非常规天然气是常规天然气的重要接替资源。世界上的页岩气资源研究和勘探开发最早始于美国,目前在美国非常规天然气已占总产量50%以上。我 Unconventional natural gas is an important alternative source of conventional natural gas. The world’s shale gas resources research and exploration and development first began in the United States, at present the United States unconventional natural gas has accounted for more than 50% of total output. I