A hole drilled to find or delimit a petroleum deposit and/or produce petroleum or water for injection purposes, inject gas, water or another medium, or map or monitor well parameters. A well may consist of one or more well paths and may have one or more terminal points.

Denotes the location of a well from a terminal point to the wellhead. A well path may consist of one or more well tracks.

The part of a well path that stretches from a drilling out point on an existing well path to a new terminal point for the well.

A mixture of gas mainly in liquid phase.

An exploration well drilled to find out whether petroleum exists in a prospect.