Non-metallic pipes—such as glass-reinforced epoxy (GRE), reinforced thermoplastic pipes (RTP) and other composites—are gaining traction across upstream flowlines, water injection and gathering networks. They promise reduced corrosion risk, lower maintenance and, in some configurations, lower lifecycle greenhouse gas (GHG) footprints compared to traditional carbon steel. At Energy Solutions, we examine where non-metallic solutions are technically mature and economically compelling, and how they fit into broader O&G decarbonization strategies.
Non-metallic pipes for oil and gas applications are typically composites made from a polymer matrix (such as epoxy or polyethylene) reinforced with fibres (such as glass or aramid) or other structures. Key types include:
These products are not plug-and-play replacements for steel in every application, but in suitable envelopes they can significantly reduce corrosion risk and maintenance.
Non-metallic pipes behave differently from steel across temperature, pressure, load and chemical exposure. Design envelopes are typically constrained by:
| Pipe Type | Typical Diameter Range | Pressure Range (bar) | Temperature Range (°C) |
|---|---|---|---|
| GRE Piping | 2"–24" | 20–100 | 0–120 |
| RTP Flowlines | 2"–8" | 50–150 | -20–90 |
| Spoolable Composite Pipe | 2"–6" | 40–120 | -20–80 |
Values are indicative; specific products may differ. Design must follow relevant international and vendor standards.
The chart below shows a stylised index (0–100) for corrosion and maintenance risk for steel vs non-metallic pipe in suitable applications.
The business case for non-metallic pipes hinges on balancing higher material CAPEX against lower lifecycle OPEX and reduced failure risk.
| Metric | Carbon Steel | Non-Metallic (GRE/RTP) | Comment |
|---|---|---|---|
| Installed CAPEX (USD/m) | 150–250 | 170–320 | Non-metallic typically 10–30% higher |
| Corrosion Management (USD/m-year) | 3–8 | 0.5–2 | Inspection, inhibitors, repairs |
| Indicative Design Life (years) | 20–25 | 25–30 | Assuming proper design and installation |
In remote or offshore settings where maintenance costs and leak impacts are high, these OPEX differences can outweigh CAPEX premiums over the asset life.
The bar chart below compares stylised lifecycle costs (CAPEX + OPEX) for steel vs non-metallic flowlines in a corrosion-prone environment.
Steel production is CO₂-intensive, but steel is also highly recyclable. Non-metallic pipes have higher embodied energy per kilogram of material, yet they can reduce lifecycle GHG through:
| Category | Carbon Steel (kgCO₂e/m) | Non-Metallic (kgCO₂e/m) | Notes |
|---|---|---|---|
| Embodied Material | 90–140 | 70–130 | Varies strongly with product and recycling assumptions |
| Maintenance & Replacements | 40–80 | 15–40 | Truck movements, new pipe, pigging, inhibitors |
| Leak-Related Emissions | 10–30 | 5–15 | Depends on service and environment |
Overall, non-metallic options can reduce lifecycle GHG by roughly 10–25% relative to conventional steel in many eligible applications, though this is highly context-dependent.
The chart below shows a stylised index (Steel = 100) of relative lifecycle GHG impact per meter.
An onshore operator in a mature field with high CO₂ and chloride content faces recurring corrosion failures on 6" steel flowlines.
Over 20+ years, lifecycle cost modelling indicates net savings of 10–20% compared to continued steel replacements, with reduced unplanned downtime and improved HSE performance.
An offshore facility upgrades part of its produced water and seawater injection network from steel to GRE piping.
The case illustrates how non-metallic systems can be justified on safety and logistics grounds even when pure financial payback is moderate.
Successfully deploying non-metallic pipes requires attention to details that differ from steel:
Despite clear advantages in some contexts, non-metallic pipes are not a universal solution.
Non-metallic adoption should therefore be targeted and evidence-based, informed by pilot projects and conservative design margins.
As methane and leak performance becomes a central KPI for upstream portfolios, low-leak infrastructure will be increasingly valued. Non-metallic pipes can play a meaningful role in this transition by:
For pipeline and integrity teams, a structured screening framework might include:
No. Suitability depends on temperature, pressure, fluid composition and mechanical loads. Non-metallic pipes are most common in produced water, low-to-medium pressure flowlines and some hydrocarbon services, but are not yet a full substitute for steel in HP/HT or very aggressive environments.
While non-metallic pipes reduce corrosion-driven leaks, they still require leak detection and monitoring. Methods may differ from steel (e.g. reliance on external sensors and pressure monitoring rather than inline inspection tools), so leak detection strategies must be adapted accordingly.
Key barriers include conservative design cultures, limited familiarity among engineering teams, variation in standards and codes, and perceived uncertainties over very long-term performance in harsh environments. Vendor diversity and supply chain capacity can also influence adoption pace.
Interface points require carefully designed transition pieces, flanges or couplings. Mechanical loads, differential thermal expansion and potential galvanic effects must be considered. Good practice is to minimise the number of transitions and standardise details across projects.
Payback depends on corrosion severity, maintenance costs and downtime impacts. In highly corrosive or inaccessible segments, paybacks of 5–10 years are common for major retrofits, with significant risk reduction benefits that may not be fully captured in simple payback calculations.
By reducing leak and failure rates and lowering maintenance needs, non-metallic pipes can contribute to lower Scope 1 emissions and improved environmental performance. They also support resilience and reliability goals, which are increasingly relevant for ESG-focused investors and regulators.
Recycling pathways for composite and polymer pipes are still developing. Mechanical recycling and energy recovery options exist, but circularity is generally lower than for steel. This is a factor to consider in lifecycle assessments and long-term sustainability strategies.
Operators should follow relevant international and national standards (e.g. ISO, API, DNV) alongside vendor specifications. Given the rapid evolution of this field, staying current with the latest editions and industry recommended practices is essential.