has emerged as the undisputed worldwide leader in oil and natural gas production, a development that bodes well for the nation a whole, considering hydrocarbons are expected to account for at least 78 percent of global energy needs through 2040. Illinois’ oil production industry continues to be a key contributor the United State’s newfound energy dominance. Here are some key industry facts.

Despite being discouraged to explore in Illinois by prominent geologists of the time, West Virginia wildcatters Michael L. Bendedum and Joseph C. Trees leased 50,000 acres in Crawford County and in the summer of 1905 drilled 930 feet on the Robert D. Athey farm, where they completed the Robert Athey #1 discovery well. The well produced 25 barrels per day, according to author Keith Miller’s book “Wildcats Along the Wabash,” and sparked renewed interest in exploration in Illinois. A year later, the Mahutska Oil Company struck and incredible well on the J.W. Shire farm in Oblong Township that initially produced 250 barrels per day, launching the Southeastern Oilfield and Illinois’ first oil boom. The Southeastern Oilfield nearly single-handedly catapulted Illinois to the status of being the country’s No. 3 oil producer from 1907-1912.

Norma Jean Donnay wrote in a 1996 article that Robinson’s population more than doubled during the first year of the oil boom.

Donnay also wrote that the Southeastern Oilfield was responsible for 98 percent of the state’s production up until about 1936.

After hitting 33 million barrels in 1910, Illinois oil production dropped off significantly over the next 25 years. But seismic exploration and drilling technological advances led to a sharp increase in production in the late 1930s, leading to a second Illinois oil boom that would somehow dwarf the first.

The years 1937-1940 were a landmark era for Illinois oil production as five major oilfields were discovered: The Clay City Consolidated Field (Clay, Wayne and Richland counties – 1937), the Louden Field (Fayette and Effingham counties -1937), the Salem Consolidated Field (Marion County – 1938), the New Harmony Consolidated Field (White, Wabash and Edwards counties – 1939) and the Dale Consolidated Field (Franklin, Hamilton and Saline counties – 1940). Details about the oil booms in Wayne, Clay and Marion counties can be found in Donnay’s outstanding article.

National Public Radio reported in 2021 that,

“By the end of 1937, there were 200 new producing wells in Illinois: 85 in Marion County, with 18 of them on the Merryman Farm” near Patoka, where NPR reported a discovery by Adams Oil and Gas company set off “a southern Illinois oil boom that lasted half a century.”

Illinois nearly tripled its oil output in 1937 alone and The Decatur Daily Review called it a “New Heyday in Little Egypt.”  But even bigger things were in store in 1938. That is when the Salem Field in Marion County was discovered and produced more than 20 million barrels in its first 12 months of operation from July 1938 to July 1939. Marion County produced 93 million barrels all by itself in 1939.

Salem Field production peaked at a remarkable 95.27 million barrels in 1940 (261,000 barrels per day), establishing it as the second-largest oilfield in the United States at the time.

Similar production was seen just to the north when the Louden oilfield  was discovered. That field has produced more than 400 million barrels to date.

Spearheaded by the discovery of these new major oilfields, the state saw its oil production jump from 7.4 million barrels in 1937 to 24 million barrels in 1938. Production nearly quadrupled to just under 95 million barrels in 1939 and then peaked at 147.6 million barrels in 1940. That total represented 11 percent of overall U.S. production that year and nearly 7 percent global production, outpacing Iran and Iraq’s combined output and exceeding the total production of every other nation with the exception of Russia and Venezuela!

The surge in production couldn’t have come at a more critical time for the United States, as Illinois’ oil production helped the Allied Forces emerge victorious in World War II. CNBC recently reported that six out of every seven barrels used by the Allied Forces during World War II was produced in the United States. Illinois was responsible for a significant chunk of that total, producing more than 470 million barrels from 1941 to 1945. In fact, FDR is said to have once stated “Thank God for Salem, Illinois” in reference to the oil boom in that part of the state during that time. Bolstered by the Illinois oil boom of 1940, the U.S. was the source of three-fifths of global oil supply by the time WWII began.

After producing 894 million barrels in the 1940s, Illinois enjoyed a mini-boom in the mid 1950s, as new technologies such as hydraulic fracturing and large-scale secondary recovery projects regularly pushed annual production over the 70 million barrel threshold. Though output has declined since that hay day, Illinois production has remained steady over the past 20-plus years at an average of more than 9 million barrels per year. Some believe that potential future development of the New Albany Shale could push production back to previous heights.

Illinois oil production has remained remarkably steady through good economic times and bad over the past 20-plus years at an average of more than 9 million barrels per year.

Illinois currently ranks 16th out of 31 oil producing states in annual production, with production occurring in 45 counties. Of the more than 14,000 producing oil wells in Illinois, more than 90 percent are “stripper” wells that produce 1-2 barrels per day. Stripper wells account for 80 percent of U.S. wells and 9.5 percent of overall U.S. oil production in 2017 (781,000 barrels per day).

According to the Energy Information Administration, there are more than four billion barrels of unrecovered moveable oil in Illinois’ reservoirs. This is roughly what has been produced in the state since commercial production began in 1905.

Hydraulic fracturing, or “fracking,” is a well completion technology that has been safely used in the Illinois Basin since the 1950s to maximize oil production. Fracking occurs after drilling has been completed and involves pumping fluid — typically 99.5 percent water and sand, with an additional mixture of chemical additives — into the target formation at pressure in order to open up small fractures and allow oil and gas to flow through the rock.

In recent years, fracking has been coupled with horizontal drilling to develop oil and natural gas resources from tight rock formations in several regions of the United States, propelling the United States to the status of being the world’s top crude oil and natural gas producer. For more on the high volume horizontal hydraulic fracturing, see the following Energy In Depth video.

Although Illinois has significant potential for New Albany shale development using horizontal drilling and high-volume hydraulic fracturing technologies, such technologies have not been employed in the state thus far. However, hydraulic fracturing remains a critical component to the conventional vertical well development that has been taking place in the state for more than a century.