稳定性分析在页岩气开发废水脱稳中的应用

Application of Stability Analysis in the Study of Shale Gas Produced Water Destabilization

页岩气开发过程中产生大量废水,为实现水资源的可持续利用,处理后回用为压裂液循环利用是大势所趋。为了提高回用率和降低回用处理成本,需要对页岩气开发废水进行脱稳。采用稳定性分析仪进行脱稳分析,研究了酸化曝气、化学絮凝、电絮凝及联合处理方法对不同地区的压裂返排液、钻井废水的脱稳过程,通过不稳定性指数等指标对脱稳效果进行了评价。稳定性分析结果表明,对于均质废水,采用化学絮凝即可实现有效脱稳,对于非均质废水,酸化曝气可促进废水的均质和凝聚,并使后续絮凝处理的絮体更为均匀从而获得更好的分离效果,再经电絮凝处理后,不稳定性指数进一步上升,絮体更密实,分离更均匀,浊度也更低。

In the process of shale gas development,a large amount of wastewater is generated.In order to achieve sustainable use of water,it is an irresistible trend to recycle it after treatment.In order to improve the recycling rate and reduce the recycling cost,it is necessary to destabilize the shale gas produced water.In this study,the stability analyzer was used to analyze the destabilization.The acidification aeration,chemical flocculation,electro-flocculation and combined treatment methods were used to study the produced water of different regions,the destabilization process and the instability index.The index has evaluated the stability of the destabilization effect.The results of stability analysis show that for homogeneous wastewater,chemical flocculation can be used to achieve effective destabilization.For heterogeneous shale gas produced water,acidification aeration can promote homogenization and agglomeration of wastewater and subsequent flocculation.The treated flocs are more uniform to obtain better separation effect,and after electroflocculation treatment,the instability index is further increased,the flocs are denser,the separation is more uniform and the turbidity is also lower.