First gas flows from Santos’ infill well offshore Australia

Australian energy player Santos has started production from its infill well off the coast of Western Australia six weeks ahead of schedule.

The Halyard-2 well in the Greater East Spar (GES) field was brought online to replace the depleted Halyard-1 well. Since the hydrocarbons produced at the GES, John Brookes, and Spartan fields are transported through the existing subsea infrastructure to Varanus Island (VI) for processing, this is expected to bring 65 million standard cubic feet per day (mmscf/d) to the VI oil and gas hub.

This is in line with the Australian player’s environment plan (EP) which received the stamp of approval from the National Offshore Petroleum Safety and Environmental Management Authority (NOPSEMA) in December 2024.

In addition to drilling Halyard-2, the EP submitted to NOPSEMA in early 2024 entails the disconnection of the existing Halyard-1 Xmas tree production tie-in and the installation of long-term cap. Subsea equipment is also expected to connect Halyard-2 to the existing pipeline end manifold (PLEM) along with pre-commissioning activities.

The activities are scheduled to take place between Q2 2024 and the end of 2026 within the Carnarvon Basin, approximately 100 km north of Onslow, Western Australia in water depths ranging from approximately 95 m to 125 m. The approximate duration for drilling and completion is around 50 days while subsea installation and pre-commissioning are expected to take about 15 days.

Furthermore, Santos says around nine million barrels of oil equivalent (mmboe) of sales gas and condensate will be converted to 2P developed reserves thanks to bringing Halyard-2 online. Kevin Gallagher, Santos’ Managing Director and Chief Executive Officer, explained this is a valuable short-cycle capex project, delivering incremental low-cost volumes into the portfolio through to 2027, and supporting a reduction in unit production costs in 2025.

According to Gallagher, the project demonstrates his company’s commitment to a disciplined low-cost operating model and focus on efficient execution of projects and strong operational results in 2025.

In mid-January, the Australian firm inked a non-binding memorandum of understanding (MoU) with Tamboran Resources Corporation to look into a potential expansion of Train 2 at its liquefied natural gas (LNG) project, Darwin LNG. The duo also intends to work on the jointly owned EP 161 acreage in the Beetaloo Basin.