油田高含聚采出水水质特性及其处理技术研究

与常规聚驱采出水相比,高含聚采出水中聚合物浓度较高,粘度较大,Zeta电位电负值较高,小油珠所占比例较大,乳化程度较高,使得高含聚采出水油水分离难度远远高于常规聚驱采出水。高含聚采出水经过24h静沉,水中残余含油量能达到过滤单元进水要求;高含聚采出水中悬浮固体随着沉降时间的延长呈现忽高忽低的交替变化,仅仅通过单一沉降方式,其去除率不高;通过引入气浮的方式,能大大缩短油水分离时间,有效提高高含聚采出水油水分离效率;离心分离技术能在很短的时间内实现油、水、固三相的有效分离,并达到聚驱高渗透回注水指标要求。

Research on characteristics of high concentration poIymer fIooding oiIfieId produced water and its treatment technoIogy

Compared with conventional polymer flooding produced water, the oil-water separation of high concentration polymer flooding oilfield produced water was much more difficult for its higher polymer concentration, higher viscosity, higher zeta potential electro negative, larger proportion of small oil drops, and higher emulsification degree. It could be seen that, after 24 hours of static sedimentation, the residual oil content in high concentration polymer flooding produced water could meet the requirement of influent water quality of filtration unit. With the deposition time prolonging, the suspended solids in the said kind of water fluctuated alternately;therefore, high removal rate of oil can hardly be obtained with single sedimentation. Air floatation which was introduced could considerably reduce the oil-water separation time; thereby improve the oil-water separation efficiency effectively. Oil, water and solid could be separated by centrifugation in a very short time, and the treated water could reach the index demand of high permeability of polymer flooding as reinjection water.