The pipelay vessel Castorone will be used to install the gas pipeline for the project. Photo credit: Saipem SpA.
The Argo and Cassiopea fields will produce from four wells connected to the new Prezioso K platform. Image credit: Vismar UK/Shutterstock.com.
The gas produced from the two fields will be processed in a new gas processing plant being built in Gela. Image credit: Valerio De Carlo/Wikimedia Commons.
The first gas from the field was produced in August 2024. Photo credit: Eni.
The Argo and Cassiopea fields, located 25 kilometers off the coast of Sicily in the Italian region of Ibleo, represent the largest greenfield gas production in the country.
The fields are jointly owned by oil and gas company Eni and hydrocarbon exploration and production company Energean. The two companies hold 60% and 40% of the shares, respectively. Energean’s 40% stake in the fields was previously owned by Edison E&P, an oil and gas production company that was acquired by Energean in 2020.
The project will be Italy’s largest new-build gas project and is expected to achieve peak net production of 100,300 barrels of oil equivalent per day. The two fields are the country’s most important production fields and will come on stream in August 2024.
The project includes a dedicated 3.6 MWp photovoltaic system that will enable the project to achieve carbon neutrality in terms of its Scope 1 and 2 emissions.
Locations of the Argo and Cassiopea gas projects
The Argo and Cassiopea fields are located in the Ibleo licensed area in the Strait of Sicily. The area also includes several other deposits such as Gemini, Centauro and Vela.
Discovery and reservoir details of the Argo and Cassiopea fields
The Cassiopea field was discovered in July 2008 by the Cassiopea 1 well at a water depth of 560 km, 22 km off the coast of Agrigento.
The Argo field was discovered in May 2007 by the Argo-1 well in a water depth of between 1,350 m and 1,520 m. The well produced 769 ft³ per day during test production.
The gas contained in the field’s deposits is of early Mesozoic to Cenozoic age and originates from Pleistocene clastic sediments.
Reserves of the Argo and Cassiopea fields
The gas reserves of the Argo and Cassiopea fields are estimated at around ten billion cubic metres, with an annual peak production of 1.5 billion cubic metres of gas expected.
Details on the development of the Argo and Cassiopea gas fields
The fields are being developed through four subsea wells, two of which are new wells and two are re-completions. The Argo field is producing from a single well, while the Cassiopea field is producing from three wells.
The four wells are connected to the new Prezioso K platform, which is installed at a water depth of 45 m and features an optimized subsea production system. The platform houses the processing and compression system for the project and is connected to the existing Prezioso platform by a 60 m long bridge.
Well control system operations and chemical injection for the fields will be carried out from the Prezioso platform. Natural gas from the offshore platform will be transported to the Gela processing plant via a new 60 km long, 14-inch diameter pipeline.
Gas processing capacities
In November 2014, Eni and the Ministry of Economic Development signed a letter of intent to transform the Gela refinery area into an environmentally friendly refinery project.
Under this MoU, the gas extracted from the fields will be treated in a new processing plant to be built on the Gela refinery site.
Construction of the wastewater treatment plant began in September 2021 with an estimated investment of more than 700 million euros ($764 million). Gas production at the plant will begin in the first half of 2024.
The development plan for the wastewater treatment plant aims to minimise the area occupied, maintain environmental sustainability and enhance the local area.
Contractors involved
Eni Mediterranea Idrocarburi, a subsidiary of Eni, awarded a contract worth 300 million euros (327.41 million dollars) to Saipem for the transportation and installation of the offshore gas pipeline connecting the four wells of the Argo and Cassiopea fields to the Sicilian coast.
Saipem deployed the ten pipelay vessels Castorone and Castoro, while the vessel Saipem 3000 installed the umbilicals connecting the Cassiopea wells to the Prezioso platform.
Italy-based engineering company Proeco has been selected to provide process, machine and engineering development as well as 3D modeling for the Prezioso K platform.
Italy-based Arighi Engineering Services has been selected by Proeco to approve the architectural front-end engineering (FEED) design of the Prezioso K platform topside modules.
