine the presence of an abnormal drilling condition during heaving motion of an offshore vessel from which the drilling operation is conducted. The invention measures the volume of fluid passing predetermined locations in the drilling system at particular points in time so as to eliminate the influence that the expansion and contraction of a telescoping section has on the total volume of drilling fluid within the system.

Abstract: Apparatus is provided for connecting to a floating structure the upper end of a pipe assembly disposed substantially vertically in an ocean and the like. The pipe can be an upwelling pipe in an ocean thermal energy conversion installation. Gimbal apparatus are coupled between the pipe and the structure concentrically about the pipe. The gimbal apparatus define two orthogonal gimbal axes about which the pipe can move relative to the structure. The gimbal apparatus carry essentially all of the load between the pipe and the structure. Ball joint apparatus are coupled between the upper end of the pipe and the structure to define the boundaries of a path of fluid flow between the pipe and the structure. The ball joint apparatus includes an element associated with the pipe and an element associated with the structure. The ball joint apparatus is centered in the intersection of the gimbal axes.

Abstract: A drilling sub-base assembly for use from an offshore drilling vessel wherein drilling operations are conducted through a moon pool and at a drilling site where the bottom soil conditions are soft or unstable such that a conventional drilling sub-base dimensioned to pass through the moon pool would not provide an adequate foundational base for the carrying-on of drilling operations. The drilling sub-base assembly includes a main section dimensioned for ease of passage through the moon pool of the vessel and secondary sections pivotally affixed to the main section on at least two opposite sides thereof to be in a substantially vertical position relative to the main section when the drilling sub-base assembly is located in the moon pool and to be in a substantially horizontal position relative to the main section when the drilling sub-base assembly is positioned on the underwater bottom.

Abstract: A downhole riser assembly includes a tubular casing embedded in the ocean floor, said casing having a constant internal diameter and an upper end extending above said ocean floor. A tubular riser pipe is disposed in the casing and has an upper end connected to a floating vessel which may be a tension leg platform. The casing and riser are rigidly connected at a considerable distance below the ocean floor, said distance being on the order of 100 feet. When the floating structure is laterally displaced from a position directly above the casing, the riser pipe contacts the upper end of the casing. This contact limits the lateral deflection of the riser at the ocean floor and thereby limits the stresses in the riser.

Abstract: A novel way of maintaining a riser in the approximate center of a moon pool of a drilling barge operating in a shallow water. A single hydropneumatic cylinder is used to support the riser from the barge laterally at four points using a series of cables, sheaves, and a load cell.

Abstract: Drilling operations are run in a riser pipe, e.g., 20 inches in diameter, which extends from a ship to an anchored wellhead assembly on the ocean floor. Various strings of casing for lining the borehole wall are run down through the interior of the riser pipe. The first string of casing run is of relatively large diameter, e.g., 9-5/8 inches in diameter. Each successive string of casing which is run in this particular well is progressively smaller in diameter. Ideally, one would need a new and smaller riser in order to maintain about the same drilling fluid upward velocity. A high upward fluid velocity can be maintained by placing sleeve inserts in the annulus space between the drill string and the riser pipe interior wall. Additional strings of sleeves may be run inside the original sleeve to obtain a multiple effective sizing of the riser pipe.

Abstract: A simplified subsea production wellhead which permits (1) pump-down tool operations for routine well maintenance and (2) vertical entry to the wellbore for major workover operations. The wellhead can be lowered by the production pipeline to a wellhead site on the sea floor. The production wellhead includes a diverter spool for releasably attaching to a subsea well. Pump-down tools can be used with the diverter spool. If vertical entry of the subsea well is required, the diverter spool can be released, raised and moved horizontally to one side of the subsea well, giving vertical entry. After workover operations, the diverter spool is again moved over the subsea well and reattached.

Abstract: A plurality of wells are clustered around a central riser which is maintained under tension from a floating platform. A plurality of spiders on the riser carry funnels in vertical alignment with the wells. The funnels are sufficiently large to permit the passage of wellhead connectors and master block valves, and the production risers include centralizers which brace the production riser from the funnels through a limited vertical range. Tensioning of the production riser is with a lower force and through a limited range which precludes disengagement of the centralizers from the funnel. Some centralizers are located to facilitate entry and attachment to the wellhead.

