液态二氧化碳增稠过程中相态变化及机理探讨

液态二氧化碳（LCO₂）压裂液黏度低一直是制约新技术推广应用的关键问题。首次利用LCO₂与增稠剂LPE和胶束促进剂CJ-1混合后LCO₂的相态变化，探讨研究LCO₂-LPE-CJ-1压裂液的增稠机理，同时借助HAAKE黏度计的D300/400系统验证LPE-CJ-1体系对LCO₂增稠效果，利用偏光显微镜对LCO₂-LPE-CJ-1压裂液的胶束形态进行验证。实验结果表明:LPE-CJ-1体系可使LCO₂-LPE-CJ-1压裂液增黏且最大黏度为112 mPa·s左右，是目前文献报道的LCO₂的最大黏度（20 mPa·s）的将近6倍。LCO₂-LPE-CJ-1压裂液体系的增稠机理是LPE-CJ-1分子间的离子络合作用后形成的棒状胶束，类似于交联聚合物形成分子间相互缠绕的三维空间网状结构体。 

Phase Change in Liquid CO2 Thickening Process and the Mechanisms Thereof

In reservoir fracturing with liquid CO2 (LCO2), low viscosity of the fracturing fluid has long been a problem restricting the spread of this new fracturing technology.The phase change of LCO2 after mixing it with a thickening agent LPE and a micelle enhancer CJ-1 has been studied to investigate the thickening mechanisms of LCO2 -LPE-CJ-1. HAAKE viscotesters (Model D300/D400) were used to verify the thickening effect of LPE+CJ-1 on the LCO2. Using polarizing microscope, the state of the micelles of the LCO2 -LPE-CJ-1 fracturing fluid was studied. The experimental results showed that LPE and CJ-1 can thicken the LCO2 -LPE-CJ-1 fracturing fluid to about 112 mPa·s, nearly 6 times of the highest viscosity of LCO2 (20 mPa·s)that had been reported previously. The thickening mechanismsare that,through ionic complexation between the molecules of LPE and CJ-1, the two molecules form rod-shaped micelles, a structure analogous to the 3-D spatial network structure formed by the intertwined molecules of a crosslinked polymer.