Abstract The Barnett Shale is one of the first unconventional shale plays developed with multistaged, fracture-stimulated horizontal wells in the world. It is located in North Central Texas near Fort Worth. At the end of 2013, the Barnett Shale had over 14,000 multistaged hydraulically fractured horizontal wells (MFHW) with approximately 7,600 of these wells with over five years of production history. In addition to these MFHW, there are approximately 4,000 vertical wells. Production forecasting for unconventional reservoirs with MFHW is a topic with a great amount of interest. The question is what are the appropriate decline parameters to be used in the forecast? Are multisegment forecasts with their own decline parameters necessary? Currently, production forecasting using a modified hyperbolic Arps equation is still widely accepted. This work provides analysis in characterizing decline parameters during and after linear flow for horizontal wells in the Barnett Shale using public data. There will be examples of MFHWs from the Barnett where the hyperbolic b-exponent will be calculated for each month of production and shown to vary with time as flow regimes change. Single well simulation will be used to characterize the different flow regimes and their effect on decline parameters. Simulation of wells with and without volume outside of fracture tips and their effect on decline parameters will be shown. The decline parameters were in an Arps forecast to match our single well simulation forecast. Uncertainty analysis of production forecast using simulation models is also presented in this work.