Decline curve anaanalysis is by far the most widely used tool for assessing oil and gas reserves from rate performance. To estimate production rate, the best curve fitting of past production performance is done in boundary dominated flow. And also decline exponent, b, could not exceed 1.
The decline exponent of low permeability reservoir can exceed 1. Dual porosity and transition flow of low permeability could cause the reserves overestimation. To compensate the overestimation, Khaled(2006) suggested Simplified Model that combine hyperbolic case and exponential case. He introduced the transition point from hyperbolic case to exponential case.
Fetkovich`s type curve is for estimating reservoir property, decline exponent, and reserves by matching between production history and type curve. For drawing type curve of shale gas field, Decline envelopes method is probabilistic forecast method easily.
In this work, Simplified Model has been used to forecasting production rate, EUR and production type curve of shale gas production in Horn river basin, Canada. As results of this study, production rate and EUR of Simplified Model is more appropriate than Arps empirical equation. Matching between Simplified Model and production history is better than Arps empirical equation, either early time or late time. Production type curve for Simplified Model can represent production decline trend of production history.