Abnormality Detection for Drilling Processes Based on Jensen–Shannon Divergence and Adaptive Alarm Limits

Accurately and promptly detecting downhole abnormalities is of great importance to ensure safe and efficient operation of geological drilling systems. In view of the lack of abnormal data and the presence of multiple operating states, this article proposes a new abnormality detection method for geological drilling processes based on the Jensen-Shannon divergence and adaptive alarm limits. The major contributions are twofold: 1) a novel framework is proposed to detect downhole abnormalities by identifying normal operating conditions first and then establishing the normal operating zones; 2) an adaptive alarm limit design method is proposed to determine the normal operating zones by modeling the relation between the distribution feature and the variational trend feature based on the boundary points. The effectiveness and practicability of the proposed method are demonstrated by an industrial case study. The results demonstrate that the proposed method has superior performance to other methods in downhole abnormality detection.