中文摘要：

致密砂岩储层孔渗低、物性差,必须经过水力压裂改造后才能具有较好的产能。为了降低施工成本和压裂液对储层的伤害,同时在高温条件下具有良好的耐剪切性能和破胶性能,需要研发一种耐高温、低伤害的压裂液体系。以改性纳米二氧化硅为交联剂,对新型耐高温超低浓度纳米二氧化硅压裂液性能进行了较为全面的评价研究。结果表明,该压裂液体系在135℃条件下剪切2 h后平均黏度为100 m Pa·s,具有良好的携砂能力。破胶液残渣质量为常规胍胶压裂液质量的37.2%,破胶液的表面张力小,具有良好的返排性,压裂液与地层水配伍性好。超低浓度纳米胍胶压裂液大幅降低了对地层的伤害程度,适用于低渗的致密砂岩储层。

英文摘要：

Because of poor properties and low porosity and permeability,tight sandstone reservoir must be modified by hydraulic fracturing in order to obtain good production capacity. To reduce operation cost and the damages brought by fracturing fluid to reservoir,thus a high temperature resistance and low damage fracturing fluid system is needed to supply a good shear resistance and gel breaking performance under high temperature. Amodified nano-silica is used as cross linking agent,the performance evaluation of high temperature ultra-low concentration nanometer HPC fracturing fluid has been studied completely. The experimental results show that the average viscosity of this fracturing system under 135℃after shearing 2 hours is 100 m Pa·s,which means a good sand-carrying ability. The residue content of gel breaking liquid is 37. 2% of the conventional guanidine gum fracturing fluid content. The gel breaking liquid surface tension is small,which means good flow back ability. The compatibility between fracturing fluid and formation water is fine. Formation damage degree is greatly reduced by using ultra-low concentration nanometer HPC fracturing fluid. It is suitable for low permeability tight sandstone reservoir.