Better reservoir knowledge and increasingly sensitive technologies are making the production of unconventional natural gas economically viable and more efficient. This efficiency is bringing tight gas, coal-bed methane, and shale gas into the reach of more companies around the world.
Especially, natural gas production from hydrocarbon rich shale formations, known as “shale gas”, is one of the most rapidly expanding trends in onshore domestic oil and gas exploration and production in the United States today. In some areas, this has included bringing drilling and production to regions that have seen little or no activity in the past. The lower 48 states have a wide distribution of highly organic shale containing vast resources of natural gas. The total recoverable gas resources in five shale -gas plays (the Barnett, Haynesville, Fayetteville, Marcellus, and Woodford) may be over 500 Tcf. Total annual production volumes of 3 to 5 Tcf may be sustainable for decades. This potential for production in the known onshore shale basins, coupled with other unconventional gas plays, is predicted to contribute significantly to the U. S.'s domestic energy outlook. No commercial shale-gas projects currently exist outside the U. S., but work continues to identify both new shale-gas reservoirs and to add incremental shale-gas production in existing reservoirs.