# Study on the Mechanism of Stress Sensitivity Changes in Ultra-Deep Carbonate Reservoirs
## 5 Discussion  
This study combines experiments and numerical simulations to conduct an in-depth study of the stress sensitivity of ultra-deep carbonate reservoirs. Our results show that the stress sensitivity of matrix and fractured carbonate reservoirs is closely related to the Young's modulus of the rock framework under the same effective stress conditions. This finding is consistent with the results of [PERSON], who found a linear relationship between the Young's modulus of the rock and stress sensitivity. However, our study further reveals that under ultra-deep conditions, the stress sensitivity of fractured reservoirs is usually higher than that of matrix reservoirs, which may be related to the development and direction of the cracks. However, during our literature review process, we found that [PERSON] [35] considered the aspect ratio of the length-to-width of cracks when studying the stress sensitivity of shale. We did not conduct a thorough investigation into this, and this is an aspect that we need to improve on.  
When discussing our research results, we must consider the limitations of our methods. Although our experimental design aims to simulate realistic geological conditions, the selection of samples and experimental conditions may not fully capture the complexity  
Figure 14: Comparison of stress sensitivity curves for matrix-type and fractured carbonates.  
Figure 15: A comparison chart of the degree of permeability loss.  
of ultra-deep carbonate reservoirs. For example, we did not simulate the influence of temperature changes on the rock mechanic properties in the experiments, which may play an important role in actual reservoirs. In addition, our numerical simulation may not fully consider all factors that affect changes in permeability, such as changes in fluid pressure and rock heterogeneity.  
Compared with traditional methods of evaluating stress sensitivity, such as [PERSON]'s flow equation solutions and [PERSON]'s perturbation analysis, our research proposes a more intuitive and quantitative evaluation method. By establishing a dual-porosity media model, we can more accurately simulate and predict the changes in the permeability of reservoirs under different stress conditions. However, during the experimental stage, due to the limitations of actual core samples, we obtained relatively few cores, which may have caused accidental results in our experiments. In addition, when dealing with complex fracture reservoir networks, our models may need further testing and adjustment.  
In practical applications, our research has important implications for the development of ultra-deep carbonate reservoirs. By accurately evaluating stress sensitivity, we may optimize drilling strategies, reduce permeability loss during production processes, and thus increase the efficiency of oil and gas field development. Future research can explore the stress sensitivity under different geological conditions and develop new experimental and simulation methods to improve the accuracy of evaluation.  
Future research should be dedicated to overcoming the limitations of current research and further validating our results, for example, by improving the representativeness of the research by increasing the quantity and diversity of the samples. In addition, future research can explore the effects of temperature, chemical reactions, and changes in fluid pressure on stress sensitivity. Through these efforts, we can better understand the complex behavior of ultra-deep carbonate reservoirs, and provide a scientific basis for the effective development of oil and gas resources.