Design of a real-time gas-kick monitoring and early-warning system for deep-water drilling

During deep-water oil and gas exploration, gas kicks can easily evolve into major safety accidents such as blowouts. Therefore, timely online monitoring and accurate early-warning identification of gas kick conditions are critical to ensuring operational safety. Safety Engineering Informatization is a course that cultivates students’ safety supervision awareness and engineering practice capabilities. The course currently uses theoretical lectures and case analyses to explain deep-water drilling gas kick monitoring without practical training support. Consequently, students often struggle to systematically master the core skills required for gas kick monitoring, including sensor signal acquisition, data transmission link establishment, and debugging of signal-processing and gas-kick identification algorithms. To address these teaching shortcomings and improve practical training quality, this study proposes the development of a teaching and experimental system for real-time gas kick monitoring and early warning in deep-water drilling based on the ultrasonic Doppler effect, thereby providing an integrated training platform that is demonstrable, reproducible, and scalable for teaching purposes.

The system adopts a modular design and consists of independent units, including ultrasonic Doppler sensors, an integrated temperature–pressure sensor, a monitoring instrument, and host computer teaching software. Each unit has clearly defined functions and can be easily disassembled for instructional demonstration. After acquiring and decoding multisource sensor data, the monitoring instrument transmits the data to the upper computer stably via the RS-485 communication protocol. The upper-computer teaching software enables real-time display and dynamic updating of key parameters such as frequency shift, temperature, and pressure. In addition, the software incorporates a gas-kick identification and early-warning algorithm, enabling rapid discrimination and alarm prompting of gas-kick events. It also supports data storage, historical review, and experimental process replay.

Using the deep-water drilling gas-kick simulation experimental setup as the test platform, representative operating conditions with a liquid-phase flow rate of 120 m³/h and a maximum injected gas content of 5% were selected to evaluate monitoring system performance. The system achieves continuous and stable online acquisition and real-time visualization of key parameters, including frequency shift, temperature, and pressure. Meanwhile, during the gas injection stage, the frequency-shift signal exhibits clear and highly repeatable abnormal responses. The built-in gas-kick identification algorithm can suppress alarm triggering when the frequency-shift signal first exceeds the warning threshold and the threshold crossing is determined to be a transient fluctuation induced by pump start-up; however, when the frequency-shift signal continues to exceed the threshold in the absence of manual pump on/off commands, the algorithm can rapidly identify a gas kick and trigger an alarm, without generating redundant alarms after pump shut-down.

Based on the ultrasonic Doppler effect, this research developed a teaching and experimental system for accurate real-time gas-kick monitoring and early warning. Its modular architecture not only improves scalability and maintainability but also facilitates students’ component cognition, principle exploration, and secondary development practices. This system fills the experimental gap in relevant teaching activities and provides students with a full-process hands-on training platform covering sensor application, data transmission, and algorithm verification, demonstrating clear value for experimental teaching as well as potential for further translation into field-deployable equipment development.