(a) An agreement must be approved by the board and executed by the commissioner to be effective if the agreement commits:
(1) a royalty interest in land belonging to the permanent school fund or the asylum funds, in riverbeds, inland lakes, channels, or areas within tidewater limits, including islands, lakes, bays, inlets, marshes, reefs, and the bed of the sea; or
(2) the free royalty interests, whether leased or unleased, reserved to the state under Section 51.201 or 51.054 of this code.
(b) An owner of the soil who is subject to Subchapter C of this chapter may grant to a lessee prior authority to pool or unitize the interest of the owner in a lease executed under that subchapter. For the agreement to bind the interest of an owner of the soil who is subject to Subchapter C of this chapter and who has not granted the lessee prior authorization to pool or unitize the interest of the owner in a sulphur lease executed under that subchapter, the agreement must be executed by the owner of the soil.