
High-Temperature Oil Well Fiber Optic Sensing Cable
Steel-tube and armored optical cable constructions for downhole temperature monitoring, with reference designs for service temperatures up to 150°C or 300°C.
The cable protects sensing fiber against heat, pressure, moisture, corrosion and mechanical loading. It is designed for heavy-oil wells, distributed temperature sensing and other harsh downhole monitoring environments.
Product Features
- Reference constructions for service up to 150°C or 300°C
- Seamless stainless-steel tube protects the optical sensing fiber
- Steel-wire-armored and multilayer-tube construction options
- High-temperature single-mode or multimode fiber options
- Reference high-temperature design rated above 60 MPa
- Configurations reviewed for well depth, pressure, chemistry and DTS compatibility
Cable Structure


Product Specification
| Parameter | High-temperature multilayer tube | Compact steel-wire armored |
|---|---|---|
| Reference model | GTKK-nXn | GTK-nXn |
| Reference outside diameter | 6.35 ± 0.10 mm | 2.9 ± 0.1 mm* |
| Reference weight | 170 kg/km | 29 kg/km |
| Fiber options | High-temperature single-mode or multimode | High-temperature single-mode or multimode |
| Tensile strength, short/long term | 9000 / 4500 N | 1500 / 1000 N |
| Crush resistance, short/long term | 9000 / 4500 N per 100 mm | 4000 / 3000 N per 100 mm |
| Pressure resistance | >60 MPa | Project dependent |
| Minimum bend radius | 190 cm | 15D / 20D |
| Operating temperature | −40°C to +300°C | −60°C to +150°C |
*Compact-cable diameter depends on fiber count. “n” represents the number of fiber cores and “Xn” the selected fiber type. Values are reference specifications; final performance must be confirmed for the requested configuration.
Optical Characteristics
| Construction | Fiber | Reference attenuation |
|---|---|---|
| Multilayer tube | Configured high-temperature fiber | ≤3.5 / 1.5 dB/km at 850 / 1300 nm |
| Compact armored | Single-mode | ≤1.5 / 1.5 dB/km at 1310 / 1550 nm |
| Compact armored | Multimode | ≤4.0 / 2.0 dB/km at 850 / 1300 nm |
Applications
Heavy-Oil Well Monitoring
Temperature profiling in thermally demanding production environments.
Distributed Temperature Sensing
Protected optical fiber for compatible downhole DTS interrogators.
Geothermal & Industrial Wells
High-temperature optical sensing where steel protection is required.
Frequently Asked Questions
What temperature ranges are available?
Reference constructions cover −60°C to +150°C and −40°C to +300°C. Final selection depends on continuous temperature, peak exposure, pressure and chemical conditions.
Can the cable be used with distributed temperature sensing systems?
It can be configured for compatible DTS systems when fiber type, wavelength, backscatter performance, termination and interrogator compatibility are confirmed.
What is the difference between the 150°C and 300°C designs?
The 150°C design uses seamless steel tubing with external steel-wire armor. The 300°C design uses multiple seamless protective layers and a larger diameter for higher-temperature service.
What information is required for a quotation?
Provide well depth, continuous and peak temperature, pressure, chemical exposure, fiber type and count, length, mechanical loads, termination, documentation and delivery destination.
Specify Your Downhole Sensing Cable
Send the well environment, temperature, pressure, fiber and termination requirements for engineering review and a project-specific quotation.
