Frequency analysis of time-series vibrational data

Abstract

Method and systems are described that obtain or collect time-series vibration data related to operation of a downhole drilling system and convert the time-series vibration data to frequency domain vibration data. The frequency domain vibration data can be evaluated to determine one or more vibrational resonance frequencies as well as corresponding non-aliased harmonic frequencies (if and when present) and aliased harmonic frequencies (if and when present) in the frequency domain vibration data. Change in the one or more vibrational resonance frequencies in the frequency domain vibration data over time can be monitored during the drilling operations to detect or predict the occurrence of a defect or failure or other unwanted conditions (e.g. HFTO) in the drilling system. A health alert can be generated in response to the detection or prediction of the occurrence of a defect or failure or other unwanted condition in the drilling system.