An observation has been done on the differential stress and has been concluded that when the differential stress is high or low with low angles of approach the hydraulic fracture releases the natural fracture. A numerical method known as eXtended Finite Element Method (XFEM) model is developed that demonstrated hydraulic fracture proliferation, and to interact with fracture in natural fractured reservoirs. This model helps in proliferating the cracks and fractures. The crack is not modeled as geometric entity in conventional finite element method and this feature proves to be an advantage in using XFEM.
This new geo-mechanical approach through the XFEM model also notifies that the natural fracture starts to debond from quite a few meters before it can intersect with the hydraulic fracture, and the diversion of the hydraulic fracture occurs before it can intersect with the natural fracture. From the study on the XFEM model it can also be concluded that the diversion of hydraulic fracture with differential stress can be decreased by high net pressure, and this amount of tensile pressure is certainly required to fracture the naturally fractured reservoirs’. The studies on XFEM model such as hydraulic fracture intersecting the pre-existing natural fracture; reservoir rock parameters, debonding, and diversion of hydraulic fracture clearly explain the performance of hydraulic fracturing in naturally fractured reservoirs.