Final Average Reservoir Pressure (pavg)

Final average reservoir pressure is the average reservoir pressure at the end of a test. It is calculated for gas and undersaturated oil wells using material balance. The final average reservoir pressure represents the amount of energy left in the reservoir for future production. It is often confused with extrapolated pressure (p*), which is an extrapolation from the semi-log analysis or model. In wells showing depletion, the final average reservoir pressure is less than the initial pressure (pi) as shown in the plot below.

For a well with no depletion, it is equal to initial pressure (pi) as shown in the plot below.