The legendary Boy Scout motto is “be prepared,” but even they would need to play serious catch-up to equal all the design, setup, configuration, commissioning, testing, smart instrumentation and predictive/proactive maintenance integrated into Royal Dutch Shell’s Prelude, the world’s largest floating liquid natural gas (FLNG) production facility. In fact, though configuration and maintenance don’t normally get as much glory as operational performance, Prelude’s testing and evaluation of its processes have been so extensive that it’s also earned the FieldComm Group’s Plant of the Year Award for 2016.

Having recently completed its long sail from South Korea to the Timor Sea off Australia’s northwest coast, Prelude is presently being stationed 200-km from the mainland. Once its connections to the local gas wells are established and final implementation is completed, it’s scheduled to begin regular operations in 2018. The 488- x 71-m vessel’s 14 production facilities, rising to about eight stories above the main deck and chock-full of FieldComm Group networking and technologies, will extract and process for transport about 3.6 million tonnes per year (Mtpa) of liquefied natural gas (LNG), 1.3 Mtpa of condensate and 0.4 Mtpa of liquefied propane gas (LPG) during its 25-year lifespan.

FieldComm on deck

Beginning with Prelude’s initial designs and continuing through to its construction and upcoming operations, Shell’s engineers report that FieldComm Group technologies are essential in enabling the production facilities to perform their advanced diagnostics, intelligent operations and predictive maintenance, and achieve their lifecycle benefits.

“FieldComm Group technologies are used extensively in every phase of the Shell Prelude FLNG project, and form the backbone of the intelligent predictive maintenance system,” says Kyle Dickson, control and automation engineer for Shell Prelude FLNG. “The use of device templates is delivering excellent conformity and quality assurance throughout the commissioning process. This has enabled a small team to achieve impressive loop check rates whilst maintaining exceptionally high levels of quality assurance. Once commissioned, equipment and unit modules have used the extensive diagnostics and alerts provided by both HART and Foundation Fieldbus technologies to great effect, specifically avoiding numerous plant trips and enabling unprecedented levels of remote support and deep-level diagnostics.”

Rong Gul, senior automation engineer and subject matter expert (SME) for smart instrumentation and instrument asset management with Shell Global Solutions, reports that Prelude’s process applications employ:

• More than 8,000 Foundation Fieldbus devices, including 2,500 valve positioners, located on all control and monitoring devices, and connected only to the DCS;
• More than 4,500 HART devices connected to the DCS and PLCs via HART multiplexers, and used predominantly on devices connected to safety instrumented systems (SIS) and fire and gas (F&G) systems;
• ValveLink and FDT/DTM on all complex instruments like guided wave radar (GWR) and valve positioners; and
• WirelessHART on certain applications.

“In a nutshell, proactive maintenance was embedded from Day 1 on this project, rather than adding it as a work process on running facilities,” explains Gul. “Factory acceptance test (FAT) preparation and testing, training, templating, selection of smart instrumentation, rigid work processes, and a management and maintenance organization firmly supporting the technology are mandatory to make proactive maintenance succeed.”

Templates enable “fix before fail”

One of the most important tools used to prepare Prelude’s production facilities for consistent, optimal operations are default, commissioning or application-specific parameters that enable diagnostic features, device options or other functions. For example, pressure, Coriolis or valve positioning devices can have hundreds of parameters, so parameter settings can be stored in corporate or onsite template files, depending on individual device types or how and where they’re applied. These parameters in templates allow users to:

• Optimize diagnostics;
• Select features and options;
• Ensure error-free downloads to devices;
• Identify application and commissioning parameters;
• Apply consistent work practices at sites to utilize smart instrument data; and
• Eliminate error messages and unnecessary troubleshooting during commissioning.

Consequently, these templates streamline commissioning because they can be used to apply standard configurations to hundreds of Foundation Fieldbus devices in a fraction of the time it used to require, which enables more effective and proactive maintenance at far less cost. “Using device templates ensures uniformity of device configuration, effectively reducing the number of commissioning parameters required to be checked by a factor of 20,” says Dickson. “The principle of ‘do it right, do it once” is guaranteed by correctly using FieldComm Group technologies. The removal of regret/rework has resulted in significant cost/schedule savings throughout the commissioning process.

