火驱原油活性氢组分变化规律认识

为识别火驱开发中是否发生高温氧化以及高温氧化程度,应用实沸点蒸馏法对新疆油田红浅试验区火驱受效前后的原油进行分离,绘制相应的实沸点蒸馏曲线,测定各馏分的酸值,并用超高分辨质谱仪对不同类型酸性化合物在负离子模式电喷雾电离源条件下进行分析,对O2类组分的等效双键指数(DBE)和碳数分布进行了详细归类。结果表明:虽然火驱受效前后原油酸值波动范围小于1.0 mg/g,但受效原油中的中低沸点组分含量和实沸点蒸馏质量收率明显提高,受效原油的部分组分氧化生成了含有活性氢官能团的化合物,在200～250 ℃、300～420 ℃沸点范围出现2个波峰;质谱分析表明,火驱见效原油O2类组分中DBE为3和4的相对丰度增大,二元、三元环烷酸占比增加。研究成果可为分析原油火驱过程和馏分产品精制提供指导。

Recognition of Variation Law of Active Hydrogen Component of Fire-Flooded Crude Oil

In order to enrich the methods for identifying whether high temperature oxidation occurs and the degree of high temperature oxidation during the fire flooding development, the real boiling point distillation method was applied to separate the crude oil before and after the effectiveness of fire flooding in Hongqian Area of Xinjiang Oilfield, the corresponding real boiling point distillation curves were plotted, and the acid value of each fraction was measured. The high-resolution mass spectrometry was used to analyze different types of acidic compounds under the condition of electrospray ionization source in negative ion mode, and the equivalent double bond index (DBE) and carbon number distribution of O2-type components were classified in details. The results show that although the fluctuation range of the acid value of crude oil before and after the effectiveness of fire flooding is less than 1.0 mg/g, the content of low and medium boiling point components in the effected crude oil and the yield of real boiling point distillation mass are significantly improved, some components of the effected crude oil are oxidized to generate compounds containing active hydrogen functional groups, and two peaks appeared in the boiling point range of 200-250 ℃and 300-420 ℃. The mass spectrometry analysis shows that the relative abundances of DBE 3 and 4 in the O2 components of the fire flooding effected crude oil increases, and the proportion of two-membered and three-membered naphthenic acids increases. The research results can provide guidance for the analysis of crude oil fire flooding process and the refining of distillate products.