Abstract: A self-contained jack up type drilling and production platform structure comprising a flotatable barge-like hull with support legs which can be jacked up and down to lower and raise the hull with respect to the surface of the sea. A removeable drilling module rests on top of the hull and extends over an opening therein between two of the support legs. Production equipment is arranged in the hull and communicates with the opening. Moveable conductor supports extend between the legs of the platform and serve to brace the drill string and production conduit conductors.

Abstract: This relates to drilling in water from a platform or vessel using a riser pipe. An inverted funnel skirt or cone is placed over slots cut in the wall of a riser pipe a short distance above its lower end. The apex end of the cone is welded to the riser pipe above the slots and drill cuttings pass through the slots and fall to the seafloor. Another embodiment includes an "L" shaped diverter flowline welded to the periphery of each hole in the riser pipe with one leg of the "L" extending a short distance below the hole.

Abstract: A modular underwater support platform having interconnecting elements is lowered into position by a conductor pipe which in turn is connected to and supported from a drill pipe. Releasable hydraulic connections connect the platform to the conductor pipe and connect the conductor pipe to the drill pipe. After the hydraulic connection between the platform and the conductor pipe is released, the drill pipe drills a hole in the subsea floor for receiving the conductor pipe. The conductor pipe is positioned in the hole, and locked to the platform for supporting the platform. A base may be connected to the bottom of the support platform which includes hydraulic cylinder and piston assemblies for leveling the support platform. Hydraulic control lines are positioned on the support platform and adapted to be in communication with the hydraulic connections when the conductor pipe is locked to the platform for hydraulically releasing the connections allowing the removal of the drill 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 maneuverable tool means for continuously maneuvering and controlling a pipe string end as it is lowered for engagement with a selected well part at the sea floor. The tool means comprises a body member attachable to the pipe string end, the body member carrying laterally directed thrust means; fluid pressure means in communication with the thrust means to impart thrust forces to the pipe string end and a remote control system for the fluid pressure means. The tool means also includes TV and sonar systems to sense the presence of adjacent objects as the pipe string end is lowered and to identify a well part with which the tool is to be cooperably associated. The tool means is provided with a lock means for temporarily retaining the tool means in a selected position in a guide funnel on a well template to facilitate installation of a guide line base means on the template.

Abstract: A marine structure for guiding a plurality of ducts from deeper to higher submerged devices such as an oil well at the sea bottom and a production or storage station, respectively. The apparatus provided in accordance with the present invention compensates for relative movement between the higher and lower device by providing a rigid column having pivots at both the higher and lower devices. A plurality of ducts are attached to the rigid column and are connected to a corresponding plurality of higher ducts by similar pivot means. The higher ducts are arranged at the higher device so as to allow for relative longitudinal movement of the higher ducts with respect to the higher device.

Abstract: A method and apparatus are disclosed for leveling a relatively massive template structure which is positionable on the ocean bottom in proximity to one or more sites of subterranean wells. Since the template is primarily utilized to mount or guide later applied drilling, completion or production equipment, it is essential that the template be positioned on its fixing piles in a precise horizontally level position. Accordingly, a plurality of sleeves are secured to the template which respectively loosely encircle the hollow fixing piles. Hydraulically operated clamp means are provided to lock the encircling sleeves at any selected vertical position to a respective fixing pile. A hydraulic elevating mechanism is lowered into the top open end of at least one such fixing pile and utilized to effect the lifting of the sleeve and adjacent portion of the template to which the sleeve is secured to a height approximating the desired level position.

Abstract: Method and apparatus for controlling down hole pressure during an offshore drilling operation is disclosed. The method and apparatus are particularly useful for drilling in deep water from an offshore surface facility which includes a drilling vessel stationed above an ocean floor drilling site in which well head equipment is embedded. A marine riser is connected to the well head equipment and extends to the drilling vessel. A drill string enclosed within the riser extends from the drilling vessel through the well head equipment and into a borehole beneath the ocean floor. Choke and kill conduit lines are connected in fluid communication with the borehole and extend from the well head equipment to the drilling vessel. According to the invention, a subsea choke valve is connected in fluid communication with the choke conduit line and with the interior of the riser whereby fluid or gas may be discharged at a controlled rate from the choke line directly into the riser annulus.

