Exxon Production Research Company

John E Ortloff

Kerry G Kirkland

Terry N Gardner

Anthony J Masciopinto

Robert E Haring

Clarence F Stelzer, Jr

Donald R Hayes

Matthew N Greer

Allen P Ziarnik

John F Gadbois

Alfred S Arcache

John J Filson

W Robert Wolfram, Jr

An apparatus is described for securing two offshore mooring sections together. The apparatus is a connector adapted to quickly disengage each mooring section so that an offshore floating storage vessel, having one mooring section attached to it, may be separated from the riser of an single-anchor-leg-mooring system, having the other mooring section attached to it. The connector comprises a pin member engageable with a hook of a latch member. The latch member is rotated once the hook engages the pin member and a plunger then advances into an open region of the hook prohibiting the rotational movement of the latch member and thereby locking the two mooring sections together.

Apparatus for quick-release of a storage vessel from a riser

The disclosure describes apparatus for mooring a vessel 10 in unprotected waters. The vessel 10 contains a recess 34 in its hull adapted for receiving a buoyant mooring element 18. The mooring element 18 is attached to the ocean floor 12 by a plurality of mooring lines 20. Means are provided for releasably securing the mooring element 18 within the recess 34. The buoyancy of the mooring element is established such that on release from the vessel 10 it sinks to a predetermined depth a spaced distance above the ocean floor. The apparatus of the present invention is especially well suited for mooring a hydrocarbon storage tanker proximate the terminus of a production riser in waters subject to ice floes.

Vessel mooring system

A mechanism for decoupling over a selected angle the rotational motion between a marine vessel moored to a single point mooring system such as a single anchor leg mooring (SALM) and the fluid swivel stack of the single point mooring system. The mechanism includes two spaced-apart stops attached to the fluid swivel stack and a coupler positioned between the stops and attached to a mooring swivel at the base of the fluid swivel stack. Shock absorbers may be positioned on each stop between the coupler and each stop.

Motion decoupling mechanism for fluid swivel stack

An improved mooring system for mooring a floating vessel to an offshore structure is disclosed. The mooring system includes a first mooring arm connected to the vessel which is in sliding engagement with a second mooring arm connected to the structure. The first mooring arm is initially at a mean position relative to the second mooring arm in the absence of loading forces induced by wind, waves, ice, or an ocean current acting on the vessel. As a loading force urges the vessel away from the structure to displace the first mooring arm from the mean position, a hydraulic pressure cylinder is compressed to furnish a restoring force which counteracts the loading force. As the loading force subsides, the hydraulic pressure cylinder urges the first mooring arm toward the mean position. In a preferred embodiment of the invention, a stop is attached to the first mooring arm to limit the excursion of the first mooring arm from the mean position. In other embodiments of the invention, a block and tackle combination can be used to vary the size and the stroke of the hydraulic pressure cylinder required to accommodate a particular loading force.

Combination mooring system

A production riser assembly includes a controlled bending guide and base assembly having a curved bend control surface which cooperates with a tension and bend shaft member associated with a riser pipe, whereby movement of the riser pipe is controlled by the movement of the tension and bend shaft member into an abutting relationship with a portion of the bend control surface of the guide and base assembly.

Production riser assembly

A combination mooring system for mooring a floating vessel to an offshore structure is disclosed. When a loading force induced by wind, waves, ice, or ocean currents does not act against the vessel, the mooring system is at a mean position. As a loading force urges the vessel away from the structure, the mooring system adapts to accommodate movement of the vessel relative to the structure. To counteract movement of the mooring system from its mean position, a buoy connected by a cable to the mooring system is progressively submerged. As the buoy is submerged, it provides a buoyant restoring force which counteracts the loading force acting on the vessel. When the loading force subsides, the buoyant restoring force urges the mooring system toward its mean position. In a preferred embodiment, the mooring system has a stop which limits the excursion of the mooring system from its mean position. Therefore, if the displacing force should exceed the buoyant restoring force, the stop will convert the adaptable mooring system to a rigid mooring system capable of handling extreme loading forces.

A clamping mechanism for connecting members in end-to-end relation having a rotatable, actuating ring to radially move loading devices into engagement with one of the members. The translation of rotational movement to radial movement is accomplished by cam mechanisms. The loading devices may be toggle links of a toggle assembly which are supported by one of the members to be connected. Rotation of the actuating ring advances the locking device into engagement which in turn connects and preloads the members.

