Investigation into the effects of different configurations of one irrigation well and six pumping wells on thermal recovery efficiency

The configurations of pumping and irrigation wells critically govern thermal recovery efficiency during subsurface water resource extraction. Numerical simulations were performed to evaluate a layout comprising one injection well and six pumping wells. The analysis focused on extracted water temperatures and thermal distributions within the surrounding rock mass. The results indicated that heat exchange between injection and pumping wells produced four distinct thermal patterns across different layout designs. These temperature distributions were categorized as Types ‘‘I’’, ‘‘III’’, ‘‘IV’’, and ‘‘V’’. Second-row placement of the injection well required 33 months to reach a steady state. This layout produced the highest heat flux density within the rock mass and pumping wells. It also exhibited the most rapid heat conduction. Third-row placement required approximately 31 months to stabilize. This configuration yielded the lowest heat flux density and the slowest heat conduction rate. First-row placement required approximately 30 months to achieve stability. This setup demonstrated superior performance. It yielded the highest single-well discharge temperature (84.44 °C) and the highest average discharge temperature across all pumping wells (77.81 °C). Consequently, this arrangement achieved the maximum thermal recovery efficiency.