Aberdeen Branch

Aberdeen Branch, Latest News

In October the branch hosted a 2-part Non-Intrusive inspection (NII) webinar. The two speakers skilfully interweaved their presentations to explain the background to recent NII adoption, and the practical aspects of the new HOIS, for the benefit of a large corrosion engineer audience.

Dr Susan Osbeck, Principal Consultant of ESR Technology started the proceedings off with a talk entitled ‘The Updated HOIS Recommended Practice for Non-Intrusive inspection”.

The inspection of pressure vessels is traditionally done by internal visual inspection (IVI) with human entry that is both risky, and disruptive to production. IVI is required to be carried out during shutdown after isolation and cleaning of equipment, and is both a costly and hazardous activity with considerable production losses incurred during this period. By contrast for NII, the assessment and inspection are carried out externally using advanced automated NDT techniques with the vessel remaining in operation.

HOIS (Harwell Offshore Inspection Service) is a very well established (>30 years) joint industry project covering all aspects of good practice for Non-Destructive Testing (NDT) in the oil and gas industry. NII is a process not a technique, and HOIS have developed a framework to improve industry confidence in it. These inspection design concepts started in high value projects in the nuclear industry and were then taken up by Oil Industry operators, particularly in the North Sea. HOIS Guidelines were originally published as DNV-RP-G103 and over the years the practice has spread worldwide throughout the Oil & Gas industry.

The NII Process – Dr Susan Osbeck.

The NII process is essentially a 4-step process.
1. Firstly, in the assessment phase the vessels’ history, process, and risks, are reviewed to determine the suitability of techniques.
2. A work scope is then developed with respect to instructions, locations and reporting requirements.
3. The inspection phase is then carried out to fully meet all requirements.
4. Finally, the process of evaluation is carried out and any repair recommendations made.

A thorough screening process is first undertaken to assess whether a vessel is suitable for NII. Once agreed, it is assessed as to whether degradation of vessel wall is expected to occur on an A, B or C type level of severity (see later for explanation of these levels), and if it can be safely predicted. Calculations can then be made of the required NII coverage for A, B or C graded vessels, and the probability of detection of any metallurgical flaws of given depth/aspect ratio. There is also consideration given to the homogeneity of any expected flaw distribution.

For the scope and inspection, the HOIS practice has recommended techniques in the form of simplified tables which relate to the vessel shape, cladding, weld types, and nozzles and flanges. The evaluation phase later looks at whether the inspection has met the requirements that were set out, i.e. was the right coverage and targeted locations achieved, were the correct scanning techniques utilised and the overall probability of detection assessed.

The latest revision was published as HOIS-RP-103 in 2020, and updates, and the new features mentioned here, can be found at: https://www.esrtechnology.com/index.php/32-news/news-articles/423-updates-to-recommended-practice-for-non-intrusive-inspection-hois-rp-103

This excellent introduction to the NII Process was followed by further insights from Neil Wilson, Principal Corrosion Engineer ENGTEQ, who discussed ‘A Corrosion Engineer’s Perspective’.

The presentation focused on detailing the physical aspects of NII which are most relevant to corrosion engineers, for example, in predicting where damage may occur and the evaluation of results. It was stressed that all NII requires buy-in at senior management level in terms of acceptance of alternative NII procedures (not every item of equipment being suitable). On the plus side there may be considerable cost savings due to increased production time (less inspection down time). Corrosion engineers are very central to the NII process in the preparation of the assessment, the work-scope, the evaluation of documented results, and in using the data obtained to drive future inspection programmes.

Neil emphasised that NII is certainly not a substitute for RBI (Risk Based Inspection) approaches and it is only one component of the overall RBI assessment process.

