Inversion-Based Assessment of the Clogging Characteristics of Injection Wells Using Analytical Calculations

Managed aquifer recharge (MAR) addresses groundwater overexploitation and its related detrimental ecological and environmental impacts. However, clogging issues pose significant challenges to the efficiency and sustainability of recharge engineering. This study focused on injection wells and surrounding aquifers as primary research components, utilizing field test data obtained from artificial groundwater recharge operations. A mathematical model was established to quantify head loss occurring within the injection well–aquifer system. To assess the hydrodynamic characteristics across various components of the recharge area, this study employed specific analytical formulas for accurate calculations. Additionally, an inversion method was utilized to identify clogging locations within the recharge system precisely. The findings indicate that the likelihood of clogging increases under elevated injection rate conditions. Moreover, when maintaining a constant flow rate, water level fluctuations within a 5-m radius of the injection well are significantly greater than those at farther distances, highlighting this near-well region as a critical zone with high potential for severe clogging. Specifically, head losses within the gravel-packed layer itself are relatively minor, contributing only 0.88%–1.19% of the total head loss. In contrast, variations in clogging thickness at the wire-wrapped screen position and the interface between the gravel-packed layer and the aquifer—attributed to the skin effect—dominate the total head loss, accounting for substantial portions of 32.60%–33.64% and 65.17%–66.52%, respectively. Therefore, targeted monitoring and effective removal of the filter cake that accumulates at multiple interfaces due to the skin effect are essential to sustain the infiltration efficiency of artificial groundwater recharge projects.