Corrosion is a common problem faced by a number of different industries. It can be defined as the deterioration of a substance (usually a metal) or its properties due to a reaction with its environment. For the oil and gas industry, this usually include costly assets such as pipelines, refineries and petrochemical plants encountering moisture, salt, oxidation, or being exposed to a variety of environmental or industrial chemicals, ultimately affecting their longevity.
According to a study produced by NACE International, corrosion is estimated to be costing the U.S. oil and gas exploration and production industry $1.4 billion each year. Broken down, $0.6 billion of this is attributed to surface piping and facility costs, $0.5 billion to downhole tubing and $0.3 billion to capital expenditures related to corrosion.
However, the application of protective coatings can assist with keeping corrosion at bay.
Anti-corrosion coatings provide a barrier which protects the structure from contact with chemical compounds or corrosive materials. Many anti-corrosion coatings have the added benefit of being non-stick (making surfaces easier to clean) and resistant to abrasions.
Aside from corrosion-resistant coatings, there are several other protective coatings on the market which are being applied each day by the oil and gas industry, such as anti-slip coatings, anti-bacterial coatings and high-temperature coatings.
To select which coating is best for the job, factors such as the surface properties of the material to be coated, the required appearance, product cost targets, the required service life and the conditions the materials will face in the field should be considered.
An evolving industry
Trends are constantly changing in the protective coatings market as research and development into new technologies, application methods and materials continue to make these coatings cheaper, faster and easier to apply.
One recent trend that has taken the industry by storm is the shift towards two-coat systems. Essentially, a two-coat system is a method in which two coatings (instead of three or more coatings) are applied to the same surface. In most cases, two coat systems involve laying down a primer, curing it, and subsequently applying and curing using a top coat. Two-coat systems have only recently been made available thanks to recent advances in protective coating manufacturers’ technology.
Coatings and environmental considerations
Versatility, ease of application and a competitive price point have made solvent-based coatings the technology of choice for years. However, when solvents from protective coatings evaporate, they emit volatile organic compounds (VOC), which are recognised as being harmful to the environment. VOCs are regulated by governments on all levels, limiting the amount of VOCs companies can emit over a certain period.
Due to increasing environmental restrictions and a need for oil and gas companies to introduce more sustainable practices, there has been a notable shift towards adopting protective coatings that contribute to reduced energy costs and a lower impact on the environment. Mainly, where possible, operators are choosing to move away from traditional solvent-based coatings to predominantly water-based coatings.
Even though some water-based coatings do contain solvents, they are usually in the form of co-solvents, which are in lower concentrations and designed to get rid of water as the coating dries. Even so, water-based coatings are known to contain significantly less solvents than solvent-based coatings (if any), which can assist in reducing an oil and gas company’s VOC output.
Aside from being harmful to the environment, VOC fumes are also toxic – causing health risks for people who inhale them. Thus, water-based coatings are increasingly being selected for applications in confined or poorly ventilated areas like fuel storage tanks. Additionally, water-based coatings have been known to assist in reducing the concentration of flammable materials that can accumulate in a small area. Advances in water-based coating technology are slowly eliminating the need to use solvent-based coatings, however, in certain industries it is not yet feasible to move away from solvent-based coatings at a large scale.
There is also an increasing adoption of metal spray coatings (also known as thermal spray coatings). Just as it sounds, metal spray coatings involve the projection of small molten or softened particles onto a prepared surface where they adhere and form a continuous coating. To create the molten particles, a heat source, a spray material and a projection method are required. Usually, this is achieved through a spray gun, but it can now also be conducted by highly-precise robots.
In all, to safeguard the longevity of oil and gas assets from corrosion, chemicals or adverse weather conditions, decision makers should consider the benefits of applying protective coatings in their operations.
Sources: Protective & Marine Coatings Market by Resin Type and End-Use Industry – Global Opportunity Analysis and Industry Forecast, 2017-2023, Allied Market Research; A new solvent-free super high build epoxy coating evaluated by marine corrosion simulation apparatus, Xiushan Yang et al.; How to select coatings to optimise component performance, Surface Technology; The Difference Between Water-Based Coatings and Solvent-Based Coatings, National Coating Corporation; Corrosion in Oil and Gas Industry: A Perspective on Corrosion Inhibitors, Mohammed Nuri Rahuma and Bobby Kannan M; Corrosion costs and preventive strategies in the United States, NACE International
