Dunn and McClelland, 13 – Professor of International Politics and Head of the Department of Political Science and International Studies at the University of Birmingham AND Associate Director for North America at the risk analytics consultancy Maplecroft in charge of energy policy (David and Mark, “Shale gas and the revival of American power: debunking decline?,” The Royal Institute of International Affairs, http://onlinelibrary.wiley.com/doi/10.1111/1468-2346.12081/abstract)//eek
Some have cast doubt on the long-term viability of shale gas wells. Paul Stevens argues that natural gas is more difficult and expensive to transport than oil, and that this will inhibit the development of a global gas market with a global price instead of regional prices.59 Shale gas also requires more wells than conven- tional gas to produce the equivalent amount of natural gas, and the longevity of shale gas wells has been questioned. Some early analysis of shale gas wells in the Barnett Play in Texas suggested that shale gas wells experienced depletion in production of 39 per cent in years one and two, 50 per cent between years one and three, and 95 per cent between years one and ten. This could suggest a lifespan of a shale gas well of 8–12 years compared to 30–40 years or more for a conventional gas well.60 However, as the technology continues to be refined, depletion rates are falling, suggesting that more efficient production is likely in the future. Deutch also argues that the extraction costs of shale gas are approximately $2–3 per 1,000 cubic feet of gas produced—somewhere between a third and a half the cost of conventional natural gas.