“In addition, using advanced diagnostics and rationalized device alerts enables predictive and targeted maintenance execution. Being in a particularly remote, isolated location, Prelude depends on having a fully realized, remote-monitoring group of engineers, conducting surveillance and advising on device issues. Commonly, it’s been possible to identify issues, specifically pertaining to control valves before the fault escalates and results in a plant upset or outage.

For instance, Prelude will draw 50 million liters of cold water from the surrounding ocean every hour to cool the natural gas, and help it bring it down to -162 °C. This is the temperature at which it liquefies into LNG and shrinks in volume to 1/600 of its gaseous state, which makes it much easier to transport. Smart devices performing this and other tasks on Prelude include control and safety valves; pressure, temperature and level transmitters for basic process control system (BPCS) and safety, flowmeters for BPCS and safety; fire and gas detection; and more.

Gul reports that implementing a proactive maintenance schedule for Prelude’s applications and components represents a game changer from traditional maintenance planning, allowing proactive maintenance to make informed, condition monitoring decisions, rather than relying on traditional reactive maintenance. “Coupling predictive maintenance data from the asset management suite with the criticality assessment of the field equipment provides a rationalized report, enabling prioritized maintenance activities.”

Gul adds the right parameter configuration of smart instrumentation and a fully functional IAMS are crucial to enabling Prelude’s proactive maintenance schedule. Templates for all devices were configured during its FAT (Factory Acceptance Test) in Singapore, and Shell Global Solutions worked with Emerson Automation Solutions to develop required asset management functions. “As a result, foundation Fieldbus devices can be configured and loop tested six times faster compared to traditional 4-20mA HART devices,” says Gul, who provides training onsite to make sure Prelude’s operators have sufficient expertise in using the appropriate tools to diagnose and decipher alerts and other information.

Commissioning and loop check savings

At the peak of its recent commissioning efforts, Dickson reports that Prelude’s staff was performing more than 500 loop checks per week, and checking multiple streams of complex functions. The vessel’s utilities plant was also running 24/7, which made maintenance challenging. Thanks to using templates for its parameters, Prelude’s staff and contractors achieved:

• Total time savings of 80% for device commissioning and loop checking across all devices that applied user configuration via templates and test devices using full-loop check procedure during FAT—not just commissioning devices in the asset management system;
• Time savings for the valve positioner loop check procedure was more than 80% for the full loop test;
• Tested all device types able to be tested in the FAT in less than three days, compared to previous test using traditional methods, which took more than two days to test just three device types; and
• Human error during FAT was identified quickly with reporting tool allowing for correction on the spot, whereas previously it was a tedious exercise to find a mistake with dozens of parameters and multiple screens.

“All benefits as we’ve gained so far are on Foundation Fieldbus only,” adds Gul. “On average, a trained team can perform a loop check on 20 Foundation Fieldbus devices per day, including a mix of valve positioners to temperature transmitters, and maybe three to five HART devices.

Remote monitoring, collaboration

Beyond all the monitoring and control systems onboard Prelude, Shell is also establishing a Collaborative Work Environment (CWE) at its local headquarters in Perth, Australia. The facility will seamlessly meld telepresence; live/historical process data; live-historical diagnostics; document sharing; and wireless personal video feeds. It will also link Shell and its Global Vendor Support Center to support engineering to optimize production and minimize upsets by using scenario modeling and test runs of plant modifications.

“Perth CWE is connected using fiber-optic links to Prelude, which will only be staffed during normal work-hours,” explains Gul. “Hence, it’s more suited for reliability and day-to-day work planning, rather than ad-hoc problem identification and troubleshooting, especially after normal working hours.”

Just as the templates save time, Gul adds that Shell and Prelude are also embracing the Industrial Internet of Things (IIoT) because it can:

• Improve safety by helping Prelude’s predictive maintenance program and advanced, remote diagnostics capabilities reduce field time for personnel.
• Improves reliability by increasing equipment and plant availability, which is critical for Prelude’s single-train LNG application; and
• Assist production with live data feeds to Shell’s dynamic simulator and predictive models, and providing a full, live view of all process and diagnostic data.

“We’re aligning our work processes and organization to a fully connected, remote LNG plant made possible by IIoT,” says Dickson. “However, our goal of fix it before it breaks will still depend predominantly on the right alert configuration, criticality ranking, and swift reaction on identified device alerts,” concludes Gul.

Technology: 

Foundation Fieldbus

HART