Physicochemical Properties and Applications of Cardanol‐Based Sulfonate Surfactant for Enhanced Oil Recovery

ABSTRACT With the continuous growth of global energy demand, surfactants have demonstrated superior performance in enhanced oil recovery (EOR). However, conventional surfactants frequently face challenges in terms of environmental sustainability and economic viability. In response to these limitations, this study synthesized a cardanol‐based surfactant (CaTa) using renewable cardanol and taurine as raw materials, and systematically investigated its application performance in EOR. The bio‐based surfactant was characterized using 1 HNMR, FT‐IR, TGA, and TEM. The interfacial tension measurement results indicated that this bio‐based surfactant can reduce the crude oil–water interfacial tension to an ultra‐low level. Additionally, when oil‐wet calcite was treated with a 0.5 wt% CaTa solution, the contact angle of water droplets on its surface decreased dramatically from 110° to 18°. Emulsion tests further showed that emulsions prepared with 0.5 wt% CaTa and crude oil exhibited an emulsification index of 82.5%. Finally, the efficacy of CaTa in EOR was validated through microscopic oil displacement experiments. These findings suggest that the bio‐based surfactant shows promising potential for EOR applications.