Sec. 87.174.  APPLICABILITY OF THIS SUBCHAPTER.  The provisions of this subchapter shall not apply to:
(1)  gas produced from a common reservoir that contains both sweet and sour gas which was being lawfully used for the manufacture of carbon black under the provisions of the source law codified in Subchapters D and E of this chapter  at the time of the passage of the source law for this section;  or
(2)  gas from gas wells located in these reservoirs which were entitled to be so used under the provisions of the source law codified in Subchapters D and E of this chapter at the time of the passage of the source law for this section.
Acts 1977, 65th Leg., p. 2545, ch. 871, art. I, Sec. 1, eff. Sept. 1, 1977.