ISO TS 21354-2020 PDF

Full title and description

ISO/TS 21354:2020 — Measurement of multiphase fluid flow. This technical specification provides a common basis for classification of applications and multiphase flow meters (MPFMs) and gives guidance and recommendations for the implementation, testing, calibration, installation and use of such meters, with particular emphasis on in-line MPFMs that measure oil, water and gas flow rates. Conventional bulk separators are excluded and wet‑gas measurement is only referenced where relevant.

Abstract

This document establishes terminology, symbols and classification schemes for multiphase flow measurement and provides recommendations on required output data, rated operating conditions, measurement uncertainty, test and calibration procedures (including factory acceptance testing and blind tests), installation, commissioning and operational verification of MPFMs. It is intended to harmonize specification and performance assessment practices for multiphase metering.

General information

• Status: Published (Technical Specification; confirmed in review).
• Publication date: 2020-11 (first edition, 2020).
• Publisher: International Organization for Standardization (ISO).
• ICS / categories: 75.180.30 (Volumetric equipment and measurements).
• Edition / version: Edition 1 (Technical Specification).
• Number of pages: 98 (ISO published PDF pagination).

Scope

ISO/TS 21354:2020 specifies vocabulary, classification and guidance for multiphase fluid flow measurement devices and systems. The specification focuses on in-line multiphase flow meters (partial- and full-separation and direct-measurement MPFMs), defines expected outputs and performance characteristics, and gives requirements and recommendations for testing, calibration, FAT, blind tests, installation, commissioning and in-service verification. Conventional two‑ or three‑phase separators are not covered; wet‑gas measurement is only noted with reference to dedicated wet‑gas guidance.

Key topics and requirements

• Standardized terminology, symbols and subscripts for multiphase metering (GVF, WLR, GOR, flow regimes, etc.).
• Classification of MPFM types (in‑line direct‑measurement, partial‑ and full‑separation) and their intended application envelopes.
• Specification of required output data, rated and limiting operating conditions, and data formats for vendor deliverables.
• Measurement uncertainty assessment and presentation of two‑phase/composition maps to characterise meter performance.
• Requirements and guidance for testing and calibration: factory acceptance testing (FAT), static and dynamic performance verification, blind tests and use of test facilities.
• Guidance on installation, electrical/power requirements, commissioning, function tests and on‑site checks.
• Recommendations for in‑service verification, adjustment procedures, and reporting of test results and uncertainty.

Typical use and users

Primary users include oil & gas operators specifying MPFMs for well surveillance, production allocation, well testing and non‑fiscal/fiscal measurement; instrumentation and MPFM vendors preparing technical offers, FAT plans and performance documentation; flow assurance and production engineers selecting and optimising equipment; metrology teams and test facilities conducting calibrations and blind tests; and regulatory or commercial stakeholders concerned with measurement uncertainty and allocation.

Related standards

ISO/TS 21354 references or complements other measurement guidance such as ISO/TR 11583 and ISO/TR 12748 for wet‑gas matters and sits under the remit of ISO/TC 28 (Petroleum and natural gas) subcommittees; laboratories and test facilities may also apply ISO/IEC 17025 for calibration and testing competence.

Keywords

Multiphase flow, MPFM, in-line multiphase meter, measurement uncertainty, GVF (gas volume fraction), WLR (water‑liquid ratio), GOR, flow regime, factory acceptance test (FAT), blind test, calibration, commissioning.

FAQ

Q: What is this standard?

A: ISO/TS 21354:2020 is a Technical Specification titled "Measurement of multiphase fluid flow" that provides terminology, classification and guidance for multiphase flow meters and their use.

Q: What does it cover?

A: It covers vocabulary, symbols, classification of MPFMs, required outputs and operating envelopes, guidance on measurement uncertainty, testing and calibration procedures (including FAT and blind tests), installation, commissioning and in‑service verification. It does not cover conventional separators and only briefly references wet‑gas guidance.

Q: Who typically uses it?

A: Oil & gas operators, instrumentation and MPFM vendors, production and flow‑assurance engineers, test laboratories and metrology teams, and commercial/regulatory stakeholders involved with multiphase measurement and allocation.

Q: Is it current or superseded?

A: The document was published in 2020 (first edition) and, according to the ISO record, was reviewed and confirmed (remains current) in a subsequent review cycle.

Q: Is it part of a series?

A: ISO/TS 21354:2020 is a standalone Technical Specification produced under ISO/TC 28 (petroleum and natural gas) technical committees. It references related technical reports on wet‑gas measurement (e.g., ISO/TR 11583 and ISO/TR 12748) and complements laboratory and calibration standards such as ISO/IEC 17025 where applicable.

Q: What are the key keywords?

A: Multiphase flow, MPFM, gas volume fraction (GVF), water‑liquid ratio (WLR), calibration, measurement uncertainty, factory acceptance testing, blind test, commissioning.