高效处理油田作业废水技术的研究及应用

Study and application on high effective treatment technology of operation wastewater in oilfield

关键词:  作业废水  催化氧化  污水处理  油田注水

Key words:  operation wastewater  catalytic oxidation  wastewater treatment  oilfield water flooding

摘要:

油田作业废水来源分散,种类繁多,成分复杂,一般经收集后混合存放,单独处理,再回注地层。但由于这些混合废水污染物含量高,乳化程度高,絮凝沉降困难,注水处理常用的“絮凝-沉降-过滤”工艺效果较差,导致注水主要指标(悬浮物含量)严重超标,不仅无法回注,即使混入普通污水中进入常规注水处理站,也会对系统产生严重冲击。采用一种固相催化空气氧化技术对污水先进行曝气氧化处理,同时配合一种复合增强破胶混凝剂改善其絮凝特性,再用普通阳离子聚丙烯酰胺絮凝剂进行絮凝沉降处理,油和悬浮物去除率分别达94.1%和97.9%,净化水水质能够达到油田注水水质标准。该方法具有工艺简单、成本低廉的优点,适合于各油田推广应用。 

Abstract:

In oilfields, there are many kinds of operation wastewater from different places, with complex components, which are commonly collected, mixed and stored in a special station, and treated exclusively and then injected into the formation. The pollutant content of mixed operation wastewater is high, the emulsification degree of it is high, and the flocculation sedimentation of it is difficult. The effect of commonly used "flocculation-sedimentation-filtration" process of water injection treatment is very poor, then resulting in the main index of water injection “suspended matter content” seriously exceeding the standard. It can not be re-injected, even if mixed with ordinary sewage then come into the conventional water injection treatment station, will also have a serious impact on the system. In this study, a new type of solid-phase catalytic air oxidation technology is used to treat the wastewater with aeration oxidation processing at first, then the flocculation properties are improved combining with an enhanced gel breaking coagulant. Then an usual cationic polyacrylamide flocculant is added for flocculation prior to following sedimentation. After treatment mentioned above, the removal rates of oil and suspended matter reached 94.1% and 97.9% respectively, and the water quality is up to oilfield injected water quality standard. This technology has the advantages of simple process and low cost, and is suitable for application in most oil fields.