Thermogenic Gas Hydrate System and Models of Gas Hydrate Occurrence Patterns
Key Laboratory for Shale Gas Resource & Exploration, Ministry of Land and Resources, Chongqing Institute of Geology and Mineral Resources, Chongqing, China.
Gas hydrate formation is mainly controlled by the temperature and pressure, and another important factor is gas concentration. Only the gas is over-saturated in the Gas hydrate stability zone (GHSZ) can gas hydrate take shape. Based on these ideas, this article gives a model of thermogenic gas hydrate system, making a conclusion that a good combination of source rock, reservoir rock and cap rock is indispensable for gas hydrate formation. In this system the good conduits and cap rock may be the most important factors, because the concentration of upward gas and where the gas could be accumulated are both mainly based on the two factors. Then, on the basis of the model, this article represents the highly idealized interaction between structural hydrocarbon traps which includes reservoir-associated water together with oil and gas superimposed by different bases of gas hydrate stability zones, and predict that there would be four types of occurrence patterns for gas hydrate in the world. At last, this article gives a model of occurrence patterns for different traps in the differential entrapment.
AAPG Search and Discovery Article #90155©2012 AAPG International Conference & Exhibition, Singapore, 16-19 September 2012