Abstract Permeability decline associated with the migration of natural reservoir fines impairs the well index of injection and production wells in aquifers and oilfields. In this study, we perform laboratory corefloods using aqueous solutions with different salinities in engineered rocks with different kaolinite content, yielding fines migration and permeability alteration. Unusual permeability growth has been observed at high salinities in rocks with low kaolinite concentrations. This has been attributed to permeability increase during particle detachment and re-attachment of already mobilised fines by electrostatic attraction to the rock in stagnant zones of the porous space. We refine the traditional model for fines migration by adding mathematical expressions for the particle re-attachment rate, particle detachment with delay relative to salinity decrease, and the attached-concentration-dependency of permeability. A one-dimensional flow problem that accounts for those three effects allows for an exact analytical solution. The modified model captures the observed effect of permeability increase at high water salinities in rocks with low kaolinite concentrations. The developed model matches the coreflooding data with high accuracy, and the obtained model coefficients vary within their usual intervals.

中文翻译：

---

胶体输运过程中的非单调渗透率变化：控制方程和分析模型

摘要 与天然储层细粒运移相关的渗透率下降损害了含水层和油田注采井的井指数。在这项研究中，我们在不同高岭石含量的工程岩石中使用不同盐度的水溶液进行实验室岩心驱替，产生细粒迁移和渗透率改变。在低高岭石浓度的岩石中，在高盐度下观察到异常渗透率增长。这归因于在颗粒分离过程中渗透率增加，并且通过静电吸引到多孔空间停滞区的岩石，已经移动的细粉重新附着。我们通过添加粒子重新附着率的数学表达式来改进传统的细粒迁移模型，相对于盐度降低的延迟颗粒脱离，以及渗透率的附着浓度依赖性。考虑到这三种效应的一维流动问题可以提供精确的解析解。修改后的模型捕捉到在高岭石浓度低的岩石中高水盐度下渗透率增加的观察效果。所开发的模型与岩心驱油数据匹配精度高，所得模型系数在通常区间内变化。