FoundOcean has completed foundation grouting for three new platforms in the North Sea. The contracts were awarded by Heerema Marine Contractors (HMC). All three jackets were designed using pile-to-sleeve connections and fabricated with grout line connections above the waterline.
The first project was for two new wellhead platform jackets in the South Arne field in the Danish sector of the North Sea: Wellhead Platform North (WHPN) and Wellhead Platform East (WHPE). The jackets were placed in water depths of 60m.
Both jackets had eight skirt piles (two per leg) through which the piles were driven. FoundOcean used its unique recirculating jet mixer (RJM) to mix and pump an ordinary Portland cement (OPC) CEM 1 grout into the annuli to make the connection between the eight piles and the sleeves.
The second installation was one wellhead platform in the York field in the UK sector of the North Sea. The York platform is a four legged steel jacket with one pile and sleeve per leg. The connection was made using the same grouted pile-to-sleeve method as the South Arne field projects.
"FoundOcean uses tried and tested procedures for offshore grouting, which are vital in such a challenging environment. Our quality assurance process is rigorous: we take grout samples at various stages of the mixing process to manufacture grout cubes. These cubes are then tested to destruction at specific periods to verify the compressive strengths," explained Paul Burns, operations director.
"During the grouting process we also measure the grout’s flowability and qualify its density using a pressurised mud balance. Technical reports are then submitted to the client to support our offshore activities."
FoundOcean has been grouting offshore foundations for energy construction companies for over 45 years. It has grouted over 170 platforms for Heerema since 1974.