Notwithstanding the provisions of any statute or law including the provisions of this subchapter, Subchapters C, F, and G of this chapter, and Sections 111.004, 111.025, 111.131 through 111.133, 111.136, 111.137, and 111.140 of this code, none of the provisions of Sections 111.081, 111.084, 111.085, and 111.091 of this code shall increase or decrease the duties or responsibilities of any common purchaser, purchaser, gatherer, or transporter of natural gas, residue gas, or casinghead gas.