Reservoir characterization and structure-sand body gas controlling effect of Shan23 sub-member in Wushenzhao, Ordos Basin

Previous studies show that the control of geological structure on gas and water distribution is extremely negative or even can be ignored in Ordos Basin. However, it is found that the structural trap has obvious control effect on the distribution of gas and water, especially in Shan(2)(3) sub-member in Wushenzhao. The characteristics of reservoir, trap types and accumulation rule of gas reservoir are discussed in this paper, and the results show that Shan(2)(3) sub-member belongs to extra-low porosity and extra-low permeability and even ultra-low permeability reservoirs. The type of gas reservoir trap is a structural-lithologic trap with a quasi-domed shape. The accumulation and preservation of natural gas are controlled by both low-amplitude structures and sand bodies.