Water contact
In the hydrocarbon industry water contact is the elevation above which fluids other than water can be found in the pores of a rock.
For example, in a traditional hand-excavated
In most situations in the hydrocarbon industry the term is qualified as being an oil-water contact (abbreviated to "OWC") or a gas-water contact ("GWC"). Often there is also a gas-oil contact ("GOC").
In an oil or gas
Capillary action can obscure the true water contact in permeable media like sandstone. Capillary pressure prevents the hydrocarbons from expelling all of the water in the pores, which creates a transition zone between the fully saturated hydrocarbon levels and the fully saturated water levels.
In poorly porous intervals, the oil-water, gas-water or gas-oil contacts can similarly be obscured, which makes estimation of
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