A recent study led by Bing Wang from the Tianjin Geothermal Exploration and Development Design Institute has unveiled promising findings regarding the reinjection of treated surface water into sandstone geothermal reservoirs, specifically focusing on the Guantao Formation in Tianjin. This research addresses significant challenges in the sustainable utilization of geothermal resources, which are abundant in the region but often face issues related to reinjection capacity and efficiency.
Geothermal energy is increasingly recognized as a vital component in the transition to sustainable energy systems, and the reinjection of geothermal fluids is essential for maintaining reservoir pressure and prolonging the lifespan of geothermal fields. However, in Tianjin, the volume of geothermal water extracted often exceeds the amount that can be reinjected, leading to potential environmental concerns. The study emphasizes the importance of exploring alternative water sources for reinjection, particularly treated surface water, to balance this discrepancy.
The researchers conducted laboratory experiments to simulate the treatment process of surface water for reinjection. They found that utilizing nanofiltration and tubular microfiltration membranes was crucial in ensuring the stability of the system. The experiments revealed that after reinjecting a mixed water sample into the sandstone reservoir, the water’s pH and total dissolved solids (TDS) decreased, indicating the formation of acidic substances and precipitates. The hydrochemical type remained consistent, primarily Cl-Na, which suggests that the reinjection process would not adversely affect the existing reservoir chemistry.
Wang stated, “The reinjection of treated surface water into sandstone geothermal reservoirs is feasible from a hydrogeochemical perspective.” This statement underscores the potential for utilizing treated surface water to enhance geothermal resource management, especially in regions like Tianjin where water scarcity and environmental sustainability are pressing concerns.
The implications of this research extend beyond academic interest; it opens up commercial opportunities for sectors involved in geothermal energy, environmental engineering, and water treatment technologies. Companies specializing in water purification and geothermal energy development could benefit from advancements in reinjection techniques, particularly as municipalities and industries seek sustainable solutions to meet energy demands while adhering to carbon neutrality goals.
Moreover, the findings provide a foundation for future field tests and the establishment of a long-term geothermal fluid dynamic monitoring network, which could further enhance the reliability and efficiency of geothermal systems. As the demand for renewable energy sources continues to grow, the integration of treated surface water into geothermal systems could become a standard practice, paving the way for more sustainable energy solutions.
This study, published in the journal Water, represents a significant step towards optimizing geothermal resource management and contributes valuable insights for the development of external water reinjection projects in hot spring health care units. The research not only supports local sustainability initiatives but also aligns with broader global objectives of carbon peaking and carbon neutrality.