Clamping mechanism for connecting members in end-to-end relation

A fairing for elongated elements is disclosed for reducing current-induced stresses on the elongated element. The fairing is made as a stream-lined shaped body that has a nose portion in which the elongated element is accommodated and a tail portion. The body has a bearing connected to it to provide bearing engagement with the elongated element. A biasing device interconnected with the the bearing accommodates variations in the outer surface of the elongated element to maintain the fairing's longitudinal axis substantially parallel to the longitudinal axis of the elongated element as the fairing rotates around the elongated element. The fairing is particularly adapted for mounting on a marine drilling riser having flotation modules.

Fairing for elongated elements

A piggable fluid swivel comprising a first element on which a second element is rotatably mounted. Grooves in both the first and second elements align to form a continuous flow passage between the elements. Openings are provided through the first and second elements and into the flow passage whereby fluid can enter through one element, flow through at least a portion of the flow passage, and then exit through the other element. A flow barrier means similar to a gate valve is provided on one of the elements and includes a baffle plate that is extendable between an open position and a closed position. In an open position, the elements can be easily assembled and disassembled. In a closed position, the baffle plate blocks backflow in the fluid passage which allows pressure to build behind any pig that may become stuck in the flow passage to free the pig and carry it from the swivel. The swivel may be coaxially stacked to provide a multiline piggable fluid swivel.

Multiline piggable fluid swivel

A limited angle piggable swivel comprising a stationary cylindrical shaft and a rotatable housing member circumferentially mounted around the shaft in sealing engagement. The shaft has a conduit extending from the base to the side. The housing member has a passageway extending therethrough. The rotatable housing member is mounted on the shaft to permit coaxial alignment of the inner end of the housing passageway with the side end of the shaft conduit when the housing member is rotated around the shaft to the proper position. In a preferred embodiment of the present invention, both the inner end of the passageway and the side end of the conduit are flared outwardly to enable the swivel to be pigged in either direction when the longitudinal axis of the passageway is offset from the longitudinal axis of the side end of the conduit.

Limited angle piggable swivel

There is disclosed a universal joint for multiple flowline system wherein all of the conduits pass through the interior of the joint. The conduits whichpass through the universal joint on axes offset from the pivot axes of the joint are provided with flexing means which enable the offset conduit to rotate around a pivot axis of the universal joint when the joint is flexed.

Universal joint for multiple flowline system

A clamp type connector for securing the ends of conduits having mating end flanges providing a fluid pressure tight connection, the connector comprising a plurality of clamp segments pivotally secured to each other in end-to-end relationship and having arcuate grooves of wedge-shaped cross-section. The conduit flanges are wedge-shaped in cross-section and adapted to be compressed tightly by the grooves of said clamp segments. The clamp segments are actuated by a double acting screw which is operable to clamp or unclamp the connection. The arcuate grooves in the clamp segments are provided with antifriction bearings, e.g. ball bearings, roller bearings or bushings, and the segments are provided with external stops limiting the movement of the individual segments in clamps having four or more segments. This clamp type connector is secured on one of the conduits and is removed or installed with such conduit. The double acting screw is capable of remote operation to permit the clamp to be installed or removed from deep water oil and gas production riser systems. The clamp is useful for securing together the ends of ordinary conduits and of special conduit components such as rotary swivels, slip joints and the like.

Low friction remotely operable clamp type pipe connector

A multiline fluid swivel comprises a plurality of vertically mounted modules, each module containing a shaft and a housing which circumferentially surrounds the shaft. A conduit within the shaft and a manifold within the housing provide a continuous fluid path through each module. Completing the fluid paths of the modules are fluid lines entering the base of each shaft and entering ports located on each housing.

Multiline swivel

An articulated riser including at least two framed structures comprised of a plurality of fluid-handling lines connected by multiple fluid-handling line flexible joints. The articulated riser of the present invention provides a system wherein fluid-handling lines may be connected between a structure on the subsea bottom and a floating vessel either for the production of crude oil and natural gas offshore, or for the operational functions before or after producing a subsea well, or any combination thereof. The articulated riser of the present invention may extend to a foundation structure situated on the subsea bottom or to an upright self-standing riser, providing a manifold for a plurality of fluid-handling lines to be connected to a floating vessel. Means may be provided for either partially or substantially totally providing buoyancy for the articulated riser.

Growing community of inventors

Houston, TX, United States of America

John E Ortloff