ABSTRACT
In Illinois, the Geological Survey processed reports on 2,260 oil and gas tests, down 18.2% from 1984. These included 454 exploratory tests (down 32.2%) and 1,806 development tests (down 15.1%). Exploratory tests were 16.5% successful; development tests had a success rate of 71.4%. Five new fields (3 gas, 2 oil), 52 extensions to fields (15 gas, 37 oil), and 43 new pay zones were reported in 1985, as were 116 wells with initial production of 100 BOPD or more. The highest initial production was 640 BOPD from a well in Crawford County. Three newly revived fields underwent substantial and significant development during 1985. Twenty-seven tests (down 32.5%) were reported drilled to a depth of 4,500 ft or greater. The deepest was a 7,250-ft well that tested the “Trenton Limestone” (Ordovician) in Williamson County. Improvement in the quality of seismic data is helping exploration efforts. Drilling is expected to substantially decline during 1986. Crude oil production in 1985 was 30.3 million bbl, up 4.8%. Natural gas production totaled 1,324 mmcf, down 13.5%.
In Indiana, the drilling rate dropped from the preceding year for the fourth consecutive year. The decline in 1985, however, was considerably more severe than any previous decline during this 4-year period. The 853 tests drilled in 1985 were 127 fewer than the tests drilled in 1984. The drilling decline was almost equally divided between exploratory holes (48 fewer holes) and development tests (46 fewer holes); the remaining decline of 33 holes was in service wells (29 service wells were drilled in 1985 compared with 62 in 1984). The success rates of 18.5% for exploratory drilling and 66.2% for development drilling represent modest declines from those of 1984. Oil production remained fairly steady in 1985. Reported production was 5,167,735 bbl, down slightly from 5,394,147 bbl reported in 1984.
In Kentucky, drilling activity continued to decline in 1985. The number of permits dropped to 5,143 in 1985, compared with 6,258 in 1984. Oil production amounted to 7,799,924 bbl, a decrease of 12,411 bbl. Increased demand for gas resulted in an increase of 11,607,984 mcf over 1984 levels for a total 1985 gas production of 73,126,199 mcf. In 1985, 990 exploratory wells were drilled, resulting in 49 new pools, 33 deeper pools, 12 shallower pools, and 217 extensions of existing pools. Total footage for the year was 5,422,427 ft, with an average well depth of 1,311 ft.
Activity in Tennessee declined in 1985 because of low oil prices. During 1985, 336 permits were issued, almost 50% fewer than the 670 permits issued in 1984. Oil and gas exploration has steadily declined in Tennessee since its high in 1981.