河南油田防聚合物动态吸附的岩心流动实验研究

Research on Dynamic Performance of Anti-polymer Adsorbent in Henan Oilfield

构建了一种聚合物防吸附体系,并对该体系的动态防聚合物吸附性能进行了评价。结果表明:渗透率越高,聚合物防吸附率越高;当温度处在40~90℃之间时,处理剂防吸附率均在70%以上;该防吸附剂体系发挥降低聚合物吸附性能的最佳pH范围为3~5之间,当流体pH=7时的防吸附率最低;该防吸附剂体系的耐盐性较好,不同矿化度(1 500~10 000 mg·L^(-1))对该防吸附剂体系的防吸附率影响不大;防吸附剂质量分数越高,聚合物防吸附率越大,且质量分数≥0.5%之后防吸附率达70%以上;高注入量(>200PV)的地层水对防吸附剂冲刷之后,聚合物在岩石表面的动态吸附量没有发生太大的变化,未冲刷时聚合物在岩心表面的吸附量为0.012 8 mg·g^(-1),冲刷之后聚合物在岩心表面的吸附量为0.013 4 mg·g^(-1),体系的防吸附率变化不大,未冲刷和冲刷后防吸附率分别为73.3%和72.2%。

A polymer anti-adsorption system was constructed,and the dynamic anti-adsorption performance of the system was evaluated. The experimental results showed that,the higher the permeability, the higher the anti-adsorption rate of the polymer;when the temperature was in the range of 40~90 ℃, the anti-adsorption rate of the treatment agent was above 70%;the anti-adsorbent system could reduce the adsorption of the polymer when the optimal pH range for the performance was between 3 and 5, and the anti-adsorption rate was the lowest when the fluid pH was 7. The anti-adsorbent system had good salt tolerance, so that different salinities(1 500~10 000 mg·L^(-1)) have little effect on the anti-adsorption rate of the anti-adsorbent system. The higher the mass fraction of the anti-adsorbent, the higher the anti-adsorption rate of the polymer, and the anti-adsorption rate gradually exceeded 70% after the mass fraction was more than 0.5%. After the formation water with high injection volume(>200 PV) scoured the anti-adsorbent, the dynamic adsorption capacity of the polymer on the rock surface did not change much, the adsorption capacity of the polymer on the core surface without scouring was 0.012 8 mg·g^(-1);the adsorption amount of polymer on the core surface was 0.013 4 mg·g^(-1) after scouring, and the anti-adsorption rate of the system did not change much, and the anti-adsorption rates of unwashed and washed-out core surfaces was 73.3% and 72.2%, respectively.