The Offset Well Test Program completed in 1981 was undertaken in order to investigate the production characteristics of Devonian shale reservoirs. The investigation involved a study of gas flow through natural fractures, the orientation and distribution of these fractures, and the gas storage/release mechanism and its effect on production. An experiment was designed to test the reservoir under strictly controlled conditions. Interference tests were conducted in Meigs County, Ohio on two wells drilled in the expected maximum and minimum permeability directions from a producing well with known completion and production history. Analysis of the test results indicate that the Devonian shale formation in the Meigs County, Ohio, area is an anisotropic, layered reservoir system. Flow characteristics indicate that the Meigs County reservoir is naturally fractured, may be represented as a dual porosity system, and may be modeled using pseudo-steady-state gas transfer from the matrix to the fracture system. The orientation of the natural fracture system was established through core observation and well test analysis as S65/sup 0/W. The maximum to minimum permeability ratio in the direction of the natural fracture system was calculated to be 8.3. Three distinct zones with independent flow characteristics were identified. The bottom zone, with permeability values significantly higher than the upper two zones, is highly fractured and is a major contributor to the gas production of Well 10056. The pressure profiles of the bottom zones relative to the upper zones were significantly different, indicating minimal communication between the layers. The knowledge of these parameters should have a significant impact on future development of shale reservoirs, through optimization of well spacing and choice of stimulation treatment to enhance gas production.