| The theory and method of sequence stratigraphy, petrology, sedimentology, gas geology, coalbed gas geology and other disciplines was applied in this paper as a guide. According to observation and study of Qiligou section and six drilling cores, such as GS-26, and statistics and analysis of more than 200 drilling cores data, this paper has does a research about types and characteristics of sedimentary facies, sequence stratigraphic framework, characters and evolution of paleogeography, relationship between sequence stratigraphy and gas characteristics.According to identification to sign of sedimentary facies, Taiyuan Formation and Jinci Formation are divided into three sedimentary facies, 8 subfacies and 15 microfacies. By identification to sequence boundaries, transgressive surface, the largest transgressive surface, Taiyuan Formation and Jinci Formation are divided into 5 third-order sequences, 10 system domains.Sequence stratigraphic frameworks is established, which is mainly controlled by tectonic subsidence and sea-level changes. On this basis, the depositional model and paleogeography evolution of Taiyuan Formation and Jinci Formation are summarized.Based on analysis and summary of characteristics of coal bed methane and shale gas, Taiyuan Formation and Jinci Formation in Gujiao mine are considered to be a complex gas system of CBM and shale gas in this paper, which is characterized by self-generation and self storage. A condensed stratum which is formed in the TST is always a favorable stratum. It is appeared in the lagoon-tidal flat sedimentary assemblage and peat bog-distributary bay sedimentary assemblage. |
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