海上油田含聚污水中原油状态分析

Measurement on Oily Forms in Produced Water from Polymer Flooding of Offshore Oilfield

污水中原油一般分为浮油、分散油、乳化油和溶解油等形式,聚合物的存在会导致污水中乳化油含量大幅增加,污水稳定性更强。本文以海上油田含聚污水为研究对象,分析得出不同形式原油的比例随含聚浓度的变化规律。研究表明,乳化油含量占含聚污水中稳定存在原油量的90%以上,是含聚污水处理的关键所在。而且,与不含聚合物的污水相比,当污水中聚合物浓度为50 mg/L时,乳化油含量显著增加。另外,与模拟污水相比,聚合物含量约为50mg/L的现场含聚污水样品中的乳化油含量更高,稳定性更强,处理难度也更大。

It is well known that there are four forms for oil in produced wastewater from polymer flooding,including oil slick,dispersed oil,emulsified oil and soluble oil. Not only the content of emulsified oil but also the water stability would increase because of the soluble polymer used as flooding agent. In the article,the water produced from polymer flooding was studied,and the oily ratio of different forms with different polymer concentrations was determined. It was found that the content of the emulsified oil was 90 percent of total crude oil exsiting stably in the simulated wastewater containing polymer,which was the key object for water treatment of polymer flooding. In the addition,the emulsified oil of the simulated wastewater obviously increased when the concentration of polymer in water was above 50 mg/L,compared to that of simulated wastewater without polymer.Meanwhile,the emulsified oil of the produced wastewater containing polymer of about 50 mg/L was higher than that of the simulated wastewater;hence,the former was more stable and more difficult to be treated with than the latter.