Artificial Island Construction In An Arctic Riverthe Norman Wells Production Islands

Abstract

Abstract In 1984, Esso Resources Canada Limited completed the construction of six artificial islands in the Mackenzie River at Norman Wells. Northwest Territories. The islands were constructed to allow oil production from a reservoir lying below the Mackenzie River. These islands were constructed as part of the expansion of the oilfield facilities at Norman Wells, Northwest Territories, the only producing oil field in the Canadian North. The Norman Wells production islands are unique in size, shape and method of construction. The river environment requires that the islands withstand (he forces of ice, rapidly changing water levels, extreme currents and waves. The islands are constructed of hydraulically placed sand fill. Their slopes are protected by a multilayered slope protection of gravel, rock and concrete armour. The major portion of constriction took place during the summer months of 1983 and 1984. Because of the short open water season the islands were partly constructed during the winter months from ice platforms on the Mackenzie River. Specialized construction techniques were developed for /he two-season operation. This paper briefly discusses island design criteria and presents details of the construction techniques. Introduction In Canada, the decline of conventional oil reserves has emphasized the importance of resource development in the frontiers and in other areas previously undeveloped because of their remote locations or harsh environments. In May 1985, Esso Resources Canada Limited expanded production from its oil field at Norman Wells, Northwest Territories, from 475 m3/day to 4400 m3/day. This $530 million expansion project is the first major development of an oil field in the Canadian North. The oil reservoir is contained in a carbonate reef; the Kee Scarp formation. About 60% of the reservoir lies below the Mackenzie River. The six artificial island drilling and production platforms completed in September 1984, play a key role in the Norman Wells Expansion Project. A completed island is shown in Figure 1. A total of 95 wells were drilled from the six islands, most of them deviated to some degree. Up to 17 wells were drilled on any one island. Radio-controlled production facilities are located on each island allowing individual well tests to be monitored from the mainland. The islands are connected to the mainland with a 26 km marine pipeline system which transports crude oil, injection gas, water and electric power between the islands and a central processing facility located on the mainland near the town of Norman Wells. The site plan of Norman Wells is shown in Figure 2 In conjunction with the expansion project, Interprovincial Pipe Line (NW) Limited constructed an 866 km long. 324 mm diameter pipeline to transport processed Norman Wells crude oil to the Canadian pipeline grid at Zama, Alberta. Esso was a pioneer in the construction of artificial islands for oil well drilling. Since 1972, Esso has constructed more than 20 exploration islands in the Beaufort Sea and Mackenzie Delta. The islands at Norman Wells, however, represent a new breed or artificial islands, as they have been constructed as permanent oil production platforms, rather than as temporary exploration structures.