Researchers have recently realized that hydraulic fracture networks are significant for the exploitation of unconventional reservoirs (tight gas, shale gas, coalbed methane, etc.). Laboratory experiments are proposed to study the evolution of fracture networks in natural fractures. The density of natural fractures and injection rate were selected as the primary dominating factors. It was concluded that the interaction between reopening and connecting of natural fractures led to hydraulic fracture networks, which can be detected by pressure fluctuations. The fracture network is composed of multiple fractures, resembling an ellipsoid with the major axis different from the maximum horizontal stress direction. The treatment pressure will be substantially raised by both the great natural fracture density and high injection rates.
Part of the book: Fracture Mechanics