Jadestone Energy still has no firm idea when it will be able to restart oil output from a floating production, storage and offloading vessel on its Montara field offshore Australia, which has been shut-in since August following a small leak two months prior.

The Singapore-headquartered independent on Thursday admitted it cannot advise a restart date for Montara, pushing average 2022 production estimates toward the lower end of its latest guidance.

Repairs to an oil cargo tank a ballast water tank have been carried out, with some smaller defects identified as part of a wider inspection and currently being repaired, Jadestone said

“Significant work has been undertaken at Montara in recent weeks, with completion of repairs in tank 2C and the 4S ballast tank being key milestones. The ongoing inspection and repair programme will underpin operational readiness and a safe restart of production,” said Jadestone chief executive Paul Blakeley.

Jadestone in October brought on board Norwegian classification society DNV as an independent reviewer for the Montara FPSO.

DNV is now progressing its ‘gap recognition review’ that is intended to assure the operator’s remediation plans and operational readiness prior to the restart of production operations.

DNV’s report on this will be considered by Australia’s offshore regulator, the National Offshore Petroleum Safety and Environmental Management Authority (Nopsema) prior to restarting Montara’s oil production through the FPSO.

“We are building a solid baseline survey on the FPSO’s remaining tanks – a fundamental step towards a risk-based inspection regime going forward. This survey, and the physical work under way on the FPSO, should help to ensure the highest levels of safety, integrity and vessel uptime in future, and maximise the life and value of the Montara fields for all our stakeholders,” added Blakeley.

The operator currently estimates its 2022 costs for the additional inspection and repair work on the floater to be US$4 million – at the upper end of its estimate in mid-August.

Jadestone appears to be faring better at its Stag oilfield, also offshore Australia. The company recently drilled two infill wells – Stag-50H and Stag-51H – and initial results from well data are in line with pre-drill expectations. These wells are being completed and are expected to be brought on stream soon.

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