旅大10-1油田含聚污水与清水配伍性研究

The Compatibility of Polymer-Flooding Wastewater and Fresh Injection Water in LD10-1 Oil Field

关键词:  回注污水  含聚污水  结垢性  配伍性CaCO3垢  聚合物聚集体

Key words:  recycled produced water  polymer-flooding wastewater  scaling tendency  compatibility  CaCO3 scale  polymer aggregate

摘要:

旅大10-1油田注水采用将水源清水和聚合物驱生产污水混合回注,不合格的注入水会引起注水系统的腐蚀与结垢,造成注水井注水量快速递减,注水不见效,注采严重失衡。以储层保护和防止损害为目的,按照行业标准(SY/T 0600-1997)预测清水与污水混合有不同程度结垢趋势;不同比例清污混合水悬浮物含量测试表明:混合污水中悬浮物含量明显增大,清污体积比为1∶1时配伍性最差;X-射线衍射对滤膜上悬浮物分析表明有碳酸钙特征峰;环境扫描电镜对滤膜上悬浮物微观形貌进行观察,单一清水中悬浮物排列不规则、呈团块状产出,有长度达50μm的结晶颗粒;清污体积比为1∶1时悬浮物呈颗粒状均匀分布,粒径为0.5μm～1.0μm。综合研究表明,残余聚合物能够抑制碳酸钙垢和混合污水中大晶体的形成,高钙镁离子则加剧含聚污水中残余聚合物的絮凝。

Abstract:

The mixture of fresh water from Guantao formation and purified polymer-flooding wastewater without any additives was used as source of injection water in LD10-1 Oil Field.For the purpose of reservoir protection and damage prevention,according to industry standards SY/T 0600-1997,the different scaling tendency of mixture was predicted.The alligate solids gained from the mixture were studied.The results are shown as follows: there are more suspended solids after mixed fresh water with wastewater,and the compatibility is the worst when the mixed ratio is 1∶1;the X-ray analysis indicates that there are CaCO3 character peaks in the suspended solids.The micro structure of suspended solids was studied by ESEM and AFM,the result shows that the suspended solids in fresh water are precipitated without regularity and formed crystal particles with a diameter of 50μm;when the mixed ratio is 1∶1,the suspended solids are homogeneous precipitated with a diameter of 0.5μm～1.0μm.The integrated researches indicate that the retained polymer in wastewater can restrain the formation of CaCO3 scale and megacryst.The fresh water containing high amount of Ca2+ and Mg2+ can enhance the aggregation of retained polymer.