Okla. Stat. tit. 52, § 52-54: Common purchasers of oil - Required to purchase -

Discrimination prohibited.

Every corporation, joint stock company, partnership or other

person, claiming or exercising the right to carry or transport crude

oil or petroleum or any of the products thereof, by pipeline for

hire or otherwise, within the limits of this state, as allowed by,

and upon compliance with the requirements of this article, as owner,

lessee, licensee, or by virtue of any other right or claim, which is

engaged in the business of purchasing crude oil or petroleum

therein, shall be deemed a common purchaser thereof, and shall

purchase all of the petroleum 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 shall

be legally excusable from purchasing and transporting all of the

petroleum produced, then it shall purchase and transport petroleum

from each person and producer ratably, in proportion to the average

daily production; and such common purchasers are hereby expressly

prohibited from discriminating in price or amount for like grades of

oil, or facilities as between producers or persons; and in the event

such purchaser is likewise a producer, it is hereby prohibited from

discriminating in favor of its own production, or storage, or

production or storage in which it may be interested, directly or

indirectly in whole or in part, and its own production and storage

shall be treated as that of any other person or producer.