Pore- and core-scale studies for development of the Kinetic Interface Sensitive tracer – A novel reactive tracer technique to measure the fluid-fluid interfacial area for dynamic two-phase flow in porous mediaCumulative thesis
Date of Examination:2022-07-21
Date of issue:2022-11-04
Files in this item
Name:Dissertation HuhaoGAO onlinesubmission.pdf
This file will be freely accessible after 2023-07-20.
EnglishFluid-Fluid Interfacial Area (FIFA) is an important parameter relevant in numerous geological applications where two phases of fluids exist and interphase reactive mass transfer can happen. For example, in geological storage of carbon dioxide, the FIFA can be monitored to evaluate the extent of capillary trapping and dissolution reaction rates. A new type of tracer, termed Kinetic Interface Sensitive (KIS) tracer is developed to measure the FIFA during dynamic two-phase flow in porous media. This thesis demonstrate a series of studies at both pore- and core-scale to investigate the reactive transport of the KIS tracer, and to validate the concept of the KIS tracer. At the pore-scale, direct numerical simulations of reactive transport of the KIS tracer are implemented with a novel Continuous Species Transfer formulation which is in consistent with the Phase-Field Method. The PFM-CST model is employed to investigate the retention of the reacted tracer solute mass due to capillary effects, during drainage in a 2D sandstone porous media, and a single 2D fracture with rough surfaces. The mobile and immobile zones are distinguished, and the corresponding FIFA, and reacted tracer solute mass in these two zones are quantified. It is showed that the KIS tracer method can be employed to selectively determine the mobile part of the FIFA. Additionally, the PFM-CST model is further employed to study the possibility of KIS tracer application in push-pull tests. The interpretation of the tracer breakthrough curves (BTCs) and how the different hydraulic parameters can affect the BTCs are investigated. Furthermore, at the core-scale, column drainage experiments employing the KIS tracer are implemented on numerous porous media comprised of glass beads and natural sands at different grain sizes, grain roundness and surface textures. The specific capillary-associated FIFA is found to be larger for sands with smaller grain sizes and for sands with rougher surfaces. Through these column experiments, the concept of KIS tracer method is validated, and the spectrum of porous media where the KIS tracer can be applied is extended. Besides, the macro-scale KIS tracer reactive transport model is employed to study the effects of heterogeneity in the 2D flume consist of two different porous materials. The deformation of the BTCs due to aquifer heterogeneity are demonstrated, and the linear relationship between the slopes of the BTCs and the averaged specific FIFA in the 2D flume are found. Finally, the pros and cons of the KIS tracer applications in dipole configurations and push-pull setups are summarized, and the further perspectives about the KIS tracer methods are discussed.
Keywords: multiphase flow in porous media, reactive transport, fluid-fluid interfacial area, computational fluid dynamics, kinetic interface-sensitive tracer