As one of the lower exploration basins, the Weihe Basin has been widely concerned in recent years. The distribution of the Upper Paleozoic strata and the characteristics of source rocks are the key factors restricting the Paleozoic oil and gas exploration in the Weihe Basin. In order to study the residual stratigraphic distribution characteristics of Upper Paleozoic in the Weihe Basin and its surrounding area, the gravity and magnetic data of the studied area are collected and collated, and combined with the research results of seismic, geology, drilling and geochemistry, the distribution of residual strata in the Upper Paleozoic is redefined. In addition, the exploration potential of the Upper Paleozoic in the Weihe Basin is discussed by comparing the characteristics of source rocks along the northern and southern margin of the basin. The results show that the existence of Upper Paleozoic in Weihe Basin, mainly located in the Xi’an sag and Gushi depression, and the thickness of the coal strata in the Gushi depression is larger than the former, especially in the south. The methane gas that produced by the source rocks was transported through a large number of fractures in the basin to the traps structure of the Cenozoic fault, and the high quality reservoirs were developed in the Cenozoic strata, especially in the upper part of the Neogene Zhangjiapo Formation .The lake deposition can form a good regional cap rock that provide favorable preservation conditions for natural gas. In addition, the existence of natural gas reservoirs can provide the basic conditions for helium accumulation in the basin. The deepening understanding of the basement gas source rocks in the Weihe Basin can provide important reference for the geological survey of the oil and gas in the Ordos Basin.
Zhang Mengting Li Wenhou Li Yuhong Li Zhichao Zhang Qian Wang Xiaochen Li Meng. Residual stratigraphic distribution and hydrocarbon significance of Upper Paleozoic in Weihe Basin and its adjacent area[J]. Chinese Journal of Geology, 2019, 54(2): 423-433.