采用复合溶剂直接对高酸值原油中的环烷酸进行抽提，经优选表明：溶剂组分A的质量分数为5%，组分B为8%，组分C为40%，组分D为0.8%；抽提的最佳剂油质量比0.15。经复合溶剂抽提，脱除率可以达到80%以上，环烷酸的粗酸值符合工业2^#酸的标准。

A new technique for extraction of NA from crude oil with high TAN was proposed. Petroleum acids in crude oil with high total acid number were extracted by a complex solvent. Optimum constituents of the complex solvent are A 5%, B 8%, C 40% and D 0.5%～1% by weight, and optimum ratio of solvent to oil is 0.15. The results indicate that more than 80% of the petroleum acids is removed, the purity of NA is high enough to be used in industry and the process has no environmental pollution because all of the solvent are recoverd and reused in the unit.