Erosion and Clogging Mitigation in Sandstone Reservoirs Through Microbial Carbonate Precipitation: A Microfluidic Study

Abstract

Erosion-clogging presents a significant challenge for weakly consolidated sandstone reservoirs containing carbonate minerals, particularly in the vicinity of CO₂ injection wells, where fluid flow can exacerbate issues of subsurface stability and injectivity. This study investigates the performance and mechanisms of Microbially Induced Calcium Carbonate Precipitation (MICP) as a reinforcement strategy through microfluidic experiments, varying pH, flow rate, and treatment cycle conditions. The results demonstrate that MICP significantly enhances erosion resistance by forming dense, multiscale CaCO3 networks via particle bridging and interfacial cementation. Crystal dissolution exhibits a size-dependent buffering effect, where smaller crystals dissolve first to elevate local pH, protecting larger crystals and delaying structural degradation. MICP also reduces clogging by forming permeable crystal bridges at pore throats, restricting coarse particle transport while preserving flow paths. The extent of erosion and clogging near the injection well is strongly influenced by initial cementation volume (VCaCO3 /VV), with a dual-threshold effect: systems with ≥4% CaCO3 remain stable, while those with <2% destabilize rapidly. High acidity and flow rates exacerbate clogging by accelerating crystal dissolution and particle migration, but MICP treatment raises the critical flow threshold and mitigates sensitivity to hydraulic forces. These findings enhance the understanding of erosion–clogging mechanisms in the near-wellbore region and highlight the potential of MICP to improve injectivity and long-term reservoir integrity in CO₂ storage applications.

Keywords: Erosion-clogging, Microbially Induced Calcium Carbonate Precipitation (MICP), CO₂ injection well, Reservoir integrity, Microfluidic experiment