疏水改性聚合物与蠕虫状胶束自组装体系的研究及压裂液应用

发布时间：2018-06-23 13:12

  本文选题：疏水改性聚合物 + 蠕虫状胶束　； 参考：《西南石油大学》2015年硕士论文

【摘要】：疏水改性聚合物与蠕虫状胶束自组装体系由于其优良的粘弹性而逐渐受到关注。但目前对高蠕虫状胶束浓度、低聚合物浓度的自组装体系的溶液性质以及疏水改性聚丙烯酰胺(HMPAM)的结构对其与蠕虫状胶束自组装效应的影响还缺乏研究。因此本论文对这两个方面进行了研究,进一步加深了对疏水改性聚合物与蠕虫状胶束自组装体系性质的认识。基于自组装体系优良的粘弹性和烃类响应性,本论文考察了其作为压裂液应用的相关性能,以期获得一种性能更优的新型低伤害压裂液。 本论文以表面活性疏水单体与丙烯酰胺通过自由基胶束共聚合制备了疏水改性聚丙酰胺,并与20mmol/L十六烷基三甲基溴化铵-水杨酸钠蠕虫状胶束构建了自组装体系；通过流变学方法考察了自组装体系的溶液行为以及HMPAM分子结构对其与蠕虫状胶束自组装效应的影响；最后构建了自组装压裂液体系,按照行业标准考察了其相关性能。 研究结果表明：随HMAPM浓度增大,自组装体系粘弹性增强,但弹性模量的比例却逐渐下降,流变性也逐渐偏离Maxwell模型。自组装体系具有良好的“剪切稀释-恢复”性,对温度和剪切更敏感；但自组装体系中具有更密集的网络结构,在相同剪切速率和温度下仍具有更高的粘度。煤油促使蠕虫状胶束向球形胶束转变,能够完全破坏自组装网络结构；正己醇使蠕虫状胶束转变为囊泡,HMPAM与囊泡之间也能形成网络结构,使体系仍具有一定粘弹性。 线性HMPAM的分子尺寸达到与蠕虫状胶束形成“有效交联”的要求后,将不再明显影响自组装体系的网络密度,但聚合物分子量越大,自组装体系流变性偏离Maxwell模型的程度越高。随线性HMPAM分子中疏水侧链含量增加,自组装体系网络密度逐渐增大；但含量过高时,疏水侧链与蠕虫状胶束中形成“无效交联”的概率增大,网络密度反而下降。减小线性HMPAM分子中疏水侧链的微嵌段长度、增大疏水侧链碳链长度以及提高HMPAM的支化度均有利于增强自主装效应。 自组装压裂液比常规清洁压裂液的耐温性高20-30℃；自组装压裂液遇烃类同样能彻底破胶,破胶液岩心伤害率与常规清洁压裂液接近,因此也是一种低伤害压裂液;相比常规清洁压裂液,自组装压裂液中表面活性剂用量低,具有控制成本和降低潜在地层及环境伤害的优势。
[Abstract]:Hydrophobic modified polymers and wormlike micelle self-assembly systems have attracted more and more attention due to their excellent viscoelasticity. However, the effects of the solution properties of high wormlike micelle concentration, low polymer concentration and hydrophobic modified polyacrylamide (HMPAM) on the effect of helminoid micelle self-assembly have not been studied. Therefore, these two aspects are studied in this paper, and the properties of hydrophobic modified polymer and worm-like micelle self-assembly system are further understood. Based on the excellent viscoelasticity and hydrocarbon responsiveness of the self-assembled system, this paper investigates its application as fracturing fluid, in order to obtain a new type of low-damage fracturing fluid with better performance. In this paper, hydrophobic modified polyacrylamide was prepared by free radical micelle copolymerization of hydrophobic monomer and acrylamide, and self-assembled system was constructed with 20 mmol / L cetyltrimethylammonium bromide and sodium salicylate worm-like micelle. The solution behavior of the self-assembled system and the effect of the molecular structure of HMPAM on the self-assembly effect of the worm-like micelle were investigated by rheological method. Finally, the self-assembled fracturing fluid system was constructed, and the properties of the self-assembled fracturing fluid were investigated according to the industry standard. The results show that the viscoelasticity of self-assembled system increases with the increase of HMAPM concentration, but the ratio of elastic modulus decreases gradually, and the rheological property deviates from Maxwell model. The self-assembly system has a good "shear dilution and recovery" property and is more sensitive to temperature and shear, but the self-assembly system has a more dense network structure and higher viscosity at the same shear rate and temperature. Kerosene can promote the transformation of worm micelles to spherical micelles, which can completely destroy the self-assembled network structure, and n-hexanol can transform the wormlike micelles into vesicles between HMPAM and vesicles, so that the system still has a certain viscoelasticity. When the molecular size of the linear HMPAM reaches the requirement of "effective crosslinking" with the worm micelles, the network density of the self-assembled system will no longer be significantly affected, but the larger the molecular weight of the polymer, the higher the rheological variation of the self-assembled system deviates from the Maxwell model. With the increase of hydrophobic side chain content in the linear HMPAM molecule, the network density of the self-assembled system increases gradually, but when the content is too high, the probability of forming "ineffective crosslinking" between the hydrophobic side chain and the worm-like micelle increases and the network density decreases. Decreasing the microblock length of hydrophobic side chain, increasing the carbon chain length of hydrophobic side chain and increasing the branching degree of HMPAM can enhance the self-assembly effect. The self-assembled fracturing fluid is 20-30 鈩，

本文编号：2057225