三元复合驱不返排解堵剂体系及配套工艺研究

Research on the non-flowback plug-removing agent system and supporting technology for ASP flooding

针对常规三元复合驱注入井解堵施工需返排残酸、易造成二次堵塞的问题,开展了由环境型高效降解剂与有机酸解堵剂组成的三元复合驱不返排解堵剂体系及配套工艺研究。通过室内实验对比了三元复合驱不返排解堵剂体系与聚合物降解剂、常规无机酸解堵剂的降解性能、温敏性能、溶垢性能、离子络合能力等性能指标。结果表明,该解堵剂体系在常温下性质稳定,在地层温度为45℃时开始反应;常规无机堵塞物溶解率可以达到90%,聚合物的降解率可以达到99%;对主要成垢离子中钙离子的络合率为59.6%,铁离子的络合率高达86.6%。现场试验15井次,单井平均降压1.18MPa,平均日增注量为9.7m^(3),平均措施有效期198d。三元复合驱不返排解堵剂体系及配套工艺实现了对三元复合驱注入井堵塞物的有效处理,保障了三元复合驱的开发效果。

In order to solve the problem that the conventional ASP flooding injection well needs to flow back residual acid in plug-removing operation,which is easy to cause secondary blockage,the non-flowback ASP flooding solution composed of an environmental high-efficiency degradant and an organic acid plug-removing agent and supporting technology were carried out.Through laboratory experiments of the ASP flooding non-flowback plugremoving system,polymer degradant and conventional inorganic acid plug-removing agent,the performance indicators such as the degradation performance,temperature sensitivity performance,scale dissolution performance,and ion complexing ability were compared.The results showed that the plug-removing agent system was stable at room temperature,and started to react when the formation temperature was 45℃.The dissolution rate of conventional inorganic blockage could reach 90%,and the degradation rate of polymers could reach 99%.The complexation rate of calcium ions was 59.6%,while the complexation rate of iron ions was high as 86.6%.The field test was conducted in 15 wells,whose average pressure drop of the single well was 1.18 MPa,the average daily injection volume increased by 9.7 m^(3),and the average effective period of the measures was 198 days.The ASP flooding non-flowback plug-removing agent system and the supporting technologies have realized the effective treatment of the blockage in ASP flooding injection wells,so as to ensure the development effect of the ASP flooding.