This document provides a method to calculate the GHG emissions during natural gas production (onshore or 

offshore), gas processing and gas transport to LNG liquefaction plant.

 NOTE 1 It can be applied to other gases as biogas or non-traditional types of natural gas.

 NOTE 2 equivalent method was developed in ISO 6338 to cover liquefaction.

 The frame of this document starts from the production wells up to the inlet valve of LNG liquefaction plant.

 NOTE 3 shipping, regasification and use will be covered in next standards to have the full chain covered.

 The document covers all facilities associated with producing natural gas, including:

 — Drilling (exploration, appraisal, and development) & Production wells,

 — Gas gathering network and boosting stations (if any),

 — Gas processing facilities (if any), transport gas pipelines with compression stations (if any).

 The document covers facilities associated with producing other products (such as, but not limited to, 

domestic gas, condensate, LPG, sulphur, power export) to the extent required to allocate GHG emissions to 

each product.

 The upstream facilities are considered “under operation”, including emissions associated with commissioning, 

initial start-up and restarts after maintenance or upset. The construction and decommissioning phases are 

excluded.

 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. Scope 1, 2 and 3 are defined in this document. All emissions sources are covered including 

flaring, combustion, cold vents, process vents, fugitive leaks and emissions associated with imported energy. 

Gases to be considered include CO2, CH4, N2O and fluorinated gases.

 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.