A Better Way to Forecast Production from Unconventional Gas Wells

Abstract

Abstract This work combines two ideas—the stretched exponential decline curve model and the novel paradigm of data-intensive discovery—to provide a controlled production forecast for any individual tight gas/shale gas well on the basis of data gathered through parameter processing for a large group of wells.. Group production for a large number of wells follows stretched exponential decline behavior of production rates, which we model using the corresponding decline curve model. Compared to the Arps model, the new approach offers numerous advantages; the two most significant ones are the bounded nature of estimated ultimate recovery (EUR) without limits on time or rate, and the straight-line behavior of a recovery potential expression that we introduce. This approach moves production forecasts in tight and unconventional gas fields from individual and subjective curve matching to a new methodology we call "group-data controlled forecast." In terms of the novel stretched exponential decline curve model, the combined process offers statistically more consistent reserve estimates and also provides a potential well monitoring tool.