Gas hydrate formation and its accumulation potential in Mohe permafrost, China
- 作者：Xingmin Zhao ; xxmmzh@163.com ; Jian Deng ; Jinping Li ; Cheng Lu ; Jian Song
- 关键词：Gas hydrate ; Permafrost ; Petroleum geology ; Mohe region ; China
- 刊名：Marine and Petroleum Geology
- 出版年：2012
- 期刊代码：37_02648172
- 类别：pw
- 出版时间：August, 2012
- 卷：35
- 期：1
- 页码：166-175
- 文件大小：1869 K
摘要
The Mohe region is an area of continuous permafrost in northernmost China with strong similarities to other known gas-hydrate-bearing regions. Permafrost thickness is typically 20-80聽m; average surface temperature ranges from 鈭?.5聽掳C to 鈭?.0聽掳C, and the geothermal gradient is roughly 1.6聽掳C/100聽m. We estimate that 204.66聽脳聽1012聽m3 of hydrocarbon gases have been generated in the Mohe basin from nearly 1000聽m middle Jurassic dark mudstones, providing ample gas source for gas hydrate formation. Numerous folds in the shallow section provide opportunities to trap gas within sandstones and siltstones reservoirs bounded by competent mudstone seals. Gas migration to the shallow section is enabled via fault fracture zones and fracture systems. Based on core description and observations of gas releases from drilled wells, we infer that the Mohe region could hold large quantities of natural gas in the form of gas hydrate.