新型超分子压裂液的流变性能研究及应用

Research on rheological properties of a new supramolecular fracturing fluid and its application

由于常规清洁压裂液中表面活性剂加量大、成本高且耐温性能差,难以大范围推广应用。根据超分子化学原理,利用疏水聚合物与新型表面活性剂研发了一种新型超分子结构的清洁压裂液,该压裂液中粘弹性表面活性剂用量少、成本低、耐温性能提高。对新型超分子压裂液配方进行优化,确定新型超分子压裂液由质量分数为0.2%的疏水聚合物PX-A和0.5%粘弹性表面活性剂J201构成。对超分子形成机理进行分析发现,表面活性剂与聚合物疏水基团形成混合胶束,随着胶束的增多,胶束结构更加密集,强度增加,相互之间发生缠结、架桥等形成密集三维网状结构,宏观上表现为溶液粘度快速上升。新型超分子压裂液的性能评价结果表明,其耐温、耐剪切性能良好,可以耐130℃高温,储能模量整体高于耗能模量,粘弹性好,携砂性能良好,摩阻低,无残渣,伤害小,且组成简单,配液方便。矿场试验结果表明,采用新型超分子压裂液压裂施工后,苏东38-64C4井测试产气量为10×104m3/d,是采用胍胶压裂液邻井产量的2倍,可节约成本25%,并在长庆油区应用4口井,效果均较好。

The traditional cleaning fracturing fluid,with high surfactant content,high cost and poor heat resistance,is hardto be applied widely. A novel cleaning fracturing fluid with supramolecular structure was developed with hydrophobic poly?mers and new surfactant by the principle of supramolecular chemistry. The new supramolecular fracturing fluid has less vis?coelastic surfactant,low cost and improved heat resistance. Its formula was optimized. Its composition is 0.2% hydrophobicpolymer PX-A and 0.5%viscoelastic surfactant J201. The formation mechanism of the supramolecular structure was ana?lyzed. It is found that the surfactant and hydrophobic polymer group are mixed to form micelles. With increasing of the mi?celles,the micelles have more dense structure,increased strength and tangle with each other forming a bridge,which resultin the formation of three-dimensional network structure and the rapid increase of solution viscosity. The performance evalu?ation results show that the new supramolecular fracturing fluid has good temperature and shear resistance. It can be resis?tant to 130 ℃ high temperature,and its storage modulus is higher than its loss modulus in general. It also has good visco?elasticity,low friction,good sand-carrying capacity,no residue and low damage. Its composition is simple,so it is easy tobe prepared. Field test results show that the tested gas production of Well Sudong38-64C4 is 10×104 m3/d after using the novel supramolecular fracturing fluid,which is 2 times than that of the adjacent wells fractured by guar gum fracturing flu?id. The cost is saved by 25%. It has been applied in 4 wells of Changqing oilfield,and the effect is good.