用于超高温延迟交联的有机锆交联剂的制备及性能

Preparation and properties of organic zirconium crosslinking agent for ultra-high temperature delayed crosslinking

以三乙醇胺和多烯多胺为复配螯合剂,制备了用于超高温油藏压裂作业中延迟交联的有机锆交联剂(简称改进有机锆交联剂),考察了制备条件对交联时间的影响以及改进有机锆交联剂-羧甲基羟丙基瓜胶(CMHPG)-延迟调节剂冻胶系统的耐温耐剪切性能,并对传统的三乙醇胺有机锆交联剂交联形成的冻胶热稳定性不足的原因进行了分析。实验结果表明,制备改进有机锆交联剂的适宜反应条件为130℃,复配螯合剂与正丙醇锆酸酯质量比为5∶2,三乙醇胺与多烯多胺质量比为1∶4;所制备的改进有机锆交联剂与CMHPG形成的冻胶体系具有低交联剂用量和低增稠剂用量特性,在CMHPG用量0.36%(w)、改进有机锆交联剂用量0.2%(φ)的条件下,交联时间为235 s,且可通过延迟调节剂调整交联时间。在剪切速率170 s^(-1)、温度180℃下,经过120 min剪切,冻胶黏度保持在90 mPa·s以上,表明该改进有机锆交联剂适用于超高温地层压裂作业。

The organic zirconium crosslinking agent for delayed crosslinking in ultra-high temperature reservoir fracturing operations was prepared using triethanolamine and polyene polyamines as a composite chelating agent.The effect of preparation conditions on the crosslinking time was studied.The temperature and shear resistance of the organic zirconium-carboxymethyl hydroxypropyl guar(CMHPG)-delayed agent system were investigated.The reasons for the insufficient thermal stability of the gel formed by traditional triethanolamine-organic zirconium crosslinking agent were analyzed.The experimental results show that the optimum reaction conditions for organic zirconium preparation are as follows:130℃,mass ratio of chelating agent to n-propanol zirconate 5∶2,and mass ratio of triethanolamine to polyene polyamine 1∶4.The gel system formed by the organic zirconium crosslinking agent and CMHPG has the characters of low crosslinking agent amount and low thickener amount.Under the conditions of CMHPG amount 0.36%(w)and crosslinking agent amount 0.2%(φ),-1 the crosslinking time is 235 s,and can be adjusted by delayed agent.At a shear rate of 170 s^(-1) and temperature of 180℃,the viscosity of the gel is maintained above 90 mPa·s after 120 min of shearing,indicating that the organic zirconium crosslinking agent is suitable for ultra-high temperature formation fracturing operations.