Development and Utilization of a Bit-Based Data-Acquisition System in Hard-Rock PDC Applications

Abstract

Abstract Drill bits are iteratively developed for specific applications to meet performance objectives such as aggressiveness, durability, stability, steerability, etc. The transition from one iteration to the next occurs when dull bits are examined, run data is analyzed and the inferences are implemented as revisions to the bit design and/or the operating parameters. Experience has shown that the efficiency of the process depends strongly upon the appropriateness and significance of the data collected. If, for example, a dominant cutter failure mechanism is incorrectly characterized as abrasive wear and is, in fact, impact wear, then the proposed solution and the development time will both be significantly affected. One method for improving the significance of the data collected is to implement a special-purpose data-acquisition system within the bit. Such a device has at least three significant advantages over available sub-based data-acquisition systems: (1) its bit-based sensors will more accurately detect bit-based events, (2) it can be economically deployed over many bits and (3) it is relatively transparent to the user. The paper describes an effort to develop, validate, and utilize a bit-based module designed to monitor accelerometer and magnetometer sensors and to record selected data. The authors also describe the effort to infer dynamic dysfunction(s) from the data in the fast-growing hard rock PDC bit application and to mitigate them via modifications to drilling parameters and bit designs.