SIST EN ISO 6338-2:2026
(Main)Calculations of greenhouse gas (GHG) emissions throughout the liquefied natural gas (LNG) chain - Part 2: Natural gas production and transport to LNG plant (ISO 6338-2:2024)
General Information
- Abstract
This document provides a method to calculate the greenhouse gas (GHG) emissions during natural gas production (onshore or offshore), gas processing and gas transport to liquefied natural gas (LNG) liquefaction plant.
NOTE It can be applied to other gases as biogas or non-traditional types of natural gas.
This document covers all facilities associated with producing natural gas, including:
— drilling (exploration, appraisal, and development) and production wells;
— gas gathering network and boosting stations (if any);
— gas processing facilities (if any), transport gas pipelines with compression stations (if any) up to inlet valve of LNG liquefaction plant.
This document covers facilities associated with producing other products (such as, but not limited to, domestic gas, condensate, Liquefied Petroleum Gas (LPG), sulphur, power export) to the extent required to allocate GHG emissions to each product.
This document covers the upstream facilities “under operation”, including emissions associated with commissioning, initial start-up and restarts after maintenance or upset. This document does not cover the exploration, construction and decommissioning phases or the losses from vegetation coverage.
This document covers all GHG emissions associated with production, process and transport of natural gas to the LNG liquefaction plant. These emissions spread across scope 1, scope 2 and scope 3 of the responsible organization, as defined in ISO 6338-1. All emissions sources are covered including flaring, combustion, cold vents, process vents, fugitive leaks and emissions associated with imported energy. Gases covered include CO2, CH4, N2O and fluorinated gases.
This document does not cover compensation.
This document defines preferred units of measurement and necessary conversions.
This document also recommends instrumentation and estimations methods to monitor and report GHG emissions. Some emissions are measured; and some are estimated.
- Status
- Published
- Public Enquiry End Date
- 01-Jun-2026
- Publication Date
- 19-Aug-2026
- Technical Committee
- DPL - Gas supply
- Current Stage
- 6060 - National Implementation/Publication (Adopted Project)
- Start Date
- 22-Jul-2026
- Due Date
- 26-Sep-2026
- Completion Date
- 20-Aug-2026
Overview
SIST EN ISO 6338-2:2026 establishes a comprehensive methodology for calculating greenhouse gas (GHG) emissions throughout the upstream portion of the liquefied natural gas (LNG) value chain, from natural gas production (onshore or offshore), through processing and transportation, up to the inlet of the LNG liquefaction plant. Developed by the Slovenian Institute for Standardization (SIST) and aligned with ISO 6338-2:2024, this standard supports organizations in the energy sector to measure, manage, and report GHG emissions consistently and transparently.
This standard focuses on emissions from a variety of sources-including combustion, flaring, venting, fugitive leaks, and imported energy-enabling companies and stakeholders to better understand and reduce the carbon footprint associated with LNG supply. It applies not only to conventional natural gas but can also be extended to alternative gases such as biogas and non-traditional sources.
Key Topics
Emission Source Coverage
The standard covers all major facilities and activities associated with natural gas production and transport to LNG plants, including:- Drilling and operation of production wells
- Gas gathering networks and boosting stations
- Gas processing units
- Transportation pipelines and compression stations
Scope of GHG Emissions
GHG accounting is performed across:- Scope 1 (direct emissions)
- Scope 2 (indirect emissions from imported energy)
- Scope 3 (other indirect emissions, where relevant)
Facilities and Product Allocation
- Emissions are allocated to all products leaving upstream facilities, such as condensate, LPG, domestic gas, sulfur, and power export, based on energy content or other approved methods.
GHG Source Identification
- Emphasis on key emission sources such as flaring, venting, combustion, fugitive emissions, and emissions from imported utilities and consumables.
Measurement and Estimation
- Recommends a blend of direct instrumentation and estimation techniques to quantify GHG emissions, ensuring both accuracy and practicality.
Preferred Units and Conversions
- Standardizes the use of measurement units and provides necessary conversion factors for consistent GHG calculations.
Applications
SIST EN ISO 6338-2:2026 delivers practical value for a range of stakeholders:
Oil and Gas Producers
Operators can utilize this framework to:- Develop GHG inventories for upstream LNG supply chains
- Identify and address emissions hotspots
- Allocate emissions accurately across multiple products
- Satisfy regulatory or voluntary reporting requirements
LNG Plant Developers
Provides robust data for evaluating the emissions profile of feed gas, supporting decision-making on facility design, procurement, and emissions reduction planning.Environmental Reporting and Auditing
Organizations preparing sustainability reports, or seeking third-party verification, benefit from a harmonized approach outlined in this standard, which aligns with major climate initiatives and reporting systems.Extension to Non-Conventional Gases
The methodology is adaptable to biogas and other non-traditional fuels, facilitating the transition to lower-carbon energy systems.ESG and Investor Relations
Transparent GHG accounting enhances stakeholder confidence, enabling operators to demonstrate progress towards net-zero goals and respond effectively to investor and regulatory scrutiny.
