吉林油田联合站老化原油成因与脱水方法研究

Generation Mechanism and Dehydration Methods of Aging Crude Oil from Stand Jointly in Jilin Oil Fields

针对吉林油田扶余采油厂联合站老化油问题严重,影响处理设施正常运行的情况,研究了老化油的组成及形成原因,考察了常规破乳剂及氧化破乳方法对老化油的破乳脱水效果,在此基础上形成了可有效处理老化油的硝酸-硝酸钾氧化破乳工艺技术。对老化油组成的分析结果表明,老化油平均含水率62.2%,乳化状态稳定;沥青质、胶质含量平均值分别为0.65%、8.80%,与净化油相差不大;含有大量的FeS颗粒与机械杂质,FeS含量平均高达501.33 mg/L,粒径分布在3.66~70.46μm之间,不溶固体杂质平均值为56.33 mg/L。老化油水相中的Fe2＋高达174~199 mg/L,S2-高达157~209 mg/L。胶体FeS颗粒的大量存在是老化油生成的主要原因。常规破乳剂处理老化油的脱水效果不明显,处理后油中含水率均大于20%。采用硝酸-硝酸钾氧化破乳方法处理老化油,在最佳加量3%、最佳反应温度65℃、沉降48 h的处理条件下,净化油含水率可降至3%以下,达到含水率5%的出厂要求。

Due to multitudinous aging crude oil generated from stand jointly in Jilin oil fields,routine units operation was disturbed.Accordingly,the components and generation mechanism of aging crude oil were researched.Chemistry demulsification and oxidation demulsification were evaluated by dehydrating of aging crude oil.The results showed that the water content in aging crude oil was of 62.2% in average,and emulsification state was steady.Asphaltene and gum contents were of 0.65% and 8.80% in average,respectively,which had no substantial difference with purified crude oil.Abundant FeS particles and impurity were found in aging crude oil.The average FeS content was of 501.33 mg/L,with a size distribution from 3.66 to 70.46 μm.The average impurity content was of 56.33 mg/L.Fe2＋ content in water phase of aging crude oil was from 174 mg/L to 199 mg/L,and S2-content was from 157 mg/L to 209 mg/L.Aging crude oil generation mainly promoted by colloid FeS particles.Chemistry demulsification decreased water content of aging crude oil to 20% above and the dehydrating effect was relatively poor.The dehydrating effect of oxidation demulsification was better than chemistry demulsification.In order to decrease the water content of aging crude oil to 3%,the optimum reaction condition of oxidation demulsification was obtained as follows： 3% HNO3-KNO3 dosage,65℃ reaction temperature and 48 hrs precipitation time.