Review and Prospect of Viscoelastic Surfactant Diverting Acid

Abstract With the rapid development of social economy, global energy demand is growing rapidly. Carbonate reservoirs have attracted much attention due to their wide distribution and large reserves. Due to the heterogeneity of carbonate reservoirs, conventional acidification technology cannot meet the production requirements, and diverting acid must be used to achieve effective development. The biggest problem of commonly used polymer-based diversion acid is the polymer residue after acidification. In recent years, the viscoelastic surfactant diverting acid (VEDA) system has attracted much attention because it can be decomposed by a simple cleaning process after the temporary plugging and diverting acid operation is completed. This paper studies the VEDA system through a large number of literature research. The properties of (VES) were introduced, and the application of viscoelastic surfactant in VEDA was analyzed. Secondly, the working principle of VEDA acid system is listed and several methods for evaluating the diverting ability of VEDA (pressure drop curve, permeability change, wormhole expansion) are introduced. Then, the VEDA rheological model established by various scholars was summarized. Finally, the commonly used VEDA system and its application in this field are summarized.