A New Rock Physics Model of Shale on the Theory of Micro-Nano Pores

Summary As the main storage space of shale reservoir, micro-nano pores have a great influence on the overall elastic property of shale. As a special type of organic mineral in shale, the state of kerogen in shale varies with maturity, meanwhile, kerogen is also the primary place for the growth of micro-nano pores. Conventional shale rock physics model cannot reflect the role of micro-nano pores, thus, we adopt a theory of micro-nano pore to describe its characteristics. Considering the micro-nanometer pores and the state of kerogen at different maturity, we establish a new rock physical model by applying the micro-nano pore model, anisotropic SCA-DEM model, anisotropic Eshelby-Cheng model and Brown-Korringa solid substitution equation. The sensitivity analysis show that the micro-nano pores have the greatest effect on the mature shale, while kerogen and clay have the least effect on the overmature shale.