聚乳酸颗粒暂堵剂的降解规律及性能

Degradation regulation and kinetics of polylactic acid temporary steering agent

针对低渗透储层开采能力低的问题,模拟储层条件,对聚乳酸(PLA)颗粒作为暂堵剂的降解规律、降解动力学、应用性能开展了研究,采用红外光谱、XRD对其进行表征。结果表明,当温度超过130℃后,聚乳酸降解较快,4 h后降解率达到38.9%;低分子量(M_(w)=5000)的PLA,在130℃下4 h全部降解;NaCl、CaCl_(2)、酸液可促进降解过程。进一步采用降解动力学证实了其结论。聚乳酸暂堵剂解堵后,岩心渗透率又可获得90%以上的恢复率。

Aiming at the problem of low permeability reservoir production capacity,the degradation law,degradation kinetics and application performance of polylactic acid(PLA)particles as a temporary plugging agent were studied by simulating the reservoir conditions,and they were characterized by infrared spectroscopy and XRD.The results showed that when the degradation temperature of PLA exceeded 130℃,the degradation rate of polylactic acid was faster,and the degradation rate reached 38.9% after 4 h;low molecular weight(M_(w)=5000)PLA was completely degraded at 130℃ for 4 h;NaCl,CaCl_(2),and acid can promote the degradation process.Further adoption of degradation kinetics confirmed its conclusions.After the polylactic acid temporary plugging agent is unplugged,the core permeability can obtain a recovery rate of more than 90%.