Characteristics and evaluation of tight gas reservoir in Shaxi miao Formation, Northeastern Sichuan Basin

The reservoir of Shaximiao Formation is mainly composed of channel coarse sandstone and fine sandstone. The rocks are dense, the lithology is single and the thickness is l arge. The physical properties of Shaximiao Formation are not clear for the northeast Sichuan area. Based on field and core physical property analysis of Shaximiao Formation in Northeast Sichuan Basin, the characteristics of porosity and permeability of Shaximiao Formation are defined, the porosity-permeability relation chart is established, and on this basis, The tight reservoir of Shaximiao Formation was evaluated, the result show that the favorable reservoir is mainly located in the intersection area of channel sand, the reservoirs are mainly of III type, followed by the reservoirs of II type, and the I type are the least.