Related Standards
To ensure comprehensive and internationally accepted GHG reporting, use SIST EN ISO 6338-2:2026 alongside related standards, including:
- ISO 6338-1: General principles for GHG calculations across the LNG chain
- ISO 14044: Life cycle assessment, requirements and guidelines
- ISO 14064-1: GHG quantification and reporting at organizational level
- ISO 14067: Carbon footprint of products
- CEN/TS 17874: Methane emissions quantification
- GHG Protocol: Corporate and scope 2 emissions reporting guidance
Implementing SIST EN ISO 6338-2:2026 positions organizations at the forefront of climate action in the LNG sector, supporting efforts to reduce GHG emissions, enhance transparency, and drive continual environmental improvement.
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Frequently Asked Questions
SIST EN ISO 6338-2:2026 is a standard published by the Slovenian Institute for Standardization (SIST). Its full title is "Calculations of greenhouse gas (GHG) emissions throughout the liquefied natural gas (LNG) chain - Part 2: Natural gas production and transport to LNG plant (ISO 6338-2:2024)". This standard covers: This document provides a method to calculate the greenhouse gas (GHG) emissions during natural gas production (onshore or offshore), gas processing and gas transport to liquefied natural gas (LNG) liquefaction plant. NOTE It can be applied to other gases as biogas or non-traditional types of natural gas. This document covers all facilities associated with producing natural gas, including: — drilling (exploration, appraisal, and development) and production wells; — gas gathering network and boosting stations (if any); — gas processing facilities (if any), transport gas pipelines with compression stations (if any) up to inlet valve of LNG liquefaction plant. This document covers facilities associated with producing other products (such as, but not limited to, domestic gas, condensate, Liquefied Petroleum Gas (LPG), sulphur, power export) to the extent required to allocate GHG emissions to each product. This document covers the upstream facilities “under operation”, including emissions associated with commissioning, initial start-up and restarts after maintenance or upset. This document does not cover the exploration, construction and decommissioning phases or the losses from vegetation coverage. This document covers all GHG emissions associated with production, process and transport of natural gas to the LNG liquefaction plant. These emissions spread across scope 1, scope 2 and scope 3 of the responsible organization, as defined in ISO 6338-1. All emissions sources are covered including flaring, combustion, cold vents, process vents, fugitive leaks and emissions associated with imported energy. Gases covered include CO2, CH4, N2O and fluorinated gases. This document does not cover compensation. This document defines preferred units of measurement and necessary conversions. This document also recommends instrumentation and estimations methods to monitor and report GHG emissions. Some emissions are measured; and some are estimated.
This document provides a method to calculate the greenhouse gas (GHG) emissions during natural gas production (onshore or offshore), gas processing and gas transport to liquefied natural gas (LNG) liquefaction plant. NOTE It can be applied to other gases as biogas or non-traditional types of natural gas. This document covers all facilities associated with producing natural gas, including: — drilling (exploration, appraisal, and development) and production wells; — gas gathering network and boosting stations (if any); — gas processing facilities (if any), transport gas pipelines with compression stations (if any) up to inlet valve of LNG liquefaction plant. This document covers facilities associated with producing other products (such as, but not limited to, domestic gas, condensate, Liquefied Petroleum Gas (LPG), sulphur, power export) to the extent required to allocate GHG emissions to each product. This document covers the upstream facilities “under operation”, including emissions associated with commissioning, initial start-up and restarts after maintenance or upset. This document does not cover the exploration, construction and decommissioning phases or the losses from vegetation coverage. This document covers all GHG emissions associated with production, process and transport of natural gas to the LNG liquefaction plant. These emissions spread across scope 1, scope 2 and scope 3 of the responsible organization, as defined in ISO 6338-1. All emissions sources are covered including flaring, combustion, cold vents, process vents, fugitive leaks and emissions associated with imported energy. Gases covered include CO2, CH4, N2O and fluorinated gases. This document does not cover compensation. This document defines preferred units of measurement and necessary conversions. This document also recommends instrumentation and estimations methods to monitor and report GHG emissions. Some emissions are measured; and some are estimated.
SIST EN ISO 6338-2:2026 is classified under the following ICS (International Classification for Standards) categories: 13.020.40 - Pollution, pollution control and conservation; 75.020 - Extraction and processing of petroleum and natural gas. The ICS classification helps identify the subject area and facilitates finding related standards.
SIST EN ISO 6338-2:2026 is available in PDF format for immediate download after purchase. The document can be added to your cart and obtained through the secure checkout process. Digital delivery ensures instant access to the complete standard document.
