Multiphysics Lattice Discrete Particle Modeling (M-LDPM) for the Simulation of Shale Fracture Permeability

Abstract

A three-dimensional Multiphysics Lattice Discrete Particle Model (M-LDPM) framework is formulated to investigate the fracture permeability behavior of shale. The framework features a dual lattice system mimicking the mesostructure of the material and simulates coupled mechanical and flow behavior. The mechanical lattice model simulates the granular internal structure of shale and describes heterogeneous deformation by means of discrete compatibility and equilibrium equations. The network of flow lattice elements constitutes a dual graph of the mechanical lattice system. A discrete formulation of mass balance for the flow elements is formulated to model fluid flow along cracks. The overall computational framework is implemented with a mixed explicit-implicit integration scheme and a staggered coupling method that makes use of the dual lattice topology enabling the seamless two-way coupling of the mechanical and flow behaviors. The proposed model is used for the computational analysis of shale fracture permeability behavior by simulating triaxial direct shear tests on Marcellus shale specimens under various confining pressures. The simulated mechanical response is calibrated against the experimental data, and the predicted permeability values are also compared with the experimental measurements. Furthermore, the paper presents the scaling analysis of both the mechanical response and permeability measurements based on simulations performed on geometrically similar specimens with increasing size. The simulated stress-strain curves show a significant size effect in the post-peak due to the presence of localized fractures. The scaling analysis of permeability measurements enables prediction of permeability for large specimens by extrapolating the numerical results of small ones.

References in corpus (9)

• Fluid-particle flow and validation using two-way-coupled mesoscale SPH-DEM
• Elastic, strength, and fracture properties of Marcellus shale
• Pore-scale modeling of fluid-particles interaction and emerging poromechanical effects
• Characterization of Marcellus Shale Fracture Properties through Size Effect Tests and Computations
• Asymptotic Expansion Homogenization of Discrete Fine-Scale Models with Rotational Degrees of Freedom for the Simulation of Quasi-Brittle Materials
• On a 2D hydro-mechanical lattice approach for modelling hydraulic fracture
• A multiscale framework for the simulation of the anisotropic mechanical behavior of shale
• Three-Dimensional Network Model for Coupling~of~Fracture and Mass Transport in Quasi-Brittle Geomaterials
• Elastic Microplane Formulation for Transversely Isotropic Materials

Cited by in corpus (3)

• Characterization of Marcellus Shale Fracture Properties through Size Effect Tests and Computations
• Homogenization of discrete mesoscale model of concrete for coupled mass transport and mechanics by asymptotic expansion
• Adaptive discretization refinement for discrete models of coupled mechanics and mass transport in concrete