Chevron Australia Pty Ltd (CAPL) is the operator of the Gorgon Gas Development, one of Australia’s largest natural gas projects located off the northwest coast of Western Australia (WA).

The first phase of the Gorgon Gas Development, the Gorgon Foundation Project (GFP), comprises the production of natural gas from the Gorgon and Jansz-Io fields. Hydrocarbon is transported from the offshore gas fields via two subsea pipeline networks to the Gas Treatment Plant (GTP) on Barrow Island, where it is processed for export as liquefied natural gas (LNG) or piped to the mainland for WA domestic gas users. This phase of the Gorgon Gas Development commenced operation in 2015.

The next phase of the development, the Backfill Fields Development, comprises the production of natural gas from seven backfill fields: Chandon, Chrysaor, Dionysus, Eurytion, Geryon, Semele, and West Tryal Rocks. The purpose of the Backfill Fields Development is to maintain gas supply to the existing GTP on Barrow Island to sustain production rates of LNG and domestic gas. These backfill fields are covered by the Gorgon Gas Development: Backfill Fields Offshore Project Proposal which was accepted by NOPSEMA in October 2025.

To inform ongoing engineering design for the future development of the Chrysaor and Dionysus (C&D) and Chandon gas fields, CAPL is proposing to undertake additional site investigation (geophysical, geotechnical, and environmental) surveys for these future field developments.

The C&D and Chandon Operational Areas are located ~55 km and ~120 km northwest from Barrow Island, and in water depths of ~125–1,230 m and ~1,145–1,370 m respectively. It is within these Operational Areas that the site investigation surveys (the ‘petroleum activity’) will be undertaken.

The petroleum activity is indicatively scheduled to commence from late-2026/early-2027. The surveys are estimated to have a combined duration of ~4–6 months, and may be undertaken as a single campaign or occur over multiple campaigns. The petroleum activity can occur 24 hours per day and 7 days per week.

Note: These schedules and durations are indicative and subject to change; therefore, the petroleum activity may occur at any time over the 5-year in-force period of the Environment Plan.

The Environment Plan documents the assessment and management of potential environmental impacts and risks associated with the site investigation surveys.