Baker Hughes signs service agreement with Coral FLNG

Earlier this year, Eni announced that the Coral Sul FLNG had received its first hydrocarbons from the Coral South reservoir offshore Mozambique. (Photo: Eni.)

Baker Hughes has signed a new service contract for maintenance and monitoring of turbomachinery equipment operations at Coral Sul FLNG, the first deep-water floating liquefied natural gas (LNG) facility operating off the coast of Mozambique on the Eni-led Coral South project.

Coral Sul FLNG is the first deep-water floating LNG facility operating on the Eni-led Coral South Project on behalf of Area 4 Partners (ExxonMobil CNPC, GALP, KOGAS and ENH). With a liquefaction capacity of 3.4 million tons/year, Coral Sul FLNG will put in production 450 billion cubic meters of gas from the giant Coral reservoir, located in the Rovuma Basin Area 4 offshore Mozambique at a water depth of around 2,000 meters. It is expected to begin operations later in 2022, becoming the first LNG project in Mozambique to come online for exports.

The initial life of the service contract has been set for eight years, and services are to commence at the end of 2022.

The contractual service agreement is an example of Baker Hughes’ shared-success model with customers, which aligns mutual incentives under an outcome-based service contract. This best-practice approach will guarantee the performance of the rotating equipment at Coral Sul FLNG under pre-determined metrics, such as reliability of compressors and efficiency and low emissions of gas turbines, the company said.

The contract also includes a provision of resident engineers, supervisors, repairs and spare parts to support maintenance activities. Baker Hughes has committed to utilizing local resources in Mozambique, helping to further grow local talent in supporting the vital energy sector.

As part of the scope, Baker Hughes will also provide remote monitoring and diagnostics services, using its iCenter capabilities, including Carbon Optimizer and a suite of other digital services based on Bently Nevada’s System 1 technology, which includes health and maintenance monitoring, data services and cyber-asset management, Baker Hughes announced.

This new service agreement builds on an existing Coral Sul FLNG contract awarded to Baker Hughes in 2017 for the project’s power and gas refrigeration process, including four turbo-compression trains with aeroderivative gas turbine and centrifugal compressor technology, as well as four turbo-generation units.

“This agreement shows how we embed our decades of LNG experience and constant collaboration with our customers to develop solutions to meet their specific needs and outcomes,” said Rod Christie, executive vice president of Turbomachinery & Process Solutions at Baker Hughes. “Demand for LNG is on the rise, illustrating how natural gas is playing a foundational role in supporting the many types of transitions along the paths to net-zero emissions.

This deal also represents the expertise and portfolio of comprehensive solutions that the recently announced Industrial & Energy Technology business segment of Baker Hughes will provide to customers.”

Introduction of hydrocarbons

Earlier this year, Italy’s Eni announced that the Coral South Project had started introducing hydrocarbons to the Coral Sul FLNG plant. Eni is the operator of the project; its partners include ExxonMobil, CNPC, GALP, KOGAS and ENH.

Following the introduction of gas in the plant, Eni announced the Coral Sul FLNG was expected to be ready to achieve its first LNG cargo in the second half of 2022, adding Mozambique to the LNG-producing countries.

Hydrocarbons introduction comes after the vessel was commissioned. The FLNG arrived at the final operating site offshore Mozambique in early January 2022; mooring and connection to six underwater production wells were finalized in March and May 2022, Eni said.

The Coral South project achieved Final Investment Decision in 2017; FLNG fabrication and construction activities started in September 2018 (Hull first steel cut), and were completed in 38 months as planned, despite the Covid-19 pandemic, with a FLNG Sail Away, from South Korea to Mozambique, in November 2021, Eni said.

While performing the construction activities in Korea, several significant activities were undertaken in Mozambique, with support from the Mozambican authorities, including the ultra-deep waters (2,000m wd) Drilling and Completion and Offshore Installation campaign that involved the highest technological and operational skills.

The Coral Sul FLNG is 432 meters long and 66 meters wide, weights around 220,000 tons and has the capacity to accommodate up to 350 people in its eight-story living quarter module. The facility is located at a water-depth of around 2,000 meters and is kept in position by means of 20 mooring lines that totally weight 9,000 tons.

Coral Sul FLNG has a gas liquefaction capacity of 3.4 million tons per year (MTPA) and will put in production 450 billion cubic meters of gas from the giant Coral reservoir, located in the offshore Rovuma Basin. Coral-Sul FLNG is the first floating LNG facility ever deployed in the deep waters of the African continent, Eni said.

One major challenge in the development of the FLNG was the weather in the Indian Ocean where the Coral Sul is located. The area is prone to cyclones and design engineers needed to take that into consideration, building a facility that could withstand challenging weather conditions, Eni said.

To ensure that Coral Sul FLNG can operate safely even in the most extreme weather conditions, the project team carried out several simulations in tanks and wind tunnels. The vessel’s designers expect the plant to stay offshore for 25 years without dry-docking, Eni said.

The Coral Sul contains four turbo-compression systems to refrigerate the product and generate power for onboard equipment.

For gas liquification, the Coral-Sul deploys an efficient APCI Dual Mixed Refrigerant solution, radically different from Petronas’ nitrogen expansion based one which is tailored to smaller capacities.

To safeguard against refrigerant compressor failure, the Coral Sul contains two parallel 50% capacity strings so if one of the two compressors fails, the other circuit will still provide half the output (versus none if the whole system shuts down). The floating plant will also have boil-off gas and booster compressors to capture and re-liquefy excess boil-off gas that escapes the cryogenic tanks as vapor. This addition improves the overall efficiency of conversion to LNG, Eni said.

Samsung Heavy Industries (SHI) team assembled the 132,000-ton hull with over 2,000 building-block structures. SHI grouped the fundamental blocks into larger subassemblies and continued building until the hull was complete. This approach simplified the manufacturing of the hull by standardising the blocks and drastically reduced construction time, Eni said.

The Coral Sul is equipped with digital oil field and maintenance technologies, utilizing advanced data analytics and key performance indicators to enable optimal plant performance. Due to the cold storage temperature, an automated well control will dictate the production rate to maximize the vessel’s available refrigeration capacity.

In 2017, Baker Hughes announced it will provide rotating equipment for the power and gas refrigeration processes of the FLNG facility. The order comprised four turbo-compression trains utilizing the aeroderivative PGT25+G4 gas turbine driving centrifugal compressors for mix refrigeration services and four turbo-generation units also driven by PGT25+G4 turbines.

Per an additional contract, BHGE supplied boil-off gas (BOG) booster compressors for re-liquefication of evaporating gas out of the LNG storage tanks. The BOG compressors can operate at temperatures as low as -292° F (-180° C).

The turbo compressor trains and turbo-generation units were manufactured at the BHGE Nuovo Pignone facility in Florence, Italy and assembled and tested in the Massa facility.