Abstract
In the past years, an increased effort was directed to improving our understanding of hydrofracturing by microseismic monitoring and analysis. We are developing a numerical method that would predict microseismicity occurring during hydrofracturing and the influence of fracturing on the permeability of the reservoir. The core of our technique is a representative pre-fractured volume of the reservoir that deforms locally and allows for the coalescence of deformation as the stress reequilibrates. Such an approach allows not only for implementation of the geological and seismic information on the scale of the representative volume but also to follow the deformation at the scale of the complete hydrofracture. We apply this technique to the hydrofracturing of the Bossier sandstone. The main goal is to predict observed microseismicity and permeability changes of the reservoir based on the modeled strains. The results show that the distribution of microseismicity is dependent on the regional stress state and the heterogeneity of the stimulated domain. If the permeability is calculated from the strains developing in the reservoir during the treatment, permeability will increase mostly in the areas of active fracturing. The next step is to fully couple the poroelasticity and the geomechanical response and to fit the model to the engineering parameters during the treatment.
