Transportation Requirements for Drilling Operations on the Arctic North Slope of Alaska

Abstract

Summary Since the OPEC oil embargo of 1973, U.S. oil companies have been placing increasing emphasis on exploring for and producing oil located within the U.S. Alaska's North Slope has received a great amount of attention recently as there exists a known transportation system (the Trans Alaska pipeline) and because geological information indicates the potential for pipeline) and because geological information indicates the potential for large producing reservoirs. Drilling on Alaska's Arctic North Slope poses a number of interesting operational problems, including transporting and supporting drilling rigs to their respective locations. Sohio Alaska Petroleum Co. has extensive experience in transporting and supporting drilling figs in development operations (Prudhoe Bay) and exploration locations both on- and offshore Alaska's Noah Slope. This paper addresses how arctic drilling figs are transported to development locations within the Prudhoe Bay Unit and to remote on- and offshore locations. Principal topics deal with the current methods by which rigs are moved and how daily drilling operations are supported. In addition, this paper discusses transportation systems that may be required when drilling operations extend beyond the Barrier Islands of Alaska's North Slope. Introduction Drilling operations on Alaska's North Slope have come a long way since the discovery of oil at Prudhoe Bay in 1968. During the early days of drilling at Prudhoe, rigs were transported to the Slope by Hercules C-130 aircraft, barges up the west coast of Alaska, or cat trains up the 375-mile [603-km] winter-haul road out of Fairbanks. In 1975, the all-weather Trans Alaska pipeline haul road to Prudhoe Bay was completed, which provided an pipeline haul road to Prudhoe Bay was completed, which provided an alternative method to bring rigs to the slope. This paper explains how drilling figs are transported to drilling locations on Alaska's North Slope. The figs and support equipment now being used in the development of Prudhoe Bay have day rates that exceed $50,000. To minimize the time it takes in the Prudhoe Bay field to move a fig from one well to the next requires the use of specially designed fig-transportation systems. Two such systems are described, one with rollers on skids and another with rubber-tire wheels coupled to a jacking system. Exploration drilling up to 60 miles [97 km] from Prudhoe Bay is being conducted. This work involves moving Prudhoe Bay development rigs to both on- and offshore locations. This paper discusses moving rigs to exploration locations by Hercules aircraft, rolligons, trucks over ice roads, and barges-the methods being used by most operators drilling on the North Slope. Arctic North Slope Environment The North Slope of Alaska is bordered to the north by the Chukchi and Beaufort Seas and to the south by the Brooks Mountain Range (Fig. 1). The entire 90,000 sq miles [233 099 km 2] of land making up the North Slope lies wholly above the Arctic Circle. Prudhoe Bay, the largest oil field in North America, is located within this region and occupies about 0.5% of the overall area. Situated on the edge of the Beaufort Sea, Prudhoe Bay is approximately 250 miles [402 km] north of the Arctic Circle and 1,300 miles [2092 km] south of the North Pole. JPT p. 2308