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FEATURE Plug and Abandonment between the material and what it’s sealing against. “In reality, the industry hasn’t fully quanti? ed what the true risks are yet.”

Interwell’s thermite barrier technology

He says, “The regulator will have to come to grips with this, probably driven by from pressure from society as a whole.”

There are also sticky questions about what level of leakage would be acceptable, given that there is natural leakage from the seabed unrelated to any oil? eld activity already.

A new (test) rig

The recently created National Decommissioning Center (NDC), part-funded by The Oil & Gas Technology Center with the University of Aberdeen, is looking at building a test chamber at their Newburgh based center near Aberdeen that could put barrier materials to the test.

With funding from the Scottish Government’s Decommission- ing Challenge Fund, the NDC tasked Aberdeen-based engineer- ing ? rm Apollo Offshore Engineering to design a rig in which barrier materials could be tested to 150 °C and 10,000 psi, cover- ing 80% of UK continental shelf (UKCS) wells. The 20-inch in- ternal diameter test chamber will be able to house cartridges that can simulate the different annuli in a well, with different tubing and casing (up to 18¾-inch diameter) arrangements, in a repeat- able way. It is also designed to simulate in? ow from the well or rock and ? ow return through the annulus. It would even have a slickline equipment interface to mimic real downhole conditions.

Dr. Richard Neilson, who’s been working on the project, says it would be a pretty unique test facility, designed with industry input, including from the OGTC’s Alternative Bar- rier Material Collaboration Group, which includes developers and operators. “Once it’s down in a well, there are things you can do to test it, “There are a number of barrier technologies being devel- such as putting instrumentation down, like pressure transduc- oped, like the use of thermite and thermite combined with bis- ers above and below. But at some point you want to see what’s muth alloy, and also resin and well scaling,” says Dr. Neilson. happening. We can set a plug and test it under pressure and then

AN UNUSUAL ABANDONMENT

The North Sea oil and gas industry’s 50-plus year heritage now means that history is being revisited as facilities – including subsea wells – installed decades ago are decommissioned.

One is the