Development and testing of kick detection system at mud line in deepwater drilling

Well control issues have posed significant challenges to deep water drilling construction. The success of early kick detection is an essential part of safe well control operations. Due to the characteristics of unresponsive prediction and low precision, conventional kick detection methods cannot meet the demands of deep water well control. This article proposed a more advanced kick monitoring method, which functions by adopting an ultrasonic device to monitor the annular flow velocity. Based on the Doppler principle, an early kick detection (EKD) prototype was successfully developed, which enables the annular flow velocity of the drilling fluid to be measured. Bearing-pressure experiments of 15 MPa were performed to verify the reliability of the ultrasonic sensor under mud line. The results of lab testing demonstrate that the EKD prototype can be used to measure stable annular flow velocities when the gas injection rate is less than 10%. The EKD prototype presented in this paper is valuable for timely kick detection in deep water drilling.