This project is a collaboration of Woolsey Petroleum Corporation (a small independent operator) and the Kansas Geological Survey. The project will investigate geologic and engineering factors critical for designing hydraulic fracture treatments in Mississippian ''chat''reservoirs. Mississippian reservoirs, including the chat, account for 159 million m3 (1 billion barrels) of the cumulative oil produced in Kansas. Mississippian reservoirs presently represent {approx}40% of the state's 5.6*106m3 (35 million barrels) annual production. Although geographically widespread, the ''chat''is a heterogeneous reservoir composed of chert, cherty dolomite, and argillaceous limestone. Fractured chert with micro-moldic porosity is the best reservoir in this 18- to 30-m-thick (60- to 100-ft) unit. The chat will be cored in an infill well in the Medicine Lodge North field (417,638 m3 [2,626,858 bbls] oil; 217,811,000 m3 [7,692,010 mcf] gas cumulative production; discovered 1954). The core and modern wireline logs will provide geological and petrophysical data for designing a fracture treatment. Optimum hydraulic fracturing design is poorly defined in the chat, with poor correlation of treatment size to production increase. To establish new geologic and petrophysical guidelines for these treatments, data from core petrophysics, wireline logs, and oil-field maps will be input to a fracture-treatment simulation program. Parameters will be established for optimal size of the treatment and geologic characteristics of the predicted fracturing. The fracturing will be performed and subsequent wellsite tests will ascertain the results for comparison to predictions. A reservoir simulation program will then predict the rate and volumetric increase in production. Comparison of the predicted increase in production with that of reality, and the hypothetical fracturing behavior of the reservoir with that of its actual behavior, will serve as tests of the geologic and petrophysical characterization of the oil field. After this feedback, a second well will be cored and logged, and procedure will be repeated to test characteristics determined to be critical for designing cost-effective fracture treatments. Most oil and gas production in Kansas, and that of the Midcontinent oil industry, is dominated by small companies. The overwhelming majority of these independent operators employ less than 20 people. These companies have limited scientific and engineering expertise and they are increasingly needing guidelines and technical examples that will help them to not be wasteful of their limited financial resources and petroleum reserves. To aid these operators, the technology transfer capabilities of the Kansas Geological Survey will disseminate the results of this study to the local, regional, and national oil industry. Internet access, seminars, presentations, and publications by Woolsey Petroleum Company and Kansas Geological Survey geologists and engineers are anticipated.