## 4 Conclusions  
This paper utilizes the digital rock analysis technique to investigate tight sandstone reservoirs' pore structure and flow behavior, explicitly considering the impact of micro-fracture characteristics. The study investigated how petrophysical properties are affected by micro-fracture characteristics, such as aperture, length, and dip angle. The findings can be summarized as follows. 1. The application of digital rock analysis technology to tight sandstone reservoirs not only addresses the limitations of traditional experiments for analyzing complex tight sandstone rock samples but also offers the advantages of reproducibility and non-destructiveness. This technique provides insights into the microstructure and flow pattern of the tight sandstone reservoirs which are crucial for understanding their fluid flow behavior. Digital rock analysis technology offers a valuable tool for understanding the complex microstructures of tight sandstone reservoirs and providing critical insights into their properties and behavior. 2. With an increase in both fracture aperture and length, the distribution of the pore throat radius in tight sandstone reservoirs shifts from a conventional Gaussian shape to a bimodal feature, displaying multiple peaks. Furthermore, the contribution of pore throat radius to the permeability of the reservoir remains constant with the increase in fracture aperture and length, emphasizing the crucial role of these two  
Figure 16: The capillary pressure curve of embedding an artificial fracture with different dip angles in different directions. (**a**) is for the X direction, (**b**) is for the Y direction, and (**c**) is for the Z direction. parameters in determining the permeability. The permeability and capillary pressure curves are significantly influenced by the fracture aperture and length in the direction of connectivity but demonstrate a negligible relationship with these parameters in the non-connective direction. 3. The study has revealed that the dip angle of micro-fractures has a more pronounced effect on the pore throat structure of tight sandstone reservoirs, particularly on the radius of the throat as opposed to the radius of the pore. The permeability and fluid flow within the reservoir are impacted in varying ways by the dip angle of the micro-fracture, with the permeability initially increasing and then decreasing in the X and Y directions as the dip angle increases. This is due to the increased dip angle between the micro-fracture and the direction of fluid flow along these axes. The influence of the micro-fracture dip angle on fluid flow is further demonstrated by shifts observed in the capillary pressure curves, particularly in the X and Y directions. The results suggest a correlation between the direction of fluid flow and the characteristics of the capillary pressure curves. 4. According to the study, an increase in both the aperture and length of micro-fractures leads to an increase in the porosity of the tight sandstone reservoir. However, the effect of the dip angle of micro-fractures on porosity remains uncertain. These micro-fractures are found to improve the porosity and increase the interconnectivity of pores within the reservoir. [PERSON], [PERSON] and [PERSON] conceived the project; [PERSON] coded the related software and carried out the simulation and analyses and wrote the original manuscript; [PERSON] and [PERSON] provided technical advice throughout the project; [PERSON] assisted with the writing of this paper; [PERSON] supervised the overall project, and all author contributed to revising and improving the manuscript. All authors have read and agreed to the published version of the manuscript. The author thanks the sponsors of this research: the National Natural Science Foundation of China (No. 52034010, 52122402, 12172334, 42090024), Shandong Provincial Natural Science Foundation (No. ZR2022 JQ23), the Fundamental Research Funds for the Central Universities (No.