A Novel Permeability Prediction Model for Deep Coal via NMR and Fractal Theory

A quantitative description of the permeability deep coal is great significance for improving coalbed methane recovery and preventing gas disasters. The Schlumberger–Doll research (SDR) model often used to predict rock permeability, but it has inherent defects in characterizing pore structure coal. In this study, a with fractal characteristics (FCP model) established based on nuclear magnetic resonance (NMR). constants SDR are theoretically explained by relevant parameters FCP model. Centrifugation NMR experiments were performed determine optimal centrifugal force dual T2 cutoff values. results show that samples mainly composed micrometer nanometer pores. adsorption pores account largest proportion, followed percolation migration addition, prediction accuracy significantly higher than other three models, which provides fast effective method evaluation permeability.