Modeling and simulation of complex fracture network propagation with SRV fracturing in unconventional shale reservoirs

Multiple hydraulic fractures in naturally fractured unconventional shale reservoirs have often induced complicated fracture network expansion, as revealed by micro-seismic fracture mapping. As productivity of conventional energy resources decreases and the proportion of reserves in unconventional oil/gas increases, the theoretical method about the modeling and simulation of complex fracture network propagation needs to be improved to innovate stimulated reservoir volume (SRV) fracturing technology. To simulate the fracture network growth, a new model based on the modified displacement discontinuity method (MDDM) coupling pseudo-3D fracture propagation model is proposed introducing the propagation pattern and criterion. The numerical result of this model is solved and the process of fracture network propagation is simulated in different natural fracture (NF) distribution and fracturing parameters. The effects of NF distribution, hydraulic fracture (HF) spacing, bottomhole pressure and segmented and multi-cluster fracturing mode on the fracture network propagation are discussed. The simulation results of complex fracture network are characterized by four parameters as well. The results show that there are reasonable fracturing parameters technically during the SRV fracturing in unconventional shale reservoirs. It is significant to reasonably and efficiently develop the unconventional shale resources by researching the fracture network propagation rules. (C) 2015 Elsevier B.V. All rights reserved.