Drilling islands in the northern Caspian Sea
Since 1998 Witteveen+Bos has been involved in the design and the construction of artificial islands for oil exploration, production and processing in the northern Caspian Sea. We have designed artificial islands and ice protection structures for 12 locations within the Kashagan field. This offshore oil field in the northern Caspian Sea is considered to be the world's largest discovery in the last thirty years. Designs have also been prepared forthe civil topsides. Most challenging for the design has been the arctic conditions and the relatively limited water depth in this part of the Caspian Sea.
For another oil field, the Kalamkas field, alternatives for the island construction method have been developed, minimising the impact on environment and maximising the preparatory construction activities onshore through the use of caisson design. Important in the design has been the arctic conditions, the presence of a local construction yard and the sea transport of caissons in shallow waters. A rock island with a cofferdam perimeter structure was designed for a third field, the Pearls field. The cofferdam is built from an existing platform that has been placed on piles. Also the island decommissioning after its 40 years lifetime has been studied to ensure minimal environmental impact.