Tight gas reservoirs present unique challenges to the reservoir engineer. Applying classical reservoir engineering techniques to these reservoirs is problematic due to the length of time required to reach pseudo-steady state flow and/or establish a constant drainage area. This leads to an inability to accurately estimate the recoverable reserves in a timely and consistent manner. This paper focuses on reserve estimation techniques for tight gas reservoirs.

Both decline curves and material balance methods were found to have serious drawbacks when applied to tight gas reservoirs that had not established a constant drainage area. Gas production analysis (GPA) utilizing a combination of the decline curves and material balance in conjunction with classical pressure transient analysis was found to be more accurate in determining reserves.

You can access this article if you purchase or spend a download.