A detailed timeline of the events that delayed the start-up of Harbour Energy’s (LON:HBR) Tolmount gas field has been published.
In its annual report and accounts, Dana Petroleum, which has a 50% stake in the Southern North Sea project, revealed a “significant non-compliance” with a key piece of kit was to blame.
Production from Tolmount had originally been on the slate for July 2021, but start-up was pushed back, and it did not go live until April 2022.
At the time, London-listed Harbour (LON: HBR) blamed the delay on faults with offshore electrical systems that had cropped up during final commissioning and testing.
Dana, owned by Korean National Oil Company (KNOC), has now shed light on the scale of the equipment glitches that were uncovered.
Big issues uncovered
In late June 2021, independent verification body DNV identified a significant non-compliance with the ATEX – “certification regulations for equipment being used in hazardous/explosive atmospheres” – during a verification visit to the Tolmount platform.
Harbour then commissioned an ATEX specialist to conduct a “detailed inspection” across all electrical equipment items on the installation.
That flagged a “significant failure rate”, and it was then agreed between parties that a “full inspection” was needed – it was completed in Q4 2021.
Rectification of all failures was complete in the first quarter of 2022, before full commissioning was carried out.
First gas was then achieved on April 24.
A tough start to life
The delays resulted in an “increased forecast for expenditure” to complete the project, something that was approved by the Dana board in December 2021.
Around that same time a downgrade of field reserves at Tolmount was also announced – it was reported that the drop could be between 20 million and 30m barrels of oil equivalent (boe).
The field had been expected to produce around 90m boe in total, at peak rates of around 28,000 boepd, according to previous guidance.
Harbour Energy operates Tolmount with a 50% stake.
Dana and Kellas Midstream struck an innovative infrastructure deal to jointly build and own the platform and export pipeline, called the Humber Gathering System (HGS).
Offshore Design Engineering (ODE) was appointed as installation operator for the HGS infrastructure.
Dana also revealed in its annual report that “excellent progress” has been made in moving the Tolmount East discovery forward.
A field development plan (FDP) for the project was lodged with the regulator in February last year, and development consent was received a few months later.
Tolmount East will be developed as a tie-back to the existing Tolmount project and is targeting around 53m boe in gas and condensates.
First gas is on the slate for Q3 next year.