Organic matter-hosted pore system in the Wufeng-Longmaxi (O3w-S11) shale, Jiaoshiba area, Eastern Sichuan Basin, China

TOC has a significant effect on bulk shale porosity; porosity measured by FE-SEM ranges from 0.46% to 1.54%, but covers only a small fraction of the shale total porosity as the FE-SEM detection limit is in a μm range. The majority of shale pore space (pores < 10 nm in diameter) below the FE-SEM detection are performed by CO2 and N2 adsorption, and have an obvious relationship with the TOC. Therefore, the Wufeng-Longmaxi shale has a predominantly organic matter pore system.