Factors that influence fluid flow in a single fracture

To investigate the influence of compression, Poisson effect and turbulence on the fluid flow process and the inversion for fracture surface geometries, we simulate two sets of fractures: one with a defined fracture height standard deviation sigma constant and a varying autocorrelation length lambda and another with a fixed lambda and a changing sigma. Under compression, the normal stress closes fractures with a large aperture and thus reduces the effective permeability. However, the Poisson effect, which is induced by the compression, has little influence on the fluid flow properties and does not affect the inversion for fracture height standard deviation or the autocorrelation length. When introducing turbulence, we observe a significant difference between the performance of the Navier-Stokes equation and the local cubic law; compared with the Navier-Stokes equation, the local cubic law overestimates the peak value of the breakthrough time curve and effective permeability, thereby underestimating the mean fracture aperture.