Potential for horizontal well technology in the U.S

In the past decade, the use of horizontal well technology has increased significantly in the U.S., contributing to the drilling of 600 to 1000 horizontal oil wells annually. A total of 86 per cent of the existing horizontal wells have been drilled in three formations, the Austin chalk in Texas, the Bakken shale in North Dakota, and the Niobrara in Colorado and Wyoming. A unique analytical system has been developed by the United States Department of Energy, National Petroleum Technology Office (USDOE/NPTO) to assess the potential for greater use of horizontal well technology for other oil resources in other geological formations. The analytical system is designed to be used in association with other enhanced recovery methods that make up the DOE's Total Oil Recovery Information System (TORIS). The DOE/NPTO collaborated with industry to identify the target resource for horizontal well technology and to evaluate its future recovery potential under different economic and technological conditions. This paper provides a national summary of the potential for additional production and reserves with more diverse application of horizontal wells in various types of U.S. oil resources, including the rest of the fractured reservoirs in the Austin chalk, other fractured reservoirs in the north and northwestern states, thin-bed reservoirs, and mature waterflood field. The results were presented in terms of production, reserves and national economic benefits with a full cash-flow analysis at oil prices in the range of $16 to $24 U.S. per bbl. It is estimated that 541 million to 1 billion bbls of new reserves are economically producible at these prices. The reserves estimates pertain to future horizontal wells in known fields only and are in addition to the reserves for the existing wells as of 1 January 1998. Potential production is substantial, ranging from 50 million to 85 million bbl per year by 2004 and then declining at a rate of 8 per cent per year in the following years. The development of these new reserves could have a positive impact on the national economy. 7 refs., 2 tabs., 5 figs