History, development, and geology of oil fields in Hocking and Perry Counties, Ohio.
Most exploratory and development drilling for oil and gas in Hocking and Perry Counties, Ohio, prior to the 1950s was based on completion results of the nearest well. Economically profitable wells have become increasingly more difficult to obtain, requiring more detailed geologic knowledge of the reservoir rock. The silurian Clinton sandstone reservoir has received most of the recent attention. The Clinton is divided into three units within this area--the stray Clinton, first Clinton, and second Clinton. Clinton sandstones belong to a deltaic complex of medinan age. Studies of mineralogy, texture, sedimentary structures and geometry indicate a variety of possible terrestrial-transitional and marginal marine subenvironments. Oil and gas accumulation is dependent on stratigraphic variation rather than structure. Apparent reservoir-controlling parameters important to exploration and secondary recovery are (1) interstitial clay content, (2) shale stringers and laminations, (3) degree of cementing, (4) grain size, (5) pore geometry, and (6) thickness. The best producing oil wells are those which have been completed in thick, shale-free distributary channel deposits and delta-platform tidal channels. The best secondary-recovery oil wells are those which ahve been completed in thick, shale-free distributary channel deposits and delta-platform tida