Abstract: Surface wellhead apparatus for use in tying-back casing from a subsea structure to a surface structure or when drilling with mudline-supported casing hangers wherein the casing is maintained in tension by means of a lock member which releasably engages with a support surface, the lock member and support surface being, on release, relatively movable in a direction longitudinal of the casing and, on engagement, locked against downward movement of the casing.

Abstract: This invention relates to a joint for risers, and particularly to a telescopic joint suitable for expandably connecting composite-pipe type riser pipes provided internally with tubing pipes. Its structural features reside in that connectors adapted to connect risers in up-and-down relationship are slidably engaged with each other and air cylinders capable of cancelling volume changes of the engaged portions, which volume changes occur due to expansion and contraction movements of the connectors, are communicated to the spacing of the engaged portions, and hydraulic cylinders adapted to cancel volume changes of the engaged portions of an internally-threaded nose portion and an externally-threaded nose portion, which engaged portions serve to communicate the upper and lower tubing pipes to each other, is communicated with the spacing of the engaged portions of the nose portions.

Abstract: System for drilling from a water surface, of the type having means for exerting and maintaining on the drilling tool a bearing stress, which is constant and normal to the surface to be perforated, no matter what the effect of the swell, wherein it comprises in combination: a base having a central passage for the drill pipe string of a drilling apparatus, which is intended to rest on the sea bed and is elastically connected to means for receiving a cylindrical box; a column formed by a cylindrical tubular central guide, for permitting the passage and guidance of the drill pipe string of the drilling apparatus, the column being surrounded by an external cylindrical tubular envelope, the hollow annular space formed between the central guide and the envelope being subdivided into a tight member constituting the lower ballast, a tight intermediate member of variable length determined as a function of the mean value of the section of water under which drilling takes place, a tight member constituting an upper balla

Abstract: A system for guiding a drill string with an attached umbilical line through a moonpool of a floating structure. The system comprises a support means, and a workhead assembly secured to the outer end of the support means. The workhead assembly is adapted to engage the drill string and umbilical line without damaging the umbilical. The workhead assembly comprises a turntable support, which is secured to the support means, and a turntable. The turntable is positioned about the drill string and umbilical, and rests on the turntable support. Rollers on the turntable allow the drill string and umbilical line to move vertically through the turntable. Roller units on the turntable support allow the turntable and the engaged tool string and umbilical to rotate with respect to the support means.

Abstract: A guidance system for centering and guiding various drill strings or risers within a moonpool of a floating structure, e.g. a caisson vessel. The system comprises one or more guidance vehicles. Each vehicle is movably mounted on a separate track. The tracks, in turn, are spaced about the moonpool wall and extend vertically along the wall of the moonpool from the top of the moonpool to a point near its bottom. Each vehicle has a frame and means to mount the frame on its respective track. Two side arms and a center arm are pivotably mounted on the frame and are movable between a closed position and an open position. Mounted at the outer end of each of the arms is an interchangeable workhead assembly which engages a drill string or riser to center and guide the drill string or riser when the arms are in their closed position. Individual lines controlled by winches above the moonpool are attached to each vehicle for independently raising and lowering that vehicle within the moonpool.

Abstract: A method and apparatus for controlling the flow of fluids from an open well bore, fluidly communicating the surface and a subterranean formation, the apparatus comprising(a) a slideable base;(b) a support positioned on the base;(c) a pipe engaging device positioned on the support above the base to urge a pipe into the open well bore; and,(d) a pipe straightener positioned on the support means to engage the pipe and straighten it above the well bore.A method for using the apparatus of the present invention is also disclosed.

Abstract: A submergible, underwater well completion habitat and a method of employing the same in the completion of wells at extended depths. The well completion habitat may be attached to an underwater well platform and maintained at a pressure of sufficient value to expel water from the work chamber and also to maintain it substantially water free so that one or more saturated divers may work within the chamber to complete the well. This abstract of the invention is neither intended to define the scope of the invention, which, of course, is measured by the claims, nor is it intended to limit the invention in any way.

Abstract: A cable clamp for securing a control cable to a kill or choke line in a mud riser used in offshore drilling of oil and gas wells is described. The cable clamp is comprised of two portions, a fixed portion which remains secured to the kill or choke line and a removable portion which can be engaged to or quickly released from the fixed portion to secure or disengage the control cable. The fixed portion includes a U-clamp, and the removable portion includes cooperating hinged members, each member mounting resilient pad and both members for securing said hinged members together to clamp said cable.

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 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: An offshore pipeline installation comprises a wellhead base and a pipeline anchor connected together to form a unit which is lowered onto a seabed. The anchor is pivotably positionable relative to the wellhead base about a vertical axis of a pilot tube. A pin pile is inserted through the tube and into the seabed to isolate the pipeline anchor from the wellhead and wellhead base in relation to forces generated in anchoring a pipeline to the pipeline anchor. The anchor is selectively positionable for alignment with pipeline means to be laid, and may include a socket mounted for pivotal movement about one or more, axis. The socket is operable to receive pipeline means laid away from the anchor. The anchor may further include a ramp which is inclined relative to horizontal. The ramp is positionable generally laterally relative to the lay path of the pipeline means so that pipeline means laid upon the ramp gravitates downwardly toward clamp means at the foot of the ramp.

Abstract: An apparatus and method of connecting a flowline to a subsea station in which such a connection may be remotely controlled and the method employed is independent of water depth. A flowline connector apparatus which includes a receptacle connector supported by a subsea station and has its axis directed toward the approach of the flowline, an elongated connector mandrel on a proximate end of the flowline, a pulling means releasably connected to the subsea station adjacent the connector receptacle, and lock means on the receptacle for interlocking engagement with the mandrel to retain the mandrel in selected longitudinal position relative to the receptacle and with a connector end of the mandrel exposed inboardly thereof. A method of securing a flowline to a subsea station.

Abstract: An apparatus for attaching a flexible line, such as a multiconductor electric cable for power and control circuits, a single flexible hose, or conventional flexible cables to a subsea station by remotely controlled means and without the assistance of divers or diver capsules or submarines. The apparatus includes a cable connecting frame structure upon which is pivotally mounted a socket-like container means which receives a receptacle means connected at one end of a flexible power cable or line. The frame structure is adapted to be releasably attached to the subsea station. A plug assembly is receivable by the socket-like container for electrical engagement with the receptacle means, and lock means holds the socket-line container in a selected position with respect to the subsea station.