Who are the largest operators in the Illinois Basin?

The largest operators in the Illinois Basin by well count are The Ohio Oil (10,782 wells), Marathon Oil Company (4,529 wells), The Texas Company (4,176 wells), Pure Oil Company (3,269 wells), Texaco (2,657 wells), out of 18,324 operators total.

How many oil & gas wells are in the Illinois Basin?

There are approximately 248,675 oil and gas wells operated across the Illinois Basin, per state regulator records compiled by Buckhead Energy (as of 2026-06-23).

Can I sell mineral rights in the Illinois Basin?

Yes. Buckhead Energy buys mineral and royalty interests in the Illinois Basin directly — a free written offer, no broker commissions, and a 7-14 day close.

Top Operators in the Illinois Basin by Well Count

The Illinois Basin spans Illinois, Indiana, and western Kentucky — a mature, shallow oil province with thousands of long-lived stripper wells and the New Albany shale.

The Illinois Basin has approximately 248,675 wells operated by 18,324 companies. Below are the largest operators by well count. Data as of 2026-06-23.

#	Operator	Wells	Producing
1	The Ohio Oil	10,782	0
2	Marathon Oil Company	4,529	0
3	The Texas Company	4,176	4
4	Pure Oil Company	3,269	9
5	Texaco	2,657	45
6	Ohio Oil Company	2,301	0
7	The Pure Oil Company	1,953	0
8	The Carter Oil	1,812	0
9	Forest Oil	1,684	0
10	Carter Oil Company	1,673	52
11	Magnolia Petroleum Company	1,672	3
12	National Associated Petroleum Company	1,620	0
13	Shell Oil Company	1,527	0
14	Ashland Oil & Refining	1,427	125
15	Tide Water Associated Oil Company	1,419	0
16	Exxon Mobil	1,308	3
17	Hercules Petroleum	1,305	154
18	Superior Oil Company	1,294	2
19	Union Oil Company Of California	1,217	0
20	Brehm C E Drilling & Producing	1,167	0
21	Gulf Refining Company	1,055	7
22	Phillips Petroleum Company	1,003	2
23	Sun Production CO Sun Oil	987	0
24	Il State Geological Survey	928	0
25	Associated Oil Production Company	845	0

Explore Illinois Basin mineral rights → Compare operators head-to-head →

Own Mineral Rights in the Illinois Basin?

Buckhead Energy buys mineral and royalty interests under wells operated by any of these companies — a free, no-obligation written offer based on your specific tract, operator, and decimal interest. No broker commissions; closings in 7–14 days.

Get a Free Offer

Operator leaderboards by basin

Permian Basin

Anadarko Basin

Powder River Basin

Denver-Julesburg (DJ) Basin

San Joaquin Basin

Williston Basin (Bakken)

Arkla Basin (Haynesville)

East Texas Basin

Michigan Basin

Bend Arch / Fort Worth Basin

Well counts compiled by Buckhead Energy from state oil & gas regulator records (data as of 2026-06-23); reflect wells where each company is the current operator of record in the Illinois Basin. Informational only.