针对华庆长6储层地层水的特点,以综合起泡能力为评价指标,对常用的6种起泡剂进行了优选,优选出ZY-1型起泡剂,起泡剂浓度为0.5%,稳泡剂浓度为764 mg/L。在此基础上,采用渗透率级差接近的两组并联岩心,进行了注入方式和注入段塞组合的优化实验。结果表明,地下起泡方式,即CO2和起泡剂交替注入的方式可以在高渗透层中形成较高的封堵压差,具有较好的驱油效果。最优的段塞组合是0.2倍孔隙体积的起泡剂+0.4倍孔隙体积的CO2气体,总注入段塞是0.6倍孔隙体积。
Aiming at the characteristic of the formation water of Huaqing Chang 6 reservoir and taking the comprehensive foaming ability as evaluation index,6 foaming agents were optimized.ZY-1 foaming agent was the optimal foaming agent,and the optimal foaming agent concentration and foam stabilizer concentration were 0.5 % and 764 mg/L respectively.On the basis of the foaming agent optimization result,using parallel cores with approximate permeability contrast,CO2 foam flooding experiment was simulated through 2 injection way.The experiment result showed that underground foaming way,CO2 and the foaming agent injected alternately,had higher plugging differential pressure and better displacement efficiency.The optimal injection slug combination was first 0.2 PV(pore volume) foaming agent solution and then 0.4 PV CO2 gas,and the total injected volume was 0.6 PV.