Modeling the Impact of Diverting Agents on Acidization of Heterogeneous Carbonate Reservoir Based on Radial System

Using diverter agents in matrix acidizing is one of the common techniques in the heterogeneous reservoirs. These agents temporary block the high-permeability layer by increasing the viscosity and thus diverting the acid to the low-permeability layer. Here, a rheological model that was developed by previous researchers is used for in-situ gelled acids by considering the main parameters such as shear rate, pH, and temperature. Then, the rheological model is combined with the extended two-scale continuum model to describe the underlying reactive transport mechanisms. The results were compared with the Newtonian acid. Furthermore, the apparent viscosity of the in-situ gelled acid is estimated and updated at each time step of the modeling. In this study, the results of the linear and radial system were compared with each other. The results show that in the linear model, the growth and propagation of acid in high permeability region is stopped due to high viscosity. Therefore, acid starts diverting from high permeability zone to low permeability zone. However, several wormholes are formed in a radial model; moreover, the wormholes prevent diverting acid from high permeability region to low permeability region. In other words, the existing model could not respond to divert acid from high-perm region to low-perm region in the radial system.