Hydro-Mechanical Modelling of underground CO2 Storage and Risk Evaluation through a Probabilistic Fracturing Model

ABSTRACT: This study provides an analysis of the influence of underground CO2 storage on the effective stress field in a representative geological formation. Large scale finite element models are used to describe the injection process. For high injection rates, different material degradation mechanisms may be activated depending on initial conditions. The case of rock fracturing due to tensile stresses (i.e. mode I) is treated. The stress intensity factor is used as the driving parameter describing the growth of initial vertical cracks. A probabilistic model based on rock heterogeneity is used to evaluate the probability of finding critical defects in the considered geological layers. Last, a crack network study based on the description of the interaction between cracks is analyzed. The results show that a crack network can be generated and that the crack network saturates quickly after the first crack activations.