Okla. Stat. tit. 52 § 91
The Commission is hereby empowered and authorized by its orders, rules, and regulations, to require that meters be installed (a) upon any pipeline used in purchasing and/or transporting oil in or out of any prorated common source of supply and/or from storage adjacent thereto and (b) upon any pipeline used in gathering and/or transporting oil from leases or storage in such common source of supply, to refineries, loading racks, and field or other storage, and/or to deliver such oil to other transportation lines in or near such fields. All meters installed pursuant to any order, rule or regulation of the Commission made or issued by it under the provisions of this section shall be of a type or types approved by it and the Proration Umpire shall be in mechanical construction and accuracy in operation, sufficient to register the oil transported through the pipeline or pipelines upon which such meters are installed with a degree of accuracy of not more than two percent (2%) from accurate. Said meters shall be installed and maintained at the cost and expense of the owner and/or operators of the pipelines on which the same are required to be installed. No owner or operator of any such pipeline upon which a meter or meters shall have been installed and/or is being maintained pursuant to orders, rules and regulations of the Commission made hereunder, shall operate such pipeline or pipelines at any time when the meter or meters thereon are not properly registering the flow of oil to the knowledge of such owner or operator or when by the exercise of reasonable diligence he or it should have known thereof, except or unless permission to do so by order of the Commission shall have been granted. Said meters shall at all times be subject to inspection and reading by the Proration Umpire, his deputies, or any person authorized and ordered by the Commission to inspect or read the same. The provisions of this section shall be applied and enforced by the Commission only when it finds and holds that the installation of such meter or meters is necessary to the enforcement of this act, and the installation of meters shall not be required generally, and for other purposes as a means of measuring oil.
Okla. Stat. tit. 52, § 91