Innovative coatings from Hempel help fight corrosion and protect asset integrity
Oil and gas assets are subject to some of the harshest working conditions any industry might face. Those environments and the increasing age of working stock present significant challenges to asset integrity professionals. Yet one of the discipline’s main tenets is that the prevention of damage is almost always better than the cure – and more often than not, coatings are the best way to meet that challenge.
Hempel is a global coatings supplier for the decorative, protective, marine, container and yacht markets. It knows how harsh operating environments can be and has engineered a vast array of ways to help tackle one of the oil and gas industry’s greatest problems. Whether topside or subsea, its technologies help to protect vital assets from corrosion, abrasion and marine fouling.
Of all the issues faced by operators, corrosion is one of the largest. It can take many different forms and can manifest itself as a variety of problems:-
General uniform corrosion both internally and externally.
Corrosion under insulation (CUI) a specific problem in the case of insulated process pipework and vessels operating within a limited temperature range.
Thinning of structural elements leading to increased fatigue.
Bacterial corrosion on process vessel internals.
Indeed, some extrapolated cost estimates from the US’ National Association of Corrosion Engineers (NACE)
put the total cost of corrosion to US oil and gas companies at around US$1.3 billion per year, US$320 million of which is associated capital expenditure. Choosing the right coating to protect an asset throughout the course of its life can therefore make a major difference to operators’ bottom lines.
Hempel’s understanding of corrosion has led to a broad portfolio of protective solutions which can help to support asset integrity regimes, throughout up- and downstream operations.
One of the easiest ways to reduce the effect of unscheduled fabric maintenance is the specification of a robust protective coating at the new construction stage and ensure that it is correctly installed and maintained.
Hempel’s Hempadur products are a range of epoxy coatings designed to protect steel from the harshest conditions. Covering both primer and intermediate coats, the main focus of the Hempadur range is to provide effective barrier properties from corrosive elements and is used widely in the protection of structural steel, pipework and storage tanks.
For offshore assets, and in particular mobile production and drilling units, the ability to protect water ballast tanks and crude oil storage tanks is of critical importance.
Premature breakdown of protective coatings in these areas is exceptionally costly to rectify given the difficulties associated with confined-space work offshore. The loss of storage capacity can have a significant operational impact on the facility whilst maintenance work is completed. In these situations Hempel’s Hempadur XO Quattro series is an ideal material of choice.
A two-component pure epoxy primer designed to protect water ballast tanks, cargo oil tanks and other immersed areas is available in a variety of grades. Its aluminium-filled grades meet the specific requirements of offshore operators.
Cracking is a common problem arising from application in difficult-to-reach areas commonly found in many tank arrangements and which is often a factor in premature maintenance. Hempel’s unique solution to this problem incorporates the use of fibres to offer increased mechanical durability and resistance to cracking due to over-thickness.
Alternatively, both an aluminium-filled and fibre-reinforced grade can be selected for ultimate protection.
Whether onshore or offshore, complex process equipment is necessary during the extraction of oil and gas to make it suitable for transport and ultimately consumption. In many cases the thermal insulation used to preserve energy and protect personnel provides another major hurdle for asset integrity planning. Corrosion under insulation, or CUI, will almost always take place unnoticed until the area is inspected – which in difficult-to-access areas may be infrequently and costly – thus the prevention of CUI is always better than the cure. Again, selecting the correct coating at new construction can make a significant difference to downtime and associated costs later in the asset’s life.
Hempel’s Versiline CUI 56990 has been specifically designed to aid the prevention of CUI. Based on silicon, the copolymer coating cures to form an inert polymer matrix which provides long-term thermal and corrosion protection. A selection of barrier pigments – flakes of inert materials which prevent corrosive agents from reaching the metals – also help maintain its effectiveness. This means that Versiline CUI can withstand significant temperature variation and cycling, from cryogenic temperatures as low as -196°C and up to 650°C, and in dry or dry/wet use, and is suitable for carbon, austenitic and duplex stainless steels.
Another of its advantages is that it can be applied to hot substrates, maintaining adhesion and its protective qualities at temperatures ranging anywhere from 10°C to 200°C. That allows operators to treat pipework on-site, and do so without a protracted cool-down period, saving time and money, and maintaining production.
Maintaining hull integrity on floating offshore production units
Hull inspection is an important element of fabric maintenance inspection for floating production units such as FPSOs. However, unlike conventional ships hulls and even mobile drilling units, once on station the opportunity for carrying out inspection at dry docking is rarely an option. Regulations require that an underwater inspection of the hull is carried out at regular intervals to compensate for this. Hempel’s range of anti-fouling products help facilitate that underwater inspection by reducing the level of fouling found on flat bottoms, vertical sides, sea chests and other areas.
Hempel offers a range of anti-fouling products from conventional self-polishing products to its class-leading fouling defence products based on Actigel technology, all designed to minimise organic fouling growth.
In addition to supplying protective coating systems Hempel is also able to assist customers with condition monitoring of protective coating systems already installed. Its team of trained coating advisors are able to carry out systematic inspections of whole or part process areas along with defect mapping and corrective recommendations where appropriate. Here Hempel is able to utilise its many years of coating supply into the maintenance industry to provide cost-effective recommendations which minimise surface preparation requirements so as to reduce impact on the customer’s operations.
By working with an experienced coatings supplier, fabric maintenance professionals are able to access detailed coatings knowledge and expertise which might not be available within their own organisation / facility as part of their ongoing fabric maintenance plan.
Contact: Simon Daly, Group oil & gas segment manager