Environmental severity measurement tool

Abstract

An environmental severity measurement tool measures acceleration along 3 axes to determine shock and vibration affecting a downhole tool in which the environmental severity measurement tool is disposed. The environmental severity measurement tool includes a replaceable battery and electronics disposed within an external housing. A pin provides a way to ensure the environmental severity measurement tool is oriented in a known orientation. Data sampled by the tool can be downloaded from the tool to an external device through a connector port of the electronics. Software in the tool controls the operation of the tool and can be configured from an external device.

What is claimed is: 
     
         1 . A method of determining usage time of a downhole tool, comprising:
 disposing an environmental severity measurement tool in the downhole tool;   sampling acceleration data along three axes by the environmental severity measurement tool;   storing the sampled acceleration data in the environmental severity measurement tool;   downloading the stored acceleration data from the environmental severity measurement tool; and   analyzing the downloaded acceleration data to determine periods of time when the environmental severity measurement tool was experiencing shock and vibration.   
     
     
         2 . The method of  claim 1 , further comprising:
 comparing the downloaded acceleration data to usage data provided by a drilling operator.   
     
     
         3 . A method of determining rotations per minute of a downhole tool, comprising:
 disposing an environmental severity measurement tool in the downhole tool;   sampling acceleration data along three axes by the environmental severity measurement tool;   storing the sampled acceleration data in the environmental severity measurement tool;   downloading the stored acceleration data from the environmental severity measurement tool; and   analyzing the downloaded acceleration data to determine rotations per minute of the downhole tool.   
     
     
         4 . The method of  claim 3 , further comprising:
 analyzing the downloaded acceleration data to determine stick-slip of the downhole tool.