Subsea clamp tensioning system

The disclosed subsea clamp tensioning system includes predictability of gasket pre-load to input closure and allows a subsea clamp tensioning system to be closed and made-up without the hindrance of frictional loads that will cause a loss of tension in a drive screw. In an embodiment, the subsea clamp tensioning system tensions the drive screw by applying a set torque load into an API class torque bucket which translates into an applied tension at the drive screw. The tension load on the drive screw applies the gasket pre-load required to create a metal-to-metal seal between the two clamp hubs. Once complete and tested, the subsea clamp tensioning system may be removed and mounted onto a connector tool for retrieval to the surface.

BACKGROUND

Tensioner system are known in the art but hazards of using them include a buildup of unpredictably frictional loads created by thread and sliding frictions in the torqueing process. Standard torque systems lack predictability of gasket pre-load to input closure (tensioning and torqueing).

DESCRIPTION OF EXEMPLARY EMBODIMENTS

Referring toFIGS. 1 and 3, generally, as discussed below, there are two hubs (not shown in the figures), one on a side of subsea clamp tensioning system1towards an outboard device such as a tree, manifold, or PLET, and one on a connector. Subsea clamp tensioning system1holds the two hubs together, typically with a metal seal installed between them to prevent leakage. The hubs typically have multiple features for sealing, alignment, and interaction with subsea clamp tensioning system1. As illustrated in the figures, a portion of tubular100may be threaded.

Subsea clamp tensioning system1comprises housing20; collar30dimensioned to fit about housing20, where collar30comprises a plurality of offset channels31; a set of adjusters33(FIG. 3) corresponding to the plurality of offset channels31; collar handle32; a plurality of tension grips40(FIG. 3) movingly disposed within interior void21(FIG. 4), the plurality of tension grips40defining a tension grip channel41(FIG. 3); subsea hydraulic motor10; and nut runner50(FIG. 3) disposed within a portion of interior void21and dimensioned to accept and engage tubular100, where nut runner50is operatively in communication with subsea hydraulic motor10and dimensioned to accept tubular100therethrough. Typically, there is one adjuster33and one offset channel31for each tension grip40.

Housing20typically comprises interior void21(FIG. 4) dimensioned to accept tubular100therethrough, first end15, and second end13disposed opposite first end15. One or more receivers17may be present at either first end15or second end13, each receiver17dimensioned to receive a corresponding guide16and/or fastener14.

Tension grip stop12may be disposed proximate second housing end13and may further be disposed at least partially within interior void21(FIG. 4). In most embodiments, tension grip stop12comprises a port dimensioned to allow a portion of tubular100to go through tension grip stop12.

Referring more toFIG. 3, each adjuster33typically comprises upper portion34configured to be larger in a dimension than its corresponding offset channel31(FIG. 1) such that offset channel31prohibits travel of upper portion34into interior void21(FIG. 4). Each adjuster33further typically comprises middle portion35connected to upper portion34which is dimensioned to travel into interior void21and lower portion36connected to middle portion34, where lower portion36is engagable with its associated tension grip40. Each adjuster also typically comprises one or more springs37disposed about a predetermined length of middle portion35. In most embodiments, upper portion34, middle portion35, and lower portion36are contiguous.

Although tension grip40may comprise any appropriate shape, it typically comprises a substantially trapezoidally shaped tension grip.

Nut runner50may further comprise one or more gears51, typically a bevel gear, which is operatively in communication with subsea hydraulic motor10. Nut runner50typically comprises nut54, operatively connected to subsea hydraulic motor10, and preferably further comprises grooves dimensioned to cooperatively engage with corresponding threads in tubular100. Nut54is typically rotationally disposed within nut runner50.

One or more seals53may disposed within housing interior void21and be operatively in occlusive communication with nut runner50.

In contemplated embodiments, referring additionally toFIG. 4, tension grip housing60(FIG. 3) is disposed at least partially within interior void21and each tension grip40movingly, e.g. pivotally at pivot47, disposed within tension grip housing60at an end of tension grip40closest to first end15. In these embodiments, interior void21may further comprise housing wall27disposed intermediate first end15and second end13, where housing wall27comprises housing wall port28sufficiently sized to accept tubular100(FIG. 1) therethrough. Tension grip housing60may then comprise first end61dimensioned to partially fit through housing wall port28; second end62disposed opposite first end61, where second end62defines a tension grip housing stop; and one or more stop springs66disposed between tension grip stop12and second end62.

In the operation of an exemplary method, subsea clamp tensioning system1is positioned about tubular100, where subsea clamp tensioning system1is as described above. Using the set of adjusters33(FIG. 3), the plurality of tension grips40may be advanced against tubular100by pulling each of the adjusters33as opposed to turning them to create a desired tension.

A nut spinning function of subsea clamp tensioning system1may be automated by having collar handle32utilize subsea hydraulic motor10to draw two clamp sections together around the hubs (not shown in the figures) after a set of connection tools (not shown in the figures) have brought the hubs face-to-face. The two subsea clamp tensioning systems1may be aligned during this process using receivers17and corresponding guides16and their opposing ends secured using tension grip stops12.

As subsea clamp tensioning system1is activated, nut runner50is allowed to continue to spin nut54to mechanically lock subsea clamp tensioning system1such as by engaging and advancing threads on tubular100. Typically, final clamp tension is created by making up tension via the built-in hydraulic piston load to create the desired gasket pre-load.

Further, collar handle32is typically allowed to snug adjusters33as subsea clamp tensioning system1is activated, e.g. by using adjusters33to advance one or more tension grips40against tubular100.

Once the operation is completed and tested, subsea clamp tensioning system1may be removed. It may also then be mounted onto a connector tool for retrieval to the surface.

The foregoing disclosure and description of the inventions are illustrative and explanatory. Various changes in the size, shape, and materials, as well as in the details of the illustrative construction and/or an illustrative method may be made without departing from the spirit of the invention.