The performance of an NII assessment Inspection was fully explained:
1. Strategy Type A, where no degradation is expected; this usually applies to Corrosion Resistant Alloy (CRA) vessels, commonly of stainless steels and Carbon steels (CS) with low degradation rates, such as vessels in dry gas service, with good service history and high confidence of no upsets that would cause internal corrosion. It also applies to CS vessels which are internally clad with a layer of CRA. Typically, one would inspect 5-10% of the vessel looking to confirm absence of degradation at all locations throughout the vessel. There is usually high focus on nozzles and ports, with a larger percentage selected and all types covered. A study of a CS vessel with hot rolled CRA bonded cladding was described, for which the data showed the results for wall thickness only, and confirmed that the cladding interface was is intact with no wall loss breach or disbondment.

2. The study then moved on to a Type A+ vessel with an internal weld overlay cladding around the nozzle which had multiple overlay welds (MOW) with a much coarser grain structure and an uneven surface determined by the weld beads. This type of structure normally causes scatter of NDT beam detection methods and it is thought impossible to detect stress corrosion cracking (SCC), or fine pitting in MOW, so how can this be assessed? The focus in this NII situation would be at the interface of cladding, and CS corrosion would be evident at the CS interface, (if present) following failure of the CRA cladding.

3. For Type B Vessel inspection, the likelihood of defects being present is often much higher, so inspection coverage is closer to 25%. The entire vessel floor would be included along with most nozzles.

4. For inspection of Type C, such as polymer coated CS, significant degradation would be expected with medium to high progression and the locations not easily predicted. Coating breakdown is often random in distribution and even with 50% of areas inspected and no flaws detected, there is still little confidence that there are no flaws, so often 100% NDT inspection is necessary. For NII it is necessary here to inspect fully for wall thickness loss, as coating condition cannot be seen or verified accurately. Such an inspection is significantly more costly of course.

NII is really for internal condition assessment only, external corrosion and issues such as corrosion under insulation (CUI) remain difficult and are assessed by other accepted procedures/technologies.

For the final stage of the process, the results must be checked against the requested work scope, e.g. are the NII findings as predicted for the category of vessel inspection? Are there new previously unidentified damage mechanisms additional to previously identified and are there others that don’t seem to be currently active?

The vast majority of NII inspection results are quantitative and these allow accurate prediction of remaining vessel life. The results also increase confidence in the prediction of degradation types and locations for future inspections, and provide useful information about density and homogeneity of corrosion. These items are typically not well covered by traditional intrusive type inspection and manual NDT, therefore this is a major advantage of using NII.

NII Inspection Strategies for Offshore Vessels – Neil Wilson ENGTEQ.

The branch held its annual joint event with IOM3/MIS (The Mining Institute of Scotland) on Tuesday 24th November 2020.
This webinar presentation was specifically designed to make members of the audience think outside the box in terms of approaches to materials selection, and how the research work of the defence and emergency services can be utilised in protection of personnel employed in the Energy Industries.

Professor Debra Carr (CEng FIMMM FCSFS CF), Defence and Security Accelerator, gave a fascinating presentation on body armour called “Saving their Skin (and other organs): Military and Police Personal Armour”. The talk focused on personal armour such as is worn by police and military personnel, the design of the garments, the specialist materials employed, and how they work to afford protection.

Protective armour can be in the form of simple tabard style waistcoats with helmets, eye protection or visors. Other types of armour such as body suits, ballistic blankets and shields are used for control of public order or ordinance disposal. The main purpose is to save lives and prevent or minimise life changing injuries.

Body map injury pattern summaries from conflicts during the last century have shown that there is a greater threat of injury to military personnel from scattering fragments than there is from direct ballistic hits such as bullets.So secondary fragments are more likely to kill or incapacitate personnel than direct impact from bullets, making general body armour covering more important than say just head or torso protection. This is borne out by surface wound mapping which demonstrates that injuries are spread generally across torso, limbs and head, rather than target the central torso or head.

Wound ballistic studies have been extensively studied using high speed video to capture images of ball bearings fired through blocks of translucent gelatine, which is a good model for human and swine tissue, and visual patterns show creation and subsequent collapse of cavities, replicating the wider damage during the passage of a bullet. The damage patterns were reproduced using prepared swine and deer carcasses to show realistic tissue damage expected in humans.

