Pressure is very vital and has a variety of applications in our society; there are several types of pressure acting on fluids. This pressure is known as the capillary pressure since it was first invented and investigated through a capillary tube. It is defined as the difference in pressure across the interface between fluids that are immiscible and rising from the capillary force. The two forces applied here are the interfacial tension and the surface tension. In other terms, capillary pressure can be defined as the pressure difference between pressures in the non-wetting phase to the pressure in the wetting face (plug, 2007).
The difference between the Capillary pressure and the Reservoir pressure.
The reservoir pressure is the pressure of the fluids exerted within the pores of deposit, which is usually hydrostatic pressure or perhaps the pressure experienced by a column of water from the formation depth to the sea level. It is always investigated by using a container and holes are made perpendicularly from the top part to the bottom. This is contrary to the capillary pressure which is the pressure difference between the two immiscible fluids. It involves the application of two fluids (Plug, 2007).
Application of capillary pressure
The first application that is used directly applied to the petroleum industry is the oil recovery from the petroleum reservoirs. Petroleum industries are one of the major and the biggest among the other industries (Liang, 2008). To recover the petroleum oil from the tank, we need to apply the capillary pressure technique to enable the oil to come to the surfaces which can then be harnessed and taken to the tanks for transportation. For movement to happen from one depth to another, we need the pressure.
Capillary pressure can also be used in the fluid distribution in the transition zones. In the extraction of oil such as the petroleum and other related crude oil such as the diesel. For this removal to take place, we need the capillary pressure.
Liang, Xiao, and Zhang Wei. “A new method to construct reservoir capillary pressure curves using NMR log data and its application.” Applied Geophysics 5.2 (2008): 92-98.
Plug, W-J., and J. Bruining. “Capillary pressure for the sand–CO 2–water system under various pressure conditions. Application to CO 2 sequestration.” Advances in Water Resources 30.11 (2007): 2339-2353.