Patent ID: 6700115
Filing Date: 2004-03-02
Classification: G01V

Abstract:
A method for determining tool standoff relative to a standoff threshold using the responses of first and second gamma radiation detectors axially spaced within the tool, the method comprising:(a) measuring a first response in a single energy window of said first detector; (b) measuring a second response in a low energy window of said second detector; (c) measuring a third response in a high energy window of said second detector; (d) computing a first apparent density from said first response and a second apparent density from said second response and a third apparent density from said third response; (e) computing a first density difference by combining said first apparent density and said second apparent density, and computing a second density difference by combining said first apparent density and said third apparent density; and (f) combining said first density difference and said second density difference with a predetermined quality indicator to determine said tool standoff relative to said standoff threshold.