What is water wet reservoir?
In water-wet conditions, a thin film of water coats the surface of the formation matrix, a condition that is desirable for efficient oil transport.
Describing the preference of a solid to be in contact with a water phase rather than an oil or gas phase.
Water-wet rocks preferentially imbibe water..
Is Oil considered wet?
Oil is not wet. Of course oil is a liquid, but ‘wet’ is used in surface chemistry with regard to interfacial tension of aqueous fluids. … Similarly in a petroleum reservoir, oil will flow slowly past oil-wet rock, much faster past water-wet rock.
How is surface wettability measured?
Water contact angle measurement is the most common method used to quantify the wettability of a solid surface by a liquid. Contact angle is defined geometrically as the angle formed by a liquid at the three-phase boundary where a liquid (L), gas (G), and solid (S) intersect.
How is capillary pressure calculated?
Capillary pressure (Pc) is the difference in pressure measured across the interface in the capillary (Pc = Pnw – Pw). This pressure results from the contrast in pressure gradients caused by the different densities of the nonwetting (ρnw) and wetting (ρw) phases (right).
What is an oil reservoir called?
A petroleum reservoir or oil and gas reservoir is a subsurface pool of hydrocarbons contained in porous or fractured rock formations. … Reservoirs are found using hydrocarbon exploration methods.
How is wettability calculated?
Wettability is determined in three ways:Measurement of the contact angle, or the product of the contact angle and the interfacial tension (the last term in Young’s equation)Measurement of the relative amounts of oil and water displaced under similar conditions.More items…•
Is wettability a rock property?
Wettability is a tendency of fluid to stick to the surface of formation when other types of fluid are present. Several rock properties have a direct relationship to wettability, for instant relative permeability, capillary pressure and electrical properties. …
What does wettability mean?
Wettability is the ability of a liquid to maintain contact with a solid surface, and it is controlled by the balance between the intermolecular interactions of adhesive type (liquid to surface) and cohesive type (liquid to liquid).
What is the difference between drainage and imbibition?
“Drainage” refers to the decreasing saturation of a wetting phase. “Imbibition” refers to the increasing wetting-phase saturation.