Using non-intrusive inspection (NII) survey technologies could be worth US$310 million (£242 million) a year to UK North Sea operators through increased production and lower maintenance costs, according to a survey by the Oil & Gas Technology Centre (OGTC) and ABB.
Most North Sea operators utilise intrusive inspection techniques to assess the condition of process vessels and tanks and ensure safe operations. This requires shutting down the platform and personnel entering the vessel to carry out a manual inspection, resulting in lost production and exposure of people to confined spaces.
Recent advances in non-intrusive inspection (NII) technology mean it is now possible, in many instances, to effectively assess the internal condition of the vessel without a shutdown or sending personnel into the vessel, says the OGTC.
But, the survey found that use of NII on the UK Continantal Shelf is limited, with some operators currently making no use of the available technology.
It also found that up to 80% of vessels could be examined non-intrusively, without requiring a shutdown, improving safety, and with the potential for 80% fewer line breaks and subsequent leak tests.
Using non-intrusive technologies has seen a 33% reduction in turnaround durations and cost savings of up to 80% compared to inspections that involve entry into a vessel.
“A significant amount of inspection work is done with invasive methods at short intervals. Typically, 85% of inspection [work] requires equipment to be shut down and isolated for the inspection work to be done. About 95-97% of the cost is enabling work, i.e. process preparation, cleaning, etc. Just 3% is the actual inspection,” Alan D-Ambrogio , VP Oil and Gas, ABB Consultinge, told the Energy Institute's Asset Integrity 2017 conference in Aberdeen earlier this year.
The OGTC has been working with Total E&P UK to conduct field trials of NII technologies on its North Sea assets. The OGTC has a set of goals: to reduce inspection costs 50% by 2021; eliminate failures by corrosion under inspection (CUI) by 2026; and have no vessel entry due to inspection by 2026 (i.e. use non-intrusive inspection – NII).
Rebecca Allison, OGTC Asset Integrity Solution Centre Manager, said: “One of our key objectives is to eliminate vessel entry for inspection by 2026 and NII is critical to delivering this."
However, Troy Stewart, Head of ABB Service, Oil, Gas & Chemicals in the UK, said: “Onshore process industries have reaped the benefits of NII for many years, but uptake in UK North Sea has been slow."
This was seen as being because of conservatism in parts of the industry, due to a perception of the lack viable NDE techniques, concerns about regulatory compliance and the availability of data within the UKCS, a lack of management engagement and a lack of transparency of the overall cost of inspection.
The OGTC is now set to carry out pilot studies with a small number of operating companies who have limited experience of undertaking NII. The objectives of this phase are to evaluate feasibility, demonstrate how to apply NII, and to identify the resulting benefits.
Read an in depth feature on this topic in OE's upcoming January issue.