Cristin-resultat-ID: 1992229
Sist endret: 28. januar 2022, 11:53
Resultat
Faglig foredrag
2021

How to give specifications of a flow meter in a precise and useful way.

Bidragsytere:
  • Kjell Eivind Frøysa

Presentasjon

Navn på arrangementet: 39th North Sea Flow Measurement Workshop
Sted: Tønsberg
Dato fra: 26. oktober 2021
Dato til: 29. oktober 2021

Arrangør:

Arrangørnavn: Norsk Forening for Olje og Gassmåling / Tekna

Om resultatet

Faglig foredrag
Publiseringsår: 2021

Beskrivelse Beskrivelse

Tittel

How to give specifications of a flow meter in a precise and useful way.

Sammendrag

Flowmeters are essential parts of a metering station for custody transfer measurements of oil and of natural gas. Such measurements have a large focus from operator, partners, customers, transporters and authorities, because of the large monetary values involved. It is therefore critical to ensure that the flow meters are of a type with expected performance, and that the flow meters are maintained and operated as they should. As an example, the Measurement Regulations of the Norwegian Petroleum Directorate [1] specify uncertainty limits at 95 % confidence level for oil metering for sales and allocation purposes of 0.30 % of standard volume. For gas metering for sale and allocation purposes the similar limit is 1.0 % of mass. In order to document compliance with such uncertainty requirements, a combination of flow meter specifications, calibration results and field data are used, in addition to uncertainty from other instruments like pressure and temperature measuring units and online gas chromatographs. In this paper, it will be shown that current vendor specifications of accuracy in flow meters do not comply with the international definition. Furthermore, the concept of repeatability is not uniquely defined in several of the vendor specifications. To complicate further, international standards for flow meters use different definitions of repeatability, in some cases also without specifying which definition they use. This makes compliance tests difficult, especially since repeatability is one of the properties that are in focus under such tests. In addition, this is also a challenge when measurement uncertainty is to be documented.

Bidragsytere

Kjell Eivind Frøysa

  • Tilknyttet:
    Forfatter
    ved Institutt for datateknologi, elektroteknologi og realfag ved Høgskulen på Vestlandet
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