Featured in Composites Manufacturing | March 2019
by Megan Headley
Infrastructure expansion in the oil and gas industry drives demand for – and on – composite components.
There are massive demands on the structures that bring oil and gas out of the depths of the earth and sea to be processed for consumption. There are intense temperatures and pressure levels, as well as high rates of friction and hazardous materials to withstand. And there’s another factor to consider: the necessity to grow new infrastructure to support this booming industry.
A 2017 report prepared for the American Petroleum Institute, “U.S. Oil and Gas Infrastructure Investment through 2035,” predicts that “rapid infrastructure development is likely to continue for a prolonged period of time. The primary drivers for robust development are still in place – shale and tight resource development is likely to continue in earnest, and markets will grow in response to the relatively low commodity prices that are being fostered by new oil and gas supplies.”
The Perfect Combination of Properties
The surging demand for oil and gas infrastructure is good news for the composites industry. Composite materials truly shine in applications that demand a combination of strength and light weight, and these are often drivers for material selection within oil and gas infrastructure projects. “Often the applications require very high strength, so a high-quality composite material is needed to be able to replace a metallic component and have the strength required,” says Ames Jacoby, technical director for CIP Composites, a Eugene, Ore.-based supplier of composite bushings, bearings and washers.
Offshore pipelines are a prime example of how composites’ unique properties can solve critical problems for the oil and gas industry. Often, pipes float along the water’s surface or are semi-submerged, so they must be flexible enough to withstand the movement of the current. Tacoma, Wash.-based polyurethane foam manufacturer General Plastics provides rigid foam buoyancy modules that help keep the pipelines afloat.
“They have to fasten these heavy pipes to the foam, and the foam has to have a certain amount of compressive strength to not only withstand the depth, but also be tough enough to handle the use and application and deployment,” explains Mitchell Johnson, CEO of General Plastics. “The oil and gas environment these materials work in is harsh. It’s not like aerospace. Things get handled pretty rough.”
General Plastics often proposes solutions that involve wrapping a composite shell around the lightweight foam to protect it from the environment. This combination provides the flotation benefit of the foam with the durability of a harder skin.
Subsea risers work similarly to pipelines, but transfer material vertically. On offshore platforms, a riser runs from the seafloor to the deck platform. Like the pipelines, they have to be able to sway within the current. Critical sections of the risers feature tapered stress joints to spread heavy loads.
Automated Dynamics, part of Trelleborg Group, provides many structures for this market, including structural insulators for the stress joints made from continuous S-2 fiberglass-reinforced polyetheretherketone (PEEK) impregnated tape. “These structural insulators transfer load while protecting against galvanic corrosion between dissimilar metals in the presence of seawater,” explains Brett Kimball, program manager for Automated Dynamics.
Corrosion Resistance from the Inside Out
The impact of environmental conditions on structural integrity is usually at the forefront of discussions between composites fabricators and end users. “Often the issues our products face are from severe environments, whether that’s a land-based well or an oil rig that is dusty and dirty and gets a lot of contaminants … or a marine environment that means exposure to sea water, barnacle growth and things like that,” Jacoby says.
Yet one of the most demanding challenges placed upon materials in oil and gas applications doesn’t come from the outside environment. In many cases, it’s the caustic material being transported within pipes or held in tanks that does the greatest damage.
Netherlands-based TenCate Advanced Composites’ products are commonly used in high-energy oil extraction alternatives to hydraulic fracturing, explains Steve Johnson, the company’s thermoset product manager. “Primarily, we’re focusing on transmissive applications, where you want low dielectric materials that you’re going to be putting energy through,” he says. For example, the company provides glass and high-density polyethylene (HDPE) thermoplastic unidirectional tapes that reinforce oil and gas pipes. The composite materials help the piping systems resist corrosion at a much lighter weight compared to metal piping.
“The environments where you have severe hot-wet with chemicals, acid and alkali are definitely a challenge. But the truth is the types of systems from which you can get the high transmissivity – and low dielectric loss – are attacked very strongly by those types of conditions,” says Steve Johnson. “So you have to have either a material that’s going to have a short lifetime or those materials are coated with something impervious, like something akin to Teflon™.”
This is the niche that TenCate works to serve, but Steve Johnson points out that the rapid breakdown typical composite solutions face in these intense environments may challenge broader use of these materials.
“From a thermoset perspective, what would enable the technology more is if we had resins that were much more resistant to the hydrolysis and chemical attack that you see in these applications,” he says. “Not to say that they aren’t [resistant] under more normal conditions, but when you get under these extreme pressures and heat, all these mechanisms speed up greatly and so you need something really, really inert to handle that environment for any length of time.”
Composites’ insulating properties often make them invaluable in these piping applications. “Most of the materials we’re focusing on in the gas and oil market are thermal insulators,” says Mitchell Johnson. In the fracking process for extracting liquefied natural gas (LNG), for example, General Plastics’ rigid polyurethane foam products serve as thermal blocks.
