ABSTRACT
This paper presents the results of a series of calculation performed to determine fracture patterns from strain localisation in rock formations. The finite difference code FLAC was used to analyze fracture generation in rectangular grids. The numerical simulations show fracture orientations, which are in agreement with analytical equations. The fracture patterns were found to be dependent on the initial heterogeneity. Analysis of the fracture distribution for different grid sizes shows a power law relating number of shear banded elements with element size, suggesting a fractal distribution within the range of scales analyzed. With the use of a curved failure surface, the procedure could be extended to predict the development of extensional fractures. Finally, the methodology was applied to typical idealized geological situations, which included rifting and uplifting in an anticlinal structure. The results show that the numerical approach is a promising technique in the determination of fracture patterns in petroleum reservoirs.
