Pore-Throat Structure and Fractal Characteristics of Tight Sandstones: A Case Study from the Chang 63 Sublayer, Southeast Ordos Basin

The micropore-throat structure is a controlling factor on the capacity of storage and seepage for tight sandstone reservoirs. Therefore, quantitatively analyzing pore-throat crucial realizing oil accumulated in To study micropore-throat, battery experiments such as casting thin sections, scanning electron microscopy, high-pressure mercury injection, petrophysical characteristics reservoirs were conducted ten samples gathered Late Triassic Chang 63 sublayer Southeast Ordos Basin, China. main pore types are intergranular pores, feldspar dissolved pores. Meanwhile, each sample was identified large medium small pores by combining result HPMI with fractal theory. corresponding mean values dimension D large, medium, 2.83, 2.69, 2.31, respectively, indicating that complex strong heterogeneity presented according to maximum dimension. In addition, ( id="M2"> P − 2 ) has negative correlation porosity, permeability, median radius, saturation, withdrawal efficiency, displacement pressure, content quartz, while positive content, sorting coefficient, coefficient variation. Thus, reservoir space all this determined size, complexity, distribution Furthermore, quartz contributes homogeneity structure, thereby improves increase content. Feldspar dissolution developed widely area, leading various diverse types, sizes, structures, dimensions. Although enhanced increasing complexity also stronger, resulting reduction fluid.