Some of the greatest threats these days to police appear to come from sharp weapons such as knives and concealed blades, low velocity pistols and shotguns. Common kitchen knives are often ‘weapons of choice’ of urban conflict. Studies of knife use and attacker behaviour are used to identify critical areas required for protection of officers. However, essential areas of coverage have to be balanced with the ability of personnel to do their job and avoid restriction of movement. PPE (Personal Protective Equipment) such as jacket and helmet design have to be arrived at through balance of these criteria.

Typical types of materials used in jackets:
1. High strength woven fabrics which are either para-aramids such as Kevlar® or UHMWPE (Ultra High Molecular Weight Polyethylene) such as Dyneema® or Spectra®, like those used in high stiffness ropes. Multiple layers of these fabrics are used to provide increasing amounts of protection, but a typical Police vest only weighs about 2 kg.
2. Sharp object protection armour which still uses old fashioned chainmail or resin coated fabrics, (the key to prevention of knife penetration is to change the kinetic energy density during an impact event by blunting the tip or capturing tip within the mail).
3. To stop penetration of fragments and pistol bullets, the specialist fabric also works by dissipating impact energy along yarns during fibre failure. Pyramidal patterns occur in the fabric due to vertical and horizontal lattice alignment of fabric. The high effectiveness of the police body armour was demonstrated by the mushrooming of 9mm pistol bullets on impact.
4. For threats such as high velocity rifle bullets, ceramic based composite backed plates are used on top of the general armour. The ceramic plates are typically alumina or silicon carbide which are up to five times the hardness of steel and bonded with composite fabric on the rear. The ceramic is impacted but being much harder, the bullet deforms and may fracture itself and its trajectory hindered. It leads to a conical deformation of the ceramic and a buckling of the adhesive and fabric backing without failure.

Professor Debra Carr went on to describe ‘Behind Armour Blunt Trauma’ (BABT), which is a non-penetrating injury resulting from armour covering the body. The bullet does not penetrate the armour but there may be minor breathlessness, bruising or occasional rib fracture.

The main challenges for the future maybe in the types and thicknesses of materials used in armour, as the key objectives are to reduce bulk and mass, whilst preserving the protection level. It is also essential to prevent restriction of movement of the wearer while increasing coverage and improving breathability, cooling and ventilation.

Protective Helmet Design – Professor Debra Carr.

For Oil and Gas drilling and other Energy / Mining applications, there are many potential applications of these corrosion free and advanced materials.

Blast test curtains supplied from US companies, are commonly used Offshore, but Professor Carr and her team are now assisting UK companies with specific Oil and Gas protection problems, and would welcome any enquiries at: djcarr@dasa.service.mod.uk

The branch sponsorship level continues to grow despite challenging times. Branch sponsors have remained extremely loyal and appreciative of the large number of technical events being provided. There are presently 17 confirmed sponsors for 2020-2021 session. Joining us this year are: Axcess Corrosion (US), IMRANDD Consultants, NCIMB (Laboratories) Ltd, Oil and Gas Corrosion Ltd.

The latest information about Aberdeen events can be found on the diary page of this magazine, and at; https://www.linkedin.com/in/aberdeen-icorr/, and all Aberdeen events are recorded and may be found at; https://sites.google.com/site/icorrabz/

Aberdeen Branch

Aberdeen Branch, Latest News

For the 2020-21 session, the branch is pleased to welcome Dr Muhammad Ejaz PhD, CEng FICorr, FIMMM as its new Chair, together with a very strong and diverse branch committee, whose details can be found at, https://www.icorr.org/aberdeen/

Aberdeen started its new session on 24 September with record attendance of 311 for its annual joint ICorr/TWI event with a webinar on “High Tensile Steel Bolts and Nuts – Hydrogen Embrittlement and Failure in Corrosive Environments” with speaker Alan Denney of AKD Materials Consulting Ltd. This very well-presented talk took a topical view of the long-standing issue of hydrogen embrittlement of high tensile fasteners, and the dramatic failures which can occur as a consequence. Alan started with the threaded components used as shear connectors for the earthquake resistance on the San Francisco Oakland Bay Bridge, and the causes of these failures. The talk then referred back to the historical problems with high tensile bolts caused by hydrogen embrittlement due to manufacture, and recent problems with high tensile bolts in building structures in London. To close the talk Alan brought us up to date with the modern offshore environment with issues due to environmental corrosion in offshore wind turbine structures, and work in Germany to define and limit the conditions for its occurrence, and potential prevention or mitigation measures.

