Innovations in Flow Rate Maximization for Geothermal Energy

Abstract Low-enthalpy geothermal energy holds substantial potential for district heating, a sector key to achieve carbon neutrality. With an increasing emphasis on renewable heating solutions, optimizing the extraction efficiency of geothermal wells can significantly improve their economic viability, making them more attractive in the shift towards sustainable energy systems. This paper examines techniques to maximize flow rates in geothermal gravel-pack completions, especially in unconsolidated sandstones, to enhance the rentability of low-enthalpy geothermal projects. Gravel-pack completions are widely used in unconsolidated sandstone formations, where they stabilize the wellbore and reduce sand production. However, limitations in sand control and formation damage can restrict flow rates, thereby impacting energy output and efficiency. Through recent advancements in Germany, new methods have been developed to address these challenges by defining critical drawdown pressures and identifying maximum achievable flow rates. Detailed analysis of these wells offers insights into managing gravel-pack performance by preventing sand migration and formation compaction, ensuring sustained high productivity. With optimized gravel-pack completions, the wells examined have achieved flow rates exceeding 300 m³/h (around 45,500 bbl/day), a substantial improvement over traditional methods. These high flow rates translate to significantly enhanced heat output, enabling a more robust and reliable heat supply. This achievement underscores the role of well optimization techniques in enhancing geothermal energy extraction from low-enthalpy sources. The results of this study highlight the potential of improved gravel-pack completions to unlock greater energy production from geothermal wells, underscoring their feasibility as a long-term investment. By reaching higher flow rates, these geothermal projects deliver not only larger heat outputs but also better economic returns. This makes them increasingly attractive for energy developers and investors aiming to support a decarbonized heating infrastructure. The findings indicate a pathway to both environmental and economic sustainability, further solidifying low-enthalpy geothermal energy as a cornerstone of future district heating.