| 摘要: |
| 高质量浓度聚合物具有较强的黏弹性,但应用中有时会出现聚合物分子聚集体尺寸与油藏岩石孔隙配伍性较差的问题。针对大庆油田储层地质特征和流体性质,通过岩心流动性实验和驱油实验,以渗流特性为评价指标,利用正交试验优选出分子内交联聚合物凝胶体系后,研究凝胶体系黏弹性和驱油效率。结果表明:调节聚合物质量浓度、配制水矿化度、w(聚/Cr3+)可获得分子聚集体尺寸较小且阻力系数和残余阻力系数较高的分子内交联聚合物凝胶体系。聚合物溶液发生分子内交联后,一方面聚合物分子线团传输运移能力增强,且刚性增强,通过岩心孔隙时形变能力减弱,滞留能力增强,可有效提升注入压力,扩大波及体积;另一方面体系黏弹性和第一法向应力差均增大,洗油效率提高,二者综合作用表现出较高的驱油效率。 |
| 关键词: 聚合物凝胶 正交试验 分子内交联 渗流特性 黏弹性 驱油效率 |
| DOI：10.3969/j.issn.1673-5005.2015.03.024 |
| 分类号::TE 358.3 |
| 基金项目:黑龙江省自然科学基金重点项目(ZD201312);东北石油大学研究生创新科研项目(YJSCX2014-017NEPU) |
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| Study on gelling effect of Cr3+ polymer gel and its influence factors |
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LU Xiangguo, XIE Kun, CAO Bao, CHEN Xin
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(Key Laboratory of Enhanced Oil and Gas Recovery of Education Ministry in Northeast Petroleum University, Daqing 163318, China)
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| Abstract: |
| Although high-concentration polymer has strong viscoelasticity, there exist the compatibility problems between polymer molecules aggregate size and reservoir rock pore size during its practical application. According to the geological characteristics and fluid properties of Daqing Oilfield reservoir, the viscoelasticity and oil displacement efficiency of the intramolecular cross-link polymer gel system were investigated after it was selected by orthogonal experiment through evaluating seepage characteristics, with core flow experiment and oil displacement experiment. It was found that intramolecular cross-link polymer gel system with smaller molecular aggregate, higher resistance coefficient and residual resistance coefficient can be obtained by regulating polymer concentration, water solution salinity and polymer/Cr3+. Once intramolecular cross-link reacted in polymer solution, on the one hand, transmission migration ability of polymer molecular clew is enhanced, and its rigidity is also improved. In this way, deformation ability of the polymer molecular clew is weakened when it flows through core pore, which can enhance the retention ability, increase the injection pressure and enlarge sweep volume effectively. On the other hand, the viscoelasticity and first normal stress difference of polymer gel system are improved, as well as the washing oil efficiency. The above two aspects insure jointly Cr3+ polymer gel has higher oil displacement efficiency. |
| Key words: polymer gel orthogonal experiment intramolecular cross-link seepage characteristics viscoelasticity oil displacement efficiency |
