N.M. Stat. § 70-7-18
Property rights, leases, contracts and other rights or obligations shall be regarded as amended and modified only to the extent necessary to conform to the provisions and requirements of the Statutory Unitization Act and to any valid order of the division providing for the unit operation of a pool or a part thereof, but otherwise shall remain in full force and effect. A one-eighth part of the production allocated to each tract under an order providing for the unit operation of a pool or a part thereof shall in all events be and remain free and clear of any cost or expense of developing or operating the unit and of any lien therefor as an encumbered [unencumbered] source from which to pay the royalties or other cost-free obligations due or payable with respect to the production from such tract. If a lease or other contract pertaining to a tract or interest stipulates a royalty, overriding royalty, production payment or other obligation in excess of one-eighth of the production or proceeds therefrom, then the working interest owner subject to such excess payment or other obligation shall bear and pay the same.
NMS § 70-7-18