Analysis of Tight Gas Well Production Histories in the Rocky Mountains

Abstract

Summary Monthly production records on more than 6,000 gas wells are analyzed to determine expected behavior of additional wells and to compare actual performance with theoretical performance as described by many authors. The wells analyzed are in the Rocky Mountains, ranging from the Green River basin of Wyoming to the San Juan basin of New Mexico. Most of these wells produce from low-permeability reservoirs and have been hydraulically fractured. Production trends are studied with three different techniques: conventional semilog rate vs. time analysis, logarithmic rate vs. time analysis, and linear flow decline-curve analysis. The primary purpose of this study is to forecast future rates and reserves. The impact of well downtime and pressure variations on observed flow rates is reviewed.