Woodside’s revised environment plan for well tie-back off Australia gets regulator’s nod

Australian energy giant Woodside has secured an offshore regulator’s acceptance of its revised environment plan for Angel platform operations – located in Commonwealth waters on the North West Shelf – to boost production via a well tie-back.

The National Offshore Petroleum Safety and Environmental Management Authority (NOPSEMA) informed on Wednesday that it had approved a revision of the operations environment plan for the Angel platform, which Woodside submitted on 22 September 2021.

The Australian giant submitted it as the operator on behalf of the North West Shelf (NWS) project’s Joint Venture partners including Woodside, BHP Petroleum (NWS), BP Developments Australia, Chevron Australia, Japan Australia LNG (MIMI) and Shell Australia.

The offshore regulator explained that the environment plan was resubmitted to account for the production from a single well tie-back located in the Lambert Deep reservoir. The petroleum activities programme outlined within the revised environment plan includes permit areas: WA-3L, WA-14PL and WA-16L.

The scope of this plan entails routine production and associated activities; routine inspection, monitoring, maintenance and repair (IMMR) of the platform and associated subsea infrastructure and well clean up and commissioning. The Angel platform consists of subsea hydrocarbon gathering systems, a riser platform and an export pipeline.

The revised environment plan covers the Angel platform, including the Lamber Deep tie-back, and a number of exploration wells not linked to the production systems. In addition, there are three production wells tied back to the Angel platform via rigid flowlines that are no longer normally producing from the Angel reservoir due to high water content and have been shut-in in late 2020. These are scheduled to be permanently plugged and abandoned.

Following plug and abandonment, the associated subsea infrastructure is planned to be decommissioned, according to the information available within the revised EP.

Furthermore, after the production from these three wells ceased, Angel topsides processing equipment and subsea infrastructure were placed into preservation mode. According to Woodside’s revised EP, the Angel topsides processing equipment is scheduled to be recommissioned for the Lambert Deep well (LDA-01) tie-back in 2022.

Moreover, Lambert Deep reservoir end of field life (EoFL) is anticipated in 2027 subject to reservoir performance. The Angel platform is designed to operate 24 hours per day, 365 days per year and this EP is intended to remain in force for up to five years from the date the regulator granted its acceptance.

Located in Commonwealth waters on the NWS of Western Australia (WA), in the production licence area WA-3-L and situated approximately 125 km northwest of Karratha in Western Australia, the Angel platform has been operating since 2008. This is an offshore not normally staffed (NNs) production platform that will produce gas and condensate from a single well tieback located in the Lambert Deep reservoir.

The riser platform consists of a single processing train, which processes the production fluids via cooling, separation, and dehydration. Afterwards, the condensate and gas are comingled for export and transported along the 49 km long export 30-inch export pipeline to the North Rankin Complex (NRC) into the first trunkline (1TL) and then onshore to the Karratha Gas Plant (KGP) for processing.

To remind, Woodside received approval from NOPSEMA in January 2021 for the Greater Western Flank-3 (GWF-3) development and the Lambert Deep (LD) development, subsea tie-backs to the GWA and Angel facilities.

Meanwhile, the energy giant last week received key approvals for the execution of its operated Scarborough project located offshore Western Australia.

As Woodside is in the process of merging with BHP, the firm revealed in February 2022 a new executive team, which will lead the new company after the merger with BHP’s oil and gas portfolio is complete, allowing the firm to take full advantage of energy transition opportunities to foster further growth.