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In this study, an efficient hydro-mechanical model of hydraulic fracture propagation is proposed using the embedded discrete fracture model in conjunction with the extended finite element method. Fracture is embedded into a common computational grid for both stress and pressure fields. A hybrid scheme of fixed stress split and Picard iterative method is presented to deal with the hydro-mechanical coupling and fracture propagation. The model is verified against other numerical solution of hydro-mechanical coupling problem and analytical solution of fracture propagation available from literature. Numerical results show that as matrix permeability increases, more fracturing fluid is required to get a desired length of fracture. The effect of Biot's coefficient is similar to that of matrix permeability. Finally, the model is extended to simulate simultaneous propagation of multiple hydraulic fractures. It's interesting to find that the effect of stress shadowing could be weakened by the poroelastic stress when accounting for hydro-mechanical coupling. The study indicates that the hydro-mechanical coupling could have significant influence on hydraulic fracturing, especially for multi-cluster fracturing of horizontal wells. [ABSTRACT FROM AUTHOR]

Shale oil flow is commonly affected by the confined phase behavior, complex fracture geometries, and geomechanical effect, which are not fully considered in the conventional compositional simulators. In this study, a coupled compositional flow and geomechanics model is presented to incorporate these effects for more accurate prediction on shale oil production performance. The compositional model considering the confined phase behavior is used to model the multiphase flow in shale formations, in which the capillary pressure is introduced into the workflows of phase stability test and flash calculation. The embedded discrete fracture model (EDFM) is adopted to explicitly describe the complex fracture geometries. The deformations of hydraulic fractures and natural fractures are handled by different constitutive models. A mixed finite-volume and finite-element (FVM-FEM) scheme is used to discretize the flow and geomechanics equations, and the coupled problem is iteratively solved by the fixed-stress splitting method. Based on the proposed model, simulations are conducted on a multi-stage fractured shale reservoir to evaluate the effects of confined phase behavior, hydraulic fracture deformation, and natural fracture network on the production performance. Results show that the bubble point pressure is suppressed by the confined phase behavior effect, which leads to higher oil production. The hydraulic fracture deformation takes effect only when the hydraulic fractures cannot be treated as infinite-conductivity under poorly-propped condition. The oil production is greatly promoted with the increase of natural fracture density due to the increase of interface area between matrix and fractures. • A coupled compositional flow and geomechanics model with confined phase behavior is developed for shale oil reservoirs. • EDFM coupled with different constitutive models are used to describe the hydro-mechanical behaviors of complex fractures. • Effects of confined phase behavior, hydraulic fracture deformation, and natural fractures on oil production are investigated. [ABSTRACT FROM AUTHOR]