The [[capillary pressure]] of a reservoir affects the magnitude and distribution of water saturation and thus the hydrocarbon volume in a given reservoir area [[Leverett, 1941]]{{citation needed}}. The capillary pressure is a function of the capillary radius, the interfacial tension, and the contact angle between the water and the solid (see [[Capillary pressure]]). In a reservoir, zones with larger pores and pore throats have lower capillary pressure, lower irreducible water saturation, and higher hydrocarbon pore volume. | The [[capillary pressure]] of a reservoir affects the magnitude and distribution of water saturation and thus the hydrocarbon volume in a given reservoir area [[Leverett, 1941]]{{citation needed}}. The capillary pressure is a function of the capillary radius, the interfacial tension, and the contact angle between the water and the solid (see [[Capillary pressure]]). In a reservoir, zones with larger pores and pore throats have lower capillary pressure, lower irreducible water saturation, and higher hydrocarbon pore volume. |