David Jamieson

David Jamieson

Deconstructing the Dismantling Safety Case

For the vast majority of offshore installations, there have been years of stable operations since the start of production. Today, in the North Sea, an increasing number are beginning to experience significant, sometimes rapid, change as preparatory work for decommissioning begins.

These changes may include the removal of hydrocarbons from topsides, the plugging and abandonment (P&A) of wells, a move to normally unmanned operations, the introduction of walk-to-work, heli-decks taken out of service or even the removal of lifeboats.

From my own experience supporting several decommissioning projects, from direct engagement with the regulator and collaboration with others through a Joint Industry Project, there are some things I’d like to share on developing a safety case strategy that fits with the preparation decommissioning and dismantling.

  • Engagement, Engagement, Engagement. Ensuring everyone is properly communicated with takes work and energy. The workforce and the safety reps need to be involved in the decision-making process around the modification or removal of safety systems. The regulator should be included early in the process with proposed plans shared and discussed. The minutes of these meetings should be kept and sent to the regulator. Not all scenarios are prescribed in the regulations and are open to interpretation. Be prepared for the regulator to revise their opinion as time passes – or for new personnel to be appointed. Building and maintaining good working relationships with the regulator over the duration of decommissioning is well worth the effort. 
  • Define your phases. From live operations, right through to dismantling, it pays to define distinct phases of operation. These may be many years or only a matter of days in duration. For each phase, the major accident hazards (MAHs), along with their safeguards, should be identified and appropriately risk assessed. Make it clear in the safety case which phase you are currently in, presenting your risk arguments clearly and succinctly.
  • SECEs, Performance Standards and Verification Scheme. Your list of safety and environmental critical elements (SECEs) for an installation, the performance standards and the verification scheme should be appropriate for the identified MAHs and their risk. These documents, and their associated safety critical maintenance burden, may be simplified along with the changes to the installation, driving significant cost reduction. But it’s important to remember that there may be periods of time when new SECEs could be required or existing SECEs need changes to assurance activities as the decommissioning programme develops.
  • PFEER Philosophy. The prevention of fire and explosion and emergency response (PFEER) philosophy of any installation is its primary and alternative means of evacuation, as well as means of escape. Under the PFEER regulations the distinction between evacuation and escape is an important one. For each phase of operation, the PFEER philosophy must be clearly documented within the safety case. That’s not enough on its own. It must also be clear to the workforce.
  • Group material changes together. Traditionally, material changes consider a single step-change in risk on an installation. Given the sometimes rapid cycle of change in a decommissioning scenario, it may be more appropriate to group several material changes together. This is likely to reduce administrative burden both for the duty holder as well as the regulator, and pave the way for productive early engagement between both parties. However, the arguments supporting the change in each phase should be clearly demonstrated in the safety case.
  • Dismantling Safety Case. Regulation 20 has been interpreted by some as a new document that must be produced early in the decommissioning phases of an installation. In fact, this document is simply a special case material change. It should be submitted when you think it appropriate but this is normally done ahead of physical dismantling operations. The dismantling case itself can be subject to subsequent material changes.

Effective duty holders and project teams recognise that decommissioning is simply another phase of the installation’s lifecycle. It would be great to have your suggested key learnings to add to this list of what matters in late-life operations for the safety case.

I was part of the team who collaborated to produce the “Guidance for UK Safety Case management during End of Life (EoL) decommissioning and dismantling”. This was launched at OE2017 this morning and can be accessed via

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