A Negative Value of the Non-Darcy Flow Coefficient in Pore-Fracture Media under Hydro-Mechanical Coupling

The Forchheimer equation is widely used in studying non-Darcy flow. Non-Darcy flow coefficient β the generally thought to be positive, and there are few studies on negative values. In this work, we performed seepage tests sandstone samples with single, T-shaped, Y-shaped fractures under different confining pressures, water angles analyze nonlinear behaviors features of Forchheimer’s coefficients pore-fracture media. At same time, trajectory fluid inside sample studied by numerical simulation. results showed that was test angle single-fracture had a greater influence characteristic media; T-shaped relatively small impact. relationship between inherent permeability k following power function, differences characteristics three were compared. use normalized hydraulic conductivity method evaluate applicability Darcy’s law. Finally, explained primary cause non-linear fractured samples.