Abstract: Threaded connectors for tubular members having metal-to-metal seals are provided. The connectors have different shapes for the contact sealing surfaces of the first and second connectors, which may be male and female connectors. In particular, the contact sealing surfaces may have mismatched surface shapes. For example, the male connector may have a frustohemispherical scaling surface while the female connector may have a frustoconical sealing surface. The disclosed mismatched male and female curvilinear surfaces, along with the flexible male connector nose, facilitate a reliable threaded connection having a metal-to-metal seal. The mismatched surfaces may provide for a wide parabolic distribution of contact stresses along the metal-to-metal seal of the curvilinear sealing surfaces.

Abstract: A riser tensioner for maintaining a tensile force on a riser extending through an opening in a deck of a floating platform includes a frame assembly that may be quickly bolted together in the field. The frame assembly includes a plurality of tensioner legs that may be installed on an un-level deck yet still provide a level support of the riser. Lower leg mounting assemblies include a slip ring for mounting directly to the deck and a deck mounting member received in the slip ring at a variable angle and having an upwardly extending shaft passing into a bore in a lower end of a tensioner leg.

Abstract: A riser tensioner assembly for supporting risers on an offshore drilling platform includes a frame assembly and a plurality of riser centralizers circumferentially spaced about the frame assembly. The riser centralizers each include a clevis supporting roller for bearing on a riser to limit lateral movement of the riser with respect to the frame assembly. The clevis includes an elongated channel along which the roller is movable to accommodate angular movement of the riser with respect to the frame assembly.

Abstract: A riser tensioner for maintaining a tensile force on a riser extending through an opening in a deck of a floating platform includes a frame assembly that may be quickly bolted together in the field. The frame assembly includes a plurality of tensioner legs that may be installed on an un-level deck yet still provide a level support of the riser. Lower leg mounting assemblies include a slip ring for mounting directly to the deck and a deck mounting member received in the slip ring at a variable angle and having an upwardly extending shaft passing into a bore in a lower end of a tensioner leg.

Abstract: A riser tensioner assembly for supporting risers on an offshore drilling platform includes a frame assembly and a plurality of riser centralizers circumferentially spaced about the frame assembly. The riser centralizers each include a clevis supporting roller for bearing on a riser to limit lateral movement of the riser with respect to the frame assembly. The clevis includes an elongated channel along which the roller is movable to accommodate angular movement of the riser with respect to the frame assembly.

Abstract: A pipe connector has a rigid seal/support ring mounted on its pin. The pin has a nose and external threads extending rearward from the nose. The rigid seal/support ring is fixedly mounted on an exterior portion of the pin farther from the pin nose than the pin threads. The rigid seal/support ring is installed by a shrink- or press-fit and has a tapered exterior seal surface. The box has a rim and internal threads that mate with the external pin threads. The box has a seal surface for engaging the seal surface of the rigid seal/support ring to form an external seal. The box also has a seal surface to form an internal seal with the nose of the pin.

Abstract: A pipe connector for offshore risers has conical thread forms. The connector has a pin with a nose, an external shoulder, and conical first and second pin threaded sections. The first and second pin threaded sections are axially separated by a pin intermediate section that is free of threads. The first and second pin threaded sections are formed on a single continuous taper and on a continuous helix. The intermediate section is also conical and at the same taper as the pin first and second threaded sections. The connecter has a box with a rim, an internal base, and a conical receptacle between the rim and the base. The conical receptacle has first and second box threaded sections that make up with the pin threaded sections. The box also has an intermediate section between its first and second threaded connections that is free of threads. The intermediate sections make up with radial interference. Upper and lower metal-to-metal sealing surfaces are located at the nose and at the base of the pin.

Abstract: Connecting a tubular string to a subsea installation. The tubular string includes a short first section and a longer second section. The length of the first section is approximately one-half the depth between the lowermost guide ring of a fixed platform and the top of the subsea installation. One end of the first section is provided with a connector and the other end with a connector and a funnel. The first section is lowered through the guide rings and connected to the subsea installation. One end of the second section is provided with a connector and the second section is lowered through the guide rings and into the funnel. Since the two adjacent ends are about midway between the subsea installation and the lowermost guide ring, the adjacent ends are easily bent into alignment by the camming action resulting when the end of the second section slides along the inside tapered surface of the funnel when the axes of the platform and subsea installation are offset.

