Floating Ice Platforms for Oil Exploration in the Arctic Islands

Résumé

Exploratory drilling for oil and gas in the Arctic Islands has been in progress since 1961. A majority of the reserves are thought to lie offshore. To drill the offshore structures a method has been developed by which the natural ocean ice is artificially thickened into ice platforms which carry the weight of conventional land drilling rigs. The first ice platform well was drilled in 1974; to date 22 platforms have been built and 13 offshore wells drilled. Ice platform design includes the analysis of stresses in the ice and deflections due to ice creep under long term heavy loads. Deflections are found to be the critical factor with loss of freeboard a possible result. The arctic environment poses numerous difficulties for construction and drilling operations and logistics are a large part of the effort. Construction of the ice platform in done by flooding the ice with sea water, using submersible electric pumps. During construction and drilling the ice platform is monitored and strains, deflections, strength, temperature, ice movement and other measurements are taken. Special equipment has been developed specifically for ice platform drilling and a subsea completion was made using the ice as a working surface. Further developments of ice platform technology are expected for oil and gas production.