The Liquid Petroleum Confinement System, (L.P.C.S.), has been designed and constructed to prevent the loss of produced crude oil into the Earth's atmosphere by retention and storage in a confined system. Historically, the petroleum industry has stored produced crude oil at individual surface well locations incorporating one or more standard atmospheric stock tanks. Crude oil stored in this manner undergoes certain physical changes, due to the vapor pressures of the escaping major constituents of the crude oil being greater than atmospheric pressure, causing "differential" and "flash vaporization". The crude oil in this physical state is observed in the form of gas and can be described by applying Boyles Law and Charles Law into the "Ideal Gas" equation PV = nRT. Any change in volume, temperature or pressure with respect to the crude oil, at the constantly changing physical and atmospheric conditions under which it is stored, causes a loss of the crude oil to the atmosphere. This loss can be as high as 50% or more of the daily produced crude oil volume resulting in atmospheric pollution and contamination as well as lost revenues to both the working interest and royalty owners. The L.P.C.S. provides an environment of storage in which the rate of vaporization and condensation become a steady state of "dynamic equilibrium". Thus the molecules of crude oil entering the vapor phase in random motion strike the surface of the liquid and are recaptured. The excess molecules can also be returned to collection and used as an on site fuel gas. The L.P.C.S. offers working interest and royalty owners' protection from the loss of production while increasing crude sales. The L.P.C.S. helps to prevent atmospheric pollution and contamination and becomes a highly efficient investment alternative to conventional atmospheric stock tanks and expensive vapor recovery systems.