A total of 1,878 new tests for oil and gas was drilled in Illinois in 1963, 39 wells more than were reported in 1962. Of the 447 wildcat wells drilled, 6.5% were successful.

Eleven new oil pools, 23 extensions to pools, and 21 new pays in pools were discovered during the year. Mississippian rocks accounted for most of the 55 discoveries with a total of 40. Silurian strata accounted for 6, Devonian for 5, and Pennsylvanian and Ordovician each accounted for 2.

Production for 1963 was estimated at 74,861,000 bbls. of oil. An estimated 64%, or about 47.9 million bbls., is oil produced from secondary recovery projects.

The amount of exploratory drilling in Illinois in 1964 is expected to approximate closely that of 1963. The search for new pools will be greatest along the margins and shelf areas of the Illinois basin, and there probably will be exploration of the deeper pay possibilities in the deep part of the basin.