## 2 Literature Review  
Externally applied stress refers to the forces acting on the reservoir rock due to various factors, including tectonic stresses, overburden pressure, and fluid injection or withdrawal [13; 14; 15]. External stressors induce reservoir deformation, leading to changes in the rock's mechanical properties, such as porosity, permeability, and fracture aperture [16; 17]. These changes, including stress-dependent permeability, porosity, and fracture aperture alterations, have significant implications for reservoir management and ultimately influence the flow of fluids within the reservoir [18; 19; 20]. The relationship between externally applied stress and multiphase flow characteristics in naturally fractured tight reservoirs is a complex and multifaceted topic that requires careful investigation because the behavior of multiphase fluids within naturally fractured tight reservoirs is profoundly affected by externally applied stress [21; 22; 23]. The interaction between hydrocarbons, water, and rock under stress conditions leads to complex phenomena, including capillary pressure variations, relative permeability alterations, and changes in wettability [24; 25; 26]. These factors have a direct impact on reservoir production rates and ultimate recovery. Understanding how these external stresses affect fluid flow through fractures is crucial for optimizing production and reservoir management. Understanding how externally applied stress influences multiphase flow within naturally fractured tight reservoirs is essential for several reasons. First, it can provide valuable insights into reservoir behavior, which can inform reservoir management strategies and enhance hydrocarbon recovery [27; 28]. Second, it can help mitigate the risks associated with hydraulic fracturing operations, ensuring that fractures propagate in a controlled manner and do not interfere with nearby wells or environmental factors [29; 30]. Third, it can contribute to the development of advanced modelling and simulation tools that can predict reservoir response to stress changes, leading to more accurate reservoir performance predictions [31]. There are numerous numerical approaches for modelling poroelastic issues. [PERSON] et al. [32], for example, developed a coupled stress and reservoir simulator with a staggered grid Finite Difference Method (FDM) to improve wellbore stability. On the other hand, [PERSON] et al. [33] developed a coupled fluid-flow/stress model to forecast stress evolution using the Finite Volume Method (FVM) in unconventional reservoirs. [PERSON] and [PERSON] [34] have reported a similar implementation of FVM because of the advantage of full cell-centered variables across fluid flow and solid mechanics. Furthermore, due to its robustness in solving diverse solid mechanics equations, the Finite Element Method (FEM) is a popular alternative, and it has been widely employed in the literature to tackle complex poroelastic situations [35]. Many research efforts and signs of progress have been made toward understanding and modelling fluid flow in fractured porous media in the past half-century. However, most studies focused on the single-phase flow [36; 37; 38] without taking into account multiphase flow and an understanding of the phase flow characteristics and development at the fracture-matrix interaction. The fracture-matrix interface is an important area to consider because it can significantly impact fluid flow in the reservoir. The properties of the interface, such as the roughness and wettability, can affect how fluids move through the fractures and into the matrix. Additionally, the stress applied to the interface can affect the connectivity between the fractures and the matrix, which can impact the overall flow behavior of the reservoir. The motivation for studying the effects of externally applied stress on multiphase flow characteristics at the fracture-matrix interface in naturally fractured tight reservoirs stems from the increasing importance of unconventional resources in global energy production.