Two new flow parameters derived from laboratory core-flood experiments are used in building mathematical models to predict the performance of an acid treatment when treatment is made with self diverting fracturing acids. The two new variables are: ΔPr is defined as the value of Δp (in the core flood experiment) when Δp switches from a first to a second linear trend at time tr ⊖r is the number of pore volumes injected when the switch occurs.