In this reservoir study of the Clinton sand, East Canton oil field, Ohio, results indicate that a properly engineered waterflood may be feasible for secondary oil recovery. Waterflood forecasts that account for a wide range of reservoir conditions are included and can be used for preliminary waterflood performance estimates. Introduction The Morgantown Energy Research Center of the U.S. Bureau of Mines has, for several years, engaged in studies of eastern U.S. oil reservoirs. The goal has been more efficient recovery and more nearly complete recovery of oil through the application of the various secondary-recovery mechanisms. The East Canton oil field in northeastern Ohio was selected for this study because of the impact of its potentially large reserves on the supply of Pennsylvania potentially large reserves on the supply of Pennsylvania Grade crude oil. Because of the unusual reservoir characteristics, secondary-recovery operations in the Clinton sand will be especially challenging for operators and engineers. Previously published reports dealt with reservoir geology and primary recovery in the East Canton field. It was recently reported that waterflooding might be feasible under certain conditions. Here we shall describe, in more detail, the reservoir factors that pertain to waterflooding, and provide the operators with a method for estimating possible oil production by waterflooding from their properties in production by waterflooding from their properties in the East Canton field. Location, History, and Development The East Canton oil field is composed of an or parts of 11 townships in Stark, Carroll, and Tuscarawas Counties in northeastern Ohio (Fig. 1). Active drilling started in 1965 in western Rose Township, Carroll County. Rapid development of the East Canton oil field, however, did not start until Oct., 1966, when the discovery well of the East Canton pool was completed. To date, the western and northern limits of the field have been defined, but the eastern and southern edges of be extended by future drilling. At present, the proved to semiproved productive area is approximately 22 miles long and 5 to 7 miles wide. By July, 1970, over 1,000 wells had been drilled, and several operators were drilling additional wells. Although ultimate primary recovery will vary depending on reservoir characteristics, volumetric calculations indicate recoveries between 28,000 and 63,000 bbl/well, based on 40-acre spacing. More recent decline curve analysis for a 15-well study area shows an approximate primary recovery of 43,000 bbl/well, using an economic limit of 90 bbl/well/ month. Initial production rates of individual wells in the field, as reported by completion records, ranged from a few barrels to over 300 BOPD after fracturing. Most wells produce from a few thousand cubic feet to several hundred thousand cubic feet of gas per day. Initial bottom-hole pressures of approximately 1,500 psi have been observed. Very few wells were plugged psi have been observed. Very few wells were plugged as dry. Peak production of the fieldapproximately 13,000 B/D was reached in Aug., 1968. Cumulative production passed the 10-million-bbl mark by July, production passed the 10-million-bbl mark by July, 1970. JPT P. 1371