Woodside seeks approval of FPSO ops revision, eyes two-well drilling campaign

Australian energy giant Woodside has submitted a revised environment plan (EP) to the country’s offshore regulator for a floating production, storage, and offloading (FPSO) vessel’s operations, including a potential drilling program, off the coast of Australia.

FPSO Ngujima-Yin; Source: Aibel

The National Offshore Petroleum Safety and Environmental Management Authority (NOPSEMA) has confirmed that Woodside’s revised five-year environment plan for the FPSO Ngujima-Yin (NY) operations activity is under assessment. The FPSO started working in 2008 and is located in Commonwealth waters of the Exmouth Sub-Basin of Western Australia (WA), approximately 43 km north of North-West Cape. The water depth at the FPSO mooring location is about 340 m with wells in water depths up to 849 m.

The FPSO NY and subsea infrastructure is situated in production license areas: WA-28-L and WA-59-L. According to Woodside, the future activities for this environment plan may include production from up to an additional two wells within the permit area. These two new wells may be drilled over two separate campaigns. While the anticipated timing for the first well is in 2025, the second well is estimated to be spud in 2026-2028. However, the drilling, installation, cold commissioning, and tie-back activities associated with the two new wells would be the subject of separate EPs.

The revised EP covers well start-up and hot commissioning for each proposed well. The FPSO Ngujima-Yin currently produces crude oil from the Vincent oil field reservoir (VIN) as well as the Norton over Laverda (NOL), Laverda Canyon Reservoir (LAV), and Cimatti (CIM) fields, which are collectively referred to as the Greater Enfield (GE) development. The project was completed in 2018, developing the three additional oil accumulations through a subsea tie-back to the FPSO, with the project scope including a major refit of the vessel, the installation of subsea infrastructure, and 12 development wells. The GE rigid production flowline operates under pipeline license WA-28-PL.

Furthermore, the activities proposed to occur within permit areas, WA-28-L, WA-59-L, and WA-28-PL encompass routine production and associated activities from existing subsea wells; crude oil offloading activities; routine and non-routine inspection, monitoring, maintenance, and repair (IMMR) of the FPSO and associated subsea infrastructure; disconnection and sailaway of the FPSO with the submerged turret production (STP) mooring and subsea infrastructure remaining in place; and non-routine, unplanned activities and incidents associated with these aspects.

This EP is intended to remain in force for up to five years following acceptance. Woodside’s NY facility consists of the FPSO vessel; processing and separation facilities for oil, water, and gas compression facilities, and associated subsea infrastructure. Under normal operations, surplus gas and produced water are disposed of by reinjection back into the reservoir.

In addition, gas reinjection provides an artificial lift for the CIM field. Regarding the GE wells, treated sea water produced topside is reinjected via dedicated water injection wells for pressure support. Following processing, the stabilized crude oil is offloaded to trading tankers for export.

While working to fortify its oil and gas arsenal, Woodside also recently sold a 10% non-operating interest in the Scarborough Joint Venture, comprising the Scarborough gas field and associated offshore and subsea infrastructure, to LJ Scarborough, a subsidiary of LNG Japan.

The gas from Scarborough will be processed at the Pluto LNG facility, where the company is constructing Pluto Train 2. The first three of 51 modules required for the Pluto Train 2 have arrived in Karratha. The first LNG cargo is slated for 2026.