CO₂-water drainage relative permeability is usually measured in laboratory using a three-stage unsteady-state flooding on cores. This three-stage flooding involves injecting water, then CO₂-saturated water, and finally water-saturated supercritical CO₂. The injection of CO₂-saturated water has been previously found to generate fines due to mineral dissolution. The generated fines can flow with injected fluids and cause pore blockage.

This paper examines the effect of fines migration and mineral reactions on CO₂-water drainage relative permeability measurements, using a sintered glass core and eight Berea sandstone cores. Three-stage and two-stage flooding are performed on the cores. Three-stage flooding sequence is same as literature. Two-stage flooding involves injection only of water and then water-saturated CO₂, to avoid the chemical reactions brought about by CO₂-saturated water injection and thereby reduce mineral reactions. Pressure difference across the cores and volumes of water produced are recorded. These data are used to generate CO₂-water drainage relative permeability functions.

Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES) analysis of the produced water and Scanning Electron Microscopy (SEM) images of the cores confirm mineral reactions occurred during CO₂-saturated water injection in Berea cores. For Berea cores, CO₂ relative permeability is reduced (by 21%–48%) during three-stage flooding when CO₂-saturated water is injected. The reduction in CO₂ relative permeability is found to be a function of water salinity and pore volumes of CO₂-saturated water injected. Experiments performed on the glass core suggest that the error in CO₂ relative permeability caused by the absence of CO₂-saturated water is negligible. Therefore, we propose that CO₂-saturated water be omitted during CO₂-water drainage relative permeability measurements.

通常在实验室中使用岩心上的三阶段非稳态驱替法来测量CO ₂排水相对渗透率。此三阶段驱替包括注入水，然后注入CO ₂饱和的水，最后注入水饱和的超临界CO ₂。先前已经发现，注入CO ₂饱和的水会因矿物溶解而产生细粉。产生的细粉会随注入的流体一起流动并导致孔堵塞。

本文研究了使用烧结玻璃芯和八个Berea砂岩芯的细粒迁移和矿物反应对CO ₂排水相对渗透率测量的影响。在核心上执行三阶段和两阶段驱替。三阶段驱油顺序与文献相同。两级驱油法只注入水，然后注入水饱和的CO ₂，以避免注入CO ₂饱和的水引起的化学反应，从而减少矿物反应。记录岩心两端的压差和产水量。这些数据用于生成CO _2-排水相对渗透率函数。

采出水的电感耦合等离子体发射光谱（ICP-OES）分析和岩心的扫描电子显微镜（SEM）图像证实，在Berea岩心中注入CO ₂饱和水时发生了矿物反应。对于Berea岩心，注入CO ₂饱和水后的三阶段驱油过程中，CO ₂相对渗透率降低了（21％–48％）。发现CO ₂相对渗透率的降低是水盐度和注入的CO ₂饱和水的孔体积的函数。在玻璃芯上进行的实验表明，由于缺少CO ₂而导致的CO ₂相对磁导率误差-饱和水可以忽略不计。因此，我们建议在CO _2-排水相对渗透率测量过程中省略CO _2-饱和水。