United Kingdom

Tullow first entered the UK offshore exploration, development and production arena in 2000, when it acquired a significant number of Southern North Sea gas assets from BP.

The acquisition comprised assets in the CMS and Thames-Hewett Areas. The portfolio was then expanded through a number of new licence awards and bolt-on acquisitions including transactions with Shell, Chevron-Texaco and Conoco-Phillips.

Tullow succeeded in extending the life of these mature gas assets through focused cost reduction, successful exploration and innovative developments. However, the fields have now reached their end of life and decommissioning activities for the area are under way.

Completed activities

Plugging & abandoning of wells

In 2015 Tullow commenced the process of flushing, cleaning and disconnecting the pipelines in order to ensure the facilities are hydrocarbon free.

In 2016 Tullow started the planning, engineering and procurement processes to plug & abandon (P&A) 12 operated wells in the UK continental shelf. Two scheduled for 2017, seven in 2018 and three in 2019. Site surveys and other preparatory works were undertaken prior to the commencement of the well P&A operations. The decommissioning programme for all Tullow operated wells in the UK North Sea was completed by the third quarter of 2019. All wells are successfully plugged and abandoned and approved by the UK regulator.

Removal and disposal of infrastructure

In October 2015, the UK Offshore Regulator on behalf of the Secretary of State approved the final decommissioning programmes for the Horne & Wren platform, Wissey and Orwell subsea installations and the connecting pipelines and umbilicals within the Thames Area Complex, in accordance with the provisions of the Petroleum Act 1998. In 2015 the first phase of the Thames Area decommissioning was successfully completed on schedule and on budget. In March 2017 the second phase of the Horne & Wren decommissioning project was completed with the successful removal of the unmanned platform. In 2019, the wellhead protection structures at Orwell, Thurne and Wissey were successfully removed with zero safety incident.

Current activities

Seabed clearance

Asset removal and sea-bed clearance activities in Tullow operated licences in the UK North Sea were completed in the fourth quarter of 2020. Final surveys are planned in order to close out the operated decommissioning programme this year. The Group’s decommissioning activities in its non-operated UK licences are ongoing and are expected to continue through to 2025’.

Decommissioning the UK non-operated assets

Tullow ceased production from its non-operated UK North Sea assets during the third quarter of 2018. The decommissioning programme commenced in 2019 with the well abandonment and infrastructure removal of these assets. Final close out of all decommissioning programmes is expected to be achieved by 2025.