Hiring a decommissioning consultant: what they should do for you

The field still produces, but its end date has started to appear in board papers, and someone has asked you to bring in a decommissioning consultant. You already know what decommissioning involves. What you need now is practical: what that consultant should do for you, when they should start, where they save you money, and how to tell a good one from an expensive one.

One idea runs through all of it. A decommissioning budget is spent offshore, but most of it is decided onshore, in the estimate, the campaign plan and the contracts. For how the liability itself is built up, see our note on decommissioning liability.

What should a decommissioning consultant do for you?

On the owner's side, the job has four parts. A good consultant covers all four, or tells you plainly which ones they leave to someone else.

1. Estimate. Build or challenge the cost from the real condition of your wells and structures, not from last year's figure rolled forward, and show what is known, what is assumed and what would change the number.
2. Campaign strategy. Decide what is done, in what order, with what rig or vessel, and whether to go alone or join neighbouring operators. Plan wells and subsea removal together, because the cheapest option for each is rarely the cheapest for both.
3. Contracting. Turn the strategy into scopes, an RFP and a contract model, then evaluate the bids and support the negotiation.
4. Supervision and close-out. Represent you offshore, check the work against the contract, manage changes and interfaces, and assemble the evidence your regulator needs to close the file.

When you compare decommissioning consulting services, check that the proposal treats these four parts as one line of work. The value sits in the hand-overs: the assumptions behind the estimate should reach the tender documents, and those documents should be what your supervisor carries offshore. A structure that needs its own removal method should get it at the strategy stage, through proper subsea engineering analysis, not improvised with the vessel on location.

When is the right time to bring one in?

While you still have choices. Time closes options one by one, and the options are where the money is.

• Some well work is cheaper while the platform still has power, cranes and crew. Once it is de-manned, the same job needs a rig or vessel brought in.
• Joining a campaign with neighbouring operators, or sharing a vessel with them, only works if your scope is ready when theirs is.
• Suitable rigs and vessels are booked well ahead, and a contractor with a gap to fill prices differently from one with a full order book.
• Well records and the people who know the asset are easier to reach before the operations team moves on.

In practice: before the campaign budget is fixed, well before you go to market, and earlier still if your team has never run a campaign. Help that arrives mid-campaign is still worth having, but by then you are paying to recover, not to plan.

A consultant who arrives after the contracts are signed can explain the overrun. Only one who arrives before can prevent it.

How does a consultant save money in the contracting?

Contractors price what they can see and add a premium for what they cannot. An owner-side consultant saves money by shrinking what bidders cannot see, and by paying for certainty only where it exists.

• Share the data. Put well records, integrity findings and survey results in the tender package. A bidder guessing at the condition of a well prices the guess.
• Draw the boundaries. Write down where each contractor's work starts and stops, above all between the wells scope and subsea removal. Undefined interfaces are where claims come from.
• Match the contract model to the uncertainty. Fix the price where the scope is well understood and use rates with clear controls where it is not. A fixed price forced onto a poorly known well buys a large contingency, not certainty.
• Make the bids comparable. Line up exclusions, weather assumptions, vessel days and standby terms, so you choose between real prices, not different readings of your scope. Our note on evaluating bids from the owner's side goes through the method.

This is the ground covered by our tendering and contracting work. One of the engagements on our cases page, Subsea decommissioning, contracted without surprises, is about exactly this stage.

What drives the cost of decommissioning consulting services?

There is no honest typical figure, because the fee follows the asset, but the drivers are predictable:

• The number of wells and, above all, the quality of their records. Poor records mean investigation before anyone can plan.
• The structures and subsea equipment, and how many need a removal method engineered rather than picked from standard options.
• How far the engagement runs: an estimate review, a full strategy, the tender, or all the way through supervision and close-out.
• What already exists. A recent, documented estimate is quicker to challenge than a spreadsheet nobody can explain.
• The regulatory regime, and how much of the submission the consultant prepares.

When you write the consultant's scope, say which of the four parts you are buying and which decisions each deliverable must support. The request for proposal then needs two lists. First, what to send the consultants you invite:

• the list of wells and structures, with what you know about their condition;
• the well records and survey data you hold, and where the gaps are;
• your current estimate and how it was built;
• the regulator involved and the date you are working to;
• any talks with neighbouring operators about a shared campaign.

Second, what to ask them to deliver:

• a cost estimate that separates facts, assumptions and risks;
• a campaign strategy with the options considered and why one was chosen;
• the tender package and a written bid evaluation;
• supervision reports and a close-out file your regulator can accept.

Ask for the fee broken down the same way, so you compare proposals stage by stage, not on one total.

Questions to ask an oil and gas decommissioning consultancy

On paper, most proposals look alike. These questions separate them.

• Who else is paid on this campaign? A consultant that also sells vessels, tooling or plugging services, or is tied to a likely bidder, has a stake in the outcome. On the owner's side, they should have none.
• Who will actually do the work? Meet the people, and ask whether whoever builds the estimate will still be there for the contracts and the offshore work.
• Can they show how they separate facts from assumptions? An anonymised past estimate or strategy report tells you more than a capability brochure.
• Which standards will they work to? That depends on location: NORSOK in Norway, OGUK in the UK, BSEE in the US, SGIP/SGSS in Brazil, API in many regions. The consultant should know which ones your regulator expects.
• Have they supervised this kind of work offshore? Plans written by people who have never watched a campaign run tend to leave out the waiting.
• What will you keep at the end? The cost model, tender documents and method statements should be yours, in a form your own team can maintain.

Watch for warning signs: a removal method recommended before anyone has read the well records, a saving promised before the scope is understood, and a proposal priced on a team you never meet.

If your campaign has not yet gone to market, tell us about the asset, its wells and structures and the date you are working to. The senior partner who scopes the work with you stays on it from the first estimate to close-out, with no bench of juniors behind them.