The Kinsale Head gas field offshore Ireland was discovered in 1971 and bought on stream in 1978. After 40 years of continuous gas production, a detailed plan for decommissioning of the field facilities is now being implemented.

Kinsale Head and a number of satellite gas fields, all operated by PETRONAS subsidiary PSE Kinsale Energy Limited, are the only producing facilities in the North Celtic Sea Basin, off the south coast of Ireland. The facilities include two fixed platforms, 10 subsea wells and extensive subsea infrastructure including 150 km of subsea pipelines and 80 km of subsea umbilicals, as well as an onshore reception terminal. Careful and innovative field management has extended the producing life from an originally estimated 20 years to over 42 years at time of Cessation of Production forecast to occur in 2020. The paper describes some of the methods used to prolong field operating life. Planning for decommissioning commenced in 2015-2016 and the paper describes the engineering and regulatory planning process followed. As this is the first-offshore field to be decommissioned in Ireland, extensive and detailed engagement with the regulatory authorities was undertaken prior to the submission of the decommissioning plan in 2018.

The paper demonstrates how a systematic and logical approach to both the regulatory approval process and the physical execution plan helps to de-risk the project. In particular, a comprehensive Environmental Impact Assessment (EIA) process was followed to underpin the selected strategy and to demonstrate a ‘best-in-class’ approach to the decommissioning program.

As part of the EIA process, a number of analytical techniques were used including Net Environmental Benefits Analysis (NEBA) and Comparative Assessment (CA); this is believed to be the first time these techniques were used for offshore projects in Ireland.

You can access this article if you purchase or spend a download.