Decline curve analysis is one of the most commonly used techniques to predict future production performance and estimate reserves from routinely available production data. This article presents obtained results from production data analysis of a naturally fractured lean gas condensate reservoir with homogenous reservoirs decline curve analysis methods. Different methods were used to estimate reservoir original gas in place and expected ultimate recovery. Results have shown that traditional Arp's equations and Fetkovich type curve cannot estimate original gas in place and expected ultimate recovery reliably; but the values of the Blasingame type curve and Agarwal-Gardner type curve can estimate them with about 8% error.