Cover story

The great gas shutdown

The Shutdown operation represented nearly 500 000 man-hours of activity, and involved maintenance of equipment, modifications to the facilities to improve operability and required regulatory equipment inspections. These activities can only be conducted with the facilities closed down and gas production halted.

Shutting down gas production 500 km offshore and LNG production onshore involves huge expense to the project, including $80 million in operational expenditures, plus another $80 million in capital expenditure, not to mention loss of revenue from sales.

So, why do it? The company is obliged by regulation to go in and inspect the pressure envelope in both facilities on a periodic basis. “These are very complex, large facilities,” explains Shutdown manager Peter Simpson. “Just from a safety standpoint, if we weren’t bound to do it, we would do it anyway. There are a lot of potential hazards out there that need to be monitored all the time.”

UK born Simpson, who has served as Bayu- Undan’s operations manager and worked as the production team leader at Darwin LNG, led a virtual brigade of highly skilled professionals who were brought in from across Australia and around the globe to perform the required tasks. A total of 750 were needed offshore and 600 onshore at the Darwin plant. They brought in valve specialists, inspection people, turbine specialists, decontamination specialists, people representing the whole spectrum of process engineering.

But by the time those specialists began arriving, the operation planners had already been working on the project for more than a year and a half. An enormous amount of planning went into completing the Shutdown, with a team of 40 people working at the Darwin LNG plant doing all the planning for over a year, plus a team of about 70 in Perth planning the offshore work required at the Bayu-Undan facility. They created a plan and schedule aiming to fi t thousands of tasks into the shortest possible window of opportunity.

While the tasks facing the Darwin LNG plant crew were challenging, the facility is physically large, and access is relatively easy with the luxury of space. Offshore, however, the facilities are very restrictive and the logistics of moving and accommodating 750 people 500 km offshore are remarkably complex. Crews were flown from Darwin to Dili on fixed wing aircraft and moved by Super Puma helicopters to the Bayu-Undan platform at sea. But the main offshore complex can only sleep just over 100 people so an additional accommodation support vessel was required.

To accommodate that workforce, a floating hotel was brought in. The Keppel FELS designed Floatel Superior made her maiden charter contract with ConocoPhillips from Singapore. Designed for the demanding conditions of the North Sea, the Floatel Superior features 440 bed accommodations in all single bed cabins, or 512 using limited double bed occupancy. It includes 50 office work stations and a telescopic gangway for safe transfer of personnel from the hotel to the Bayu-Undan facility. According to Simpson, the accommodation was first class. “They provided three or four meals for 500 plus people on any given day,” he recalls. “And it ran like clockwork. The hotel had an onboard crew of about 40 people plus the catering company that did the food production had about 45.”

Offshore, crews were involved in modifications on the export system, maintenance work, and inspection of the facilities where access was normally restricted. Onshore, the Darwin LNG facilities were upgraded with turbines replaced with newer models, allowing the company to increase LNG production volumes. Steam generators were removed and replaced.

For the first time, operational staff played important management roles in a Shutdown. “That was a tremendous success because they’ve got a lot of ownership in both facilities,” reflected Simpson. “Usually the shutdowns are run by team specialists that come in and plan it all and do it all, but they don’t really have that intimate ownership of the facilities. So we approached this differently this time and it was very successful.”

“Local businesspeople knew about the shutdown and they understood how big it was. We got a lot of support from them.”

While most Territorians were blissfully unaware this massive undertaking was happening, many Darwin businesses were actively involved. All catering was supplied by Territory fi rms. Fabrication and support engineering was supplied locally, mainly from Monadelphous and specialist contractors. Coates Hire provided tooling and other equipment, warehousing was done in Darwin. “That’s not forgetting the 400 people we had staying at the Airport Hotel,” says Simpson. “They were transported out to the plant every day by local hire buses. Local businesspeople knew about the shutdown and they understood how big it was. We got a lot of support from them.”

The Shutdown manager described the outcome of the month-long operation as ‘magnificent.’ They achieved every critical shutdown objective at both facilities. “It was the most successful shutdown we’ve achieved and that’s because we’re getting more experienced at that,” says Simpson. “We approached it slightly different this time extending the planning period and involving the operations people that actually run the facilities. We usually come out of these shutdowns with a little bit of a hangover of work we didn’t get to, but we got to everything this time. Safety of our people is always our number one concern and at the end of the day, the safety of everybody working on the project is what really measures the success of the operation.”