Ralph N. Nelson, Hy-Bon Engineering Company, Inc.
Crude oil volume may be lost from a storage tank in the form of vapor and/or gas known as vaporization. This loss of well bore volume, which is not recoverable, is normally expelled to atmosphere. The prime question to the producer of crude oil, is what are the economics of recovering the stock tank vapor? The principles of fluid vaporization are based upon the fundamental laws of physics and will not be fully discussed at this time. Volatile liquids placed in a closed vessel, such as a stock tank, will vaporize throughout the space above the liquid until equilibrium of vapor pressure is attained. This rate of vaporization is affected by a number of operating conditions and by the type of fluid. Generally, the fundamental factor affecting the volume of vapor loss for a given fluid gravity is the ambient temperature, which is variable, and is appreciable in more areas.