Displacement Discontinuity Method Modelling of Hydraulic Fracturing with Pre-Existing Fractures

Xie, L.M. (Seoul National University) | Min, K.-B. (Seoul National University) | Shen, B. (CSIRO Earth Science and Resource Engineering)



Hydraulic fracturing has been an essential technique for enhancing production in oil, gas and geothermal reservoirs for decades. Constructive interactions between induced fractures by hydraulic stimulation and pre-existing ones are critical to the success of stimulation treatment and understanding this complex process remains a challenging task. A coupled hydro-mechanical (HM) process has been implemented based on the existing fracture mechanics modeling code FRACOD (Fracture Propagation Code) where the Displacement Discontinuity Method (DDM) is used to simulate rock fracturing processes. In the paper, we presented theoretical foundation of the code with the focus on the implementation of HM coupling. Two verification cases were provided in which the FRACOD results show a very good agreement with the analytical ones from Kirsch solution and the hydraulic fracturing process in intact rock has been successfully modelled. Finally, two demonstration examples were conducted to simulate the hydraulic fracturing in fractured rock mass to account for the interaction between induced and natural fractures.