中高温可控延迟合成聚合物压裂液的研制

Preparation of a Medium/High Temperature Resistant and Delay-Controllable Crosslinked Polymer Fracturing Fluid

采用自由基水溶液共聚法，以丙烯酰胺（AM）、丙烯酸（AA）、2-丙烯酰胺-2-甲基丙磺酸（AMPS）等为功能单体合成了AM/AA/AMPS三元共聚物稠化剂（BHY9-6）。以BHY9-6为基液，加入一种中高温复合交联剂（QI-23）及其他添加剂得到了一种可控延迟的合成聚合物压裂液（简称B-Q压裂液）。研究了B-Q压裂液的交联性能、耐温耐剪切性能和破胶性能等。实验结果表明，通过控制交联剂静置时间、交联剂pH或基液pH中的一个或几个因素，可将B-Q压裂液的交联时间控制在合适的范围内（如40～120 s）。B-Q压裂液中各添加剂之间的配伍性好，对压裂液的交联时间及挑挂性能基本无影响，对耐温耐剪切性能的影响较小。B-Q压裂液经破胶后，破胶液黏度均小于3 mPa·s、破胶液表面张力均低于22 mN/m、无残渣、对地层伤害较小、破胶性能良好。B-Q压裂液与华北油田、东北油田、胜利油田等压裂用水配伍性好，性能优良，具有广泛的应用前景。

A terpolymer（BHY9-6） was synthesized from acrylamide（AM）,acrylic acid（AA） and 2-acrylamide-2-methyl propane sulfonic acid（AMPS） through aqueous solution copolymerization. By adding a medium/high temperature composite crosslinking agent（QI-23） and other additives to the BHY9-6 base fluid,a delay-controllable copolymer fracturing fluid （B-Q fracturing fluid）was prepared. The temperature resistance,shearing performance,crosslinking performance and gel breaking performance of the B-Q fracturing fluid were investigated. The results showed that the crosslinking time could be adjusted in a certain range（e.g. 40-120 s） by changing one or several factors,namely standing time of crosslinking agent,pH of crosslinking agent and pH of the base fluid. The additives barely affected the crosslinking performance of the B-Q fracturing fluid,and slightly influenced its temperature resistance and shearing performance. The B-Q fracturing fluid could be completely broken. The gel breaking fluid with viscosity of less than 3 mPa·s and surface tension of less than 22 mN/m has no residue and little formation damage. The B-Q fracturing fluid has good compatibility with the fracturing water of oilfields.