Distributed Fiber Optic Sensing for Real-Time Monitoring of Gas in Riser during Offshore Drilling

Area of Science:

• Petroleum Engineering
• Well Control Technology
• Sensing and Monitoring Systems

Background:

• Effective well control relies on understanding wellbore dynamics and influx prediction.
• Offshore gas influx detection is challenging due to limited full-scale validated datasets.
• Existing kick detection methods often fail to reliably detect gas influx at the source.

Purpose of the Study:

• To address the lack of validated datasets for gas kick migration in full-scale offshore annular conditions.
• To pioneer the application of fiber optic sensing for real-time monitoring of gas in marine risers.
• To validate a novel sensing paradigm through well-scale experiments.

Main Methods:

• Conducted well-scale experiments at the PERTT facility, simulating offshore marine riser environments.
• Instrumented the experimental setup with distributed fiber optic sensors and pressure/temperature gauges.
• Performed two-phase flow experiments to study dynamic gas migration under full-scale annular conditions.

Main Results:

• Demonstrated the feasibility of using fiber optic sensing for monitoring gas in risers.
• Provided a physical model for studying dynamic gas migration in full-scale annular conditions.
• Generated critical insights into two-phase flow dynamics in offshore drilling risers.

Conclusions:

• Distributed fiber optic sensing offers a significant improvement over conventional kick detection methods.
• The study provides real-time, distributed downhole data for accurate and reliable gas influx monitoring.
• Results indicate the migration speed of gas in marine risers, highlighting the need for further investigation for enhanced well control.