Santos NA Darwin Pipeline Pty Ltd (Santos) is the operator of the existing Bayu-Undan to Darwin Gas Export Pipeline (the Pipeline). The Pipeline transports dry natural gas from the Bayu-Undan (BU) Field located in Timor-Leste waters to the Darwin liquefied natural gas plant (DLNG).

The Pipeline has been in operation since 2005. As the BU Field is approaching the end of its commercially productive life, the Pipeline will transition from operations to a preservation state. The activities that may be undertaken under this EP, include the following:

• Operations phase - Transporting dry natural gas though the Pipeline from the BU Field. Line-packing the Pipeline up to maximum operating pressure (occurs during periods of maintenance and will also occur towards the end of production at the BU Platform). Back-feed of gas from the Pipeline to the BU Platform for power generation.

• Preservation phase - During the preservation phase the Pipeline will remain filled with reservoir gas, which will preserve the integrity of the line. This phase begins when the gas is no longer being used for power generation at the BU Platform. The Pipeline will remain in preservation phase until it is either decommissioned or repurposed for carbon capture and sequestration (CCS). Planning for decommissioning and CCS will occur during the life of the EP and will require separate approvals.

• Pipeline inspection, maintenance, monitoring and repair (IMMR) - Typically a single vessel is used to conduct IMMR activities. Inspections/monitoring surveys are infrequent and of short duration (typically 1-3 weeks depending on the type of survey). If maintenance or repair is required, a vessel may be used at a targeted location for approximately 1 day to 4 weeks. IMMR activities are preferably undertaken from May to November, outside of cyclone season, to minimise or avoid operational disruptions. However, depending on the type of maintenance or repair requirements, IMMR activities could occur at any time during the year.

The Pipeline within the scope of the EP is operated under the following licences: BU-1-PL (Timor-Leste waters); WA-8-PL and NT/PL1 (Australian Commonwealth waters); and NTC/PL1 and PL20 (NT waters). It extends for approximately 502 km from the subsea isolation valve (which is approximately 480 m downstream of the BU Platform) to the beach valve at the DLNG. The ‘Operational Area’ extends 500 m from the Pipeline centreline (i.e. 500 m each side of the Pipeline), along the length of the Pipeline, within which the Petroleum Activity will take place