Abstract Polymer gels have received an increasing attention as profile control agents in the heterogeneous reservoir water-flooded layers. The article focus on the profile control mechanism of polymer gels by plugging macropore. The micro-structures of polymer gel and pore were characterized by scanning electron microscopy (SEM). And the core displacement equipment was used to evaluate the properties of plugging properties. The variation of pore structure is measured by SEM, mercury intrusion meter and nuclear magnetic resonance instrument. Investigation results show that the molecules form a network structure with many dense layers after 15 days of cross-linking reaction, which results in the increase of the viscosity of the system from 15.3 to 6325 mPa‧s. After the polymer gel forms a micelle at the middle end of the core and blocks the pores, the plugging rate of the core reaches 99.2%. The results obtained in this paper reveal the mechanism of plugging characteristics of polymer gels, and further prove the great potential of polymer gels to enhance oil recovery in oilfields.

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聚合物凝胶驱后岩石孔隙结构变化研究

摘要 聚合物凝胶作为非均质油藏水淹层的调剖剂越来越受到关注。文章重点研究了聚合物凝胶堵塞大孔的调剖机理。聚合物凝胶和孔隙的微观结构通过扫描电子显微镜（SEM）进行表征。并利用岩心置换设备对堵漏性能进行评价。通过扫描电镜、压汞仪和核磁共振仪测量孔隙结构的变化。研究结果表明，分子在交联反应15天后形成了许多致密层的网络结构，使体系的粘度从15.3增加到6325 mPa·s。聚合物凝胶在芯的中端形成胶束并堵塞孔隙后，岩心堵漏率达99.2%。本文的研究结果揭示了聚合物凝胶的封堵特性机理，进一步证明了聚合物凝胶在油田提高采收率方面的巨大潜力。