Pore-scale investigation on reactive flow in porous media considering dissolution and precipitation by LBM

The reactive transport process in oil gas reservoirs is complicated due to the coupling between dissolution and precipitation. In the present study, based on lattice Boltzmann method, the coupled dissolution and precipitation process in randomly generated porous media by quartet structure generation is investigated at the scale of geological pores. The fluid velocity, temperature and concentration in porous media are solved by multicomponent flow lattice Boltzmann model, multicomponent thermal lattice Boltzmann model and mass transport lattice Boltzmann model, respectively. The solid phase is updated by volume of pixel method. The results show that the dissolution reaction rate has a positive impact on the consumption of reactants. For different precipitation reaction rates, there exists an optimal value resulting in abundant precipitate and sparse solid distribution. Reaction equilibrium constant affects reaction rates slightly but influence the solid morphology heavily. The coupled dissolution and precipitation process accelerates with the increase of Peclet number, but the precipitate produced increases with the decrease of Peclet number.

Automated summary

In this study, the coupled dissolution and precipitation process in oil gas reservoirs is investigated at the scale of geological pores using the lattice Boltzmann method. It is found that the dissolution reaction rate positively impacts the consumption of reactants, while the precipitation reaction rate affects the precipitate quantity and solid morphology. The coupled process accelerates with an increase in the Peclet number, but the amount of precipitate increases with a decrease in the Peclet number.