Comparison of Pore-Scale and Darcy-Scale Simulation of Acid Injection in Carbonate Formations

Summary The numerical study presented in this paper, based on the use of Darcy and Darcy-Brinkman equations in pore-scale and Darcy-scale, gives a better understanding of the wormholing phenomenon. We have shown that the fluid phase dispersion coefficients used by Panga et al., 2005 match pore-scale simulation results reasonably. However, the mass transfer coefficient is not properly predicted by semi-empirical model ( Panga et al., 2005 ) when compared with pore-scale simulation. Here importantly, Darcy equation is found to be non-applicable when used to predict the flow inside the wormholes created by acid injection into carbonate formations. This has been shown for two cases with and without wormholes. Thus, Darcy equation used by researchers to determine optimum conditions for acid injection is not accurate.