Wormlike micelles formed by amidosulfobetaine surfactants present advantage in increasing viscosity, salt-tolerance, thermal-stability and shear-resistance. In the past few years, much attention has been paid on rheology behaviours of amidosulfobetaine surfactants that normally bear C18 or shorter tails. Properties and oil displacement performances of the wormlike micelles formed by counterparts bearing the long carbon chain have not been well documented. In this paper, the various properties of C22-tailed amidosulfobetaine surfactant EHSB under high salinity (TDS = 40g/L) are investigated systematically, including solubility, rheology and interfacial activity. Moreover, its oil displacement performance is studied for the first time. These properties are first compared with those of C16-tailed counterpart HDPS. Results show that the Krafft temperature(T_K) of EHSB decreases from above 100°C to 53°C with the increase of TDS to 40 g/L. Increasing concentration of EHSB in the semidilute region induces micelle growth from rod-like micelles to wormlike micelles, and then the worms become entangled or branched to form viscoelastic micelle solution, which will increase the viscosity by several orders of magnitude. The interfacial tension with oil can be reduced to ultra-low level by EHSB solution with concentration below 4.5 mM. Possessing dual functions of mobility control and reducing interfacial tension, wormlike micelles formed by EHSB present a good displacement effect as a flooding system, which is more than 10% higher than HPAM with the same viscosity. Compared with the shorter tailed surfactant, the ultra-long tailed surfactant is more efficient in enhancing viscosity and reducing interfacial tension, so as to enhance more oil recovery. Our work provides a helpful insight for comprehending surfactant-based viscoelastic fluid and provides a new viscoelastic surfactant flooding agent which is quite efficient in chemical flooding of offshore oilfield.

由氨基磺基甜菜碱表面活性剂形成的蠕虫状胶束在增加粘度，耐盐性，热稳定性和抗剪切性方面具有优势。在过去的几年中，人们对氨基磺基甜菜碱表面活性剂的流变行为给予了极大的关注，这些表面活性剂通常带有C18或更短的尾巴。由具有长碳链的对应物形成的蠕虫状胶束的性能和驱油性能尚未得到充分证明。本文系统地研究了高盐度（TDS = 40g / L）下C22尾氨基磺基甜菜碱表面活性剂EHSB的各种性能，包括溶解度，流变性和界面活性。此外，首次研究了其驱油性能。首先将这些属性与C16尾部对应的HDPS进行比较。Ť _ķ随着TDS升高至40 g / L，EHSB的温度从100°C降低至53°C。半稀释区中EHSB浓度的增加会导致胶束从棒状胶束生长到蠕虫状胶束，然后蠕虫缠结或分支形成粘弹性胶束溶液，这将使粘度增加几个数量级。浓度低于4.5 mM的EHSB溶液可将与油的界面张力降低至超低水平。EHSB形成的蠕虫状胶束具有流动性控制和降低界面张力的双重功能，具有良好的驱油效果​​，比相同粘度的HPAM高出10％以上。与较短的拖尾表面活性剂相比，超长尾表面活性剂更有效地提高粘度和降低界面张力，从而提高采油率。我们的工作为理解基于表面活性剂的粘弹性流体提供了有益的见解，并提供了一种新的粘弹性表面活性剂驱油剂，在海上油田的化学驱油中非常有效。