Indefatigable (Perenco)

Location

The Indefatigable field is situated in the Southern North Sea, approximately connected to other installations via a network of pipelines, including a connection to the Leman field and ultimately to the Bacton Gas Terminal (BGT) off the coast of East Anglia.

Field Characteristics

• The field is located in shallow water and is part of the larger gas production infrastructure in the Southern North Sea.
• It was modified in 2003 to convert it into a Normally Unattended Installation (NUI), simplifying the process systems to maintain a straight-through process from the platform wells to the export pipeline.

Operational History

• The field operatorship was transferred from BP to Perenco in 2003.
• Despite efforts to continue production, high operational costs and a reduction in gas production led to the conclusion that continued operations were uneconomical. The Cessation of Production (COP) documentation was accepted by the Oil and Gas Authority (OGA) on May 5, 2021.

Infrastructure

• The Indefatigable field includes several installations, notably the 18A platform.
• The 18A platform is connected to the 23A installation via the export gas pipeline PL76, which then connects to the Leman 27B platform and onwards to the Bacton Gas Terminal via a 63-mile, 30-inch pipeline system.

Decommissioning

• Perenco has filed a decommissioning programme for the removal of the topsides of the Indefatigable 18A installations.
• The decommissioning plan involves using a decommissioning jack-up barge (JUB) to plug and abandon (P&A) the platform wells and make the platforms hydrocarbon-free.
• Separate programmes will be filed for the decommissioning of the jackets and pipelines associated with the Inde 18A installations.

Ownership and Partners

• Perenco UK Limited holds a 76.92% equity interest in the Indefatigable field.
• Rockrose UK CS 15 Limited holds a 23.08% equity interest. Other companies, such as Amoco (U.K.) Exploration Company, LLC, and others, have negligible or no current equity interests.

Environmental and Regulatory Considerations

• The decommissioning programme includes an Environmental Assessment Justifications (EAJ) document to assess the environmental impacts, such as seabed disturbance and atmospheric emissions, associated with the decommissioning activities.
• Perenco will submit the required variations to the Pipeline Work Authorisations (PWA) to the OGA and notify the Health and Safety Executive (HSE) of the decommissioning activities.

Current Status

• The field is currently in the decommissioning phase, with Perenco actively engaged in the removal of the topsides and planning for the decommissioning of the jackets and pipelines.
• The company is also involved in various industry initiatives, including the OEUK Supply Chain Forum, OEUK Decommissioning Forum, and the East of England Energy Group (EEGR), to ensure efficient and environmentally responsible decommissioning practices.