Abstract: 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% HCl,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 000mPa·s;DQ-3 system can resist temperature of 40~90℃,and is insensitive to salinity(above 10g/L);the core water blocking rate of DQ-3 is over 95%,whereas oil blocking rate is below 45%.

Key words: Acidic plugging agent,    , Gel,    , Plugging performance,    , Changqing oil fields

摘要： 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100000mPa·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%。

关键词: 酸性堵水剂,    , 凝胶,    , 封堵性,    , 长庆油田