Cost-Effective Corrosion Detection Sensor for Above-Ground Oil and Gas Flowlines

Area of Science:

• Materials Science
• Sensor Technology
• Corrosion Engineering

Background:

• External corrosion poses a significant threat to the integrity of aboveground oil and gas pipelines (flowlines).
• Current monitoring methods may be insufficient for small-diameter pipelines, necessitating innovative solutions.
• Early detection of corrosion is crucial for preventing failures and ensuring operational safety.

Purpose of the Study:

• To propose and develop a novel fiber-optic strain sensor for monitoring the external corrosion of small-diameter aboveground oil and gas pipelines.
• To design a cost-effective and easily deployable sensor system.
• To establish analytical methods for sensor design and performance prediction.

Main Methods:

• Development of a sensor concept based on fiber-optic strain sensing.
• Utilization of a pre-stressed sacrificial structure made from pipeline material.
• Monitoring strain changes in the sacrificial structure due to corrosion-induced deterioration.
• Derivation of analytical equations for sensor design.
• Verification of analysis using finite element analysis (FEA) software.

Main Results:

• Successful development of analytical equations for designing the sensor structure to achieve desired strain values.
• FEA verification confirmed the analytical model's accuracy.
• The proposed sensor is simple, cost-effective, and manufacturable.
• Deployment on existing pipelines requires no structural modifications.

Conclusions:

• The developed fiber-optic strain sensor offers a practical solution for monitoring external corrosion in oil and gas flowlines.
• While not providing continuous corrosion rate, it effectively measures the average corrosion rate over the sacrificial structure's lifespan.
• The sensor's simplicity and cost-effectiveness make it suitable for widespread application in pipeline integrity management.