No abstract

No abstract

This contribution aims to study the influence of the saturation degree on the fracturing process. Therefore, a continuummechanical model for fluid-driven fracturing in partially saturated porous material is presented on the basis of the Theory of Porous Media and the phase-field approach to fracture. The material is described on the macroscopic scale as an immiscible mixture of three phases, i.e. a solid phase, representing the solid skeleton, and two fluid phases percolating the pore space. Hereby, capillarity effects between the fluid phases are taken into account. The fracturing process is modelled with a phasefield approach, characterising a diffuse crack pattern. The crack propagation in the solid skeleton is driven by the pressure field of the injected fluid. Finally, a numerical example showing the coupled process of crack propagation in partially saturated porous materials is discussed.

Hydraulically induced fracturing is widely used in practice for several exploitation techniques. The chosen macroscopic model combines a phase‐field approach to fractures with the Theory of Porous Media (TPM) to describe dynamic hydraulic fracturing processes in fully‐saturated porous materials. In this regard, the solid's state of damage shows a diffuse transition zone between the broken and unbroken domain. Rocks or soils in grown nature are generally inhomogeneous with material imperfections on the microscale, such that modelling homogeneous porous material may oversimplify the behaviour of the solid and fluid phases in the fracturing process. Therefore, material imperfections and inhomogeneities in the porous structure are considered through the definition of location‐dependent material parameters. In this contribution, a deterministic approach to account for predefined imperfection areas as well as statistical fields of geomechanical properties is proposed. Representative numerical simulations show the impact of solid skeleton heterogeneities in porous media on the fracturing characteristics, e. g. the crack path.