The three conditions for Hydrogen Embrittlement.

Following on from its well-received April/July events, ICorr Aberdeen /MCF jointly ran a new series of ‘Lunch and Learns’ between 5 and 9 October. Opening the week was a fascinating talk by Simon J. Sparke – International Well Integrity Ltd, on the “History of well integrity and its business impacts to the Oil and Gas industry”. Graham Greenwood Sole – Corrocoat, then described their advanced glass flake technologies and S/T aerosol type solutions for marine corrosion protection. Gary Whyman – Emerson Automation, followed with the question, “What is proactive maintenance, and how does it differ from preventive and predictive maintenance? Moving onto Renewables, Neil Gallon – Rosen UK, considered Integrity management of hydrogen transportation pipelines and to close the week, Svenn Magne Wigen – Force Technology Norway, discussed subsea survey utilisation of highly sensitive field gradient sensors for optimisation of CP life extension.

Interpretation of Field Gradient Data. FORCE TECHNOLOGY Norway AS.

On 15 October, the branch welcomed Oceaneering for a ‘virtual’ Industrial visit, hosted by Ian Drummond (Regional Business Development Manager – Europe & Africa) on the theme, “Integrity Management and Digital Solutions: Fly, Swim or Crawl?”

Oceaneering is a global provider of engineered services and products, primarily to the offshore energy industry. From remote inspection to capturing and managing data more effectively, Oceaneering offers a range of integrity solutions that optimise inspection and maintenance regimes to deliver significant time and cost savings.

SME technical presentations of three key business areas, with the focus on techniques to identify and predict external corrosion, were given together with simulations of these technologies.

Lisa McCrory – Product Manager – Integrity, presented Inform InspectTM

Inform InspectTM is an intuitive and flexible digital asset inspection tool that enables users to plan, schedule, execute and review inspection work scopes in real time, significantly reducing end to end inspection times. It allows international co-operation between technicians and subject matter experts. It is cloud based tool that allows remote working using tablets at site, through which the technician can execute the inspection and send back the work pack for review and report generation. Targeted rejection is sent back to the technician and as threshold alerts are also in the system, notification is given that results have crossed over pre-set alarm levels such as MAWT (min. allowable wall thickness for piping or vessel) or NOM. (nominal value of material schedule). They can choose whether to accept or reject the results or send back for review. All data is stored in a secure global portal and the system also has built in training modules through the web portal. Inform InspectTM is field proven and connects seamlessly with integrity and maintenance management systems to deliver credible up to date inspection data. Multi-method inspections of visual, electromagnetic, ultrasonic and radiographic can all be managed through questionnaire templates that are customised through client / project input.

Illustration of Oceaneering Inform Inspect.TM.

Jim McNab – Non-Destructive Testing SME, presented the Trip Avoidance X-Ray Inspection System (TAXI™)

It’s fair to say, the industry as a whole respects conventional radiography as a trusted, very reliable, easily interpreted method with a high PoD even for the smallest flaws like corrosion pits, however, it’s associated with safety issues, it’s time consuming, disruptive and has a limited deliverable format i.e. a single conventional film only a few people get to see.
TAXI™ has managed to largely address all of these ‘negatives’ especially for CUI, where the majority of leaks occur in smaller than 4” OD pipes, with the added bonus of having very limited effects on nucleonic level control instrumentation.

