In the rapidly evolving energy sector, the construction of pumped storage power stations is gaining momentum as a crucial component of grid stability and renewable energy integration. However, the accuracy of high-pressure water injection tests in deep boreholes has long been a contentious issue, with conventional methods often leading to significant errors. A groundbreaking study published in the journal Engineering Science and Technology (工程科学与技术) by lead author YANG Wenchao, aims to address this challenge by introducing an external water pressure reduction coefficient, potentially revolutionizing the way these tests are conducted and interpreted.
Pumped storage power stations rely on deep boreholes to facilitate water flow between upper and lower reservoirs, generating electricity during peak demand and storing energy during off-peak hours. The high-pressure water injection test is a critical step in assessing the permeability and splitting pressure of rock formations, ensuring the structural integrity and efficiency of these power stations. However, traditional calculation methods have often overestimated external water pressure, leading to inaccurate parameters and suboptimal engineering designs.
YANG Wenchao’s research delves into the intricacies of these calculations, identifying the root cause of the discrepancies. “The current specification for pressure calculation assumes that the external water pressure exerted by the borehole water on the test section equals its full hydrostatic pressure,” explains YANG. “This assumption leads to an overestimated external water pressure, which is the primary cause of parameter errors in deep-borehole high-pressure water injection tests.”
To rectify this, YANG introduces an external water pressure reduction coefficient, recalibrating the additional hydraulic pressure calculation under various groundwater conditions. This adjustment brings the external water pressure closer to actual field conditions, yielding more rational computational parameters. The method was validated through a case study at a pumped storage power station, demonstrating significant improvements in the accuracy of permeability rates and splitting pressure calculations.
The implications of this research are far-reaching for the energy sector. By providing more accurate parameters, the modified reduction coefficient approach enables better characterization of rock mass permeability and fracturing pressure. This, in turn, allows for more effective mobilization of the rock’s anti-seepage potential, optimizing designs, and reducing project costs. As the construction of pumped storage power stations continues to expand, with boreholes reaching greater depths, the accuracy of high-pressure water injection test parameters becomes increasingly critical.
The study’s findings suggest that incorporating external water pressure reduction coefficients into high-pressure water injection test calculations can achieve a more scientific balance between design safety and construction costs. This approach not only enhances the quality of survey and design works but also paves the way for more efficient and cost-effective pumped storage power station projects.
As the energy sector continues to evolve, driven by the need for renewable energy integration and grid stability, innovations like YANG’s reduction coefficient method will play a pivotal role in shaping the future of pumped storage power stations. By addressing the long-standing issue of inaccurate high-pressure water injection test parameters, this research offers a promising solution that could significantly impact the commercial viability and operational efficiency of these critical energy infrastructure projects.