Acid fracturing is a well stimulation process commonly used in low-permeable carbonate reservoirs. Carbonates are generally low permeable but with high storativity and are natural candidates for acid fracturing. Increased hydraulic fracture penetration with minimum acid fluid loss is the key to effective stimulation in carbonates. It is a program integrating acid fracture penetration, fluid loss control, fluid diffusion, conductivity, reservoir fluid flow model, and well productivity index with a two-dimensional hydraulic fracture model. It shows the post-fracture productivity index, which increases by three to five times, depending on the treatment parameters. The present work will assist the designer in estimating the range of treatment parameters based on parametric sensitivity analyses.