聚合物凝胶在多孔介质中封堵效果实验

Experiment on the plugged effects of the polymer gel in the porous media

为了分析聚合物凝胶在多孔介质中的封堵规律,利用岩心实验结合核磁共振(NMR)、扫描电镜(SEM)微观分析技术,从聚合物浓度、注入速度及注入量的角度研究凝胶对岩心的封堵效果。结果表明:在一定的凝胶体系实验条件下,当凝胶浓度升高时,突破压力和封堵率提高,核磁共振T2谱峰面积逐渐缩小,水占岩心孔隙度分量逐渐下降,凝胶在岩心中的运移能力变弱,胶体滞留量增多,封堵性能变好;较快的凝胶注入速度会导致岩心突破压力和封堵率降低,核磁共振T2谱峰面积增大,水占孔隙度分量升高,岩心中的凝胶滞留量减少,封堵效果变差;当凝胶注入量增加时,压力曲线变化幅度逐渐增大,突破压力和封堵率提高,核磁共振T2谱峰面积逐渐减小,水占孔隙度分量下降,岩心中各处的凝胶滞留量大幅提高,胶体的运移能力下降,封堵效果变好。

To analyze the plugging rules of polymer gels in the porous media,the plugged effects of the polymer gel to the core were studied from the viewpoints of the polymer concentration,displaced rate and injection volume for the core displacing experiment by the NMR and SEM micro analyzing technologies.The results show that under the a certain testing condition of the gel system,when the gel concentration rises,so do the breakthrough pressure and the plugged rate,T2 spectrum peak area of the NMR is gradually decreased,the water proportion of the core porosity is gradually decreased as well,the migrating capacity of the gel in the core becomes weak,so the gel remained amount turns more,thus the plugging performance changes better;the faster gel injection rate can result in the reductions of the breakthrough pressure and plugged rate,the peak area changes large,so does the proportion,while the remained amount reduces and the plugged effects become poorer;when the gel injection volume rises,the changed amplitude of the pressure curve gradually enlarges,the breakthrough pressure and plugged rate enhance,the peak area gradually reduces,the proportion decreases,the remained amount of the gel in every part of the core enhanced to a great deal,so the migrating capacity of the gel reduces and the plugged effects change better.