Cassiopea

Location

The Cassiopea and Argo gas fields are situated approximately 25 kilometers offshore the Sicilian coast in the Strait of Sicily, within the licensed Ibleo Area.

Ownership and Operation

The project is jointly owned by Eni, which holds a 60% interest and operates the field, and Energean, which holds a 40% interest. Energean's stake was previously held by Edison E&P before it was acquired by Energean in 2020.

Discovery and Reservoir Details

• The Cassiopea field was discovered in July 2008 by the Cassiopea 1 well at a water depth of 560 meters, 22 kilometers offshore the coast of Agrigento.
• The Argo field was discovered in May 2007 by the Argo 1 well in water depths between 1,350 and 1,520 meters. The well flowed at a rate of 769 cubic feet per day during test production.
• The field reservoirs contain gas in early Mesozoic to Cenozoic Age Pleistocene-Age clastic sediments.

Reserves and Production

• The estimated gas reserves at the Cassiopea and Argo fields are approximately 10 billion cubic meters (bcm).
• Peak annual production is expected to be around 1.5 bcm of gas.

Development Details

• The fields are developed through four subsea wells, comprising two new wells and two re-completions. The Argo field produces from a single well, while the Cassiopea field produces from three wells.
• The wells are tied back to the new Prezioso K platform, installed at a water depth of 45 meters. This platform is connected to the existing Prezioso platform via a 60-meter-long bridge and hosts the treatment and compression system for the project.
• Natural gas from the offshore platform is transported via a new 14-inch diameter, 60-kilometer-long pipeline to the Gela processing plant.

Gas Processing and Infrastructure

• A new treatment plant is being constructed at the Gela refinery area, with construction starting in September 2021 and an estimated investment of over €700 million. This plant aims to minimize surface area, maintain environmental sustainability, and enhance the local area.
• The gas produced is processed at this new treatment plant and then fed into the national grid, contributing to Italy's energy needs.

Environmental and Sustainability Aspects

• The project features a dedicated 3.6 MWp photovoltaic panel installation to ensure the project achieves carbon neutrality for Scope 1 and 2 emissions.

Contractors and Partners

• Eni Mediterranea Idrocarburi awarded a €300 million contract to Saipem for the transportation and installation of the offshore gas pipeline. Saipem used the Castorone and Castoro ten pipe-laying vessels, and the Saipem 3000 vessel installed the umbilicals connecting the Cassiopea wells to the Prezioso platform.
• Proeco, an Italy-based engineering company, was contracted for process, mechanical, and machine engineering, as well as 3D modeling for the Prezioso K platform. Arighi Engineering Services was subcontracted by Proeco for architectural front-end engineering design (FEED) endorsement of the Prezioso K platform topside modules.

Production Start and Future Plans

• Gas production from the Argo and Cassiopea fields started in August 2024, just three years after the start of works.
• The project includes tie-in points for other discoveries and low-risk exploration prospects such as Panda, Panda West, Gemini, Centauro, and Vela to maintain production.

This project is Italy’s largest greenfield gas development and plays a central role in Eni's strategy to increase the use of domestic natural gas for energy security and as a low-emission source.