基于超声多普勒的钻井井筒气侵监测实验研究OA

During oil drilling,high-pressure gas zones easily lead to gas invasion,which can cause severe accidents such as blowouts.Early detection of gas invasion is crucial for well control safety.This paper proposes a method for monitoring gas invasion at the riser wellbore using continuous ultrasonic Doppler,which features short response time and low monitoring cost.A simulated experimental platform for wellbore gas invasion monitoring is designed accordingly,and experimental studies on the propagation characteristics of continuous ultrasonic Doppler signals in gas-water and gas-drilling fluid two-phase flows are conducted.By varying pipe diameter,gas flow rate,liquid medium,and monitoring position,time-domain and frequency-domain analyses are performed on the acquired ultrasonic Doppler frequency shift signals.The results show that based on the variation law of ultrasonic Doppler signals,the gas flow rate in the pipeline and the corresponding flow pattern can be measured;real-time monitoring of gas invasion is achieved by comparing with the threshold for gas invasion detection,providing effective technical support for the early detection of wellbore gas invasion.