新型连续混配型清洁压裂液体系研究

Study on in-situ continuously-mixed viscoelastic surfactant fracturing fluids

通过对粘弹性表面活性剂分子结构的分析,筛选出了低温下溶解性能好、易成胶的长链烷基季铵盐表面活性剂VES-1、VES-2,并通过与激活剂(水杨酸钠)、聚合醇等进行配方优化组合,确定了YCQJ-2清洁压裂液稠化剂的配方,同时评价了1.0%～5.0%YCQJ-2清洁压裂液的性能。结果显示,YCQJ-2清洁压裂液稠化剂与清水按照一定比例混合,即可形成粘弹性较好的冻胶,破胶容易,表/界面张力低,对岩心的伤害率低于15.0%,而且可以实现就地连续混配、连续施工,简化了施工程序,节约成本,保护环境。

Two quarternary ammonium salt surfactants VES-1 and VES-2,which have good solubility in low temperature,were screened by analyzing molecular structure of viscoelastic surfactant.By optimum ratio of VES-1,VES-2 and other components,a novel viscoelastic surfactant thickening agent（YCQJ-2） was prepared and performance of YCQJ-2 clean fracturing fluid was evaluated.The results showed that a viscoelastic fracturing fluid would be formed when the thickening agent（YCQJ-2） mixed with fresh water in certain proportion.And the clean fracturing fluid,which has the characteristics of good rheological property,easily to be broken down,low damage to formation（15.0%）,can be continuously prepared and pumped in-situ during fracturing treatment process.