Preparation of Cleaning Agent for Treatment of Abandoned Oil PipelineFajie Yang, Shengmei Chi, Yufen Wen, Hongtao Wang, Jing Li, Feng Zhu, Chunman Li and Wang TianE3S Web Conf., 194 (2020) 04027DOI: https://doi.org/10.1051/e3sconf/202019404027