以氨基磺酸（SA）为芯材、乙基纤维素（EC）为壁材，采用油相相分离法制备了EC/SA微胶囊。研究了EC黏度、芯壁质量比及搅拌速率等因素对微胶囊包封率的影响。利用红外光谱（FT-IR）、扫描电镜（SEM）对所得微胶囊进行表征，并测试其在不同温度下的缓释性。最佳工艺条件为：EC黏度为180~220 mPa·s、芯壁比为10∶3、搅拌速率为500 r/min。红外光谱和扫描电镜结果表明，氨基磺酸被成功包覆于乙基纤维素内。释放实验结果表明，在80℃时释放率为78.13%；随着释放环境温度的升高，微胶囊释放速率和累积释放率均增加，缓释时间可达80 min，满足现场施工需求，可实现地层深部酸化；对微胶囊释放效果进行数学拟合，结果表明，释放模型符合一级动力学模型，释放行为主要受囊芯从囊壁中延缓扩散控制。

EC/SA microcapsules are prepared through oil phase separation method using sulfamic acid (SA) as core material and ethyl cellulose (EC) as wall material.The effects of EC viscosity,core/wall ratio and stirring rate on the encapsulation efficiency of microcapsules are studied.The obtained microcapsules are characterized by FT-IR and SEM,and tested at different temperatures.The optimum process conditions are gained as follows:EC viscosity is in the range of 180-220 MPa·s,the ratio of core to wall is 10:3 and stirring rate is 500 r·min^-1.Results from FT-IR and SEM indicate that sulfamic acid is successfully coated into ethyl cellulose.The release test results show that the release rate reaches 78.13% at 80℃;the release rate and cumulative release rate of microcapsules both increase with the release of ambient temperature,and the sustained release time can reach up to 80 min,which can meet the on-site construction requirements and realize deep acidification.Through mathematically fitting the microcapsule release effect,the results show that the release model conforms to the first-order kinetic model,indicating that the release behavior is controlled mainly by the slow diffusion of core from capsule wall.

彭志刚(1976-),男,博士,教授级高级工程师,博士生导师,研究方向为油气田应用化学,1483141754@qq.com。