Enagás completes permanent sealing of Castor’s 13 wells

Key highlights
  • All 13 wells permanently sealed with three plugs installed in each well.
  • Work used the Noble Resolve jack-up and conductors were cut off more than 3 metres below the seabed, clearing seabed pipes.
  • Operations comply with OEUK P&A guidelines and plugs were approved by an independent Well Examiner under Royal Decree 1339/2018.
  • Estimated cost of the permanent sealing is €241 million, pending final certifications.
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Enagás Castor UGS Wells Permanent Sealing, Vinaròs · Spain
Closed
2019-10-31
2026-10-05

Scope of the work

Enagás completed the permanent sealing of the 13 wells at the Castor underground gas storage by installing three permanent plugs in each well, following the Council of Ministers decision of 31 October 2019 for permanent sealing and decommissioning.

Execution and site status

The campaign used the Noble Resolve jack-up floating offshore platform to place mechanical and cement barriers that restore geological isolation. Well conductors were cut off more than three metres below the seabed to remove protruding pipework, leaving the seabed cleared and the site ready for the final plugging and abandonment of offshore and onshore surface facilities.

Regulatory compliance and cost

Sealing operations were carried out to Spanish rules and international offshore plugging and abandonment standards (OEUK P&A Guidelines). All permanent plugs received third‑party approval from the Well Examiner as required by Royal Decree 1339/2018. The total estimated cost for permanently sealing the wells is €241 million, pending final certifications.

Preparatory phases and facility layout

The work followed prior hibernation steps mandated by Royal Decree‑Law 13/2014, including a Phase 0 analysis, Phase 1 inertisation, Phase 2 equipment conservation and Phase 3 temporary well sealing. The Castor installation includes an onshore operations centre in Vinaròs, an offshore WHP and PUQ 21.6 km offshore, a 30‑inch pipeline (21.6 km subsea, 8.7 km onshore) and 13 wells (8 production, 4 monitoring, 1 reinjection).

Source: Enagas Renovable

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