Experimental Visualization of Downhole Drilling Vibration Using Industrial Drilling Dynamic Recorder

Abstract

Abstract Housing miniature sensors within bottomhole assemblies (BHA) have proven to provide crucial real-time and valuable post-well analysis for drilling dynamics optimization and vibration mitigation. The downhole dynamic behavior of the BHA is often misinterpreted and requires special data preprocessing for effective optimization. The objective of this work is to establish an understanding and standardization of downhole vibration data analysis using a scaled laboratory BHA equipped with a high frequency industrial drilling dynamic (DD) field sensor and trajectory mapping station. A novel downscaled test assembly adhering to the geometric and material property relations of a field-size BHA section was designed and manufactured to investigate the nature of lateral vibrations. Axial excitation, i.e., weight on bit (WOB) fluctuation, and rotation were induced respectively using an electromagnetic shaker and an electric motor. A downhole drilling dynamic recorder was housed near the bit-end. BHA trajectory was mapped using inductive displacement sensors at multiple locations, along its length, to test the capability and accuracy of the DD field recorder. The wellbore structure was built with transparent material for direct visual correlation between the BHA movement and the drilling dynamic recorder. The results from this experiment provide precise and insightful visual information for the BHA movement correlation with the dynamic data acquired from a continuous high-frequency downhole field sensor. Real-time induced axial WOB fluctuation was recorded using a high-frequency drilling dynamic recorder and the induced axial force was distinctly addressed with the level of magnitude and frequency. The BHA vibration behavior of high-frequency accelerations, critical lateral vibration phenomena such as whirling motion, angular velocity (RPM) responses, and vibration behavior shift at the harmonic frequencies were characterized in relation to both the nature of induced forces at the bit and the acquired downhole field sensor data. The novel experiment establishes both quantitative and qualitative relations between DD data and physical vibration behavior during drilling. The experimental results showed the benefit of drilling dynamic recorders and it is accurate in predicting severe lateral vibrations while for the first time providing visual representation to aid in vibration data interpretation.