## 7 Conclusions  
Modelling transient multiphase fluid flow in naturally fractured tight reservoirs is a challenging task that requires careful consideration of the stress-dependent petrophysical properties and the stress-dependent flow characteristics, especially at the fracture-matrix interface. This study adopts a coupled FEM-CFD numerical modelling technique in order to accurately predict oil recovery from fractured reservoirs. The results obtained through the use of a well-validated coupled FEM-CFD model show that as external stress loading increases, the porosity and permeability of the naturally fractured tight reservoir decrease, which is expected under real-world conditions. Increasing the stress loading on the reservoir sample 1.5-fold, the matrix porosity decreases by 0.13% and the matrix permeability reduces by 1.3%. The intact rock's contribution to the determined strain and conductivity of the fractured core is low due to minimal pore strain and low permeability. It has been observed that the fracture aperture and its vertical displacement decrease as the external stress increases, reducing the mean fracture aperture. Therefore, stress also has a profound impact on fracture permeability, which was found to decrease by up to 29% as external loading increased from 6.9 MPa to 17.2 MPa. Moreover, the capillary pressure decreases due to an increase in stress loading at the fracture-matrix interface. The fracture-matrix interface becomes water-wet when the stress loading increases, while the relative permeability curves shift towards the right. These results provide meaningful insights into the multiphase flow behavior of naturally fractured tight reservoirs under externally applied stress and highlight the importance of understanding these phenomena in various geological and engineering applications. These findings are also invaluable for optimizing oil recovery strategies and making informed decisions in the field of petroleum engineering. Further research in this area can help refine models and improve the efficiency of oil recovery processes in fractured reservoirs. While the current study focuses on the effects of stress on multiphase flow at the fracture-matrix interface, further research could involve a more comprehensive analysis of dynamic stress changes, such as those induced by hydraulic fracturing or reservoir depletion. Incorporating real-time field data and extending the simulation to include thermal effects could provide deeper insights into the performance of enhanced oil recovery methods. Additionally, integrating machine-learning techniques to predict reservoir behavior under varying stress conditions could significantly enhance the model's predictive capabilities and offer a more efficient approach to reservoir management.  
[PERSON] contributed to the conceptualization, data preparation, simulation, technical testing, writing, and interpretation. [PERSON], identified as the corresponding author, played a key role in the conceptualization, review, editing, feedback, supervision, project management, model accuracy assessments, and writing. All authors have read and agreed to the published version of the manuscript.  
The research received no external funding.  
Not applicable.  
Data Availability Statement: Data is contained within the article.  
The authors declare no conflicts of interest.