The commissioner on behalf of the state or any fund that belongs to the state may execute agreements that provide for operating areas as a unit for the exploration, development, and production of sulphur and may commit to the agreements:
(1) the royalty interests in sulphur reserved to the state or any fund of the state by law in a patent, award, mining claim, or contract of sale or under the terms of any lease legally executed by an official, board, agent, agency, or authority of the state; or
(2) the free royalty interests, whether leased or unleased, reserved to the state under Section 51.201 or 51.054 of this code.