LNG

UK-based major Shell is completing a fourth-month maintenance turnaround of the “Prelude FLNG” production vessel that operates off the northwest coast of Australia and which has suffered shutdown over the last few years because of technical issues as well as industrial unrest among workers.

The FLNG vessel is moored 400 kilometres (250 miles) north of the town of Broome on Western Australia’s Kimberley coast and has 3.6 million tonnes per annum of production capacity.

Shell has attempted to tackle some long-term technical issues at the facility with maintenance and work that started in August 2023.

Demand window

“Prelude FLNG” will be coming back on stream to capture the winter demand surge in Japan, China, South Korea and Taiwan.

The LNG carrier “Symphonic Breeze” is expected at the “Prelude FLNG” production hull early in December.

Shipping data showed that the “Symphonic Breeze” departed from the Japanese port of Naoetsu on November 23 with the destination of the vessel with 145,500 cubic metres capacity given as the Shell export facility.

Prelude FLNG has suffered several outages since it started production in June 2019, including a fire that led to a full power loss in December 2021 and several other automatic shut-downs because of fire alarms going off.

“Prelude is a complex facility in a remote offshore location,” said Shell in a statement.

“This is its first major turnaround and we continue to work through the process methodically taking as much time as required to ensure safe execution of all activities,” said the London-headquartered company.

“During the turnaround, additional scopes of work were identified and a decision made to extend maintenance to complete these scopes ahead of restart,” Shell added.

Feed gas

For the Shell project, the Concerto gas field and the nearby Prelude field provide the feed gas for the LNG and the new Crux field is also being developed.

The “Prelude” joint venture is owned 67.5 percent by Shell and 17.5 percent by Inpex Corp. of Japan, operator of the Australian Ichthys project from where the carrier the “Symphonic Breeze” has lifted many cargoes for Japan.

The Inpex Ichthys plant is located at Bayden Point in the Northern Territory of Australia, close to the Darwin LNG plant operated by Santos.

The Santos facility is seeking to bring on stream more feed gas from the Barossa gas project.

A further 10 percent of “Prelude” is held by the South Korean LNG buyer Korea Gas Corp. and 5 percent by CPC Corp. of Taiwan.

The Australian energy safety authorities have ordered the closure of the “Prelude” floating liquefied natural gas production plant offshore northwest Australia after the latest incident in an electrical utility on board and reported on December 2.

The Shell-operated FLNG vessel is moored 400 kilometres north of the town of Broome on Western Australia’s Kimberley coast and has 3.6 million tonnes per annum of capacity.

The Australian National Offshore Petroleum Safety and Environmental Management Authority (NOPSEMA) issued the order for a deeper safety probe by Shell.

This means Shell will likely be halting the offloading of LNG cargoes from “Prelude” into 2022 while the unreliable power shutdown issues are investigated .

The direction from NOPSEMA means the FLNG hull, the largest in the world, will be off stream until Shell can convince the regulators that the problem has been permanently fixed.

NOPSEMA has directed Shell to review what happened on the Prelude between December 2 and 6 and then develop a detailed plan to implement “all necessary corrective actions.”

Shell must also provide NOPSEMA with monthly reports on its progress from early March 2022.

Onboard inspectors

Shell must additionally convince the safety regulator that it can safely recover essential power and other services after a power outage alarm sounds.

“The failure to restore reliable power was seen to represent an ongoing impact and risk to the health and safety of the personnel on the facility,” said the NOPSEMA statement.

After visiting the 488m-long vessel NOPSEMA inspectors concluded that Shell “did not have a sufficient understanding of the risks of the power system on the facility, including failure mechanisms, inter-dependencies and recovery” mechanisms.

According to Shell, smoke triggered the automatic fire detection and management systems in the early December incident and an evacuation of most of the 200 or so crew on board was started. All workers on the facility were accounted for and no injuries reported.

The Shell facility was previously shut down for 11 months after electrical issues. Operations only resumed in February 2021 following an “electrical trip” in early 2020 and three incidents which NOPSEMA had described at the time as “dangerous occurrences”.

For the Shell project, the Concerto gas field and the nearby Prelude field, with combined resources of around 3 trillion cubic feet, are providing the feed gas to produce the LNG.

The Prelude joint venture is owned 67.5 percent by Shell and 17.5 percent by Inpex Corp. of Japan, operator of the Australian Ichthys project.

A further 10 percent of Prelude is held by LNG buyer Korea Gas Corp. and 5 percent by CPC Corp. of Taiwan.