The basins that produce the Nation’s natural gas are surprisingly deep. Many contain sedimentary columns that are 30,000 feet or more in depth. However, less than 1 percent of all wells drilled in the United States to date have penetrated below 15,000 feet.

Nonetheless, in 1998, “deep” reservoirs—arbitrarily defined as occurring more than 15,000 feet subsurface—accounted for 7 percent of domestic production. The National Petroleum Council projects this share will need to grow to 12 percent by 2010 to ensure that America’s growing demand for natural gas is met.

The deep gas resource target is enormous—about 29 percent of the Nation’s ultimate potential gas resource is deep gas. But challenges facing expanded deep gas production are significant. At such great depths, wells encounter extraordinarily high temperatures (greater than 400 °F) and pressures (greater than 15,000 psi), as well as extremely hard, abrasive rock and corrosive environments. Such conditions seriously challenge the capabilities of the sophisticated downhole equipment used in modern drilling.

Under these conditions, only the most promising deep prospects are economic to drill because of the high risks and costs entailed in deep drilling. The cost of drilling and equipping the average deep gas well (17,400 feet) is about 12 times that of the average Lower 48 onshore gas well drilled to 6,000 feet. History has also shown that with an ultra-deep well, the last 10 percent of the bore hole can account for 50 percent of the well's cost.

Under a program dubbed “Deep Trek,” NETL supports efforts to advance the understanding of deep gas environments and the development of new technologies that promise to dramatically reduce deep drilling costs and bolster drilling efficiencies. DOE kicked off the Deep Trek program in March 2001 with a workshop to accelerate planning for advances in deep drilling technologies. A CD, “Deep Trek Workshop Proceedings,” can be obtained through the NETL CD ordering system.

To date, DOE has awarded 19 Deep Trek projects totaling over $36 million, (with $12 million contributed by research partners) and is currently managing another seven projects focused on resource assessment and improved imaging technology for deep reservoirs. Many of these projects have focused on developing the electronics and tools needed for the development of an integrated deep drilling and deep imaging system that will enable the economic recovery of an additional 100 Tcf of natural gas through 2020.

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