PAINTSQUARE BLOG

Asset integrity can be defined as the ability of an asset to perform its required function effectively and efficiently while protecting health, safety and the environment.

Asset integrity management is the means of ensuring that the people, systems, processes and resources that deliver integrity are in place, in use and will perform when required over the whole lifecycle of the asset.

Photos: Lee Wilson

An asset’s location and environment can prove extremely challenging for the duty holders who need to maintain the integrity of a platform/plant from corrosion.

Corrosion and the inevitable aging of plants and offshore installations are major issues. An asset’s location and environment can prove extremely challenging for the duty holders who need to maintain the integrity of a platform/plant from corrosion.

This integrity, however, is essential in order to keep the asset operating safely and productively over its full lifecycle. Therefore, maintenance of the very fabric of oil and gas installations is vitally important for prolonging the lifespan of a valuable business asset, as well as ensuring that the plant is fully functional and the workforce is accommodated in a safe and aesthetically pleasing environment.

This entry covers some of the challenges for the fabric maintenance (F&M) of oil and gas installations.

Fabric Wear and Corrosion

As a plant/oil installation grows older, the very fabric of the plant begins to wear. This has major safety-critical factors attached to it, such as the potentially explosive release of hydrocarbons from corroded pipework, vessels, valves and flanges.

The loss of integrity of structural supports, walkways and stairways can prove to be catastrophic, so it is of vital importance that owners and operators implement constant proactive and scheduled maintenance plans for their installations. 

Corrosion is a huge concern for owners and operators, and managing corrosion should be a major priority for oil companies.

Problems:

• External/internal corrosion;
• Corrosion under Insulation;
• Structural degradation/failure (e.g., fatigue);
• Hydrocarbon leaks from flanges and pipework/vessels;
• Passive Fire Protection degradation; and
• Failure of Safety Critical Elements (SCE).

As I have mentioned many times, the United Kingdom’s offshore oil and gas industry is now in a position where many of its North Sea platforms have been producing and in service for 25 to 30-plus years. In many cases this is well beyond the intended lifespans of many of the assets, especially considering the severity of the corrosion environment in which these platforms are situated—C5M in accordance with ISO 12944 in most cases.

The Value of Maintenance

Age in itself creates an abundance of challenges for owners and operators. As platforms age, operators must have a comprehensive fabric maintenance plan in place—to extend the life and productivity of the structure, as well as to prevent any failures that could lead to a major incidents offshore, halting production and putting workers at risk of serious injury.

“Aging is not about how old your equipment is; it’s about what you know about its condition, and how that’s changing over time,” according to U.K.'s Health and Safety Executive (HSE).

Prolonging maintenance is not a viable option to any duty holder and simply increases operating costs, reduces efficiency and most importantly poses far greater safety risks to workers. However, as often addressed in books, blogs and articles, in order to execute a successful maintenance campaign there needs to be a fully planned, orchestrated and executed maintenance strategy in place. It is not a case of turning up with a pot of paint.

Why Embark on a Fabric Maintenance Campaign?

Executing a successful F&M campaign can be extremely challenging as there are many factors to be considered. I have seen a huge influx in paint inspectors becoming lead F&M coordinators and supervisors in recent years. However, being a certified paint or coating inspector does not make one a successful F&M supervisor.

The roles and responsibilities, with the exception of the quality of the maintenance work carried out, are completely different and there is so much for a supervisor or a coordinator of a maintenance campaign to take into consideration, particularly on an offshore installation. These include:

• Bed Space
• Materials
• Logistics
• Manpower
• Access
• Safety
• Storage
• Tools
• Quality
• Supervision

And there are many more!

It is well known that, due to the recent drop in the price of oil, a lot of owners and operators are prolonging fabric maintenance or at least decreasing the scope because they claim F&M campaigns are extremely expensive. I concur—they certainly can be; however, this comes down to a number of factors:

• Lack of planning;
• Unidentified scope;
• Inexperienced personnel heading the F&M campaign (this is a major issue);
• Misinterpretation of data;
• Data not available;
• No maintenance strategy in place;
• Carrying out maintenance on structures and elements which are not safety critical or for which it is not necessary;
• Lack of direction to the workforce;
• Improper use of access;
• Misunderstanding of logistics (particularly for offshore locations); and
• Lack of communication between onshore engineering and offshore supervision.

