Abstract: A History of Illinois Basin Oil Exploration

SMITH, AVERY E.
Independent/Consultant

The Illinois Basin includes the southern half of Illinois, the southwestern third of Indiana, and most of the western half of Kentucky. This basin has produced, since the early 1900s, about 4- 1/2 billion barrels of oil, some gas, and plenty of human interest material. Three fields, found between 1900 and 1907, have produced approximately 16% of the basin's total. In 1907 Illinois was the third leading oil state. This early production, which peaked at 33 million barrels during 1910, came from the marginally located LaSalle Anticline.

The deeper part of the basin was ignored by explorationists until the late 1930s. Major oil companies, using new seismic techniques, discovered most of the basin's major oil fields between 1937 and 1941. An early and exciting stimulus to this exploratory effort was the discovery of the Clay City field, ushered in by a 2,640 BOPD "gusher."

During the decade, 1926-1936, the Illinois Basin graduated from cable tools to rotary drilling, from horses and mule teams to bulldozers, from wagons to trucks, from surface geology and "creekology" to seismic exploration and refined subsurface techniques, and from dogeared driller's logs to downhole geophysical surveys.

The peak production year was 1940, during which about 156 million barrels of oil were produced. Except for a couple of interruptions, production since has steadily declined to the current annual level of about 20 million barrels.

Through the years many oil-related stories of people and events have become part of the region's folklore.

AAPG Search and Discovery Article #90930©1998 AAPG Eastern Section, Columbus, Ohio