Analysis of the Gas Production from Marcellus Shale Horizontal Wells Using Decline Curves

Many challenges present themselves when production is being forecasted in ultra-low permeability unconventional reservoir systems. Some of the major challenges are the lack of understanding of the interaction among the fluid flow, the hydraulic fracturing, the reservoir characteristics in these complex systems, and the limited production history. Therefore, the production performance of the shale gas wells over the longer time periods has not been established. A familiar technique for predicting the future production rates, when the only available data are past production rates, is Decline Curve Analysis (DCA). Several DCA methods have been proposed for shale wells, but their application remains problematic. Therefore, a reliable and yet easy to apply predictive tool for accurate prediction of the production performance of the Shale Gas wells is Needed. Marcellus Shale is an important source of natural gas located in the Appalachian Basin. In this study, a number of production data were collected from Marcellus shale gas wells to be analyzed and to develop a reliable and easy methodology to apply a predictive tool in order to improve the conventional DCA for obtaining an accurate prediction for the production performance. A Prediction Technique has been developed and proposed to continuously adjust the conventional DCA prediction for the limited production history of the Marcellus Shale Gas Wells