1. n. [Geology]

An accumulation, pool or group of pools of oil in the subsurface. An oil field consists of a reservoir in a shape that will trap hydrocarbons and that is covered by an impermeable or sealing rock. Typically, industry professionals use the term with an implied assumption of economic size.

See: accumulation,  field,  hydrocarbon,  oil pool,  oilfield,  reservoir,  seal,  trap

2. n. [Geology]

The surface area above a subsurface oil accumulation is called an oil field.

See: accumulation,  field,  hydrocarbon,  oil pool,  oilfield,  reservoir,  seal