Ocean’s Sea Nova Platform System is a self-installing jack-up structure. It differs from conventional drilling jack-ups in that moment support is provided at both the upper and lower ends of the un-braced column legs, hence the legs are subject to lower stresses. Furthermore, the jacking system is attached during installation only. There are no high fatigue areas such as exist in a conventional jack-up and the locking system is both simple and low-stressed.

Sea Nova can be fully commissioned onshore with only minimal tie-in and pressure testing on location. 

As the Sea Nova structure is a simple un-braced 4-legged structure, it has no complicated K-joints or nodes to inspect. The exposed area of steel in the splash zone or beneath Mean Sea Level (MSL) is less than for a similar performance conventional platform hence corrosion and marine growth are less problematic. The column legs are dry to the seabed and thickness checks can be conducted from the inside by platform personnel (i.e. no diving or ROV inspection required). Cleaning marine growth is a relatively easy operation and because of this and the simpler inspection regime, maintenance costs are considerably reduced.

Note the platform stiffness is comparable with a conventional braced structure.

A significant advantage of the design is Sea Nova’s ability to be easily removed and re-used. This obviates high decommissioning provision and is particularly attractive to the sequential development of multiple fields or areas.

The design fully conforms with all relevant codes and standards normally applicable to offshore structures worldwide and Sea Nova  will withstand the severe wave regime existing in the North Sea and can, therefore, be located anywhere.

The design features discussed below give Sea Nova the lowest infrastructure cost per barrel  of any structure (fixed or floating) of comparable performance!

Ocean’s Sea Nova Platform System is flexible providing a large deck area.

As the Sea Nova Platform design is driven by lateral (environmental) loading, it can carry a very significant payload without increase in the steel member sizes or weight. The topside structure comprises a flat-trussed structure with two or more large pancake decks facilitating maintenance-friendly equipment layouts.

The Sea Nova topside structure is supported by four tubular columns extending from one of the foundation options specified above.

It can accommodate:

          ■  dry trees, 
          ■  process equipment,
          ■  power generation,
          ■  control systems,
          ■  helideck,
          ■  accommodation
          ■  all associated facilities.

Sea Nova typically incorporates an integrated helideck that can accommodate a large service (S76 or equivalent) helicopter. The design allows helicopter operations to continue during all offshore activities including wireline, coil tubing and workover operations during which a lubricator mast can be erected at any well position.

The helideck can be integral or separate and  Sea Nova will support a crane, cantilevered vent or flare or other associated facilities.

A boat landing option is also available and this can be retractable with remote controlled lowering and raising.  This was used on our MOD platforms so is a proven alternative.

In its normal (and most economical) configuration Sea Nova is fitted with a concrete gravity base structure (GBS). The GBS typically comprises a rectangular hollow reinforced concrete structure of proven design. It is self-floating and when deballasted its inherent buoyancy is used to aid towage and installation. No specialised vessels or heavy-lift facilities are required during installation hence reducing costs whilst increasing project flexibility.

The base can be fitted with detachable footpads that are tailored to meet a specific site’s characteristics in relation to level, need for skirts etc. The use of these footpads simplifies later removal of the platform at the end of its field life. New footpads can subsequently be fitted to suit a later deployment at a new field with different seabed conditions.

The steel tubular legs are cast into the GBS enclosed inside a circular reinforced concrete sleeve that spans between the upper and lower horizontal slabs of the base itself. In addition to this a large steel collar located above the upper reinforced concrete slab is used to transfer applied loads into the gravity base at relatively low stress levels. A system of ballast pipework is fitted to allow differential ballasting or de-ballasting of the base structure.