Abstract: Viscoelastic compositions suitable for use as diversion agents in a process for acidizing a carbonate-based subterranean oilfield formation are disclosed. The compositions comprise water, a tall oil fatty acid (TOFA)-based amidoamine betaine, a C1-C4 alcohol, and propylene glycol. The invention includes an acidizing process that utilizes a mineral acid and an effective amount of the viscoelastic composition. The viscoelastic compositions effectively divert acid flow, thereby optimizing acid utilization and minimizing acid spend. The compositions fully develop formations, stabilize and/or promote formation of worm-like micelles, and maintain a high, stable viscosity during an acidizing process. Surprisingly, the compositions perform well at low surfactant does, high pressures, and temperatures greater than 350° F. The compositions can tolerate higher levels of corrosion inhibitors than known alternatives and can be used in formations having ferric ion contents greater than 10,000 ppm.