Deepwater Drilling for Arctic Oil and Gas Resources Development: A Conceptual Study in the Beaufort Sea

Abstract

Surveys from the U.S.G.S, notably, have recently re-assessed the Arctic Circle and its deepest parts. Geology-based probabilistic analyses have found that significant oil and natural gas reserves, about 25% of the world's undiscovered resources, may be held in the deep Arctic Alaska (Bird, 2008; Houseknecht et al, 2010). Such studies are of the utmost interest for developed and emerging countries to help them meeting their growing demand in fossil fuels. As of today, the bulk of investigations, projects and technical papers concerning drilling for arctic oil and natural gas resources, have concerned the onshore hydrocarbon accumulations or the near shore deposits (OTA, 1985; Bercha, 1984; Matskevitch 2006; MMS, 2008). However, when trying to access the arctic deeper waters, only a few structures are available today to drill in these polar environments. Offshore operations in the Arctic Ocean are essentially impacted by extremely cold weather temperatures yielding the presence of sea ice, icebergs, floes and long period of darkness. Nevertheless, deepwater drilling and production in the Arctic Ocean provides an attractive but extremely ambitious challenge for our industry. Because the U.S. Beaufort Sea has an average water depth of 3,240 ft, deepwater drilling provides an interesting and innovative option to develop enormous reserves of oil and natural gas. This paper presents a conceptual study for exploratory and development wells in the harsh deepwater arctic environment of the U.S. Beaufort Sea by using a modified and winterized drill-ship with ice strengthened material or an icebreaker converted into a drilling vessel. In addition, ice management is discussed, considering a fleet of at least two icebreaker vessels to guaranty station keeping in first year sea ice and multi-year sea ice environments in order to conduct year-round operations with the floater. Also, the drilling and production phases will be discussed even in presence of icebergs or large ice floes. Finally, the paper briefly covers environmental regulations and economics. The main goal of this study is to help the oil and gas industry breaking the last barrier in exploration drilling and production by proposing structures and facilities that will enable to operate year-round in both open water and permanently ice-covered waters of the Arctic Circle.

Experimental Set-Up for Testing Cement Sheath Integrity in Arctic Wells

“…The latter type of "geohazard" comprises subsea permafrost and gas hydrates, which can be buried as deep as 600-900 m below the seafloor and have thicknesses of several hundred meters (Paepe and Melnikov 2001). The inlet temperatures of all unheated injected fluids will also be lower in Arctic environments, thereby increasing the potential for downhole thermal shocks (Carpenter et al 1992, Kutasov and Caruthers 1988, Pilisi et al 2011). Such cold formations will also cool down the well during shut-in periods, and can lead to freezing of water-based fluids (Singh et al 2007).…”