Horizontal well fracturing technology is widely applied in tight or shale oil and gas reservoirs. Therefore, accurate and efficient dynamic simulation of multiphase flow in a fractured reservoir becomes an important issue. With more innovative fracturing technology, the number, shape, and interconnected relationship of hydraulic fractures have changed: 1) from a single fracture in fractured vertical wells to multi-cluster fracturing fractures in horizontal wells; 2) from symmetrical regular fractures to multi-angle irregular fractures; 3) from a single unconnected surface fracture to interlaced complex fracture network.

Fractured horizontal wells have now diversified which can imply the development of secondary oil recovery technology (water injection and gas injection). A single injection production pattern can imply multiple modes such as alternate injection, cyclic injection, and huff-n-puff. Traditional water injection and gas injection have developed into enhanced oil recovery (EOR) technologies such as polymers, surfactants, and bacterial culture fluids. We need to establish numerical simulation methods of fractured reservoirs to adapt to the new technology for simulation and optimization.

The aim of this Special Issue is to collect original research articles about the study of advanced numerical methods for the simulation of multiphase flow in fractured reservoirs. We hope that this Special Issue can also highlight multiphase flow as a vital tool for the development of unconventional reservoirs and the multi-phase migration simulation of underground fractured formations. Review articles discussing the state of the art are also welcome.

Potential topics include but are not limited to the following:

• Continuous medium or multi-medium model
• Discrete fracture model
• Discrete fracture network model (DFN)
• Embedded discrete fracture model (EDFM)
• Projection-based embedded discrete fracture model (pEDFM)
• Coupling of multiple models
• Order-reduction method
• Multi-scale method
• Applications of advanced numerical models in fractured reservoirs
• Simulation of dynamic behaviour of fractures