Production - Domestic - Oil and Gas Development in Illinois in 1941

In 1941 Illinois produced 134,139,000 bbl. of oil, or 9.5 per cent of the total for the United States, and ranked fourth among the states. The production for 1941 declined 9.2 per cent from the previous year's total of 147,647,000 bbl. Daily average production for 1941 was 366,000 bbl. At the beginning of the year daily production was slightly more than 326,000 bbl. and it remained at appoximately that amount until June, when there was a slight increase. The increase continued until the peak of 431,260 bbl. daily was reached for the week ending Oct. 4. Daily average production at the end of the year was approximately 387,500 barrels. The increased production during the last half of 1941 was largely due to the rapid development of the Johnsonville field, Wayne County, the Rural Hill field, Hamilton County, and the Benton field, Franklin County—new fields discovered in the current year (Fig' 1)—and the Woodlawn pool, discovered in 1940. Discoveries In 19 counties in southern Illinois, 44 new fields were discovered in 1941 (Fig. 2 and Table 2), and extensions to 40 fields were successfully completed (Table 3). At the end of the year there were 10,496 wells in the fields discovered since Jan. I, '937, as compared with 71965 wells at the end Of '940. The area proved for production in the new fields increased from 78,040 acres at the beginning of 1941 to 97,483 acres at the end of the year (Table I)—an increase of 19,433 acres, of which 9,955 acres are in the fields discovered during the current year, and the remainder of 9,478 acres in extensions to pools discovered earlier. Drilling During the past year, 3838 wells were completed in Illinois (Table 4), of which 2912 were oil producers, 13 were gas producers and 913 were dry holes; 76 per cent of the wells drilled were producers. Of the total number drilled, 591 wells are classified as "wildcat" and of these 84 (1 in 7) were successful in obtaining production. The results of an investigation to ascer-tain the reason for the locations of the wildcat wells are set forth in Table 5. Of the 591 wildcat wells, the 292 known to have been located by scientific methods were 21.6 per cent successful. The total footage of wildcat wells drilled in 1941 was 1,341,743 ft., of which a total of 216,995 ft. was drilled in successful wells. Exploration MEthods Subsurface geology and geophysics, largely the reflection seismograph, are still the principal methods used in exploration and development in the state. The number of seismograph parties operating throughout the year was as follows: seven parties on Jan. I, 1941; five on Apr. I; four On July I; eight on Oct. I; fifteen on Jan. 1: 1942.