Fig. 8: Interactions between stimulated fractures and fault reactivation during hydraulic fracturing.
From: The bound growth of induced earthquakes could de-risk hydraulic fracturing
A series of HF stages of increasing complexity (text labels) are considered alongside a hypothetical well (black & grey rectangle). In the simple case, the host rock is initially split in tension via stimulated fractures (grey polygons) and may also subsequently reactivate in shear. In the complex case, small pre-existing faults (black polygons) can also be reactivated in shear slip. The clustered case hydraulically connects a series of stages/perforations into a single fracture/fault network. In the last case, stimulated fractures intersect a large fault system that is critically-stressed for slip. By watching the growth of earthquake magnitudes, CAP-tests can discern between bound cases (blue circles) and unbound cases (pink circles).
