The characterization of solute transport dynamics in both the injection wellbore and the aquifer is essential for parameter estimation in the divergent flow tracer test. However, many previous studies usually ignore the transport dynamics in the wellbore and represent it with simple injection modes. In this study, a new model was developed by considering the transport dynamic in the injection wellbore. A semi-analytical solution of the new model was derived and validated to better analyze the effects of the wellbore and aquifer on the anomalous transport dynamic and mass exchange in the injection wellbore–aquifer system. The results show that the injection wellbore has a significant effect on solute transport in the aquifer. As the Peclet number (Pe1) in the wellbore increases, the value of peak concentration of the breakthrough curves (BTCs) in the aquifer increases and the value of late-time tailing of the BTC decreases. Particularly, the simulated BTC by the new model reduces to the traditional model when the Pe1 is large enough. The aquifer inversely influences the sub-diffusion in the wellbore such that an increase in porosity in the aquifer leads to a stronger sub-diffusion in the wellbore, while a decrease in dispersivity in the aquifer leads to weaker sub-diffusion in the wellbore. These findings shed light on the quantification of sub-diffusion in the wellbore–aquifer system.
Pan et al. (Thu,) studied this question.
Synapse has enriched 5 closely related papers on similar clinical questions. Consider them for comparative context: