Inspect and protect: discussing new tech for North Sea asset integrity

Reversing the decline in production efficiency is a key goal for operators on the UK Continental Shelf. A new report highlights emerging technologies that could help solve two of the industry’s trickiest issues affecting asset integrity and therefore efficiency – process vessel inspection and corrosion under insulation. Oil & Gas UK upstream policy director Mike Tholen discusses the report’s findings and the need to collaborate on the industry’s most intractable problems.


As the UK oil and gas industry works amid hostile market conditions to maximise economic recovery from the North Sea in the wake of the Wood Review and its recommendations, the linked issues of asset integrity and production efficiency have emerged as a key theme. Production efficiency on the UK Continental Shelf (UKCS) has fallen from 80% to 60% over the past decade, with challenging operating conditions, ageing equipment and tightening profit margins conspiring to make production shutdowns – planned and unplanned – more common and more costly for the industry.   

Reflecting the Wood Review’s emphasis on cross-sector collaboration to improve the industry’s fortunes in the North Sea, a wide range of stakeholders have been coming together to brainstorm solutions to the asset integrity problem. A good example is the Asset Integrity Theme Landscaping Study, published by Lockheed Martin in May. The report was commissioned by Oil & Gas UK on behalf of the Oil and Gas Technology Leadership Board, and drew support and input from organisations including Total E&P UK, Amec Foster Wheeler, the Oil & Gas Innovation Centre and the Industry Technology Facilitator.

Although the report makes use of feedback from an impressive array of contributors (including the UKCS’s major operators and prime contractors, government authorities, centres of excellence, trade associations and nearly a dozen universities), it is laser-focussed on two particular issues that have a major impact on offshore asset integrity: process vessel inspection and corrosion under insulation (CUI).

Process vessel inspection – the evaluation of the insides of pressure vessels that separate hydrocarbon liquids and gases – is a significant contributor to the length of production downtime during shutdowns, as current methods mostly involve having a technician manually enter the vessel to carry out checks, which is time-consuming and risk-intensive. CUI, meanwhile, is a form of corrosion that is persistent and hard to spot, as it is hidden underneath the insulation layer, which can be expensive and disruptive to remove. The report cites industry data suggesting that CUI is behind 60% of pipe leaks on the UKCS and represents between 40% and 60% of the region’s pipe maintenance costs.

These issues present two clear challenges to the industry: inspecting process vessels without a human having to enter, and checking for CUI without having to strip away insulation. The study summarises emerging imaging and inspection technologies that could have an impact on these challenges – including ultrasonic, radiography, thermographic imaging and acoustic resonance – and analyses technologies (or combinations of technologies) with particular potential to improve the situation.

We spoke to Oil & Gas UK upstream policy director Mike Tholen to discuss the report, the North Sea’s asset integrity challenge and the need to collaborate on the industry’s most intractable problems.

Chris Lo: Could you outline the asset integrity and efficiency challenge that exists for North Sea oil and gas producers?

Mike Tholen: Maintaining key infrastructure and ensuring the asset integrity of offshore installations and subsea facilities is crucial to the industry's efforts to recover the remaining barrels of oil and gas from the mature basin of the UK Continental Shelf. The industry is operating in a mature basin where a key priority is to ensure asset integrity to deliver safe, reliable and sustainable operations and improve production efficiency. 

CL: In the context of maximising the North Sea's remaining hydrocarbon recovery, how important is it that downtime during planned maintenance shutdowns is reduced, and unplanned downtime is minimised?

MT: Better management of planned maintenance shutdowns is a very important aspect of production efficiency. Working with industry, Oil & Gas UK has developed guidance to ensure efficient execution of all types of shutdowns including maintenance, inspection activities, engineering and construction work, ranging from new tie-ins to modifications to help minimise the frequency, duration and resourcing of shutdowns.

"Better management of planned maintenance shutdowns is a very important aspect of production efficiency."

Within the wider context, Oil & Gas UK is leading industry work on maintenance optimisation to improve major accident hazard management processes and operational efficiency. This year it will publish a document on optimisation reviews to share good practice in managing safety and business-critical equipment maintenance. The intention is to monitor uptake of the document and gauge the effectiveness of efforts in this area. 

CL: What was the initial thinking behind commissioning the Asset Integrity Theme Landscaping Study? Is it intended to serve as a clear one-stop guide for the industry on promising technologies that could extend the life of oil and gas fields on the UKCS?

MT: Yes, it is a guide which collates all the relevant technologies, including those developed by other industrial sectors, which could be developed and adapted to improve production efficiency. This guide refers specifically to process vessel inspection and for managing corrosion under insulation of onshore and offshore structures. 

CL: Process vessel inspection was a focus of the study, as current methods require manual entry – which technologies are best-suited to overcoming this problem?

MT: The study indicates that no single technology is prevalent for either process vessel inspection or CUI detection and management, and that several methods may be used in conjunction. However, a couple of technologies were outlined as those that could most immediately be adopted.

The report suggests the low-frequency electromagnetic technique, which detects defects by passing a low frequency magnetic field through magnetic plate or pipe, as it offers good prospects for carrying out process vessel inspections at moderate cost and risk with technology.

CL: Which technologies could play a role in dealing with CUI faster and more effectively in the future?

MT: The report recommends that the pulsed eddy current technique could offer good prospects at moderate cost and risk. This works by driving an electromagnetic field through the insulation and into the pipe and the technique is potentially able to detect larger areas of corrosion even through corrosion jacketing. 

CL: The report notes that a lack of overall co-ordination in this area increases the risk of duplicated research and other issues, as well as potentially causing problems with the compatibility of different equipment. Would you agree that this is a problem, and how should it be addressed?

MT: The Technology Leadership Board (TLB), which now feeds into the Oil and Gas Authority's Maximising Economic Recovery from the UK Continental Shelf (MER UK) Forum, plays a key role in ensuring that technology development is strategic and co-ordinated. Its aim is to ensure technology development is collaborative, focused on priority areas and suitable for multi-field application. 

CL: Do you think the government should be doing more to incentivise the development and deployment of tech to improve asset integrity and production efficiency?

MT: Representatives from various government agencies participate in and support the TLB as it works through its current priorities, including the Department of Business, Innovation and Skills; the Scottish Government; Scottish Enterprise; and Innovate UK.  

CL: How is Oil & Gas UK working to bring the lessons from the Asset Integrity Theme Landscaping Study to the attention of the offshore oil and gas industry?

MT: Oil & Gas UK commissioned the Asset Integrity Landscaping Study from Lockheed Martin on behalf of the MER UK Technology Leadership Board and the document is available for free on the website. Information about publications is disseminated via a variety of channels including press releases; twitter; e-bulletins; the in-house magazine Wireline; and events such as the Technology Showcase, which Oil & Gas UK co-hosts with the Industry Technology Facilitator.