1. This section is applicable to all allocation and custody transfer metering stations measuring production from oil and gas wells within the state of North Dakota, including private, state, and federal wells. If these rules differ from federal requirements on measurement of production from federal oil and gas wells, the federal rules take precedence.

2. As used in this section: a. "Allocation meter" means a meter used by the producer to determine the volume from an individual well before it is commingled with production from one or more other wells prior to the custody transfer point. b. "Calibration test" means the process or procedure of adjusting an instrument, such as a gas meter, so its indication or registration is in satisfactorily close agreement with a reference standard. c. "Custody transfer meter" means a meter used to transfer oil or gas from the producer to transporter or purchaser. d. "Gas gathering meter" means a meter used in the custody transfer of gas into a gathering system. e. "Meter factor" means a number obtained by dividing the net volume of fluid (liquid or gaseous) passed through the meter during proving by the net volume registered by the meter.

1. f. 'Metering proving' means the procedure required to determine the relationship between the true volume of a fluid (liquid or gaseous) measured by a meter and the volume indicated by the meter.3. The owner of meter proving equipment shall file with the director an inventory of all conventional pipe provers or master-meter provers used to test the accuracy of oil meters. Inventories must be updated on an annual basis, and filed with the director on or before the first day of each year, or they may be updated as frequently as monthly, at the discretion of the operator. Inventories must include the following:- a. Meter information:
2. (1) Prover:
   1. (a) Type.
   2. (b) Serial number.
   3. (c) Prover volume.
   4. (d) Most recent water draw certificate.
3. (2) Master meter:
   1. (a) Make and model.
   2. (b) Size.
   3. (c) Serial number.
   4. (d) Master meter factor.
   5. (e) Most recent meter proving certificate.
4. (3) An inventory of all meters used for custody transfer and allocation of production from oil and gas wells, or both must be filed with the director upon request.4. The director must be notified of all custody transfer meters placed in service. The owner of the custody transfer equipment shall notify the director of the date a meter is placed in service, the make and model of the meter, and the meter or station number. The director must also be notified of all metering installations removed from service. The notice must include the date the meter is removed from service, the serial number, and the meter or station number. The required notices must be filed with the director within thirty days of the installation or removal of a meter.

All allocation meters must be approved prior to installation and use. The application for approval must be on a facility sundry notice and shall include the make and model number of the meter, the meter or station number, the serial number, the well name, its location, and the date the meter will be placed in service.

Meter installations for measuring production from oil or gas wells, or both, must be constructed to American petroleum institute or American gas association standards or to meter manufacturer's recommended installation. Meter installations constructed in accordance with American petroleum institute or American gas association standards in effect at the time of installation shall not automatically be required to retrofit if standards are revised. The director will review any revised standards, and when deemed necessary will amend the requirements accordingly.

5. All persons engaged in meter proving or testing of oil and gas meters must be registered with the director. Those persons involved in oil meter testing, by flowing fluid through the meter into a test tank and then gauging the tank, are exempted from the registration process. However, such persons must notify the director prior to commencement of the test to allow a representative of the director to witness the testing process. A report of the results of such test shall be filed with the director within thirty days after the test is completed. Registration must include the following:

a. Name and address of company. b. Name and address of measurement personnel. c. Qualifications, listing experience or specific training.

Any meter tests performed by a person not registered with the director will not be accepted as a valid test.

6. Oil and gas metering equipment must be proved or tested to American petroleum institute or American gas association standards or to the meter manufacturer's recommended procedure to establish a meter factor or to ensure measurement accuracy. The owner of a custody transfer meter or allocation meter shall notify the director at least ten days prior to the testing of any meter.

a. Oil allocation meter factors must be maintained within two percent of original meter factor. If the factor change between provings or tests is greater than two percent, meter use must be discontinued until successfully reproven after being repaired or replaced. b. Oil custody transfer meter factors must be maintained within one-quarter of one percent of the previous meter factor. If the factor change between provings or tests is greater than one-quarter of one percent, meter use must be discontinued until successfully reproven after being repaired or replaced. c. Copies of all oil allocation meter test procedures must be filed with and reviewed by the director to ensure measurement accuracy. d. All gas meters must be tested with a minimum of a three-point test for static and differential pressure elements and a two-point test for temperature elements. The test reports must include an as-found and as-left test and a detailed report of changes. e. Test reports must include the following: (1) Company name of test contractor. (2) Pipeline company name. (3) Meter owner name. (4) Producer name. (5) Well or central tank battery (CTB) name. (6) Well file number or CTB number. (7) Test personnel's name. (8) Station or meter number.

1. f. Unless required more often by the director, minimum frequency of meter proving or calibration tests are as follows:
2. (1) Oil meters used for custody transfer must be proved monthly for all measured volumes which exceed two thousand barrels per month. For volumes two thousand barrels or less per month, meters must be proved at each two thousand barrel interval or more frequently at the discretion of the operator.
3. (2) Quarterly for oil meters used for allocation of production in a diverse ownership central production facility. Semiannually for oil meters used for allocation of production in a common ownership central production facility.
4. (3) Semiannually for gas meters used for allocation of production in a diverse ownership central production facility. Annually for gas meters used for allocation of production in a common ownership central production facility.
5. (4) Semiannually for gas meters in gas gathering systems.
6. (5) For meters measuring more than one hundred thousand cubic feet [2831.68 cubic meters] per day on a monthly basis, orifice plates must be inspected semiannually, and meter tubes must be inspected at least every five years to ensure continued conformance with the American gas association meter tube specifications.
7. (6) For meters measuring one hundred thousand cubic feet [2831.68 cubic meters] per day or less on a monthly basis, orifice plates must be inspected annually.
8. g. Accuracy of all equipment used to test oil or gas meters must be traceable to the standards of the national institute of standards and technology. The equipment must be certified as accurate either by the manufacturer or an independent testing facility. The certificates of accuracy for all equipment used to test gas meters must be made available upon request. The owner of a conventional pipe prover or master meter prover shall notify the director at least ten days prior to the testing of any prover. Certification of the equipment must be updated as follows:
9. (1) Annually for all equipment used to test the pressure and differential pressure elements.
10. (2) Annually for all equipment used to determine temperature.
11. (3) Biennially for all conventional pipe provers.
12. (4) Annually for all master meters.
13. (5) Five years for equipment used in orifice tube inspection.
14. h. All meter test reports, including failed meter test reports, must be filed within thirty days of completion of proving or calibration tests unless otherwise approved, and must be submitted by email in a portable document format (.pdf) or another format approved by the director. Test reports must be filed on, but not limited to, all meters used for allocation measurement of oil or gas, all meters used in custody transfer, conventional pipe provers, and master meter provers.7. Variances from all or part of this section may be granted by the director provided the variance does not affect measurement accuracy. Requests for variances may be granted verbally by the director but must be filed by the meter owner on a facility sundry notice.

A register of variances requested and approved must be maintained by the director.

History: Effective May 1, 1994; amended effective July 1, 1996; September 1, 2000; July 1, 2002; April 1, 2018; April 1, 2020; April 1, 2022; April 1, 2024; April 1, 2026.

Law Implemented: NDCC 38-08-04, 38-08-20