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Subsea Expo
NSRI

The voice of the UK subsea industry

Energy Institute Innovation Commendation for SDS

09 December 2013

Subsea Deployment Systems, based in Westhill, received a commendation at this year’s Energy Institute’s Awards. This is a well-established competition, recognising the efforts of the global energy industry demonstrated by individuals and organisations. Award categories cover important areas such as Environment, Safety, Communication, Community Initiative, as well as rewarding excellence in Innovation and Technology. SDS’s award was in the Innovation category for its alternative method for the installation of large subsea structures. Arnbjorn Joensen, SDS Operations Director, commented that it was particularly pleasing for a small company such as SDS to receive the commendation given the global nature of the competition.

The Subsea Deployment System (SDS) is a low cost alternative to a conventional lifted installation that meets or exceeds the weight and depth capacities of existing vessels. It is also less weather sensitive than a conventional installation resulting in increased operating windows and greater schedule flexibility.

Subsea installation has historically been based on the principle that structures need to be lifted into place and the bigger the structure the bigger the crane required. However, the SDS creates a near neutrally buoyant system by coupling the structure to a fully submersible deployment vehicle (SDV) to support the subsea structure during transportation, positioning and installation. The complete assembly is transported to site using a submerged tow which largely eliminates the effects of the surface environment. It also avoids the often critical phases of offshore over boarding and lowering through the splash zone. Final positioning and set down is achieved by means of chains lowered into the SDV which push the assembly down to the seabed. The chains behave as soft springs and minimize dynamic loading. Once the assembly is on the seabed further ballast is added incrementally to balance the buoyancy of the deployment frame before it is disconnected from the structure. This allows a small crane vessel or anchor handling tug to install or recover any structure independent of its size or weight.

The technology behind the individual aspects of the SDS is well proven and based on simple engineering principles but the combination provides a uniquely simple solution to an increasing problem.

The system has been proposed by independent bodies for both the installation of structures and for the decommissioning of pipeline bundle towheads. A major oil company has also stated that they consider it as a proven concept offering significant cost savings and another has asked that SDS align with one of their existing suppliers with a view to bringing it to market. However, the conservatism within the industry has resulted in the typical "race to be second” and consequently the system is still at the concept stage.

SDS is actively seeking a partner who can assist in taking this exciting innovation to market.