Abstract:

Shale gas means the internal residual natural gas resource in mudshale, which exists in the form of adsorption, liberation, dissolution, etc., and is generated in diverse geologic settings in mudstone or shale, and has saturated multiform residual requisitions of rocks and entered the threshold of expulsion yet not being completely expulsed. With the increasing of exploration in North America, Europe and Asia, the research in the reserve characteristics and the hydrocarbon accumulation mechanisms of shale gas has achieved extraordinary progress. However, there are still many problems in the research in shale gas, for instance, the concept of “shale gas” does not express the scientific meaning of shale oilgas reservoir; there are not a definite genetic mechanism and an effective judgment of shale gas; the distribution and generation of shale gas are not clear and the united method of prescription does not exist. In view of the current cognition of shale gas, the authors prescribe the shale gas resource in China by the critical saturating capacity of residual hydrocarbon and the ratio of oil and gas expulsed by hydrocarbon due to the decline of temperature and pressure in the process of drilling and extracting.

Key words:  shale gas, mudshale oilgas reservoir, unconventional oilgas reservoir, hydrocarbon resource evaluation