Pressure plant equipment sometimes has nucleonic level control instrumentation which monitors the fluid levels in vessels. Gamma rays from a normal source used in NDT on pipes is sensed by the nucleonics. The separator misinterprets the signal thinking the vessel has evacuated its fluids inventory. To avoid these ‘false alarms’, conventional radiography is carried out by temporarily isolating the equipment, running the plant ‘blind’ risking unmonitored process operational issues, or deferring to plant shutdown to allow liquidation of radiography workscopes.

For the UK continental shelf, data shows that plant failure and unplanned shutdowns account for nearly 20% of production losses, approx. 100 million barrels of oil equivalent in 2019.
TAXI™ delivers pulsed X-radiation, which has little effect on nucleonic instrumentation while giving high quality digital x-ray images in 8 seconds. 20-25 exposures can be performed per shift, up to 4 times more than standard radiation techniques – allowing uninterrupted operation and production. Control room liaison is still critical, but there has been new confidence with this system. It uses digital detection media which absorb radiation quicker (compared to conventional film) and has a larger exposure latitude/dynamic range. There is therefore no need to use multiple exposure on thicker pipes, or on pipes filled with denser liquids and sediment. Extensive verification testing of the system was carried out to ensure it worked in a range of conditions and settings.

Digital radiographs demonstrating exposure latitude/dynamic range of the system were shown of thick wall double insulated pipe filled with fluid and internal sediment, clearly visible. A badly corroded pipe with external corrosion scab radiograph revealed unexpectedly that cracks were in the scab rather than the pipe wall. X-rays of Swagelok™ fittings had such detail that small faults could be determined in the assembly of fittings to the pipes.

Illustration of Oceaneering TAXI™ X-Ray Set.

Other key benefits of the system were the small area of radiation used, the reduced radiation exposure time, and use of no radioactive materials which require ‘dangerous goods’ classification.

Finally, Iain Jarvie – Senior Consultant Engineer, presented the Vibration Induced Fatigue Digital Twin technology.

According to UK HSE data, from 1998 to 2015 there were 303 fatigue related hydrocarbon releases in the UK sector, of which 125 could have led to a major incident. Could these have been prevented?
Vibration and the resulting stress cycles, due to fluid flow, can cause fatigue cracks. The cyclic stress amplitudes that can cause a crack can be more than 10 times lower than the yield stress of the material. These cracks propagate through the material leading to loss of containment and hydrocarbon release.
The Energy Institute ‘Guidelines for the avoidance of vibration induced fatigue in process pipework’ are used throughout industry to manage this problem. The method relies on a risk based approach with regular visits to the plant by specialist engineers. The guidelines have reduced the number of failures, however HSE data shows that vibration induced fatigue is still a significant problem for the oil and gas industry.

Oceaneering have developed new ways to tackle this problem, including:

• A vibration measurement tablet that can be used by operator personnel, 
 which automatically uploads data to the cloud for onshore assessment;
• A helmet camera system that provides a live 2-way audio and video 
 feed from the asset, allowing operator personnel to assess a problem 
 with onshore specialist support; and
• Pipework Digital twin Technology

The digital twin is fed by live sensor data and uses a library of pre-solved model solutions to find the best fitting representation of the pipework. Machine learning algorithms are then used to interrogate live measurement data and extract the force spectra acting on the pipework, allowing a real time fatigue damage assessment and real time root cause analysis. This technology has been used extensively in the aircraft industry. Its application in oil and gas has the potential to reduce or eliminate vibration related fatigue failures. Corrosion can reduce fatigue strength by 35%, the digital twin technology allows this effect to be included and quantified. The live remote monitoring and fatigue assessment provided by the digital twin reduces/eliminates the need for engineer visits, with issues being identified and mitigated using onshore resources.

An extensive Q&A Session chaired by Ian Drummond closed this very successful Event.

The full recording of this event is available for viewing at: https://www.oceaneering.com/tradeshows/icorr-a-virtual-industrial-visit/
Aberdeen Branch maintain an extensive database of past presentations covering all areas of corrosion management. Copies of these can be found at: https://www.icorr.org/aberdeen/ and a photo gallery at: https://sites.google.com/site/icorrabz/event-gallery. The branch also has a new You Tube channel at: https://www.youtube.com/channel/UCNW-HoZVEMA79-4Y6k5E0ow/featured
Full details of upcoming events may be found on the main ICorr Website https://www.icorr.org/events/list/ or by contacting: ICorrABZ@gmail.com

Aberdeen Branch News

Aberdeen Branch, Latest News

The branch has always been active in organising technical talks, annual conferences, industrial visits as well as collaborations with other institutes in various subjects that overlap with corrosion management. On the technical aspect, attending the monthly events gives members a chance to gain perspective on how others approach their work and to stay up to date with the current corrosion management tools. Apart from gaining knowledge, it is a perfect setting to get out of the rut of a normal workday and to network with other like-minded people. Also, you never know if you could be sitting next to a prospective employer, or client!

In addition to the technical aspects, the branch also supports, and helps, young engineers progress their careers, in line with ICorr values, and the latest addition to the branch committee, Mei Ling Cheah, is a perfect example of this.

Mei Ling Cheah began her higher education in 2008, at the University of Science, Malaysia gaining a BEng (Hons) in Materials Engineering, followed by Post-Graduate studies at The University of Manchester and the award of Master of Science (MSc) in Corrosion Control Engineering in 2013. She then started work immediately as a graduate Corrosion Engineer at CAN (Offshore) Ltd., Aberdeen, acting as the focal point for all integrity and corrosion matters for Bluewater’s FPSO. She was responsible for the delivery of RBI, pressure system inspection work scopes, fitness for service assessments, and technical reports outlining corrosion related issues, ensuring the constant update of risk-based assessments for all integrity related offshore facilities, and development of shutdown scenarios.

The following 3 year chapter in her life took her to Lloyd’s Register Aberdeen, working as a Corrosion Engineer on asset life extension assessments for SABIC petrochemical plant static equipment and piping, for sites at Teesside (UK), Mount Vernon (USA), Burkville (USA) and Petrokemya North & South (KSA). Other overseas related projects at Lloyd’s included RBI for the S-Chem (Saudi) petrochemical refinery, and a corrosion study for the ZADCO Sulphate Reducing Plant, where the scope of work included static equipment and piping criticality assessment and generating inspection plan for all static equipment, piping and PSV’s. As well as dealing with a number of UK offshore facilities, new experiences of pipeline corrosion management were gained, including cathodic protection reviews and developing corrosion control schemes. Most recently she joined the Aberdeen based IMRANDD Asset Integrity Management Firm, where she provides ongoing engineering support for Chrysaor’s offshore assets – Armada, Lomond and North Everest.

According to Mei Ling, her journey into the field of corrosion started with her fascination on what was known as the greatest technological prediction for half a century, Moore’s Law – cramming more transistors onto integrated circuit boards which lead to the age of computing and personal mobile devices. One of the challenges of keeping up with Moore’s Law was around the limitations with materials science, which decided her to study Materials Engineering at university. It was during this when they had a module on energy storage and battery systems that got her interested in the subject of electrochemistry. The process in a battery and corrosion of steel are chemically similar.

Mei Ling’s CV is typical of new corrosion engineers, in that experienced engineers in the branch are supporting her as she works toward Chartered status. In addition, Mei Ling is assisting Young ICorr nationally under chair, Caroline Allanach.

If you are a newly qualified engineer working the corrosion protection industry, then, just as with Mei Ling, your local branch can support you in your career development. A list of branch contacts can be found on the diary page of this magazine.

As usual, full details of future Aberdeen branch events can be found on the diary page of this magazine and on the ICorr Website, or by contacting, ICorrABZ@gmail.com. Copies of the majority of past branch presentations can be found at, https://www.icorr.org/aberdeen/, and a photo gallery for all Aberdeen events can also be found at, https://sites.google.com/site/icorrabz/event-gallery.

It should be noted that the planned ‘Industrial visit (Oceaneering), an Alternative/Interactive Industrial Event’, will now take place on 15thOctober 2020.