(246d) Modeling and Analysis of Wormhole Formation in Carbonates with Diverting Acids

We develop a semi-empirical complete rheological model for diverting acids that accounts for the effect of change in temperature, shear rate/pressure drop, and pH/concentration. A previously developed two-scale continuum model is modified to include non-Newtonian and diverting behaviors and used with the rheological model to analyze the stimulation of single/dual core set-ups with both Newtonian and diverting acids at constant injection rate. The acidization curve is found to be shallower for diverting acids as compared to Newtonian acids. We show that an efficient stimulation of dual core set-ups with Newtonian acids can be achieved if it is operated in uniform dissolution region based on total injection rate. Finally, we show that when dual core set-ups are stimulated with diverting acids, flow is diverted from high-perm core to low-perm core and from low-perm core to high-perm core several times until the exit concentration exceeds a certain value that depends on the fluid characteristics.