Comparing Oil Field Composites to Traditional Materials

According to the IMPACT (International Measures of Prevention, Application, and Economics of Corrosion Technologies) report by NACE International in 2013, economic losses related to corrosion accounted for $2.5 trillion annually. This was equal to 3.4 percent of worldwide gross domestic product (GDP), with nearly $1.4 trillion of these losses associated with corrosion in the oil and gas sector. Failures of equipment due to corrosion also reportedly comprise more than 25 percent of incidents regarding safety in the oil and gas industry.

While oxidation can undoubtedly be an issue, particularly with water injection systems, it’s not the leading cause of corrosion in this sector. Problems with corrosion in the oil and gas sector are generally associated with carbon dioxide, hydrogen sulfide, and other constituent compounds found within an oil field. Thus, the industry has increasingly used composites that resist corrosion to combat the deterioration and erosion of oil and gas equipment. In today’s oil fields, composites are replacing traditional materials like metal alloys due to their other advantages.

In the Oil Field: Composites vs. Conventional Materials

Evaluating materials traditionally used in an oil field with composites requires looking at their various properties. Metal-based components are particularly prone to corrosion, often due to as-manufactured defects. These issues can lead to equipment failures that endanger the environment and those working onsite. For this reason, oil and gas companies must carefully assess the material properties of equipment used in an oil field. Composites often offer properties superior to those of traditional metallic materials. 

Various contraptions, machinery, and tools used by the oil and gas sector are particularly vulnerable to corrosion. Most of the equipment used for oil and gas production also requires substantial capital investment, with each piece working together with the other parts to act as a system. Composites or traditional materials can be used for these diverse types of equipment at each production stage in an oil field.

Equipment used in oil and gas extraction includes: 

• Bearings
• Centrifuges
• Compressors
• Drill masts
• Fluid handling hoses
• Gauges and other metering equipment
• HVAC (heating, ventilation, and air conditioner) equipment and systems
• Industrial ball valves
• Pipes
• Pumps
• Seals
• Separators
• Stainless steel and other non-corrosive fittings
• Valve actuators
• Welding supplies

Controlling corrosion in oil and gas equipment involves considering both the environment in which it will be used and the materials from which it’s made. Material selection plays an important role in controlling corrosion, including from carbon dioxide, hydrogen sulfide, oxygen, salts, water, and other impurities within oil or gas. Additionally, oil and gas equipment designs must handle service fluids’ pH, high pressures, and temperatures.

Composites are well compared with many traditional materials used by the gas and oil sector when selecting the best material for an oil field. Often, cost restrictions play a role in material choice, while regulatory requirements and industry standards also need to be considered. The choice of material must consider environmental aspects, reliability during operation, risk of failure, worker safety, and various other parameters. Material choice can be especially limited for offshore and undersea operations, where replacement costs can be prohibitive.

Materials Traditionally Used in Oil Fields

Traditionally, carbon steel and stainless steel are the two most common metal alloys used for oil and gas extraction equipment. Both these materials handle extreme heat and resist corrosion well while offering high strength. Carbon steels all contain from .5 to 2.1 percent carbon, with copper, manganese, silicon, and other elements often added to alter the alloy’s properties. Carbon steel’s high strength makes it exceptionally wear-resistant, though it’s more predisposed to corrosion. However, This can be mitigated by adding chemicals to the alloy or coating components. Drill pipes, tubing, and wellheads are often made from carbon steel.

Stainless steels contain at least 10.5 percent chromium, which gives the alloy a passive layer that protects it from corrosion. Elemental metals like molybdenum or nickel are often added to augment corrosion resistance. Duplex stainless steel is the most stable price, as it uses proportionally less chrome and nickel, the market price for which varies considerably. Duplex steel offers considerable corrosion resistance while also featuring good strength qualities. Types of stainless steel are used for pumps, tubing, and valves, while the duplex variety is used for flow lines, risers, and underwater wellheads.

Other metals are also commonly used for certain equipment. For example, a nickel-steel alloy known as Inconel is commonly used for components for gas turbines, downhole tooling, and drilling equipment used on offshore oil or gas platforms. Additionally, titanium is used for undersea piping, heat exchangers, and wellhead components, while high-strength low-alloy (HSLA) steel is often included in oil or gas platforms and pipelines, along with the structural makeup of oil rigs.

Oil Field Composites 

Composites play an essential role in any modern oil field. As gas and oil companies seek to develop new fields in ever harsher environments, the equipment used there must withstand these more demanding conditions. These days, drilling rigs and platforms must endure the subfreezing temperatures of the Arctic, the dry heat of deserts, and the corrosive effects of saltwater on offshore platforms in the ocean. Oil field composites are used for everything from bearings to pistons, with properties developed to tolerate the most severe environments.

