Understanding the fluid flow behavior in crossed fractures is of great significance to through natural rock fracture system. To investigate linear and nonlinear regime transitions fractures, theoretical analyses numerical simulations were first performed identify factors that cause hydraulic pressure head loss. Then, their influence on onset further evaluated by performing dynamic computation different configurations. The parameter identification shows surface roughness, aperture, scale,...

Many fractures are present in the crust and dominate fluid flow mass transport. This study proposes a fractal model of permeability for fractured rock masses that includes properties both fracture networks surface tortuosity. Using this model, mathematical expression is derived based on traditional parallel-plate cubic law theory. functions as equivalent tortuous network terms maximum length lmax, dimension distribution Df, porosity ϕ, orientation θ, proportionality coefficient between...

Freeze–thaw action is a key factor in the deterioration of dynamic mechanical behavior rocks cold regions. This study used yellow sandstone, which prevalent seasonally region Xinjiang, China. The sandstone samples were subjected to various temperatures and range freeze–thaw cycles. Impact tests performed using Split Hopkinson Pressure Bar (SHPB) system on treated samples. effects freezing temperature changes impact load properties frozen–thawed examined. Additionally, damage fractal...

Accurate description of cavity geometric structure and quantitative estimation the permeability porous media are crucial for understanding fluid flow mass transport in various geosciences geological engineering. A fractal model was constructed by combining theory, Poiseuille's law flow, Darcy's law, taking into account characteristic parameters three-dimensional (3D) pore fracture network structure. The mechanical response tortuous capillaries analyzed theoretically to elucidate dynamic...

Fluid flow regimes affect the determination of hydraulic conductivity fractured rocks, and critical criteria for onset nonlinear fluid transitions in discrete fracture networks (DFNs) rocks have yet to be established. First, factors causing transition regime intersections rough surface fractures are theoretically numerically analyzed. This reveals that is governed by aperture, density intersections, roughness, Reynolds number (Re). Then, these identified parameters redefined DFN models,...

Understanding the flow behaviors of two-phase fluids in rock mass fractures holds significant importance for exploitation oil and gas resources. This paper takes with different surface roughness characteristics as its research object conducts experiments on gas–water seepage laws under various confining pressures shear displacements. The results indicate that higher fracture roughness, larger equivalent width single-phase permeability gas/water fractures. During flow, when water phase split...

A prediction model for estimating the permeability of fractal rough surface fractures is proposed, in which mechanical aperture and contact ratio are incorporated into mathematical equations. Fracture surfaces different roughness were generated via an improved successive random addition algorithm. series fracture that considers normal stress, shear displacement constructed to investigate evolution behaviors geometry permeability. The results indicate joint coefficient profile distribution...

The main objective of this paper is to investigate the evolution rock fracture slug structures and decongestion strategies for natural gas extraction processes. For purpose, level set method was used simulate structure under effect different flow ratios, surface wettability, tortuosity. results show that an increase in water-to-gas ratio tortuosity leads a significant proportion fracture, while contact angle decrease fracture. Based on above law, quantitative characterization two-phase...

Shale gas reservoirs are typical dual-porous media where complex pore structures and fracture networks significantly impact transport. However, accurately predicting permeability in such media, especially networks, remains challenging. The network is modeled as of a bundle rough tree-like networks. proposed model comprehensively describes the structural characteristics pores fractures shale reservoirs, including fractal distribution diameters apertures, surface, branching Then, model's...

The mechanical evolution of coal is evident when the pore pressure and surrounding stress alone influence it. However, response saturated under coupling effect confining needs further investigation. This study identifies behaviors burst tendency dry condition where simultaneously increase but keep constant difference by conducting a series triaxial compressions on high samples. results show that elastic modulus (E) strength (σpeak) from 3.4 to 4.8 GPa 78.5 92.6 MPa, respectively, macro shear...

Equivalent hydraulic aperture and fracture surface roughness are two significant factors affecting the fluid flow behaviors in rock fractures. To understand role of through 3D self-affine rough fractures, surfaces with joint coefficients equal to 2.5, 7.5, 12.5, 17.5 were established, Navier–Stokes equation was used compute these fractures a mechanical increase from 0.2 mm 0.8 gradient mm. The results show that when is mm, impact on considerable, while this effect decreases obviously...

The reliability of segmentation x-ray computed tomography (CT) images based on user-selected thresholds is important for analyzing supercritical CO2 (ScCO2)-water-induced microstructural damage in coal. In this study, a novel approach introduced by integrating the gray-level co-occurrence matrix (GLCM) method with CT to analyze evolution coal treated ScCO2-water. factors influencing GLCM calculation are also examined. heat maps and statistics were employed visualize quantitatively damage....

Understanding the behavior of fluid flow and solute transport in fractured rock is great significance to geoscience engineering. The discrete fracture network predominate channel for through as permeability several magnitudes higher than that matrix. As basic components network, investigating crossed fractures prerequisite understanding rock. First, a program based on successive random addition algorithm was developed generate rough surfaces. Next, series models considering shear effects...

Ensuring the stability of slopes is critical to safe operation geotechnical engineering. Evaluating slope minimize geologic risks induced by destabilization significant in reducing casualties and property damage. A conventional, single-coefficient strength reduction method widely applied analyses, but this ignores attenuation degree different parameters destabilization. new double-strength considering contributions mechanics’ proposed study for evaluating nonhomogeneous slope. First, role...

Geothermal recovery involves a coupled thermo-hydro-mechanical (THM) process in fractured rocks. A fluid transient equilibrium equation, considering thermal conduction, convection, and heat exchange, is established. The evolution of the reservoir permeability variance fracture aperture due to change stress field are derived simultaneously. THM coupling accomplished through iterative hydromechanical thermo-hydro processes. To overcome difficulty geometric discretization, three-dimensional...

Understanding the fluid pattern is of special significance for estimating hydraulic conductivity fractured rock masses. The nonlinearity flow in discrete fracture networks (DFNs) originates from inertial effects and enhanced by complex geometric topologies, which produces additional viscous friction subject to inertia effects, consequently transitioning nonlinear regime. Therefore, it important obtain critical conditions transition a laminar turbulent flow. To investigate role aperture...

Geothermal recovery involves a coupled thermo-hydro-mechanical (THM) process in fractured rocks. The fluid transient equilibrium equation considering thermal conduction, convection, and heat exchange is established. evolution of the reservoir permeability variance fracture aperture due to change stress field are derived simultaneously. By iterative coupling hydromechanical thermo-hydro processes, THM realized. To overcome difficulty geometric discretization, three-dimensional coupler model...