Mammoet secured consulting services agreement with Commonwealth LNG. (Credit: Mammoet)
Summit and Commonwealth signed MOU to collaborate in the supply of LNG. (Credit: Business Wire)
Arup will provide specialist engineering services for the development of LNG modular storage tanks. (Credit: Arup)

Commonwealth LNG is a planned LNG liquefaction and export terminal set to be located on the US Gulf Coast near Cameron, Louisiana, US.

The 8.4 million tonnes per annum (MTPA) liquid natural gas (LNG) facility will be developed by a namesake company Commonwealth LNG LLC.

The project is in the late stages of the Federal Energy Regulatory Commission (FERC) review process.

The FERC issued a final environmental impact statement (EIS) for the Commonwealth LNG Project (Project) in September 2022. The commission will consider the staff’s recommendations to take a decision on the project.

Commonwealth LNG expects to receive full approval by the end of 2022. The company targets a final investment decision (FID) by the third quarter of 2023 and commence commercial operations in Q3 2026.

Once complete, the project aims to become the low-cost provider for the upcoming US LNG liquefaction projects.

Location and site details

Commonwealth LNG will be located on the west bank of the Calcasieu Ship Channel less than one mile from the Gulf of Mexico near Cameron, Louisiana.

The export terminal will be constructed on 118.8 acres of a 393-acre parcel of land in south-central Cameron Parish.

The facility is expected to feature six gas pre-treatment trains and four flares in two systems; six 50,000m3 LNG storage tanks; a marine facility with an LNG carrier berth, barge dock, and vessel manoeuvring area; and a 3-mile long pipeline with a 42-inch-diameter.

Commonwealth LNG has secured long-term commercial leases for the 393-acre area. The lease is segregated into three phases- development, construction and operations.

The operations period will commence with the start of commercial operations and will continue for 20 years. It also includes three ten-year extension options that will take the total period to 50 years.

Project details

Commonwealth LNG would receive natural gas from the natural gas pipeline facilities, capable of approximately 1.44 Bcf/d of natural gas to the terminal.

The gas will be then liquefied and stored at the terminal and subsequently loaded onto LNG carriers docked at the LNG carrier berth for export.

The terminal’s six liquefaction trains have an average liquefaction capacity of 1.4MTPA each.

The feed gas will be passed through the onsite metering station and a pre-treatment unit before entering a liquefaction train.

The pre-treatment unit will remove hydrogen sulphide, carbon dioxide, mercury, water, and heavy hydrocarbons from the feed gas.

The feed gas will then get condensed in the liquefaction train as it passes through a three-part heat exchanger system. The gas is also exposed to a progressively cooler mixed refrigerant.

Commonwealth will store the LNG produced by liquefaction in six storage tanks with inner and outer walls and a capacity of 50,000m3. The tanks will be 167ft tall and 149ft in diameter.

Marine facility

The marine facility at the terminal will include an existing ship turning basin in the Calcasieu Ship Canal, a barge dock, an off-loading platform, and a single vessel LNG carrier berth capable of supporting carriers with capacities ranging from 10,000m3 to 216,000m3.

LNG carriers using the terminal will use a turning basin to turn the vessel downstream before docking at the LNG berth. The turning basin has been constructed as part of the Calcasieu Pass LNG project.

The 100ft by 90ft LNG carrier berth will consist of a single chip slip recessed along the western shore of the Calcasieu Ship Canal.

Other Infrastructure

A flare system will be installed at the terminal for venting excess natural gas. Two such stacks will be constructed for the liquefaction facilities and marine facility respectively.

A 120MW power plant will also be constructed to supply electric power to the facility. The plant will be equipped with three 75MVA natural gas turbine generators.

The electricity will be distributed across the facility using transformers, circuit breakers and motor control centres.

Two diesel stand-by generators with battery backup systems will also be installed for emergencies.

Other infrastructure at the facility will include a storm protection system and a stormwater drainage system.

In addition, the site will include a fire suppression facility, separate systems for refrigerant and LNG, administrative and maintenance buildings and parking and riding facilities among others.

Pipeline details

The three-mile-long natural gas pipeline will transport natural gas to the terminal from three existing pipelines in Cameron Parish- dual 20-inch- and 12- inch-diameter Bridgeline pipelines and one 16-inch-diameter Kinetica pipeline.

It will also have two interconnections with existing Bridgeline and Kinetica pipelines in the north-northwest of the proposed terminal location.

Contractors and agreements

Commonwealth LNG project is supported by an array of companies that offer engineering,  construction and professional project support services such as Technip Energies, Air Products, Baker Hughes, Arup, Bay Ltd and Mammoet among others.

Arup will provide specialist engineering services for the development of LNG modular storage tanks, while Mammoet has been selected for the delivery of heavy hauling expertise in Front End Engineering Design (FEED) and FERC permitting process.

The financial and legal advisors of the Commonwealth LNG project are King & Spalding, PWC and K&L Gates.

In September 2022, Commonwealth LNG and Woodside Energy Group-subsidiary Woodside Energy Trading Singapore announced the conversion of their non-binding heads of agreement (HOA) into two binding LNG Sale and Purchase Agreements (SPAs).

Under the SPAs, the Commonwealth LNG export facility will supply up to 2.5MTPA of LNG over 20 years.

In August 2021, Bangladesh’s Summit Oil and Shipping Co. Ltd. (SOSCL) signed a memorandum of understanding (MoU) with Commonwealth LNG on LNG supplies to Asia.