The Design and Construction of Beaufort Sea Drilling Islands—Sag Delta 7 and 8

The planning, design and construction of two offshore exploratory drilling islands, constructed in the Alaskan Beaufort Sea during the summer of 1980, is described. Emphasis is given to areas of the work that are either unique to the Alaskan Beaufort Sea or involve modifications to the artificial island technology developed in the Canadian Beaufort Sea. The construction of the islands using a land gravel source, transport and handling of the gravel by highly efficient equipment, and placement of the gravel using the limited marine equipment available at Prudhoe Bay is described. The development of an economical slope protection system, with a design life of 3 yr, in Arctic environment and the monitoring and maintenance program planned to minimize the propagation of anticipated damage and maximize the effectiveness of the slope protection system is described, and knowledge gained to date is also included.