Differences in reservoir permeability can lead to poor acidizing results. The use of viscoelastic diverting acid during acidizing can significantly improve production.
At the initial stage of the treatment, the acid preferentially enters high-permeability zones or natural fractures. As the viscosity of the acid system increases, these zones effectively become “low-permeability” pathways. The acid then begins to enter previously low-permeability zones, which become relatively higher-permeability pathways.
Due to this intelligent viscosity-switching effect, the entire reservoir interval can be acidized more uniformly, unlocking the production potential of low-permeability formations.