紫外线杀菌技术与油田采出水的适应性分析

Adaptability analysis of ultraviolet sterilization technology and oilfield produced water

紫外线杀菌技术具有运行成本低、杀菌彻底的特点,在市政污水等领域应用较多,但在油田采出水处理中应用较少。本文分析了油田采出水中以硫酸盐还原菌(SRB)为主的有害菌对油田生产的影响,从其注水以及对管道腐蚀的影响看,有害菌数量仍需严格控制。紫外线杀菌技术与采出水水质的适应性分析表明,紫外线杀菌装置对不同采出水的杀菌效果差异较大。现场应用表明,紫外线杀菌技术与生化加微滤处理系统后的水质具有较好的适应性,将其安装在注水罐后端,在进口含油量低于1.5 mg/L、固体含量低于3.5 mg/L、不含硫化物的水质条件下,出口有害菌可稳定控制在25个/mL内。从装置运行成本看,紫外线杀菌技术运行成本为0.074元/m^(3),较化学杀菌技术运行成本降低87.7%,可大幅降低水处理成本。

In the treatment of produced water from low-permeability oil fields,SRB is the main control project,and chemical sterilization methods are often used in the treatment.However,there are problems such as high drug costs,strong bacterial resistance,delayed adjustment of fungicides,high concentration of SRB,and poor effectiveness in killing scale.The impact of harmful bacteria mainly SRB in oilfield produced water on oilfield production was analyzed.From the impact on corrosion and water injection,it could be seen that the number of harmful bacteria still needed to be continuously controlled.Based on practical application of ultraviolet(UV)sterilization under different water treatment processes in low-permeability oil fields,comparative analysis and correlation with changes in water quality indicators,it was clear that the existing ultraviolet sterilization technology had good adaptability to the biochemical oil removal and microfiltration treatment technology of produced water.From the perspective of water quality,under the conditions of no sulfides,oil content below 1.5 mg/L,and solid content below 3.5 mg/L,the number of harmful bacteria at the outlet of the device could be stably controlled within 25 mL^(‑1).From the perspective of device operation cost,the operating cost of UV sterilization technology was 0.074 yuan/m^(3),which was 87.7%lower than that of chemical sterilization technology and significantly reduced water treatment cost.