225 ILCS 725/23.16

From and after the effective date of the order of the Director creating a unit and prescribing the plan of unitization applicable thereto, the operation of any well producing from the pool or portion thereof within the unit area defined in the order, by persons other than the unit operator or persons acting under its authority or except in the manner and to the extent prescribed in such plan of unitization shall be unlawful and is hereby prohibited.