Corrosion is a huge concern for owners and operators, and managing corrosion should be a major priority for oil companies.

Naturally there are many more, but factors such as those above will, of course, greatly increase the costs of fabric maintenance. However, there are simple solutions to greatly reduce the costs—and, regardless, the overall potential costs of prolonging maintenance can prove to be four times greater than an F&M campaign, and let’s not put a value on the cost of life!

Planning for a Successful F&M Campaign

Ultimately in order to carry out a successful F&M campaign of an oil and gas installation there are many factors to consider with many questions to be answered.

• What is the scope of work?
• Has the scope of work been identified and measured?
• Has a full survey been carried out by a competent surveyor/inspector?
• Is there an external/internal corrosion management system in place?
• If so, have the safety critical elements and non-safety critical elements been identified and prioritized?
• If so, how have these been prioritized in the correct order for scope/maintenance execution?
• How are the fabric inspection and remedial action tasks prioritized and how are the priority ratings reviewed?

These are the first questions to be asked prior to any campaign being implemented. To collect answers, a full survey of the installation is required in order to determine the general condition of the platform and the scope of work. It’s easy to turn up with a few pots of paint and some insulation, but this is not the solution to an installation’s life plan.

Fabric maintenance needs to be planned and strategically implemented in order to be successful. Many tools and systems are available to help identify the scope of work, such as risk based inspection (RBI) and external corrosion management systems (ECM).

Risk Based Inspection and Scope of Work

To put it simply RBI refers to risk mitigation through inspection programs using risk analysis methodologies. RBI is the process of developing an inspection plan based on knowledge of the risk of equipment failure.

RBI schemes are a planning tool used to develop the optimum plan for the execution of inspection activities. RBI uses the findings from a formal risk analysis, such as a Corrosion Risk Assessment, to guide the direction and emphasis of the inspection planning and the physical inspection procedures.

RBI is used to:

• Optimize the inspection schedule (assuming that there is one);
• Establish critical elements and focus inspection effort onto the most critical areas;
• Ensure risk is reduced to as low as reasonably practicable (ALARP); and
• Identify and use the most appropriate methods of inspection.

Inspection and monitoring strategies should cover an asset’s entire lifecycle; however, this is not always the case. An F&M manager may need to consider this prior to building the F&M statement of work (SOW).

For example, if the conditions of safety-critical elements (SCEs) are not known, then an RBI would have to be carried out. This would generate a full inspection/survey of all equipment. The data would need to be collected as per system/subsystem and input into a data management system such as SAP and Maximo.

Prolonging maintenance is not a viable option to any duty holder and simply increases operating costs, reduces efficiency and most importantly poses far greater safety risks to workers.

This can prove extremely time consuming; however, it is the only way of fully identifying the work scope. A duty holder who wants to implement an F&M scope on an asset where RBI or a Corrosion Risk Analysis (CRA) has never been implemented would have to implement a full site survey in order to predetermine conditions.

Even if there is a history of RBI and CRA, this would not prove to be helpful to an F&M provider if the data is not available.

And I can’t stress enough that RBI should be carried out prior to any work commencing. I have personally worked on some of the world’s largest F&M campaigns and shutdowns, and trying to establish the scope as you go leads only to pandemonium and chaos; this subsequently leads to substantial maintenance costs.

Most retrieved data from a corrosion survey or coating and insulation evaluation is usually put into a Corrosion Management System (CMS); however, there are many variables that need to be considered—for example, what is the age of the data? Corrosion is a time-dependent phenomenon, and what was once not so bad may now be critical; these are all huge factors to consider.

Know Everything about the Structure

Now I can’t stress enough that the starting point in the development of any corrosion management scheme and subsequent fabric maintenance campaign is to understand the specifics of the structure or asset at hand.

This includes review of the available as-built documentation, drawings, P&IDs and other investigations and reviews already undertaken.

Where information is not available and/or additional information is required—i.e., to determine the cause of a defect or as-built condition of the structure—it is likely that direct inspection and testing will be required.

