Abstract

Drill stem test pressures from wells contained in Petroleum Information's computer database were analyzed in an attempt to determine the existence of pressure compartments in the Mesaverde Formation of the Green River and Washakie basins. Initial and final shut-in pressures from production tests were graphed versus each other and versus depth and elevation to display functional relationships as well as zones of anomalous pressure. Potentiometric surface maps were constructed using the maximum shut-in pressure. These maps were used to define the geometry of anomalously pressured zones.

The pressure-elevation plots and potentiometric surface maps clearly show the existence of anomalously pressured zones in the Mesaverde Formation in both the Green river and Washakie basins. The anomalously pressured zones as determined from potentiometric surface maps are discrete areas on the scale of individual oil fields.