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 riser column particularly for use in deep water comprises a central tube connectable by its lower end to a submerged installation, for example a well, and including means permitting the central tube to oscillate relative to the installation, and connected at its upper end to a suspension table associated with a surface support, for example a platform, and bearing support means intermediate its ends at a level below that at which waves are effective, and a plurality of satellite tubes arranged around the central tube, each satellite tube having a bottom part extending from the intermediate support means to the submerged installation and a removable top part extending from the support means to suspension table and releasably connected to the bottom part thereof for withdrawal from the column following disconnection of the column from the installation, for example, in the event of a storm.

Abstract: A subsea station or installation in which one or more rigid elongated base template frames are adapted to be permanently positioned on a sea floor. Each base template frame includes a plurality of framed receptor openings, each adapted to receive a module guide base for aligning and releasably connecting thereto module unitary assemblies, each of which carries selected equipment in a protected manner. Extending along each side of the base frame are elongated side structures releasably connected to the base frame and recoverable for maintenance and service, each side structure extending outboardly of the sides of the base frame and being adapted to carry fluid conducting lines, power lines, and a rail means for guidance of a submarine capsule along the length of the base frame.

Abstract: A subsea production chamber including a vessel having a cylindrical shell with a head secured to each end of said shell, a plurality of tubular members secured vertically through said shell with each end of each of said members being open on the exterior of the shell and positioned to receive subsea guide posts, a flange secured to said shell, a spool for connecting to a production well, said flange being secured to said spool for connecting said production well into said vessel, a hatch opening into said vessel, and a connector extending through said vessel to conduct production flow to external production flow lines.

Abstract: Process for drilling a hole in the earth's crust in which the bottom of the drill hole is frozen in front of or near the drill bit by a cold driling liquid in which liquid particles that have been frozen to solid parts or have been solidified have been taken up whether or not by addition. In this way the bottom of the drill hole is always so hard -- also upon drilling in soft or plastic formations, such as clays, -- that use can be made of diamond drill bits or other drill bits normally used for hard formations, in order that the number of times a drill bit is to be replaced can be strongly reduced. The purpose of adding ice is to make it possible for a sufficient amount of frigories per unit of time to be introduced into the drill hole, so that at greater depths the temperatures at the drill bit are decreased to such a degree that here, too, use can be made of drill bits for hard formations here described.

Abstract: A sub-sea template and moveable guide structure assembly for conducting sub-sea drilling and production operations selectively between a plurality of adjacent sub-sea wells has a sub-sea well template having a plurality of template sections, each of these sections having a plurality of well bore guide means in laterally spaced series relative to the longitudinal extent of the template; tool guide means for guiding a sub-sea well tool into a well bore guide means; carriage means and means for movebly mounting the carriage means to the template, the carriage means moveably mounting the tool guide means on the template for relative movement therebetween.Sonic alignment means associated with the moveable guide structure and a sub-sea well tool are provided for sensing a spatial relationship between the guide structure and the well tool as the well tool is lowered onto the guide structure.

Abstract: Apparatus for drilling a well at a location submerged below a body of water includes a buoyant foundation structure. The foundation structure is floatable on the surface of the body of water and is subject to vertical motion in response to waves and the like. A riser handling and tensioning mechanism is mounted to the foundation structure and is operable for moving a riser pipe along a substantially vertical line from and to the foundation into and out of connection with the submerged location. The riser handling and tensioning mechanism is also operable for applying tension to a riser pipe connected to the submerged location. The handling and tensioning mechanism includes vertically disposed hydraulic rams mounted to the foundation structure. Holding means are releasably engageable with a riser pipe adjacent its upper end and are connected to the rams for movement along the riser line by the rams.

Abstract: A subfloor comprising leg-supported modules and drop in panels adapted to be installed in and around a grid of Christmas trees in the well bay area of a production platform.

Abstract: A sea floor template with vertical well guides or slots is lowered to the sea floor. Guide rails, such as a railroad track, are supported on top of the frame of the template in a path which extends along each well slot. A drilling guidance carousel is lowered to the template. Rollers on the drilling guidance carousel engage guide rails so that the carousel can be moved to each template well slot. Guidelines extend from the drilling guidance carousel to a floating drilling vessel for guiding drilling equipment from the vessels down through the template well slot which is aligned with the carousel well slot. Preferably, the template well slots are arranged in a circle at each corner of a rectangular sea floor template. The guide rails are arranged concentrically with the central axis of the circle of template well slots. Locking means are provided to hold the carousel drilling frame well slot aligned with any selected one of the well slots in the sea floor template.

