Impact of composition on pore structure properties in shale: Implications for micro/mesopore volume and surface area prediction

Pore structure properties such as pore volume, surface area, and pore size distribution (PSD) are the key petrophysical parameters in shales that control storage capacity, hydraulic conductivity, and the gas adsorption in potential. The nature of pore volume, surface area, and PSD are largely dependent on shale composition, which is highly heterogeneous in different formations. However, the quantitative effects of the clay content and total organic carbon (TOC) content on micropore and mesopore structural properties have not been fully explored yet. Here, we quantified the impact of clay and TOC contents on micro-/mesopore volume, surface area, and PSD using three shale formations with large compositional variations. The results indicate that clay and TOC contents synchronically influence the shale micro-/mesopore structure properties, but they function in different pore size ranges. The micropores are predominantly contributed by organic matter pores. For the first time, we discover that the mesopores ra...