Gas Hydrates in the Qilian Mountain Permafrost, Qinghai, Northwest China

Qilian Mountain permafrost,with an area of about 10×104km2,is located in the north of Qinghai-Tibet plateau. It has of perfect conditions and great prospecting potential for gas hydrate. The Scientific Drilling Project of Gas Hydrate in the Qilian Mountain permafrost,which locates at the Jugenghu Mining Area in the Muli Coalfield,Tianjun County,Qinghai Province,has been implemented by China Geological Survey in 2008~2009. Four scientific drilling wells have been completed with a total footage of 2059.13m. Samples of gas hydrate were collected separately in the holes of DK-1,DK-2 and DK-3. Gas hydrate is hosted under permafrost zone at the 133~396m interval. The samples are white or ivory crystal and easily burning. Distinct low temperature anomaly has been identified by infrared camera. The gas hydrate-bearing cores strongly bubble in water. Gas-bubble and water-drop emit from the samples and then retain characteristic honeycombed structure. The typical spectrum curve of gas hydrate is detected using Raman spectrometry. Furthermore,the logging profile also indicates high electrical resistivity and sonic velocity. Gas hydrate in Qilian Mountain is found within a thinner permafrost zone with a shallower buried depth and characterized by more complex gas component and coalbed methane origin,suggesting a new type of hydrate.