An overview of the Scientific Drilling Project of Gas Hydrate in Qilian Mountain Permafrost, northwestern China

Four scientific drilling wells, namely DK-1, DK-2, DK-3 and DK-4, with a total footage of 2059.13m, for The Scientific Drilling Project of Gas Hydrate in Qilian Mountain Permafrost, were performed and completed by China Geological Survey and some other units during 2008-2009. Samples of gas hydrate were collected separately in the 133-396m interval from holes DK-1, DK-2 and DK-3. It was for the first time to discover gas hydrate in the permafrost of China as well as in the middle latitude permafrost of the world. Gas hydrate from the Qilian Mountain is a new type hydrate characterized by a relatively thin permafrost zone, shallow buried depth, complex gas components, and dominant thermogenic gas. In addition, geological, geophysical, geochemical and drilling techniques and essential equipment for gas hydrate in permafrost have been developed, thus providing a foundation for further investigation and research.