Distributed Temperature Sensing (DTS) using optical fiber technology enables real-time, long-distance monitoring of pipeline temperature and integrity, crucial for leak detection and operational safety.

Overview of DTS Technology

Distributed Temperature Sensing (DTS) systems transform standard fiber optic cables into continuous temperature sensors along the pipeline. A laser pulse is sent through the fiber, and the backscattered light is analyzed to determine temperature at each point along the cable. This method relies on Raman or Brillouin optical scattering and uses Optical Time Domain Reflectometry (OTDR) or Optical Frequency Domain Reflectometry (OFDR) to localize temperature readings with high spatial resolution, often down to one meter .

Applications in Pipeline Monitoring

For Croatian pipelines, DTS technology can provide:

• Leak detection: Sudden temperature changes along the pipeline can indicate leaks or ruptures .
• Operational monitoring: Continuous temperature profiling ensures pipelines operate within safe thermal limits .
• Hazard detection: DTS can detect hot spots caused by friction, blockages, or external environmental factors such as landslides or construction activity .
• Long-distance coverage: Modern DTS systems can monitor up to 60 km from a single instrument and extend to 300 km using optical amplifiers, making them suitable for extensive pipeline networks .

Advanced Features

• Enhanced DTS (eDTS) combines temperature and acoustic sensing, allowing detection of both thermal anomalies and vibrations, which improves leak detection and structural monitoring .
• Distributed Acoustic Sensing (DAS) integrated with DTS can detect small temperature changes and acoustic events in real time, enhancing pipeline safety .
• High-resolution data acquisition: Interrogators sample backscattered light at high speeds (1–10 GSPS), enabling precise localization of temperature variations along the fiber .

Implementation Considerations

• Cable design: Specialized sensing cables are often required for extreme temperatures or strain monitoring, as standard telecom fibers may not withstand harsh pipeline conditions .
• Remote monitoring: Reading units can be placed remotely, and loop or single-end configurations allow flexible deployment along the pipeline .
• Integration with monitoring platforms: Systems like ONMSi or portable DTS units allow permanent or temporary monitoring, providing both temperature and fiber integrity data .

Benefits for Croatian Pipelines

• Real-time monitoring reduces response time to leaks or overheating.
• Preventive maintenance lowers operational costs by identifying issues before failures occur.
• Extended pipeline lifespan through continuous thermal management.
• Environmental protection by early detection of leaks, minimizing ecological impact. In summary, optical fiber-based DTS and DFOS technologies offer a robust, scalable, and precise solution for monitoring Croatian pipelines, combining long-distance coverage, high spatial resolution, and integration with acoustic sensing to ensure operational safety and efficiency .