酸性堵水剂DQ—3的实验研究

Experiment Study on Acidic Plugging Agent DQ-3

结合变粘酸的酸化原理,以酸液稠化剂为主要原料,配以交联剂和缓蚀剂,制得了酸性堵水剂DQ-3。优选出酸性堵水剂DQ-3的最佳配方(质量分数):10%HCl+0.7%稠化剂+0.4%交联剂+0.05%缓蚀剂。采用瓶试法成胶实验和岩心流动实验评价了DQ-3的各项性能。结果表明,DQ-3体系的残酸质量分数小于0.1%时(pH为2～3),体系反应形成凝胶,粘度大于100 000mPa·s;DQ-3体系耐温40～90℃,对矿化度(大于10g/L)不敏感;DQ-3堵水剂的岩心堵水率大于95%,堵油率小于45%。

Based on the acidizing principle of variable--viscosity acid, a acid blocking agent （DQ-3） was prepared with acid densifier as major raw materials, and with crosslinker and inhibitor as additives, to achieve combination of near--wellbore unblocking and far- wellbore blocking. The formula of acid blocking agent （DQ- 3） is optimized ： 10 % HCI, 0.7 % densifier, 0.4% crosslinker and 0.05% inhibitor. Various performances of DQ--3 were evaluated by gel test （bottle test method） and core flow test. The results show that when residual acid concentration of DQ 3 system was less than 0.1 % （pH= 2-3）, gel is formed under system reaction, and viscosity is more than 100 000 mPa · s; DQ--3 system can resist temperature of 40-90 ℃, and is insensitive to salinity （above10 g/L） ; the core water blocking rate of DQ--3 is over 95%, whereas oil blocking rate is below 45%.