Monitoring Fracture Network Stimulation Using Micoseismic Data

The successful exploitation of many reservoirs requires fracture networks, sometimes naturally occurring, often hydraulically stimulated. Microseismic data acquired in such environments hold great promise for characterising such fractures or sweet spots. The loci of seismic events delineate active faults and reveal fracture development in response to stimulation. However, a great deal more can be extracted from these microseismic data. Inversions of shear-wave splitting data provide a robust means of mapping fracture densities and preferred orientations, useful information for drilling programs. They can also be used to track temporal variations in fracture compliances, which are indicative of fluid flow and enhanced permeability in response to stimulation. Furthermore, the frequency-dependent nature of shear-wave splitting is very sensitive to size of fractures and their fluid-fill composition. Here we discuss a range of methods for extracting spatial and temporal variations in sub-seismic scale fractures.