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.