Imbibition is a fluid flow process in which the saturation of the wetting phase increases and the nonwetting phase saturation decreases. (e.g., waterflood of an oil reservoir that is water-wet). Mobility of wetting phase increases as wetting phase saturation increases. Mobility is the fraction of total flow capacity for a particular phase.
If a water-wet rock saturated with oil is placed in water, it will imbibe water into the smallest pores, displacing oil. If an oil-wet rock saturated with water is placed in oil, it will imbibe oil into the smallest pores, displacing water.
Drainage is a fluid flow process in which the saturation of the nonwetting phase increases. Mobility of nonwetting fluid phase increases as nonwetting phase saturation increases e.g., waterflood of an oil reservoir that is oil wet Gas injection in an oil or water wet reservoir. Pressure maintenance or gas cycling by gas injection in a retrograde condensate reservoir. A water-wet reservoir that accumulation of oil or gas in a trap does so by drainage.
Drainage is a fluid flow process in which the saturation of the nonwetting phase increases. Mobility of nonwetting fluid phase increases as nonwetting phase saturation increases e.g., waterflood of an oil reservoir that is oil wet Gas injection in an oil or water wet reservoir. Pressure maintenance or gas cycling by gas injection in a retrograde condensate reservoir. A water-wet reservoir that accumulation of oil or gas in a trap does so by drainage.
Primary and waterflood oil recovery is affected by the wettability of the system. A water-wet system will exhibit greater primary oil recovery.
