Corrib

Corrib Gas Project Profile

Location

The Corrib gas project is located in the Atlantic Ocean, approximately 83 kilometres (52 miles) off the northwest coast of County Mayo, Ireland, in an area known as the Slyne Trough. The field is situated in water depths of about 355 metres (1,165 feet).

Discovery and Development

• The Corrib natural gas field was discovered in 1996, marking the first reported commercial natural gas discovery in Ireland since the Kinsale Head gas field was discovered in 1971.
• The first appraisal well was drilled in 1997.

Ownership and Operation

• Initially, the project was operated by Royal Dutch Shell with a 45% ownership stake. Other partners included Statoil (now Equinor), Marathon, and Enterprise Oil.
• In 2018, Shell sold its share to the Canada Pension Plan Investment Board, and Vermilion Energy became the operator, expanding its ownership stake to 20%.
• By 2021, Vermilion Energy acquired Equinor's 36.5% stake, becoming the majority owner with a 56.5% stake, while Nephin Energy holds the remaining 43.5%.

Field Details

• The Corrib gas field is a deepwater conventional gas field with reserves estimated to be about 1 trillion cubic feet (28×10^9 m³) of gas, which is approximately 70% of the volume of the Kinsale field.
• The gas originates from a Triassic Sandstone reservoir 3,000 metres (9,800 feet) below the seabed. The natural gas is very pure, consisting of approximately 97% methane and ethane, with minimal hydrogen sulfide and only 0.3% carbon dioxide.

Infrastructure

• Offshore Facilities: The field has five production wells drilled by the Transocean Sedco 711 semi-submersible drilling rig. Each well has a "Christmas tree" structure for control and monitoring. Flexible individual flowlines connect the wells to a production manifold, which feeds the gas into the main pipeline. There is no production platform installed in the field.
• Pipeline: The pipeline from the Corrib field to the landfall at Glengad is approximately 90 km in length, with a diameter of 20 inches (510 mm) and operating pressures of 120–345 bars (12,000–34,500 kPa). The onshore pipeline, which is about 9 kilometres (5.6 miles) long, runs from the landfall to the gas processing plant at Bellanaboy Bridge.
• Onshore Gas Pipeline: The Corrib Onshore Gas Pipeline project involved constructing an 8.3 km pipeline, with 4.9 km of it installed in a 4.2m diameter segment lined tunnel 10m below the sea bed. This project was critical for connecting the offshore pipeline to the onshore gas terminal and processing plant.

Production

• Gas production at the Corrib field commenced in 2015.
• The field currently accounts for approximately 100% of Ireland’s daily natural gas output. Peak production was achieved in 2017, and based on economic assumptions, production is expected to continue until the field reaches its economic limit in 2081.

Environmental and Safety Concerns

• The project has faced significant opposition and environmental concerns, particularly regarding the pipeline route through the area of Rossport, close to local residences. There have been concerns about the safety of the pipeline and potential escape routes in the event of a rupture.
• The project also involves discharging waste from the refining process into Broadhaven Bay, which has raised environmental concerns.

Development Timeline

• 1993: The deepwater exploration licence was granted to Enterprise Oil and its partners.
• 1996: The Corrib natural gas field was discovered.
• 1997: The first appraisal well was drilled.
• 2001: Consents and approvals for the project were issued.
• 2002: The plan of development for the field was approved.
• 2009: Work on the offshore section of the pipeline was completed.
• 2011-2015: Construction of the onshore pipeline began in July 2011 and was completed in December 2015.

Community Engagement and Awards

• The Corrib Onshore Gas Pipeline project involved extensive community engagement and consultation. RPS Group worked with local stakeholders over an 18-month period to inform the route selection process. The project won the Engineers Ireland Outstanding Project of the Year Award in 2016.

The Corrib gas project is a significant national infrastructure project, providing much of Ireland's future gas supplies and serving as the country's only domestic source of natural gas production.