Fractal characteristics of shale pore structure and its influence on seepage flow

The migration law of shale gas has a significant influence on the seepage characteristics of shale, and the flow of the gas is closely related to the pore structure. To explore the influence of shale pore parameters on permeability in different diffusion zones, the pore structure of the shale in the Niutitang Formation in Guizhou, China, was analyzed based on liquid nitrogen adsorption experiments and nuclear magnetic resonance experiments. The relationship among fractal dimension, organic carbon content (TOC), and BET specific surface area was analyzed based on the fractal dimension of shale pores calculated using the Frenkel‒Halsey‒Hill model. Shale permeability was calculated using the Knudsen number and permeability equation, and the influence of the fractal dimension and porosity in different diffusion zones on shale permeability was analyzed. Previous studies have shown that: (1) the pores of shale in the Niutitang Formation, Guizhou are mainly distributed within 1‒100 nm, with a ...