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Publication Date: 2017-Jul-05
Document File: 8 page(s) / 10M

Publishing Venue

The Prior Art Database


Disclosed is a Tree Protection Structure

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[0001]          In the oilfield, the need for utilizing trees at wellheads is commonplace.  However, for the subsea oilfield, a protective structure is often desired at the tree due to the hazards of the subsea environment.  Unfortunately, constructing and installing a massive protection structure at each tree can be a time consuming and costly endeavor.  Thus, the present publication details new forms of modular structures and installation techniques that may be helpful in reducing time and expense when seeking to provide subsea tree protection.

[0002]          Embodiments of a system of fully encapsulating/protecting a Subsea tree are shown below.  Thus, protection from various interactions associated with shallow water trawling (fishing) activities (trawl board/beam impact, trawl net snagging), and general dropped object protection from miscellaneous items/equipment is provided.

[0003]          There is uniqueness with regards to the fabricated protective structure (Side panels and Canopy), specifically the way in which they are deployed and interface with the existing tree frame and telescopic legs to fully encapsulate the tree and protect it from the mentioned scenarios.

[0004]          The design allows for a flexible and light weight tree system (Tree, TPS Panels, Canopy) that can be all deployed separately through a moonpool of approx. 5.5m square. Full access to the tree and its components is possible during the commissioning/start-up phase after installation of the Side panels and Canopy. These features make this design unique and a valuable asset within the marketplace.


[0005]          In various locations around the world there are common problems associated with fishing activities in relatively shallow waters and installed subsea oil and gas equipment (Tree’s, Wellhead’s, Manifold’s). These issues relate to snagging or impacts from fishing trawl gear (Nets, Beams, Clump weights, trawl boards, etc.) which can cause significant damage to the subsea equipment, fishing gear, marine environment, and previously has even resulted in the loss of life. Over the years various measures have been implemented to reduce this risk, such as introducing fishing exclusion zones around the subsea equipment and fishing vessel radar technology, but the mentioned issues have still been encountered. The Oil and Gas industry have introduced various designs in an attempt to solve these issues, these  range from large independent ‘canopy’ type structures to ‘integral’ fixed or fold out structural members in an attempt to provide a fully ‘overtrawlable’ aspect to the equipment; these designs do however have issues as noted. Namely, the ‘canopy’ type structures are often very heavy and large meaning they cannot be deployed subsea through a rig moonpool which forces the use of other equipment (large cranes deploying the tree off the side of the rig and/or separate deployment vessels) at sign...