225 ILCS 725/23.1
The owner or owners of any tract of land which is productive or capable of being productive of oil or gas or any owner or operator of an oil and gas leasehold on which productive wells are situated, under a lease authorizing the lessee or his assigns to explore for and remove oil and gas, from any sand, strata, or formation, shall be permitted, in the interest of oil and gas conservation, to use any enhanced recovery method for the purpose of recovering the oil and gas contained therein; provided, that the owner or operator of a well to be used for any enhanced recovery method shall make a written application to the Department for authority so to do, and provided that written approval has been granted him by the Department; and provided further that the operation shall be done under the rules and regulations of the Department; and further provided, that use of any enhanced recovery method shall not be deemed to be an unlawful act.
225 ILCS 725/23.1