Potential distribution of gas hydrate in the Qinghai-Tibetan Plateau

The Qinghai-Tibetan Plateau is the largest permafrost in China with an area of 150×104km2, which is a potential and prospective region for gas hydrate. Based on the mean annual ground temperature, the thickness of frozen layer, thermal gradient in frozen layer (2.22℃/100m) and thermal gradient below frozen layer (4.18℃/100m), the stability zones and their thickness of gas hydrate with pure methane, pure carbon dioxide and various measured gas compositions from the Qinghai-Tibetan Plateau permafrost are calculated by using the thermodynamic method, and the potential distribution regions of gas hydrate are predicted and mapped. The results show that the Qinghai-Tibetan Plateau permafrost is of basic thermodynamic condition for formation of gas hydrate even including pure methane hydrate. According to temperature and pressure conditions, the best prospective region for gas hydrate is Kalakunlun Mountains, and next is Xikunlun Mountains, then Qiangtan Basin, and Qilianshan Mountains etc. However, combined with gas sources, transportation and reservoir conditions, Qiangtan Basin is the best prospective region for gas hydrate, next is Qilianshan Mountains and Fenghuoshan-Wuli, and then includes Kunlun Mountains Yakou Basin, Tanggula Mountains-Tumen, Kalakunlun Mountains, Xikunlun Mountains-Kekexili Basin etc.