The type and extent of survey and testing undertaken will be prescribed in order for the engineer to develop a full and detailed understanding of the type and condition of materials, construction and defects exhibited by the structure in question. This may include destructive and non-destructive testing [NDT] and sampling as well as laboratory analysis

A survey is vital and the surveyor should always be on the lookout for problematic areas. Visual inspection is an important step in any in-service inspection routine; it is used to identify external anomalies and clues to anomalies such as rust staining on insulated pipe work. It also allows for a more focused use of NDT techniques to detect other internal anomalies such as fatigue cracks, corrosion, erosion, abrasion, cavitation, mechanical damage, wear and tear, distortion, and poor workmanship.

The data from the NDT and corrosion survey would then be input into the CMS which, depending upon the results, would also contribute to the F&M SOW as well as the prioritization.

This data should then be interpreted by a competent engineer—not the painter or the painting supervisor—in order to determine the risk and the priority; we are talking critical elements.

Critical versus Noncritical

Essential for the integrity of any installation are the SCEs. These are the parts of an installation and its plant (including computer programs) that serve to prevent, control or mitigate major accident hazards (MAHs) and the failure of which could cause or contribute substantially to a major accident.

The overall potential costs of prolonging maintenance can prove to be four times greater than an F&M campaign.

There often tends to be a lot confusion in regard to what is critical and what is not, and this needs to be fully identified, agreed on and prioritized by onshore engineers prior to SOW execution.

For example, we all agree that a deluge system would be classed as an SCE on an offshore installation; however, would a deluge support be classed an SCE? For me there is no confusion because if the deluge system is not supported there is no system; however, you have an idea of how far we can go with SCE.

This is why a site survey is so important and it’s vital that the survey team are well versed in scope identification including being familiar with structural drawings, P&IDs and system and sub-system identification.

The survey for an F&M campaign will include but not be limited to:

• RBI (risk based inspection);
• Corrosion survey;
• Coating condition survey;
• Insulation survey; and
• Passive fire protection survey.

The corrosion survey often requires the use of NDT inspection methods, and the coating condition survey often leads to varied other forms of inspection, since we have to remember that not all coating issues can be visually detected.

Speaking of the unseen, this leads me to….

Corrosion Under Insulation

Corrosion under insulation (CUI) is considered to be one of the greatest problems associated with high-temperature insulated steel pipework and vessels and has been plaguing the oil and gas industry for many years now.

It is widely accepted that the highly aggressive corrosive environment produced underneath insulating products, coupled with the fact that the evidence of any corrosion cell is hidden, ultimately has the potential to lead to catastrophic and expensive failures.

As we are well aware, once moisture permeates an insulation material, a highly aggressive corrosive environment is generated at the interface between insulation material and the substrate. This moisture is often unable to escape and therefore becomes entrapped at the interface, resulting in extended periods of moisture contact and an active corrosion cell and further build-up of corrosive contaminants.

Inspection and monitoring strategies should cover an asset’s entire lifecycle.

CUI is a blog post within itself and something I plan to write about later in the year; however, CUI has the potential to greatly increase F&M costs. I have seen many maintenance shutdowns on oil and gas platforms due to CUI and maintenance scopes that were poorly executed due to the CUI not being detected or scoped.

In Conclusion

To put it simply: maintenance programs should run like a well-oiled engine; it just depends how regular its oiled and how much oil is put into it. Information and communication are key, and data collection and data interpretation are paramount.

This was highlighted as a major failure in the HSE, Key 3 external corrosion management report. However, there needs to be a strong line of communication between onshore and offshore with all parties agreeing upon the scope and the scope priorities.

ABOUT THE THE BLOGGER Lee Wilson Lee Wilson, CEng, FICorr, is a NACE Level 3-certified CIP Instructor, NACE Corrosion Specialist, NACE Protective Coating Specialist and Senior Corrosion Technologist, as well as an ICorr Level 3 Painting Inspector and Level 2 Insulation Inspector. The author of the best-selling Paint Inspector’s Field Guide, Lee was named one of JPCL Top Thinkers: The Clive Hare Honors in 2012. Contact Lee. SEE ALL CONTENT FROM THIS CONTRIBUTOR