The Velocity Dependence of Dynamic Capillary Pressure During Imbibition Displacement in Microscale Quartz Capillaries

Abstract

Studies have been done to elucidate the velocity dependence of dynamic capillary pressure in the process of water displacing oil under constant pressure drops in hydrophilic capillaries with 0.92 μm in radius. Experimental results show that this dependence is closely correlated with the relative viscosities of the liquids involved. When the liquids are equal in viscosity, the displacement proceeds with constant rate and the dynamic capillary pressure stays almost unchanged, while it increases gradually with a increase in velocity in the case of water displacing more viscous oil, in contrast, it decreases gradually with a reduction in velocity when water displaces less viscous oil.

Experimental Investigation of Molecular Deposition Filming Flooding in a Low-Permeability Oil Reservoir

“…Spontaneous imbibition is the process by which a wetting phase fluid (e.g., water) is drawn into the porous medium (e.g., rock) to displace another immiscible nonwetting phase fluid (e.g., oil) . It is now widely recognized that the spontaneous imbibition in a thin tube or capillary is driven by capillary pressure ( p c ), which depends on IFT, contact angle, and capillary radius.…”

“…Spontaneous imbibition is the process by which a wetting phase fluid (e.g., water) is drawn into the porous medium (e.g., rock) to displace another immiscible nonwetting phase fluid (e.g., oil). 38 It is now widely recognized that the spontaneous imbibition in a thin tube or capillary is driven by capillary pressure (p c ), which depends on IFT, contact angle, and capillary radius. If the contact angle (θ) is greater than or equal to 90°, the fluid cannot spontaneously permeate into the capillary, and an external driving force is needed to overcome the capillary resistance.…”