Fracture Modeling Using Advanced Numerical Techniques

Extensional strain in the brittle crust is usually accommodated by opening mode natural fractures. These opening mode fractures grow perpendicular to the direction of least compressive principal stress and can form under a combination of loading conditions, including elevated pore pressures, folding of geological strata, burial/uplift of heterolithic layers, and slip along preexisting faults. Fractures occur in varying orientations, form clusters, and have different propagating lengths and apertures. Analytical solutions such as curvature analyses, restoration techniques, elastic continuum models and stochastic approaches for natural fracture prediction have been favored over more sophisticated continuum and hybrid (finite-discrete) analyses because of their computational efficiency and ease of implementation. This argument is somewhat dated in light of advances in computer processing speed and capabilities. Truly predictive methodologies must emphasize accurate modeling of the material response throughout the deformation. This study demonstrates recent advances in natural fracture predictive capabilities using advanced discontinuum and continuum analyses. Advanced numerical analysis coupled with a fracture initiation criteria enable geologically realistic fracture modelling at a range of scales. These new numerical capabilities help identify fracture sweet spots that can form due to a variety of loading conditions.