<p>This study aimed to evaluate the effect of injection rates of urease enzyme and reactant (urea and CaCl₂) solutions on enzyme-induced calcium carbonate precipitation (EICP) when enhancing the sealing capacity of a geologic medium. First, to this end, the optimal urease concentration was determined by fitting experimental data of urea decomposition by urease enzyme with time to the rate equation of urea hydrolysis. Using this, the batch modeling was conducted to examine the effects of concentrations of enzyme and reactant on EICP. Then, the reactive transport modeling was performed to identify the impact of injection rate on the calcite precipitation at a core scale with 4 injection cycles. The batch modeling results showed that the concentration of enzyme affected the rate of calcite precipitation, while that of reactant affected the amount of calcite precipitation. The reactive transport modeling showed that the amount of calcite precipitation increased with the number of injection cycles. In addition, the area where calcite was mainly precipitated in the model domain varied depending on the injection rate, with relatively faster injection rate resulting in more homogeneous calcite precipitation across the domain. Furthermore, the calculated permeability decreased by up to 90% compared to the initial value after 4 injection cycles. Thus, our modeling results demonstrated that EICP could significantly enhance the sealing capacity of a geologic medium. This study also suggests that a reactive transport model can be useful to establish an appropriate injection strategy, such as injection rate and cycle, for field application of EICP.</p>