Modeling of scale-dependent perforation geometrical fracture growth in naturally layered media

Abstract

In this study, the discrete lattice simulation of multi-scale fracture growth in layered media is conducted and validated against fracturing laboratory observation and field micro-seismic monitoring. The results reveal that the perforation can substantially influence hydraulic fracture initiation and extension. The vertically-oriented-perforation induced fracture will effectively initiate with moderate near-wellbore complexity, promoting fracture crossing at bedding interfaces. The interlaced design of perforation cluster can alleviate the stress shadow effect and facilitate uniform fracture propagation. The far-field fracture complexity are related to the bedding interfacial properties: more tensile interfaces tend to arrest induced fractures and restrict their vertical growth, while more fracturing fluid will be diverted into the permeable interfaces of lower shear strength. The complex fracture networks has the potential to trigger fault reactivation or serve as conduits for underground water, thus causing induce seismicity or aquifer contamination. The findings can enrich the understanding of multi-scale fluid-solid coupling mechanisms and further help us prevent geological hazards.