US Patent 11187714 Processing downhole rotational data

Systems and methods for processing downhole rotational data. An example method includes commencing operation of a processing device to continually calculate a downhole oscillation index by receiving downhole rotational speed data indicative of downhole rotational speed of at least a portion of a drill string during drilling operations, calculating a fundamental oscillation time period of the drill string, calculating a time length of a time window based on the fundamental oscillation time period, and processing the downhole rotational speed data encompassed within the time window.