In essence, the process of mining LNG involves injecting liquid nitrogen down into the gas deposit to lower the temperature enough to transform the gas into a liquid. The LNG is then pumped to the surface. And as Mitchell Johnson explains it, “On a raised pipeline you need some kind of a thermal break between the refrigerated pipe and the metal bracket that’s above ground, otherwise you lose a lot of energy down into the ground.” General Plastics provides rigid foam supports that are custom-designed to hold those pipes in place while serving as a thermal break.
Reduction in Maintenance Costs
It’s not just new drilling techniques and infrastructure placing demands on materials. Existing infrastructure has equally heavy demands, especially when it comes to reducing the high costs of maintenance.
For offshore platforms in particular, maintenance is a tricky and expensive business. A study from the energy market research firm Douglas-Westwood estimated offshore maintenance alone at $672 billion in 2018. So when the switch to composite components can help lower maintenance demands, these materials can gain ground in oil and gas industry applications. Composite materials are now able to point to products that stand the test of time as evidence of their low-maintenance properties.
“Strongwell’s grating was first used on an offshore platform in 1979 and is still in service,” says Barry Myers, corporate marketing manager for Strongwell, a pultruded FRP manufacturer in Bristol, Va. “Many of Strongwell’s products are a good fit in the oil and gas industry because of their light weight, corrosion resistance and low maintenance requirements.”
The company’s DURADEK® fiberglass reinforced grating was first installed in 1979 on Shell’s Ellen platform (now operated by Aera Energy LLC), just off the shore of southern California. According to Strongwell, there’s been little indication that the wide-ranging abuse the grating has suffered over its 40-year history – from accidental sandblasting and paint overspray to abrasion from the platform’s surface safety valves – has had much effect on the durable phenolic resin-based, pultruded grating.
An added benefit has been that the composite material lends itself to reducing wear on workers. The non-skid grating features a wide bearing bar that end users report is easier to kneel on than traditional serrated steel grating.
Jacoby says CIP’s products are sought after for high-wear offshore applications. Examples include mooring lines that anchor tankers to the seafloor and the anchor pin bearings that secure these lines in place. These components are highly loaded, Jacoby points out, making strength a leading material requirement.
Typical mooring line materials, as well as many of the bronze bearings used to connect these lines, require regular grease or lubrication to reduce the effects of wear over time. Bronze bearings in particular need a boundary layer of lubrication to prevent damage from ongoing metal-to-metal contact. On top of this, the lubrication systems require regular cleaning to remain functional.
This isn’t the case for composites infused with lubricants. “We do a lot of mooring solutions because they’re able to put our material in and not really have to apply a grease or maintenance cycle for good service and longevity,” says Jacoby.
CIP Marine™ products incorporate the solid lubricant polytetrafluoroethylene (commonly known by the brand name Teflon) and molybdenum disulfide within a polyester resin, which is then reinforced with polyester textile to create a dimensionally stable material with the strength to replace bronze. The composite ultimately has a lower coefficient of friction than bronze in static and dynamic situations, able to achieve 50 percent lower coefficients of friction than bronze, reports CIP. By incorporating lubrication within the material itself, CIP is able to extend the operating life of these offshore components while reducing the maintenance costs.
The resin selection also has an impact on wear, Jacoby notes. “If the application is highly loaded and there’s some reasonable speed to it, [the component] is going to have some frictional demands,” he points out. “Temperature resistance in a resin system is an important factor, because that will dictate the wear rate. The better the resin is able to handle the temperature scenario, the better it’s going to be able to resist wear.”
In this case, industry regulations may also play into the switch to composites. CIP has found that the Environmental Protection Agency’s 2013 requirement that all marine vessel oil-to-sea interfaces use environmentally acceptable lubricants has led to logistical challenges in finding compatible products for existing solutions. When the need for lubricant is eliminated, the problem is largely solved.
Breaking Down the Competition
One of the greatest challenges to getting broader use of composites into oil and gas applications is changing the mindset of users of traditional metallic options to consider advanced composite solutions. “Or, even worse, they have used a poor-quality FRP and now have no interest in using our materials,” Myers says. “Thankfully, the rigorous fire and performance standards related to oil and gas prevent some lower quality materials from being admitted onto oil and gas rigs.”
While the main competition is steel, composites are able to break new ground through new material combinations and processing technologies. “We work directly with customers to solve their challenges,” says Jacoby. “We find out the geometry of the component they’re using today, the criteria for the application in terms of loads, speeds and the environmental conditions, and the kinds of temperature they are seeing. We do some calculations on the application.” And from there, a new product is born.
Mitchell Johnson agrees that the fun part of working with composites is the nearly endless design options. “You just need to think outside the box as to what problems you need to solve and give us a little bit of time to get there,” he says. “We can usually provide a composite solution.”
This innovative mindset is a perfect fit for an oil and gas industry currently seeking to push past its traditional limits.