ORALS

In this study, we shall investigate the effect of plastic deformation and inherent anisotropy of rocks on the hydraulic fracturing process. For this purpose, we propose an efficient numerical solution by combining the extended finite element method (XFEM) and the embedded discrete fracture model (EDFM) for studying hydraulic fracturing under coupled thermal-hydraulic conditions in an elastic-plastic porous medium. We consider both the fluid flow (and heat transfer) through the porous medium and the exchange between the medium and fracture. An efficient iterative scheme is developed to deal with the interaction between rock deformation, fracture propagation, fluid flow and heat transfer. The proposed method is assessed through comparisons with analytical solutions for a number of well-established problems. A series of numerical calculations are performed in order to investigate the effect of plastic deformation and inherent anisotropy of rocks on the process of hydraulic fracture propagation. Particular attention will be paid to the analysis of the process zone ahead of fracture in the context of anisotropic and plastic rocks.

References:
Zeng, Q., Yao, J., 2016. Numerical simulation of fracture network generation in naturally fractured reservoirs. Journal of Natural Gas Science and Engineering 30, 430-443.
Zeng, Q.D., Yao, J., Shao, J., 2018. Numerical study of hydraulic fracture propagation accounting for rock anisotropy. Journal of Petroleum Science and Engineering 160, 422-432.
Zeng, Q.D., Yao, J., Shao, J., 2019. Study of hydraulic fracturing in an anisotropic poroelastic medium via a hybrid EDFM-XFEM approach. Computers and Geotechnics 105, 51-68.