Abstract: A subsea wellhead structure including a casing hanger having an exterior downwardly facing shoulder for landing within a well bore, a central bore, means for connecting a casing thereto, an upper exterior surface tapering downwardly and outwardly, and an external surface below said shoulder tapering downwardly and inwardly for centering said hanger on landing, a seal assembly with a metal seal sleeve having downwardly extending fingers, an internal metal annular bulbous sealing surface and an external metal cylindrical sealing surface, means for latching said seal sleeve in sealing position, a protector sleeve and means for releasably securing said protector sleeve to said seal assembly and said latching means, the latching means including retaining means preventing premature setting or movement of the latching means prior to the setting of said sealing means.

Abstract: A hanger apparatus for suspending an upright inner pipe from an outer pipe including a pair of load-bearing rings interposed between the two pipes. The inner and outer pipes have opposed frustoconical load-bearing shoulders receiving the rings therebetween. In one embodiment, both rings engage the inner and outer pipes, with an upper ring being driven outwardly into a locking position by a lower ring. In this case, the upper ring is split while the lower ring is solid. In a second embodiment, an outer ring engages both the inner and outer pipes while an inner ring is nested into the outer ring and engages the inner pipe. In this second embodiment, both rings are split.

Abstract: A connector for male and female members, the connection being established by a stab-in action and being released by a rotational action. The connector includes a male member having an external helical groove, a female member having an internal helical groove, and a resilient helical coil received in the groove of one of the members and extending outwardly therefrom in the relaxed condition. The helical coil can have a circular or polygonal cross-section and has an end secured to the member carrying it to prevent gross displacement therebetween. The helical grooves in the male and female members having opposed, upwardly and inwardly tapering load-bearing surfaces receiving the helical coil therebetween in the connected condition. These tapering load-bearing surfaces can have the same or different angles of taper.

Abstract: A hanger apparatus for suspending an upright inner pipe from an outer pipe including a pair of load-bearing rings interposed between the two pipes. The inner and outer pipes have opposed frustoconical load-bearing shoulders receiving the rings therebetween. In one embodiment, both rings engage the inner and outer pipes, with an upper ring being driven outwardly into a locking position by a lower ring. In this case, the upper ring is split while the lower ring is solid. In a second embodiment, an outer ring engages both the inner and outer pipes while an inner ring is nested into the outer ring and engages the inner pipe. In this second embodiment, both rings are split.

Abstract: A tension connector, and offshore platform mooring system embodying the connector, characterized in that the connector can be made up remotely and released remotely. The connector comprises a male connector member, typically attached to a string of pipe which serves as a mooring element, and a female connector member, typically secured to an anchoring base at the bottom of a body of water. The connector is made up simply by inserting the male member downwardly into the female member by manipulating the pipe string. Advantageously, two remote release means are provided, one operating hydraulically, the other by manipulation of the pipe string.

Abstract: In connectors, particularly for underwater well installations, for securing two members together under large clamping forces, an annular locking means is actuated by means including cam surfaces which coact through rolling antifriction members, the actuating means being so constructed and arranged as to reduce the lengths of the cam surfaces and better retain the antifriction elements.

Abstract: Connector, particularly for use in underwater well installations, for securing members together under large clamping forces. The connector is characterized by two successive stages of actuation of a locking means, typically a split ring or set of arcuate segments, with the actuating force of the second stage being applied by camming surfaces via low friction means to establish a high compressive preload without use of especially large power devices.

Abstract: A weight-set pack-off unit for sealing the annulus between inner and outer pipes, such as a mandrel casing hanger and a wellhead body in a well. The pack-off unit includes an expandable split ring receivable in a groove in the outer pipe to prevent upward movement of the pack-off unit relative to the outer pipe. The split ring is supported by a second ring which is shear-pinned to the pack-off unit and which moves the split ring into the locking position. The pack-off unit has a downwardly facing load-bearing shoulder in engagement with an upwardly facing load-bearing shoulder on the inner pipe, thereby increasing the unit's capacity to carry downward loads.