Detailed analysis of downhole weight-on-bit, torque, bending moment and vibration signals measured between bit and hole opener have provided clear insight into the dynamic response of hole opening BHAs in interbedded formations. Based on transmitted real-time information from an advanced downhole multi-sensor data acquisition and processing system, application-specific drilling procedures and guidelines have been developed to avoid or to identify and overcome critical dynamic situations downhole. Applying the new procedures, several hole sections in the GOM were drilled for the first time in one run from casing shoe to casing shoe. Here previous attempts had resulted in failures of the drilling equipment or even in twist-offs. The paper starts with a list of observations made with the downhole multi-sensor tool placed between bit and hole opening device. Log examples with downhole and surface drilling data demonstrate the dynamic response of hole opening BHAs. For the first time, the paper presents downhole measurements showing the changes in weight on bit versus weight on reamer when drilling interbedded formations. Again, log examples are used to document the effect of the drilling procedures that were applied to successfully resolve critical downhole situations. The paper concludes with a summary of the lessons learned in planning and executing hole opening applications with shoe to shoe performance.
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