A study on the factors affecting bound water film formation in porous media

The thickness of the bound water film within the porous media significantly impacts the extraction difficulty during the water injection process for developing hydrophilic reservoirs. In order to gain a comprehensive understanding of the pivotal factors that influence the formation of a bound water film in porous media and their respective degrees of influence, this paper employs the capillary bundle model as a basis for analysis. The examination commences with an analysis of the fluid forces within the capillary tubes. Subsequently, the relationship between the thickness of the bound water film and the aforementioned factors is investigated through theoretical derivation and local sensitivity analysis. The results demonstrate that the formation of a bound water film is influenced by several key factors, including displacement pressure difference, oil viscosity, oil-water interfacial tension, and contact angle. The combined effect of these four factors significantly impacts the thickness of the bound water film. The objective of this study is to provide theoretical guidance for the optimal development of hydrophilic reservoirs through the water flooding.