稠油热采井场恶臭异味成因分析及治理研究

目的 解决稠油热采井场因存在难闻恶臭异味,从而影响油井正常生产的问题。 方法开展了油井伴生恶臭气体含硫化合物分析、以油藏微生物种类为主的生物成因分析和以稠油水热裂解实验为主的热成因分析；针对恶臭气体,开展了喷雾处理工艺研究,比较了亚氯酸钠、过硫酸钠和高锰酸钾对恶臭气体的处理效果;考查了喷雾强度、喷雾压力对恶臭气体处理效果的影响。 结果具有一定含量且嗅觉阈值低的甲硫醇、乙硫醇等低分子含硫化合物为稠油井场的恶臭异味主要物质,油藏微生物以海杆菌、假单胞菌和沙雷氏菌为主,不具备产生甲硫醇、乙硫醇等恶臭异味气体的代谢途径,稠油水热裂解产生大量甲硫醇、乙硫醇等恶臭异味气体。质量浓度相同的亚氯酸钠比过硫酸钠和高锰酸钾对恶臭异味气体脱除率高,确定为喷雾处理剂；优化喷雾强度为3.0 m³/(m²·h),喷雾压力为0.4 MPa,对质量浓度为2 000 mg/m³的恶臭气体脱除率可达100%。 结论稠油热采井场的恶臭异味主要为甲硫醇、乙硫醇等低分子含硫有机物,来源于稠油热采开发过程中的水热裂解反应,以亚氯酸钠为处理剂的喷雾处理工艺可以消除甲硫醇、乙硫醇等恶臭异味,为稠油资源的热采开发提供保障。 

Study on the origin and treatment of odor gas in heavy oil thermal recovery well site

ObjectiveSolve the problem of bad odor in heavy oil thermal recovery well site, which affected the normal production of oil wells. Methods The analysis on sulfur compounds in associated odor gas from oil well was carried out, as well as the biogenic analysis based on microbial species in the reservoir and the thermogenetic analysis based on heavy oil hydrothermal cracking experiment. In view of odorous gases, the spray treatment process was studied and the effects of sodium chlorite, sodium persulfate and potassium permanganate on the odor gas was compared. Besides, the influence of spray intensity and spray pressure was also investigated. ResultsLow molecular sulfur-containing organics such as methyl mercaptan and ethyl mercaptan with certain contents and low olfactory thresholds were the main components of odor in heavy oil well site. The microorganisms in the reservoir were mainly seabacillus, pseudomonas and serratia, and there was no metabolic pathway to produce odor gases such as methyl mercaptan and ethyl mercaptan. A large amount of odor gas including methyl mercaptan and ethyl mercaptan were produced by hydrothermal cracking of heavy oil. When at the same mass concentration, sodium hypochlorite could achieve higher removal rate of odor than sodium persulfate and potassium permanganate. The removal rate of the odor gas with the concentration at 2 000 mg/m³ was 100% when the optimized spray intensity and the spray pressure was 3.0 m³/ (m²·h) and 0.4 MPa, respectively. ConclusionsThe odor gas of heavy oil thermal recovery well was mainly low molecular sulfur organic compounds, such as methyl mercaptan and ethyl mercaptan, which came from the thermal cracking reaction of heavy oil during thermal recovery. The spray treatment process using sodium chlorite as a treatment agent was capable of eliminating odor such as methyl mercaptan, ethyl mercaptan, which could provide a guarantee for thermal recovery of heavy oil resources.