A study on physico-chemical percolation mechanism of combination flooding system

Combination flooding system contains various chemical agents. Both interactions between these chemical a-gents and reservoir rocks and the distribution and chemical reaction of the chemical agents in different phases can influence the mechanism and pattern of physico - chemical percolation during combination flooding. Based on previous studies, this paper discusses the physico - chemical action and oil displacement mechanism of combination flooding. The physico - chemical influential factors in combination flooding process can be summed up as several equivalent factors and the physico - chemical percolation equations of combination flooding can be summed up as a convection diffusive equation with absorptive action considered. Oil displacement percolation mechanisms of combination flooding system in water wetting and oil wetting porous mediums are quite different Under water wetting conditions, crude oil is entrapped in combination flooding system and is carried through pore throats. While under oil wetting conditions, combination flooding system enters into pores, forms W/O emulsion with crude oil, and passes through pore throats in deformed shape. The percolation equations presented can be used to predict transmission patterns of chemical agents.