The GreenStream Pipeline is an offshore gas pipeline (OPL) that transports natural gas from Libya to Italy. It forms part of the larger Western Libyan Gas System.
GreenStream, a joint venture of Eni North Africa (50%) and National Oil Corporation of Libya (NOC) (50%) owns the pipeline.
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Construction works on the project commenced in 2003, and it started operations in 2004.
The operations halted briefly in 2011 for approximately eight months due to the conflict in Libya. After following a testing period, the pipeline restarted commercial operations in October 2011.
GreenStream Pipeline Route
The GreenStream Pipeline exports natural gas from Mellitah on the Western part of the Libyan coast to Gela in Italy. It is the longest subsea pipeline that passes through the Mediterranean Sea.
Mellitah is located on the coast of Libya at approximately 80km west of Tripoli, while Gela is on the coast of Sicily.
The offshore stretch of the pipeline is around 516km.
GreenStream Pipeline Infrastructure
The GreenStream Pipeline infrastructure includes a gas compression station at Mellitah (Mellitah Gas Compression Station), one offshore pipeline, an offshore spur, a receiving terminal at Sicily (Gela Terminal or the Sicily Receiving Terminal), and a measurement station.
The $700m Mellitah Gas Compression Station, located adjacent to the gas treatment plant, compresses the gas up to the pressure required for the export to the Italian Gas Transport Network.
The single 32-inch Nominal Diameter (ND) offshore pipeline (OPL), which exports the gas to Sicily, is 516km long. The pipeline reaches a depth of around 1,127m near Malta, a key feature for a large-diameter pipe laid in S-lay mode.
A single 32-inch ND offshore spur (SPUR) 7.4km-long is laid to connect the offshore pipeline to the receiving terminal. The SPUR is laid in a water depth of 19.5m. The Receiving Terminal in Sicily (SRT) receives the gas and feeds into the Italian Gas Transport Network.
A reduction and measurement station is located in the district of MGCS.
Operational Details
Greenstream pipeline enables supplying natural gas from the Wafa onshore field and the Bahr Essalam offshore field in the western part of Libya to Italy.
The Wafa Field is located 520km southwest of Tripoli, while Bahr Essalam is located within Block NC41 in the Mediterranean Sea approximately 110km from Tripoli.
The gas recovered from the fields is supplied to Mellitah compression station on the coast for treatment. The gas is compressed to a pressure of up to 212 bar to export it to the Gas Transport Network of Italy.
A portion of the production is also supplied to the local market for domestic use.
Greenstream pipeline has an average capacity of 8bcm/pa, and a maximum of 11bcm/pa.
GreenStream Pipeline Contractors
Saipem, an offshore and onshore engineering services provider, was the main contractor of the pipeline project. The company was responsible for offshore engineering and construction works, and pipeline laying.
It used Castoro Sei and Crawler vessels for laying the offshore pipeline via S-lay method.
Boskalis Offshore carried out the shore approach and landfall work including trench excavation (onshore and offshore), installation of pull arrangements, assistance during pipe pull and backfill of the trenches.
VMT’s SLS-Microtunnelling LT was used to install a new gas pipeline in the Sicilian town of Nicosia.
In July 2024, Saipem won the contract to deliver supervisory and subsea intervention services for the pipeline including the onshore and offshore sections at the Gela and Mellitah terminals.
The contract activities will be managed by Sonsub, the centre of excellence of Saipem for robotics, underwater technologies, and services.
The scope of the contract includes the management of survey data and critical spares, asset integrity services, and readiness services for repair interventions.
Sonsub will provide repair intervention services via its SiRCoS technology.
Since 2008, Saipem has been delivering asset integrity, maintenance, and emergency services for the pipeline.