Standards Content (Sample)
SLOVENSKI STANDARD
01-september-2026
Izračuni emisij toplogrednih plinov v oskrbovalni verigi z utekočinjenim
zemeljskim plinom (LNG) - 2. del: Proizvodnja zemeljskega plina in transport do
obrata za utekočinjanje zemeljskega plina (ISO 6338-2:2024)
Calculations of greenhouse gas (GHG) emissions throughout the liquefied natural gas
(LNG) chain - Part 2: Natural gas production and transport to LNG plant (ISO 6338-
2:2024)
Berechnungsverfahren der Treibhausgasemissionen (THG) in der gesamten
Flüssigerdgas-(LNG-)Kette - Teil 2: Erdgasförderung und Transport zur LNG-Anlage
(ISO 6338-2:2024)
Calcul des émissions de gaz à effet de serre (GES) dans la chaîne gaz naturel liquéfié
(GNL) - Partie 2: Production du gaz naturel et transport à l’usine GNL (ISO 6338-2:2024)
Ta slovenski standard je istoveten z: EN ISO 6338-2:2026
ICS:
13.020.40 Onesnaževanje, nadzor nad Pollution, pollution control
onesnaževanjem in and conservation
ohranjanje
75.020 Pridobivanje in predelava Extraction and processing of
nafte in zemeljskega plina petroleum and natural gas
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
EN ISO 6338-2
EUROPEAN STANDARD
NORME EUROPÉENNE
July 2026
EUROPÄISCHE NORM
ICS 13.020.40; 75.020
English Version
Calculations of greenhouse gas (GHG) emissions
throughout the liquefied natural gas (LNG) chain - Part 2:
Natural gas production and transport to LNG plant (ISO
6338-2:2024)
Calcul des émissions de gaz à effet de serre (GES) dans Berechnungsverfahren der Treibhausgasemissionen
la chaîne gaz naturel liquéfié (GNL) - Partie 2: (THG) in der gesamten Flüssigerdgas-(LNG-)Kette -
Production du gaz naturel et transport à l'usine GNL Teil 2: Erdgasförderung und Transport zur LNG-Anlage
(ISO 6338-2:2024) (ISO 6338-2:2024)
This European Standard was approved by CEN on 19 July 2026.
CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this
European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references
concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN
member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by
translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management
Centre has the same status as the official versions.
CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway,
Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Türkiye and
United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2026 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 6338-2:2026 E
worldwide for CEN national Members.
Contents Page
European foreword . 3
European foreword
The text of ISO 6338-2:2024 has been prepared by Technical Committee ISO/TC 67/SC 9 "Production,
transport and storage facilities for cryogenic liquefied gases” of the International Organization for
Standardization (ISO) and has been taken over as EN ISO 6338-2:2026 by Technical Committee CEN/TC
282 “Refrigerated Liquefied Gases (RLG) SEVESO infrastructure design and operation” the secretariat of
which is held by AFNOR.
This European Standard shall be given the status of a national standard, either by publication of an
identical text or by endorsement, at the latest by January 2027, and conflicting national standards shall
be withdrawn at the latest by January 2027.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN shall not be held responsible for identifying any or all such patent rights.
Any feedback and questions on this document should be directed to the users’ national standards body.
A complete listing of these bodies can be found on the CEN website.
According to the CEN-CENELEC Internal Regulations, the national standards organizations of the
following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria,
Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland,
Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Republic of
North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Türkiye and the
United Kingdom.
Endorsement notice
The text of ISO 6338-2:2024 has been approved by CEN as EN ISO 6338-2:2026 without any
modification.
International
Standard
ISO 6338-2
First edition
Calculations of greenhouse gas
2024-08
(GHG) emissions throughout the
liquefied natural gas (LNG) chain —
Part 2:
Natural gas production and
transport to LNG plant
Calcul des émissions de gaz à effet de serre (GES) dans la chaîne
gaz naturel liquéfié (GNL) —
Partie 2: Production du gaz naturel et transport à l’usine GNL
Reference number
ISO 6338-2:2024(en) © ISO 2024
ISO 6338-2:2024(en)
© ISO 2024
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on
the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below
or ISO’s member body in the country of the requester.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: +41 22 749 01 11
Email: copyright@iso.org
Website: www.iso.org
Published in Switzerland
ii
ISO 6338-2:2024(en)
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 2
4 Principles . 2
5 GHG inventory boundaries . 2
6 Quantification of GHG emissions . 3
6.1 General .3
6.2 Defining the upstream system .3
6.2.1 General .3
6.2.2 Gas production feeding LNG liquefaction directly .3
6.2.3 Oil production with associated gas feeding LNG liquefaction .3
6.2.4 LNG liquefaction fed from gas grid .4
6.2.5 LNG liquefaction supplied with non-fossil feed .4
6.3 Identification of GHG sources and quantification approach .5
6.3.1 General .5
6.3.2 Emissions from fuel combustion . .5
6.3.3 Emissions from flaring and venting .5
6.3.4 Fugitive emissions .6
6.3.5 Emissions associated with imported energy, utilities, and consumables .6
6.4 Calculation of GHG emissions .7
6.5 Preferred units .7
6.6 Allocation .7
6.7 Carbon capture .8
7 GHG inventory quality management . 8
8 GHG reporting . 8
9 Independent review . . 8
Bibliography . 9
iii
ISO 6338-2:2024(en)
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out through
ISO technical committees. Each member body interested in a subject for which a technical committee
has been established has the right to be represented on that committee. International organizations,
governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely
with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are described
in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the different types
of ISO document should be noted. This document was drafted in accordance with the editorial rules of the
ISO/IEC Directives, Part 2 (see www.iso.org/directives).
