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GRE Downhole Tubing and Casing

Glass Reinforced Epoxy (GRE) downhole tubing and casing are filament-wound composite pipes designed for oil, gas and geothermal well applications. These non-metallic tubulars blend high-strength glass fibers with epoxy resin to provide a lightweight, corrosion-resistant alternative to steel well casing. GRE tubing and casing meet industry standards (e.g. API Q1, ISO 14692) and are rated for high pressures and elevated temperatures, making them ideal for sour-gas wells, injection wells and deep monitoring wells. Standard joint lengths (typically 30 ft/9.1 m) are connected via threaded or adhesive-bonded couplings, and sizes range from around 1½″ to 9⅝″ (40–250 mm) with pressure ratings up to ~3500 psi.

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Key Features

High-tensile filament-wound construction (epoxy resin with high-strength glass fiber) for superior strength-to-weight.
Corrosion and chemical resistance in saltwater, H₂S/CO₂ environments and acidic fluids – GRE does not rust or pit.
Lightweight design enables easier handling and installation versus heavy steel tubing.
Range of sizes (1½″–9⅝″) and pressure classes (up to ~3500 psi) for various well conditions.
Compliance with ISO 14692 and API specifications ensures quality and safety.
Premium threaded connections (e.g. 4 TPI “Downhole” threads) or butt-and-wrap adhesive joints for leak-tight service.
High-temperature epoxy curing (up to ~212°F/100°C) for sustained performance.

Benefits

Long service life in corrosive wells – GRE can significantly outlast steel in aggressive downhole fluids.
Reduced downtime and maintenance: rusting and scaling are minimized, lowering intervention frequency.
Improved safety: non-conductive pipe prevents galvanic corrosion and interference with downhole sensors.
Cost-effective: lighter pipe saves on rig-up labor and reduces shipping costs, yielding lower total cost of ownership.
Eliminates need for corrosion inhibitors or exotic alloys in many well environments.

Applications

Oil & Gas Wells: Production tubing and casing in wells with CO₂, H₂S or high salinity.
Injection and Disposal Wells: Saltwater and chemical injection wells where steel would corrode.
Geothermal Wells: Handling hot brines in geothermal energy drilling.
Monitoring Wells: Observation wells requiring non-conductive, chemical-resistant materials (avoiding interference with sensors).
Water Supply / Irrigation: Potable or irrigation wells with highly abrasive or corrosive water.

Technical Specifications (Typical)

Material: Filament-wound glass-fiber reinforced epoxy (GRE)
Diameter (Nominal): Ranges from 1½″ to 9⅝″ (40 mm to 250 mm)
Pressure Rating: Up to approximately 3500 psi (24.1 MPa)
Maximum Temperature: Up to 212°F (100°C)
Joint Length: Nominal length of 30 ft (9.1 m)
Connection Types: Threaded (e.g. 4 TPI DH), Tapered adhesive, ANSI flanges
Applicable Standards: ISO 14692, API Q1

Unique Selling Points (USPs)

Proprietary Layering: Advanced filament-winding sequences yield higher tensile strength and collapse resistance than competitive GRE designs.
Extensive Track Record: Proven usage since the 1990s in major oilfields (e.g. Chevron Australia, Olympic Dam) with ongoing support and service.
Custom Engineering: Our in-house well-simulation program (STARWell) helps select and tailor tubing designs for specific well conditions.
Onsite Support: Comprehensive make-up tools and handling equipment are available, with field service to ensure correct installation and joint integrity.
Comprehensive Compliance: Meets stringent offshore and onshore standards for safety and quality (e.g. API, ISO) to ensure reliability in demanding well operations.