Ellon

Location and Field Composition

The Ellon Field is located in the Alwyn Area of the North Sea, and it is developed as a satellite field to the Alwyn North twin platforms. The Alwyn Area includes the Alwyn North Field, as well as the Dunbar and Ellon fields, which constitute the Alwyn South Area.

Development and Production

• The Ellon Field was developed with twin subsea wells that are tied back to the Dunbar platform. Production from the Ellon subsea wells commenced at the end of 1994, along with the production from the Dunbar platform wells.
• The production from Ellon and Dunbar is commingled and exported via a 22-km, 16-in. multiphase insulated pipeline to the Alwyn North platforms, where receiving facilities were installed.

Infrastructure and Technology

• The development of the Ellon Field utilized a tender-assisted drilling (TAD) concept, with the semisubmersible rig Sedco 706 bridge-linked to the Dunbar platform for the drilling phase.
• To minimize costs and maximize the use of existing infrastructure, the Dunbar platform, which serves the Ellon Field, was designed with a four-legged jacket and minimum topside processing facilities.

Operational and Economic Strategies

• Following the startup of the Dunbar and Ellon fields, it was recognized that oil production would decline after a short plateau, leading to increased operating unit costs. To address this, a focused business planning and systematic review were undertaken to reduce operating expenditures and increase production and reserves.
• New transportation and processing agreements were negotiated, including a new Alwyn liquid export pipeline installed between Alwyn and the Shell-operated Cormorant Alpha platform. This provided a cost-effective transportation facility for the long term.
• The operating budget for the entire offshore complex, including the Ellon Field, was maintained at the same level as before the Dunbar startup, despite the new developments. This was achieved through efficient management and the implementation of new technologies.

Future Developments and Investment

• The Alwyn Area, including the Ellon Field, has seen significant investment in new projects aimed at maximizing the value of the assets. Over a three-year work program, capital expenditure was approximately £120 million per annum.
• These investments included drilling additional exploration and appraisal wells, such as the Triassic wells drilled from the platform, which have been connected for production via early production systems (EPS). These efforts aimed to increase recoverable reserves and maintain the production plateau.

Performance and Outcomes

• The strategies implemented have led to several major successes, including the extension of the production plateau to 2005 and the expected life of the fields beyond 2015.
• Operating expenditure has progressively improved to upper quartile performance, and it is expected to remain at this level.

Overall, the Ellon oil project is a key component of the broader Alwyn Area development, leveraging advanced technologies and efficient operational strategies to maximize the life of field value and maintain economic viability.