ISO draws attention to the possibility that the implementation of this document may involve the use of (a)
patent(s). ISO takes no position concerning the evidence, validity or applicability of any claimed patent
rights in respect thereof. As of the date of publication of this document, ISO had not received notice of (a)
patent(s) which may be required to implement this document. However, implementers are cautioned that
this may not represent the latest information, which may be obtained from the patent database available at
www.iso.org/patents. ISO shall not be held responsible for identifying any or all such patent rights.
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and expressions
related to conformity assessment, as well as information about ISO's adherence to the World Trade
Organization (WTO) principles in the Technical Barriers to Trade (TBT), see www.iso.org/iso/foreword.html.
This document was prepared by Technical Committee ISO/TC 67, Oil and gas industries including lower carbon
energy, Subcommittee SC 9, Production, transport and storage facilities for cryogenic liquefied gases.
A list of all parts in the ISO 6338 series can be found on the ISO website.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www.iso.org/members.html.
iv
ISO 6338-2:2024(en)
Introduction
Natural gas will play a key role in the energy transition (e.g. by replacing coal to produce electricity) and the
use of liquefied natural gas (LNG) to transport natural gas is expected to increase. The process of liquefying
natural gas is energy-intensive. Gas producers are increasingly accountable for their greenhouse gas (GHG)
emissions and the ambition to reduce them. Furthermore, there is an emerging marketing demand for GHG
data to enable commercial mechanisms such as offsetting to be utilized.
There is no standardized and auditable methodology to calculate the carbon footprint of the whole LNG
chain (including but not limited to the well, upstream treatment, transportation, liquefaction, shipping,
regasification and end user distribution). Various standards indicate possible approaches but are
inconsistent in their results or not easily applicable.
The ISO 6338 series covers each part of the LNG chain and enables a consistent GHG inventory.
The KPIs and related requirements to access to key international initiatives, agreements and reporting/
accounting standards on climate ambitions and zero carbon emission strategies are given in ISO 6338-1:2024,
Annex B.
Attention should be paid to activities that can occur in different parts (e.g. gas treatment and distribution
upstream of the liquefaction plant).
NOTE It is not possible to make like-for-like comparisons, or define a certification scheme, for one block only.
v
International Standard ISO 6338-2:2024(en)
Calculations of greenhouse gas (GHG) emissions throughout
the liquefied natural gas (LNG) chain —
Part 2:
Natural gas production and transport to LNG plant
1 Scope
This document provides a method to calculate the greenhouse gas (GHG) emissions during natural
gas production (onshore or offshore), gas processing and gas transport to liquefied natural gas (LNG)
liquefaction plant.
NOTE It can be applied to other gases as biogas or non-traditional types of natural gas.
This document covers all facilities associated with producing natural gas, including:
— drilling (exploration, appraisal, and development) and production wells;
— gas gathering network and boosting stations (if any);
— gas processing facilities (if any), transport gas pipelines with compression stations (if any) up to inlet
valve of LNG liquefaction plant.
This document covers facilities associated with producing other products (such as, but not limited to,
domestic gas, condensate, Liquefied Petroleum Gas (LPG), sulphur, power export) to the extent required to
allocate GHG emissions to each product.
This document covers the upstream facilities “under operation”, including emissions associated with
commissioning, initial start-up and restarts after maintenance or upset. This document does not cover the
exploration, construction and decommissioning phases or the losses from vegetation coverage.
This document covers all GHG emissions associated with production, process and transport of natural gas
to the LNG liquefaction plant. These emissions spread across scope 1, scope 2 and scope 3 of the responsible
organization, as defined in ISO 6338-1. All emissions sources are covered including flaring, combustion, cold
vents, process vents, fugitive leaks and emissions associated
...