Liquefied natural gas cargoes have resumed from Shell’s Prelude FLNG vessel offshore Australia following the latest shutdown, which lasted more than four months.

“Our focus at Prelude remains on the long-term and delivering safe, sustained and reliable performance into the future,” the UK supermajor said.

Australian regulator the National Offshore Petroleum Safety and Environmental Management Authority (Nopsema) has closed its Direction 1860 now Shell has demonstrated Prelude FLNG can “safely recover essential power and associated essential services following a loss of power, and that the safety systems and essential support systems operate to maintain safety of personnel”.

Prelude FLNG’s most recent incident occurred on 2 December when it lost power completely and then had unreliable and intermittent power for three days.

Essential services including lighting, safety systems, communications, potable water systems, sewage treatment and air conditioning were affected and seven people were treated for heat-related conditions.

On 23 December, Nopsema instructed Shell to “undertake an investigation and create a plan, schedule and commitment to take all necessary corrective actions and demonstrate that the facility can operate safely in the event of power loss before production can commence”.

Prelude FLNG has a nameplate production capacity of 3.6 million tonnes per annum of LNG, 1.3 million tpa of condensate and 400,000 tpa of liquid petroleum gas.

Shell operates the floater with a 67.5% interest on behalf of co-venturers Inpex on 17.5%, Kogas with 10% and CPC having 5%.

Within the next few month, Shell with different partners — SGH Energy and Osaka Gas — is expected to take the final investment decision on its Crux field development, which will be a tie-back to Prelude FLNG.