Tripping indicator for MWD systems

摘要

A method for surveying a formation includes conveying a survey instrument into the wellbore; measuring one or more parameters of interest relating to a wellbore tubular in the wellbore; and operating the survey instrument after the measured parameter of interest indicates that the wellbore tubular is being tripped out of the wellbore.

主权项

1. A method for surveying a formation having a wellbore, comprising:
conveying a wellbore tubular having a survey instrument into the wellbore; monitoring a plurality of drilling parameters at a downhole sensor of the wellbore tubular in the wellbore to determine an order in which changes are made to the plurality of drilling parameters and to measure time periods associated with the changes to the plurality of drilling parameters; determining at a downhole processor a sequence of changes to the plurality of drilling parameters that indicates commencement of tripping of the wellbore tubular out of the wellbore, wherein the sequence includes pre-determined time periods associated with the changes to the drilling parameters; and using the downhole processor to energize the survey instrument when the order in which changes are made to the plurality of drilling parameters and the associated time periods matches the sequence indicating commencement of tripping of the wellbore tubular out of the wellbore.