OCTG Tubing
- OCTG tubing is a small-diameter steel pipe inserted inside the casing string through which reservoir fluids (oil, gas, and water) are produced to the surface. It is also used for injection of water, gas, or chemicals into the formation for enhanced recovery. Tubing is manufactured by seamless or ERW processes, with diameters ranging from 1.900" to 4½" (48.3 mm – 114.3 mm). It is typically supplied in lengths of approximately 30 feet with threaded connections. Unlike casing, tubing is subject to repeated tension, pressure cycling, and corrosive fluids, requiring higher mechanical strength and corrosion resistance.
Certified:
OCTG tubing pipes are manufactured in full compliance with API 5CT (11th Edition) , equivalent to ISO 11960. Products are available with EN 10204 Type 3.1/3.2 mill test certificates and bear the API Monogram. Premium connections can be supplied to API 5B or customer-specific proprietary specifications. Additional certifications include ISO 9001, ISO 14001, and ISO 45001.
Application:
OCTG tubing is the production conduit of an oil or gas well, serving as the primary flow path for reservoir fluids reaching the surface. It also facilitates injection operations for secondary and tertiary recovery.
Production Conduit – Tubing conveys hydrocarbons from the reservoir to the wellhead and surface facilities. Its smaller diameter optimises flow velocity, minimises pressure drop, and prevents paraffin or hydrate deposition.
Injection Operations – Tubing is used for water flooding, gas lift, steam injection, and chemical injection to enhance recovery rates and maintain reservoir pressure.
Well Intervention – Tubing provides access for wireline, coiled tubing, and slickline operations for well logging, perforating, and downhole maintenance, enabling efficient well management and production optimisation.
Grade Selection by Well Conditions – Selection depends on well depth and service environment. J55 is used for shallow, low-pressure wells; N80 for medium-depth wells; L80 with variants (L80-1, L80-9Cr, L80-13Cr) for sour service and mildly corrosive CO₂ environments; P110 for deep, high-pressure, high-temperature wells; and C90/T95 for extreme sour service with high-strength requirements.
Corrosion-Resistant Alloys (CRAs) – For highly corrosive environments (high CO₂ / H₂S / chlorides), 13Cr, Super 13Cr, 22Cr, 25Cr duplex, and nickel-based alloys are available.
Onshore & Offshore – Tubing is used across all well types, including vertical, deviated, horizontal, and deepwater wells, often paired with premium gas-tight connections for critical high-pressure and high-temperature applications.
Specification:
| API 5CT OCTG Tubing Technical Specification | ||
| Parameter | Specification / Range | Description |
| Outer Diameter (OD) | 1.050" to 4-1/2" (26.7 mm to 114.3 mm) | Standard smaller diameter sizes designed to transport oil or gas to the surface inside the casing. |
| Wall Thickness & Weight | Linear Weight:1.14 lbft to 18.10 lbft | Thickel walls relative to diameter compared to casing, accommodating high fluid flowing velocities and pressures. |
| Wall Thickness:3.18 mm to 9.52 mm | ||
| Length Range | • Range 1:20.0 ft - 24.0 ft (6.10 m - 7.32 m) | Range 2 is the industrial standard choice for seamless completion operations. |
| • Range 2:28.0 ft - 32.0 ft (6.53 m - 9.75 m) | ||
| • Range 3:38.0 ft - 45.0 ft (11.58 m - 13.72 m) | ||
| Steel Grades | • Standard:JSS, N80-1, N80-Q (General flowing wells) | Specified by API SCT:L60 (including L60-9Cr and L60-13Cr) is highly common for CO2 corrosion resistance. |
| • Slow Service:LSP, CBD, T90 (Conservative H2S environments) | ||
| • High Strength:P110 (Deep wells / High pressure) | ||
| Manufacturing Process | Seamless (SMLS)-Mandel Mill or Plug Mill | Seamless is mandatory for almost all production tubing applications to eliminate weld seam fatigue from high velocity fluid flow. |
| Connection Types | • NUE (Non-Upset End - 10 round threads) | EUE thicknesses the wall at the end to reinforce thread strength. Premium threads are critical for gas wells and high-derivation profiles. |
| • EUE (External Upset End - 6 round threads) | ||
| • Premium Connections (Metal-to-metal gas rights seals) | ||
| Product Specification Level | PSL1, PSL2, PSL3 | Strict quality tier system managing chemical trace elements;structure homogeneity, and mechanical testing strictness. |
| Essential Verification Tests | • Hydrotic Testing (mandatory full-body pressure check) | Ensures zero defects along the pipe body to withstand continuous long-term friction, pressure differentials, and sour gases. |
| • Electromagnetic Inspection (EMI) / Eddy Current) | ||
| • Strengthiness and Diff. Testing (using tool clearance density) | ||
| • Ultrasonic Testing (UT) & Coupling Inscopes | ||
Standard:
| Category | Standard / Thread Type | Description | Application |
| API Standard | API 5CT | Specification for Casing and Tubing | Oil & Gas Wells |
| API Standard | API 5B | Threading, Gauging and Thread Inspection of Casing, Tubing and Line Pipe Threads | Oil & Gas Industry |
| API Thread | NU (Non-Upset) | API standard tubing connection with non-upset ends | General Oil & Gas Wells |
| API Thread | EU (External Upset) | API standard tubing connection with externally upset ends | Oil & Gas Production |
| API Thread | IJ (Integral Joint) | Integral joint connection, suitable for applications requiring a compact connection | Oil & Gas Wells |
| Special Thread | Premium Connection | High-performance connection designed for enhanced sealing and mechanical performance | High-Pressure & High-Temperature Wells |
| Special Thread | Gas-Tight Premium Connection | Special connection providing improved gas-tight sealing performance | Sour Gas & High-Pressure Wells |
| Special Thread | Metal-to-Metal Seal Connection | Premium connection featuring metal-to-metal sealing for improved pressure integrity | High-Pressure & High-Temperature Applications |
| Special Thread | High-Torque Connection | Special connection designed for higher torque capacity and improved resistance to connection failure | Deep & Challenging Wells |
Process:
Packing:
