Numerical studies on displacement-imbibition process of pore-network extracted from the microfluidic chip

The flow law of two-phase flow under complex capillary structure can be applied to explain the variability of development efficiency during the displacement, imbibition, and huff-and-puff process with different construction parameters. Microfluidic chips have attracted considerable attention as an effective laboratory research method on the displacement and imbibition processes in the complex pore-network. While, laboratory methods provide only an extremely limited amount of information, numerical simulation can reveal more detailed flow field information of two-phase flow in complex pore-network. In particular, computational dynamics methods can simulate the fluid flow process in the complex capillary structure. To this end, our study aimed to analyze the influence of different parameters on the oil recovery and swept area by relying on numerical simulations, dynamic analysis, and previous studies. Furthermore, by using distribution maps with flow filed and phase filed, we uniquely focused on the flow field information and dynamic process analysis during the displacement-imbibition process to elucidate the mechanism of remaining oil, trapped and displaced. Moreover, we examined the sensitivity characteristics of cumulative oil recovery during the displacement-imbibition process within a reasonably narrow parameter variation range. Lastly, some follow-up improvement suggestions were provided to facilitate the oil recovery under displacement-imbibition process.