Retired offshore oil & gas infrastructure lives on as rig-to-reef project

Hibiscus Petroleum, a Malaysian independent oil and gas exploration and production company, has confirmed that facilities related to a decommissioned oil field infrastructure, which reached the end of its service life, got a new lease on life thanks to a rig-to-reef project off the coast of Malaysia.

T7 Global secured a letter of award last year with Hibiscus Oil & Gas Malaysia, formerly known as Repsol Oil & Gas Malaysia, to provide engineering, preparation, removal, and disposal services for the South Angsi Alpha (SAA) decommissioning project at the South Angsi field on Block 305/314, 130 km off Terengganu coast in Peninsular Malaysia, within in the south-western part of Malay Basin.

The field’s facilities encompassed a process platform, South Angsi A, and the bridge-linked FSO Angsi installed at the field in August 2005 at a water depth of 75 m. The initial discovery was made in March 2003 but the first oil came in August 2005. Once the production was shut-in in September 2019, the SAA field ceased operations a few days later.

The SAA topside, a mobile offshore application barge (MOAB) type, was a four-legged self-erecting steel construction barge facility bridge linked to the FSO via a telescopic 56-75 m personnel transfer bridge (PTB). This was a full production facility consisting of the wellhead and processing facilities with water injection and gas facilities.

After 15 years of service, the FSO Angsi was demobilized in April 2020. FPSO Ventures, which was hired as the operations and maintenance (O&M) operator, handled pre-operations work at the conversion yard and O&M for the entire duration of service from 2005 followed by the demobilization work for the FSO in 2020.

Tan Kay Zhuin, T7 Global Group’s Chief Executive Officer (CEO), explained in January 2023 that there was an initiative for rig-to-reef repurposing, entailing the conversion of structures into artificial reefs to enhance the marine habitat at the intended location.

The regulatory endorsements regarding in-situ rig-to-reef for the SAA platform were obtained in September 2022, following the crafting of the concept in the conceptual phase by Hibiscus’ internal technical experts working closely with the relevant stakeholders in 2018. The tentative window for Pulau Tenggol reefing was in mid-December 2023.

Furthermore, four major sections of the substructure were envisioned to be laid in situ, creating what the Malaysian firm dubbed the largest reefing substructure in the region, in a bid to enhance the diverse marine ecological state of the SAA location.

As part of the collaboration with the Department of Fisheries Malaysia (DoF) and Petroliam Nasional Berhad (PETRONAS), a portion of the substructure measuring 8 m x 21 m x 17 m was planned to be reefed in Tenggol Island, Terengganu.

The project is expected to promote a way to make future decommissioning activities more cost-effective while enhancing marine biodiversity and addressing the sanctity of food security. The rig-to-reef initiative, which is believed to be a part of a sustainable toolbox arsenal that oil and gas operators have at their disposal, could contribute to these companies’ environmental, social, and governance (ESG) agendas.

According to Hibiscus Petroleum, the South Angsi Alpha rig-to-reef initiative has been launched. The project entails the conversion of the firm’s decommissioned SAA facilities into an artificial reef at Pulau Tenggol in Dungun, Terengganu.

This is aligned with the Malaysian company’s sustainability policy, said to recognize the critical role of preserving biodiversity and protecting ecosystems to maintain ecological balance in its areas of operations.

“Through this initiative, we aim to leave a positive impact on the environment that will enhance the area’s marine biodiversity and its conservation efforts, whilst promote sustainable fishing and ecotourism,” highlighted Hibiscus Petroleum.

The project launch comes several months after a study – done by researchers from University College Cork and the University of Plymouth – on the future of offshore structures, disclosed in Nature, emphasized that several thousand marine artificial structures (MAS) would need to be decommissioned by 2030.

Since these researchers argued that oil rigs could be repurposed to create artificial reefs, securing benefits for the environment and society, the findings prompt a call for law change to allow different options for decommissioning marine structures to be considered.

Hibiscus Petroleum recently expanded its portfolio by acquiring the Brunei affiliate of France’s TotalEnergies to solidify its position as an independent E&P player in the ASEAN region.