Lab-on-a-chip systems in imbibition processes: A review and applications/issues for studying tight formations

摘要

For waterflooded tight oil formations, imbibition is a dominant mechanism for oil recovery. Although substantial imbibition experiments have been conducted in lab-on-a-chip systems, few of them have etched patterns with representative pore/throat features of tight rocks and are studied in Liquid-Liquid systems. This study aims to summarize the achievements of pore-scale imbibition experiments and point out the potentials/issues faced in applying micro/nanomodels for studying imbibition mechanisms in tight oil formations. This review first summarizes pore/throat features in tight rocks to provide benchmarks for evaluating micro/nanomodel designs. Then, recent efforts on pore-scale imbibition studies are documented based on pore-scale phenomena, testing materials, and pattern designs. Finally, the challenges and recommendations of applying lab-on-a-chip systems for imbibition studies are discussed from six aspects: the representability of channel designs, wettability issues, surface roughness effects, blocking events, pressure handling, and experiment repeatability.