CALIPER TOOL WITH IN-SITU TEMPERATURE COMPENSATION

摘要

A tool for evaluating the internal surfaces of tubular is provided, wherein one or more arms extend outwardly from the tool into contact with an inner wall of the tubular, and changes in the dimensions or condition of the inner wall result in changes in the position of the ends of the arms relative to the tool. This motion is converted, through an electromagnetic transducer, into an electrical signal, the accuracy of which deteriorates as the temperature of the tool changes. Calibration transducers are provided on the tool to provide correction factors to convert the electromagnetic transducer output into an accurate reading of the distance of the end of the arms from the tool thereby increasing the accuracy of the assessment of the inner wall of the tubular.

主权项

1. A tubular wall geometry evaluation tool comprising:
a housing having at least one probe arm extendable therefrom into contact with the inner wall of the tubular and an electromagnetic transducer associated with the probe arm and configured to provide an electrical output indicative of the extension distance of the probe arm from the housing; a first calibration transducer configured to output a signal representative of a full extension a probe arm from the housing; a second calibration transducer associated with the housing and configured to output a signal representative of a full extension a probe arm from the housing, the first and the second calibration transducers maintained sufficiently adjacent to the electromagnetic transducer associated with the probe arm to encounter the same temperature as that encountered by the electromagnetic transducer associated with the probe arm during use of the tool.