Developments in East-Central States in 1965

Abstract

Total oil production in Illinois, Indiana, Kentucky, and Tennessee during 1965 was 94.5 million bbls., a decline of 7.0% from 1964. Exploratory wells drilled in the four states totaled 1,077, a decrease of 145 wells or 12%. Gas production, essentially all from Kentucky, increased from 76 Bcf. in 1964 to 82.7 Bcf. Although the bulk of the oil production and the major exploratory effort were still concentrated in the Illinois basin, more attention was attracted by shallow discoveries on the Cincinnati arch in south-central Kentucky near the Tennessee line, on the south flank of the Michigan basin in northwestern Indiana, and in the Appalachian basin in eastern Kentucky. In Tennessee, 20 tests were drilled in 1965, 5 less than in 1964. They included a field discovery, a pool discovery, an extension, a successful development well, and 16 exploratory failures. Tennessee oil production was about 10,000 bbls. and gas production was about 85 MMcf. Oil production in Kentucky decreased slightly from 19.8 million bbls. in 1964 to 19.4 million bbls. in 1965. Gas production in eastern Kentucky remained approximately constant, but production in western Kentucky increased due to development of the Midland field into a major gas source. Of 437 exploratory tests in Kentucky, 54 (12.4%) were successful. Significant reserves of both oil and gas were discovered in Mississippian reservoirs along the southern margin of the Illinois basin in western Kentucky, but the release of mineral deposits underlying Camp Breckinridge will add greater reserves. A Lower Ordovician Knox discovery led to a drilling program in Clay and Laurel Counties, eastern Kentucky, which developed further reserves in Middle Ordovician reservoirs. A spectacular discovery in Upper Ordovician rocks at extremely shallow depths on the Cincinnati arch in central Kentucky near the Tennessee border had resulted in much leasing and drilling activity by the end of the year. Oil production in Indiana increased slightly, from 11.3 million bbls. in 1964 to 11.5 million bbls. There were 285 exploratory tests drilled in Indiana, 12 less than in 1964. Most of the 5 new fields, 18 new pools, and 6 extensions were in Mississippian strata in southwestern Indiana, the Illinois basin section of the state. Discovery of a small field in Devonian strata at a depth of less than 300 ft. on the southern margin of the Michigan basin was instrumental in opening a large area in extreme northern Indiana for further exploration. Oil production in Illinois declined 9.0% in 1965 to 63.6 million bbls. Oil and gas drilling declined 21%, from 1,577 tests in 1964 to 1,245 in 1965. Of 337 new exploratory tests, 24 successful tests were responsible for the discovery of 9 new fields, 2 new pools, and 13 extensions. A 13,051-ft. test to the Precambrian in the deep part of the Illinois basin found no oil below the Mississippian. At the end of the year many depleted wells were being deepened a short distance from the Ste. Genevieve Limestone to dolomite reservoirs in the next underlying formation, the St. Louis Limestone.