UK approves decommissioning plan for subsea facilities on MacCulloch field
UK authorities have approved the decommissioning plan for the subsea infrastructure and associated infield pipelines on the Chrysaor-operated MacCulloch field, located in the UK North Sea.
The decommissioning plan draft for the MacCulloch field was submitted by former operator ConocoPhillips back in June 2019.
Under the approved decommissioning plan, the anchors will be decommissioned in situ while all other subsea installations will be removed to shore for either re-use or recycling.
Also, all pipelines will be recovered to shore for reuse or recycling.
The operatorship of the MacCulloch field was transferred to Chrysaor following the acquisition of ConocoPhillips’ two UK subsidiaries for US$2.675 billion in late September 2019.
The MacCulloch field is in the UK Central North Sea (CNS) Block 15/24b, in a water depth of 149 metres.
Developed in 1996/97, the field had an expected life of ten years. Production started via the FPSO North Sea Producer in August 1997. The vessel was owned by the North Sea Production Company (NSPC).
MacCulloch production was conducted via two drill centres, West (WDC) and East (EDC), located 1.6 km and 2.9 km to the West and South East of the vessel location, respectively.
Oil and gas were exported from the FPSO vessel to the Repsol Sinopec-operated Piper Bravo platform through its owned 10” oil pipeline and 6” gas pipeline.
Preparation for decommissioning of the MacCulloch field started on the 3rd May 2015. The first phase of decommissioning continued until August 2015 when the North Sea Producer, the FPSO vessel, was removed from the area. Thereafter, the vessel was taken to Teesside by the owners for re-use and recycling.
During this initial decommissioning phase, the pipelines were flushed and made hydrocarbon free, and the risers and mid-water arches were retrieved for recycling/disposal.
In 2017, all of the wells were suspended with two isolation barriers using a light well intervention vessel, the Helix Well Enhancer.
Source: Offshore Energy Today