Composites play an integral role with properties perfect for the oil field, particularly in offshore oil and gas extraction. Composite plastics often better serve these applications than metal alloys traditionally employed in such places. Several types have already proven invaluable in the oil field. Composites like PTFE (polytetrafluoroethylene), polycarbonates, phenolics, PEEK (polyether ether ketone), and cast nylon (polyamide) have all become commonplace in the development and extraction of oil and gas deposits.

As an oil field composite, PTFE offers excellent chemical resistance and low friction coefficient and operates across a wide range of temperatures without losing its structural stability. This composite also insulates well against electricity, with excellent dielectric properties. Other fluoroplastics like FEP (fluorinated ethylene propylene) and PFA (fluorinated ethylene propylene) are also used in the oil field, composites that, along with PTFE, are among the most inert materials in the world. PTFE is used for bearings, bushings, downhole drilling equipment, gaskets, seals, thrust washers, and valve seats. Fluoroplastics generally protect sensors used for level detection and temperature controls.

Transparent and about a sixth of the weight of glass, polycarbonates are also hundreds of times more potent. Polycarbonates offer more transparency to visible light than glass, featuring excellent dielectric properties. Additionally, this composite prevents moisture absorption while having extraordinary toughness and impact resistance. Its ability to retard flames makes it useful for inclusion in safety walls, while the composite is commonly used for glazing larger equipment.

Phenolic composites comprise cotton, glass, or paper layers impregnated with synthetic resins. Extraordinarily hard and dense, these rigid composites weigh only about half that of aluminum. Resistant to abrasion, impact, and material fatigue, phenolic composites also have low friction coefficients. They can have insulating and other electrical characteristics, even at various temperatures and humidity. Resistant to corrosion, phenolic composites are used for ballistic protection, bushings, collars, gaskets, rings, spacers, thrust washers, and other purposes.

 With outstanding abrasion-resistant and dimensional stability properties and excellent strength, high-performance composites like PEEK work well in environments where oil or gas are extracted. This composite functions at high temperatures while resisting moisture, including saltwater and steam. PEEK retains physical properties at the high temperatures and pressures under which equipment must operate in an oil field. Composites like PEEK are typically used in downhole drilling machinery and valve seats.

In an oil field, composites like cast nylon can replace metal alloys like aluminum, brass, bronze, and even steel. This is due to cast nylon’s extraordinary durability, tensile strength and toughness. It’s chemical and heat resistance, cost-efficiency, lightweight, and low friction coefficient make it a precious material for an oil field. Composites containing cast nylon are often used for bearings, bushings, gaskets, seals, thrust washers, and valve seats.

Advantages of Oil Field Composites

Plastic composites can replace metal alloys and other traditional materials in an oil field. Composites offer considerably better corrosion resistance, exceptional impact resistance, and durability. Yet, oil field composites can provide more advantageous characteristics.

In an oil field, composites provide the following advantages: 

• Corrosion resistance: Able to withstand harsh saltwater environments and many kinds of chemicals, composites are often chosen for bearings, bushings, gland seals, and valves used for undersea applications where maintenance or replacement of parts can only be done with great difficulty.
• Cost-efficiency: With a notably long lifespan and relatively low cost, oil field composites decrease the need to replace parts as often; this means less downtime due to lower maintenance costs, which can save oil and gas companies significant amounts of money.
• Easily formed: Most composite plastics are easily moldable, making them ideal solutions for customized components. They can even replace older parts made from traditional metal alloys.
• Flame resistance: Oil field composites can be flame retardant while offering insulating characteristics.
• Friction coefficient: Many composites’ low friction coefficient properties, in conjunction with their high corrosion resistance, make them a good choice for pistons in oil fields and rigs. 
• Temperature resistance: Composites work well in both extremely hot and cold conditions, with certain polymer composites able to operate at temperatures from -320°F to 930°F (-196°C to 499°C).
• Weight: Traditional metal alloys used for gas and oil applications are heavier than polymers. Composites are often used for piping and bearings on oil rigs, as their lighter weight increases buoyancy and decreases the stress on a rig’s beam supports.

Composites like ABS (acrylonitrile butadiene styrene) plastic sheet, HDPE (high-density polyethylene), and UHMW (ultra-high-molecular-weight) polyethylene are often used for their corrosion-resistant properties.

Oil Field Composites from Spaulding

The performance of materials matters in an oil field. Composites are the future of the oil and gas industry, making operations more reliable, profitable, and quicker. At Spaulding Composites Inc. we understand the harsh conditions under which equipment used by the oil and gas industry must operate. With Spaulding’s extensive library of customizable composites, we can help businesses in the oil and gas industry design materials that will fit your application. To learn more about what we can do for you, contact one of the knowledgeable representatives at Spaulding Composites today.