Abstract: An offshore drilling installation comprising an underwater base spaced from an underwater buoy and in communication therewith by a connecting conduit. The underwater buoy represents the upward extension of the sea bed which serves to support an above-sea platform. The underwater buoy is further secured to the sea bed by mooring lines. Oil containing means is provided in the underwater base.

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.

Abstract: A guidelineless subsea wellhead system includes TV/sonar guidance components which direct operating and/or service equipment into a position adjacent a subsea wellhead. An offset funnel mounted on the wellhead is used to guide a probe, which is mounted on a riser, into alignment with the wellhead. The probe is used to guide the riser and the service equipment into exact alignment with the wellhead so that tasks such as well entry, tree installation, well reentry, tree cap removal, tree cap replacement and downhole wireline operations can be completed without any cable guidelines. The system can also be used with the usual guidelines to increase the speed and accuracy of connecting to the wellhead.

Abstract: A system and method are disclosed which eliminates the use of a riser pipe in underwater drilling operations. The system includes a mud sump connectable to the top of a submerged wellhead and has a bottom with a mud inlet provided therein and an upwardly extending wall cooperating with the bottom to support a quantity of mud, the sump restricting the water to contact with only the upper surface of the mud as the mud passes upwardly through the mud inlet in the bottom. A hose, separate from the drill string, is used to carry mud to the surface of the water. A pumping means is used to pump mud through the hose in response to the quantity of mud supported within the sump to thereby return the mud to the surface of the water without the use of a riser pipe.

Abstract: A scissored sea-floor well template for positioning spacing of subsea wells or piling in the sea floor. Two arms, each having a pontoon template at each end thereof, are pivotally connected. The two arms are rotated about the pivot to a closed position for transportation to the marine site at which they are to be used. Inasmuch as the template is provided with pontoons, it can be towed and does not have to be loaded on a barge although it could be. Upon reaching the well site the arms are opened so that the pontoon templates assume the desired shape. The arms are then locked in this extended position and the scissor well template is then lowered to the ocean floor.

Abstract: A marine riser system for use in deep water drilling operations from a floating vessel is disclosed. The riser system permits detachment of the lower end of the riser from the wellhead enabling the riser to be set aside to a position which is clear of the wellhead. Support means adjacent the wellhead can be used to support and position the riser when it is set aside. Tensioners, support mechanisms and guidance means are provided to move the riser back and forth between the wellhead and support means. In this manner, casing and tools having diameters larger than that of the riser can be inserted into the wellhead without returning the riser to the surface. Drilling operations with large diameter drill bits can also be conducted with the riser in the set aside position.

Abstract: A termination means for a plurality of riser pipes at a floating platform including a termination member for supporting said plurality of riser pipes, said termination member being supported and suspended by constant tension means on said platform. The plurality of riser pipes include a central riser pipe and satellite riser pipes arranged around said central riser pipe. Each of the satellite riser pipes extend through the termination member and are supported from said termination member by fluid pressure actuated tension compensator means which serve to tension each of the riser pipes. The termination means is adapted to both rigid and flexible riser pipes.

Abstract: A universal Cardan joint coupling device for pivotally connecting an off-shore oil-field working articulated column to a base member resting or anchored on the sea bed, wherein the improvement consists in that at least one of the pivot axes of said joint is connected to two supports rigidly connected to said base member and provided on either side of said joint, by means of two lock-bolt means aligned and displaceable along said axis and adapted to cooperate with bolt-clasps or keepers provided in said supports.

Abstract: A heave compensator is disclosed particularly adapted for use in compensating the flow through a riser pipe employed in offshore drilling apparatus for surges and ebbs produced in the flow therein by the rising and falling of the surface platform or vessel in relation to the ocean floor. A telescoping section substantially identical to that incorporated within the riser is carried by the floating platform or vessel at a location remote from the telescoping section of the riser. The compensating telescoping section is connected into the flow pipe on one end and closed at the opposite end. The two telescoping sections are disposed normal to the earth's surface whereby gravity tends to extend the compensating telescoping section. The two lower portions of the respective telescoping sections are interconnected by a flexible cable passing over a sheave carried by the platform or vessel.

Abstract: A sub-sea well head comprising a connector and a christmas tree which is enclosed in a capsule is characterized in that a master valve is contained within a member forming the foot of the christmas tree, the member penetrating and being sealed into the bottom of the capsule and supporting the capsule, and in that the master valve is contained within a part of the member within the capsule.