**5. Discussion and Conclusions**

Based on the established rock-mechanics multi-physical field fluid–solid coupling hydraulic-fracturing mechanical model and the assumptions and boundary conditions in computational fluid mechanics and rock mechanics, the turbulent control equation of the internal flow field in the borehole, the boundary laminar-flow control equation, and the fluid–solid coupling boundary conditions were obtained, and the rock-mass model borehole surface was substituted as the load boundary condition to simulate the impact of the stress shadow effect on the fracturing effect under different borehole spacings. At the same time, the borehole diameter and spacing suitable for the geological conditions of the example were compared.

In practice, the conclusions of this paper are the following:


**Author Contributions:** Conceptualization, S.W.; methodology, S.W.; software; J.L.; validation, S.W.; formal analysis, S.W.; investigation, S.W.; resources, S.W.; data curation, S.W.; writing—original draft preparation, S.W.; writing—review and editing, J.L.; visualization, J.L.; supervision, S.W.; project administration, S.W. All authors have read and agreed to the published version of the manuscript.

**Funding:** This research received no external funding.

**Institutional Review Board Statement:** Not applicable.

**Informed Consent Statement:** Informed consent was obtained from all subjects involved in the study.

**Data Availability Statement:** The experimental and analytical calculation data used to support the findings of this study are included within the article.

**Conflicts of Interest:** The authors declare that there are no conflicts of interest regarding the publication of this paper.
