A new modeling approach to natural fracturing process

Robust understanding of natural fracture distribution and connectivity is crucial in hydrocarbon and geothermal energy development. Unfortunately, such characterization of the fractured formation remains a major challenge to the industry. We propose the variational approach to fracture modelling, which provides a unified framework for studying fracture nucleation and initiation, autonomous propagation and the growth of an arbitrary number of fractures. In this study, we model fracture nucleation and the sequential infill fracturing of an entire brittle layer, as reported by several authors of out-crop based studies. In addition, the relationship between mechanical stratigraphy and fracture density is captured by studying the effect of the mechanical properties of the fracturing and non fracturing layers on the distribution of fractures within the brittle layers. From a parametric analysis, it is found that the mechanical properties and geometry have a strong effect on the density, spacing and overall distribution of fractures and the initiation of bedding parallel slip. Copyright 2013 ARMA, American Rock Mechanics Association.