Equipment, Equipment & Technology, Middle East

Minimizing outage inspection time

Issue 5 and Volume 17.

The RasGas site

Credit: GE Power Services

A gas turbine inspection outage was completed in a record seven days for an on-site power project, write Rami al-Hammouri and Joseph El Ghoul

Mastering outage execution is the result of thorough planning, continuous improvement and lessons learned, combined with advanced tooling, unconventional lean initiatives, having a skilled and experienced team in place and, most importantly, an efficient and successful collaboration with the operator.

All of these factors came together to allow GE’s Power Services business to set a new global outage record during a major gas turbine maintenance inspection project – a process that requires the units to be taken apart – that GE performed with RasGas Company Ltd in April 2016.

Headquartered in Doha, Qatar, RasGas is one of the world’s premier integrated liquefied natural gas (LNG) enterprises that transformed a regional resource into a key component of the global energy mix. RasGas is a Qatari joint stock company with more than 3000 employees, owned by Qatar Petroleum (70%) and ExxonMobil (30%). Qatar remains the world’s largest LNG exporter, providing 77 metric tonnes annually to the market, which is roughly one third of the global supply.

With other countries looking to increase their LNG production and export capacity, and additional countries like Australia working to convert its domestic coal seam gas supplies into an alternative source of LNG for the Asian market, RasGas has been continuing to optimize its existing LNG production trains within the Ras Laffan Industrial City to maintain its competitive position as the world’s leading LNG supplier.

Over the last several decades, GE has been both a primary supplier of the generation equipment that powers the LNG production trains as well as a long-term service provider to help optimize the reliability and maximize the availability of the RasGas operation, supporting the company’s objectives and to meet and exceed its production targets for its global customers.

For the latest outage project, despite the tough working conditions in a harsh desert environment and under the highest level of safety measures in oil and gas production facilities, GE’s Power Services team demonstrated its project execution capabilities by collaborating with RasGas to deliver a global record for completing major inspections on two GE-supplied Frame 7EA DLN-1 gas turbines in just seven days, beating the previous nine-day record that was set in 2015 by the same team in a similar maintenance event.

Devising and executing the strategy

The scope of GE’s outage work for RasGas included a rotor change-out, stator vanes replacement, shim migration implementation and extended auxiliary scope. While this explains the ‘what’ of the project, it is the ‘how’ that enabled the work to be completed in record time. This is where GE’s close working relationship with RasGas – built over a decade of collaborating on the development of the art of outage execution – played a crucial role.

Back in 2004, a major maintenance inspection of the turbines used to take about 20 to 21 days. During the past years, teams from the two companies began discussing innovative ways to reduce outage duration and RasGas challenged GE to devise a strategy to complete the major inspection in the shortest period of time and minimize the downtime of LNG production.

The challenge was well-accepted and the teams generated ingenious methods to shorten the inspection envelope, including building new tooling capabilities, maintaining consistency of execution personnel leading towards creation of the ‘tiger’ execution team, and conducting several lean sessions to eliminate ‘waste’ in the execution methodology – with results showing a steady improvement over the years and contributing to the success of the 2016 fast-track inspection.

Reducing outage length by one third

GE and RasGas’s outage project teams worked tirelessly for months to plan their fast-track outage project, lining up all the necessary equipment and resources to ensure the work was properly executed. Work was executed on a 24-hour basis, with shift crews working and taking rest breaks in turns to ensure work was continuously being performed. Rest shelters were situated at a close vicinity to the gas turbine to avoid transportation delays and maximize craft labourers’ productivity.

To overcome the limitation of having only one overhead crane and using only one crane operator to lift gas turbine components and other equipment, the companies brought in two crane operators to allow for continuous lifting operations during rest break times. The teams also added extra trucks to help ensure more seamless loading and unloading at the site and the nearby laydown area.

One of the most important decisions during the planning process was the use of RasGas’s on-site high-tech workshop to perform vital, time-sensitive machining and fabrication work. For typical outages, certain work is outsourced to third parties. However, RasGas noted it could save valuable time by using its own on-site workshop, which the company built and has enhanced over the years.

The numerous time-saving retrofits that RasGas had performed in previous years also served as a major contributor to minimizing the outage duration. Upgrades included exhaust quick-disconnect modification, which converted the internal and external bolting mechanism – which used to consume at least two days during disassembly – to only external bolting, thus allowing the removal of the exhaust plenum components in less than eight hours.

In short, the more closely the two companies collaborated on the project, the more efficient they became. Ultimately this project was completed in seven days – a third of the time it took to execute an outage in 2004.

‘Both RasGas and GE worked hard to push the boundaries of innovation on many fronts. Achieving this major efficiency improvement is unprecedented in the industry, and it took great effort from the team. What is most significant is that such world-class results were achieved without jeopardizing safety,’ said Fahad Mohammed Al Khater, RasGas COO.

‘This outage offers several best practice lessons for future service projects. Regardless of the circumstances, GE or RasGas couldn’t have done this alone. The best-case scenario is when you have two companies that were able to jointly develop a strategy to reduce the outage duration and then executed that plan to perfection,’ said Azeez Mohammed, president and CEO of GE’s Power Services MEA.

For RasGas, the milestone outage project represents its continuous commitment to maintaining its leadership role in the global LNG production and export sector by demonstrating quick recovery from any future unplanned or planned maintenance activity.

Meanwhile, for GE, in addition to deepening its relationship with RasGas, the latest outage project further underscored the company’s enhanced global capabilities to deliver its total power plant technology and services to help other industrial organizations meet, and potentially exceed, their business and environmental goals.

Pushing the outage envelope

Completing the RasGas gas turbine maintenance inspection project in such a short period of time would help the company achieve higher safety and cost savings as it allows an early startup of the turbines, resulting in additional LNG production.

However, while GE and RasGas were able to achieve remarkable time on this maintenance outage, a fascinating question emerges: how much further can the industry go in reducing the length of major inspection outage projects?

Rami al-Hammouri and Joseph El Ghoul are Contract Performance Managers for RasGas Company Ltd – GE Power Services

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