South Morecambe

Location and Geology

The South Morecambe gas field is situated approximately 30 kilometers west of Blackpool in the East Irish Sea, UK. It lies within blocks 110/2a, 110/3a, and 110/8a, at water depths ranging from 17 to 35 meters (or approximately 20-25 meters for the specific platforms DP3 and DP4).

Discovery and Production

The field was discovered in 1974 by the drilling of the 110/2-1 discovery well. Production commenced in 1985, making it one of the earliest developed fields in the Morecambe Hub.

Field Development

The South Morecambe field is part of the Morecambe Hub, which includes the North Morecambe, South Morecambe, and Rhyl fields. The field has been developed using seven fixed jacket platforms:

• Three manned Central Processing Complex (CPC) platforms.
• Four Normally Unmanned Installations (NUIs): DP3, DP4, DP6, and DP8. These NUIs are tied back to the central processing complex.

Infrastructure

• Platforms: The DP3 and DP4 platforms, which are part of the decommissioning project, were installed in 1983 and 1984, respectively. Each platform features six well slots and 16 conductor slots, supported by a four-legged steel jacket. They are equipped with basic processing facilities and a utility module.
• Pipelines and Cables: Gas from the DP3 and DP4 platforms is exported to the Central Processing Platform 1 (CPP1) via a 24-inch concrete-coated gas pipeline. Chemicals are supplied from CPP1 via a 2-inch monoethylene glycol line. Electric and fibre-optic cables provide power and control to the platforms.
• Processing and Export: Gas from the field is processed at the Barrow Gas Terminals, located near Barrow-in-Furness in Cumbria, before entering the National Transmission System.

Production History and Current Status

• The field reached its peak production in 1999 and has since been in decline. Despite this, it remains a significant contributor to the UK's gas supply, currently accounting for approximately 1% of the country’s daily output.
• As of recent updates, the field has recovered 99.07% of its total recoverable reserves, with production expected to continue until the field reaches its economic limit in 2028.

Decommissioning

• Due to the reduced production rate, the DP3 and DP4 platforms were approved for decommissioning by the Offshore Petroleum Regulator for Environment & Decommissioning (OPRED) in September 2019. Decommissioning work began in 2020.
• The decommissioning process includes preparing the 12 associated wells for permanent plugging and abandonment, flushing and preparing the pipelines for decommissioning, and dismantling the platform substructures for potential re-use or recycling. Over 95% of the equipment, steel, and other components are planned to be recycled.

Ownership and Operation

• The South Morecambe gas field is owned by Centrica and Stadtwerke Munchen, and it is operated by Spirit Energy Production UK.

Environmental and Maintenance Aspects

• The operations at the Morecambe Bay fields have been optimized to minimize environmental impact. Waste production is minimized through the design of operations, and reuse and recycling are maximized. Environmental surveys and maintenance activities are regularly conducted to prevent and mitigate any environmental incidents.

Historical Significance

• At its peak, the Morecambe Hub, which includes the South Morecambe field, met 20% of the UK’s domestic gas demand. The combined fields in the East Irish Sea have produced over 6.5 trillion cubic feet of gas since production started in 1985.

In summary, the South Morecambe gas field is a mature but still significant asset in the UK's gas production landscape, with ongoing efforts to extend its production life and ensure responsible decommissioning of its infrastructure.