The scope of work covered the following activities:

• Assessment of input data, such as geological conditions, water depth, type of offshore platform, meteorological conditions, topside and jacket structure, construction equipment and lifting crane;
• Development of basis of design for the suction pile foundations;
• Assessment of the feasibility of using suction piles at the locations specified by the Client;
• Produce a concept design for the substructure including the suction pile foundation;
• Identify and prepare strategies for reducing installation risks; and
• Perform preliminary installation engineering.

The geotechnical assessments required to determine a site’s suitability for a suction can foundation are complex in nature and require consideration of the in-place and installation conditions. Each site was assessed separately - the highly variable soils require different foundation designs.

ICON’s experience in designing and installing suction piled foundations allowed the Client to add value to the existing WHP designs with a credible and robust engineering solution.    

The study provides the following key findings:

• Not all locations had soils that were technically feasible for suction can foundations;
• Suction can weight during transportation governs the lower jacket member design.  Novel transportation techniques should be used to reduce the leg loading during transit and jacket weight;
• Transportation and installation optimisations are possible with a two-piece substructure.  Two-piece substructures are potentially jackup rig installable;
• The suction can foundation design concept could be extended to the Client’s range of larger jacket designs; and
• Novel suction pumping systems are required to reduce the installation risk and cost.