The Department of Energy (DOE), Morgantown Energy Technology Center (METC) has been supporting the development of flow models for Devonian shale gas reservoirs. The broad objectives of this modeling program are to: (1) develop and validate a mathematical model which describes gas flow through Devonian shales; (2) determine the sensitive parameters that affect deliverability and recovery of gas from Devonian shales; (3) recommend laboratory and field measurements for determination of those parameters critical to the productivity and timely recovery of gas from the Devonian shales; (4) analyze pressure and rate transient data from observation and production gas wells to determine reservoir parameters and well performance; and (5) study and determine the overall performance of Devonian shale reservoirs in terms of well stimulation, well spacing, and resource recovery as a function of gross reservoir properties such as anisotropy, porosity and thickness variations, and boundary effects. During the previous annual period, a mathematical model describing gas flow through Devonian shales and the software for a radial one-dimensional numerical model for single well performance were completed and placed into operation. Although the radial flow model is a powerful tool for studying single well behavior, it is inadequate for determining the effects of well spacing, stimulation treatments, and variation in reservoir properties. Hence, it has been necessary to extend the model to two-dimensions, maintaining full capability regarding Klinkerberg effects, desorption, and shale matrix parameters. During the current annual period, the radial flow model has been successfully extended to provide the two-dimensional capability necessary for the attainment of overall program objectives, as described above.