超声波多普勒隔水管气侵监测系统设计与海上测试

为了研究超声波多普勒隔水管气侵监测测量原理的正确性和海上应用的可行性，开展了室内实验和现场试验。通过室内实验，得到了油基钻井液在不同含气情况下超声波多普勒信号与含气率之间的关系，验证了利用多普勒信号畸变进行气侵识别的有效性和适用性；通过开展陆上井现场试验，确定了隔水管气侵监测系统设计的关键参数，验证了超声波多普勒设备对大壁厚环空内部流动监测的可行性；设计并加工了隔水管气侵监测系统样机。通过在海上钻井过程中的实际应用，测试了监测系统的稳定性，得到了隔水管内部流动状态的监测信号，验证了隔水管气侵监测系统在海上现场应用的可行性。

Design and offshore tests of monitoring system on gas cut of riser based on ultrasonic Doppler

To study the correctness of measurement principles and the feasibility of offshore application for monitoring the gas cut of riser based on ultrasonic Doppler, the laboratory experiments and field tests were carried out. The relationship between the ultrasonic Doppler signals and gas fraction under different gas contents of oil-based drilling fluid were obtained through the laboratory experiments, which verified the effectiveness and applicability of carrying out the gas cut identification by using the Doppler signals distortion. The key design parameters of the monitoring system on gas cut of riser were determined through the field tests of onshore wells, which verified the feasibility of monitoring the internal flow within the annulus with large wall thickness by using the ultrasonic Doppler equipment. A prototype of monitoring system on gas cut of riser was designed and developed. Through the practical application in the offshore drilling process, the stability of the monitoring system was tested, and the monitoring signals of internal flow status in the rise were obtained, then the feasibility of the monitoring system on gas cut of riser in offshore field application was verified.