Yan Lifei (Utrecht Univ.) will present his work on experimental and numerical studies on the Impacts of salinity and wettability for two-phase interfacial behavior at the micro-scale.
Two-phase flow in porous media is not only widespread in nature and daily life, but also broadly used in various industrial technologies, including textile technology, inkjet printing, fuel cell application, CO2 sequestration, enhanced oil recovery and contaminate hydrology. In oil and natural gas exploration, a better understanding of multiphase flow in porous media is a crucial aspect of improved oil and gas displacement efficiency. Low salinity water flooding (LSWF) is a tertiary method for improved oil recovery (EOR), which has substantially lower salinity than conventional sea water or formation water injected into a reservoir. In our study, three main research questions have been answered: how do the osmosis and emulsification impact the water transport and the corresponding oil mobilization? What is the effect of low-salinity on the ion transport in a thin aqueous film on a charged solid surface? How does the wettability of solid substrate impact the interface behavior for two-phase flow? To solve the issues, we used three aqueous solutions and two alkanes in a series of microfluidic experiments with hydrophobically coated glass micro-chips for mimicking the low-salinity waterflooding process in an oil-wet rock formation. Wettability is a crucial factor for pore-filling events in multiphase flow. To accurately calculate the flow velocity and phase interface positions over time, we conduct a series of microfluidic experiments of drainage and imbibition processes with three modified surface wettability for two-phase flow. the effect of wettability needs to be considered in numerical and analytical models to enable the accurate description of the pressure response during such a pore-filling event. We have developed a numerical model based on the volume of fluid method (VOF) and validated it with the experimental data.