Abstract
A new downhole torsional vibration sensor built into a rotary steerable system has provided a new monitoring system for improving drilling efficiency and avoiding downhole failures related to torsional vibration. The strength of the new sensor is that it measures rotational changes right at the bit as compared to the usual 50-100 feet behind the bit with conventional MWD/LWD sensors. In addition, the sensor is always at the same location regardless of BHA configuration, which provides a higher level of consistency in torsional vibration measurement. The ability to evaluate bit performance objectively has consequently resulted in better bit design and rotary steerable tool performance.
The new torsional efficiency monitor has been used in areas where torsional vibration was recognized as a problem. This paper will discuss the application of the real-time downhole monitor and the results from detailed analysis of the data from the initial field runs in these harsh environments. The ability to immediately detect the occurrence of torsional vibration and to take corrective action before failures occur has significantly improved the ability of the rotary steerable system to survive harsh conditions.
