Okla. Stat. tit. 52 § 23
Every corporation, joint-stock company, limited copartnership, partnership or other person, now or hereafter claiming or exercising the right to carry or transport natural gas by pipeline or pipelines, for hire, compensation, or otherwise, within the limits of this state, is allowed by, and upon compliance with the requirements of this act, as owner, lessee, licensee, or by virtue of any other right or claim, which is now engaged or hereafter shall engage in the business of purchasing natural gas shall be a common purchaser thereof, and shall purchase all the natural gas in the vicinity of, or which may be reasonably reached by its pipelines, or gathering branches, without discrimination in favor of one producer or one person as against another, and shall fully perform all the duties of a common purchaser; but if it shall be unable to perform the same, or be legally excused from purchasing and transporting all the natural gas produced or offered, then it shall purchase and transport natural gas from each person or producer ratably, in proportion to the average production, and such common purchasers are hereby expressly prohibited from discriminating in price or amount for like grades of natural gas or facilities as between producers or persons; and in the event it is likewise a producer, it is hereby prohibited from discrimination in favor of its own production, or production in which it may be interested directly or indirectly in whole or in part, and its own production shall be treated as that of any other person or producer. All persons, firms, associations, and corporation are exempted from the provisions of this act, except from the provisions of Section (9) nine hereof, where the nature and extent of their business is such that the public needs no use in the same, and the conduct of the same is not a matter of public consequence, and for this purpose the district courts of the state and the Corporation Commission are hereby vested with jurisdiction to determine such exemptions in any action or proceeding properly before them, and provided by the laws now in force in this state regulating the purchase and transportation of oil.
Okla. Stat. tit. 52, § 23