Western Sichuan, Northern Permian Sedimentary And Oil And Gas Relations

Under the guidance of the theories of sedimentation, paleontology, stratigraphy, reservoir geology and digenesis, synthetically applying the methods of the conjunction of spot-line-surface, macro-microscopic and field-indoor, there is a comprehensive study for the upper Permian series in stratum, rock, sedimentary facies and diagenesis, especial for the type and characteristics of sedimentary facies, in the paper.Based on the above, the vertical evolutionary model of the sedimentary environment is explained by the study of the elevation profile and transverse profile and the regional geological characteristics. At the same time , the plane distribution of sedimentary facies is determined according to the Walther phase rule and the single geological factor analysis. Furthermore the sedimentary stereoscopic model in Wujiaping stage and in Changxing stage are established. The controlling factors of sedimentation are tectonics and fluctuation of sea level. The evolutionary model organic beach or reef reservoir, controlling factors of which are sedimentation, digenesis and tectonics ,are established according to the result of sedimentary facies and digenesis. At last regional distribution of reservoir has been predicted.Comprehensive study indicates the dark, 50-300 m thick upper Permian series, which is rich in the organic material (OM) and biota , is beneficial to formation and protection of petroleum and natural gas. Moreover the stratigraphy possess with better reservoir ability. The reservoir distributed in shallow glacis along Beichuan Tongkou - Guangyuan Changjianggou ,He 12 well - She 1 well - Jiange - Cangxi Yongningpu -Long 4 well - Bian 1 well in Wujiaping stage and in platform edge beach along Beichuan Tongkou - Jiangyou Shuigentou - Jiange -Cangxi Yongningpu - Nanjiang .