In the quest to harness the Earth’s heat more efficiently, a groundbreaking study led by Hongwei Wang from the Center for Hydrogeology and Environmental Geology Survey, China Geological Survey, Ministry of Natural Resources, has shed new light on the potential of enhanced geothermal systems (EGS). The research, published in the journal ‘Geothermal Energy’, delves into the complexities of heat extraction and fluid dynamics in geothermal wells, offering insights that could revolutionize the industry.
The study focuses on the Fenton Hill Hot Dry Rock (HDR) project, a pioneering endeavor in geothermal energy. Wang and his team developed a sophisticated time-dependent seepage and heat exchange model to understand the intricacies of heat transfer within the formation–wellbore–fluid system. Their findings reveal that optimizing various factors can significantly enhance the efficiency of geothermal energy production.
One of the key discoveries is the optimal output of 3.4 MW that can be achieved in the horizontal segment of a double-well EGS at an injection rate of 30 kg/s. This is a game-changer for the industry, as it demonstrates the potential for substantial energy output from a single well configuration. “The extraction temperature shows a positive correlation with factors such as heat production and electrical power generation,” Wang explains, highlighting the direct impact on energy output.
The research also introduces the concept of multiple fracturing horizontal wells (MFHW), a novel approach that could transform geothermal energy extraction. By increasing the number of perforation fractures, enhancing artificial fracture spacing, improving the perforation angle, extending the horizontal segment, reducing well diameter, and employing a longer vertical heat insulation pipe with lower thermal conductivity, the heat production potential can be significantly optimized. This multi-well EGS model, particularly the two-injection-one-production configuration, shows superior performance, with heat production being twice as efficient as that of the traditional one-injection-one-production double-well EGS model.
The implications of this research are vast. For the energy sector, this means more efficient and cost-effective geothermal energy production, which could make geothermal a more competitive renewable energy source. The ability to optimize heat production through well design and fluid dynamics could lead to a surge in geothermal projects, reducing reliance on fossil fuels and mitigating climate change.
As the world seeks sustainable energy solutions, Wang’s research provides a roadmap for enhancing geothermal energy systems. By understanding and optimizing the factors that influence heat transfer and fluid dynamics, the industry can move towards more efficient and productive geothermal energy extraction. This study, published in ‘Geothermal Energy’, is a significant step forward in the quest for cleaner, more sustainable energy sources.
