Definition - What does Artesian Well mean?
An Artesian Well is an oil well that is drilled into an artesian aquifer. In some conditions, an underground reservoir may have a high pressure, which causes the underground water level to rise to the level of hydrostatic equilibrium. When a wellbore is drilled in such a reservoir, the underground water flows to the surface due to the high pressure creating an artesian well. It is also known as a Flowing Artesian Well.
Petropedia explains Artesian Well
Well tests carried out during the oil well exploration phase may lead to the discovery of an underground reservoir referred to as a confined aquifer. This situation is also known as an artesian aquifer, in which the reservoir contains groundwater and other elements. The elements are usually stacked in a very high pressure. When a well is drilled in this reservoir, the underground elements flow up to the surface due to hydrostatic equilibrium. This situation, thus makes the well to flow on its own; hence, the name Flowing Artesian Well.