Wireless casing collar locator

Abstract

A wireless casing collar locator includes a pipe coupling detector configured to be conveyed through a wellbore. A detection device is associated with the pipe coupling detector. The detection device generates an output indicative of detection of a pipe coupling in response to the output of the pipe coupling detector. The locator includes an acoustic transmitter functionally associated with the detection device. The transmitter is configured to apply an acoustic impulse to a conveyance device used to move the locator along the wellbore in response to communication to the transmitter of the output of the detection device. A surface receiver and processing unit used to convert acoustic energy into electrical energy for processing in real time to determine the location of the pipe detector in wellbores.

1 . A wireless casing collar locator, comprising:
 a pipe coupling detector configured to be conveyed through a wellbore;   a detection device associated with the pipe coupling detector, the detection device generating an output indicative of detection of a pipe coupling in response to the output of the pipe coupling detector; and   an acoustic transmitter functionally associated with the detection device, the transmitter configured to apply an acoustic impulse to a conveyance device used to move the locator along the wellbore in response to communication thereto of the output of the detection device.   
   
   
       2 . The locator of  claim 1  further comprising an acoustic surface receiver functionally associated with the downhole system that converts the acoustic waves traveling through the conveyance into an electrical signal for processing by an electronics system in real time. 
   
   
       3 . The locator of  claim 1  wherein the pipe coupling detector comprises a magnetic casing collar locator. 
   
   
       4 . The locator of  claim 1  wherein the detection device comprises a pulse generator. 
   
   
       5 . The locator of  claim 1  wherein the acoustic transmitter comprises a plurality of stacked piezoelectric disks. 
   
   
       6 . The locator of  claim 1  wherein the conveyance comprises a slickline. 
   
   
       7 . The locator of  claim 1  further comprising an acoustic signal detector in signal communication with the conveyance device proximate the Earth's surface. 
   
   
       8 . The locator of  claim 7  wherein the acoustic signal detector comprises an accelerometer. 
   
   
       9 . A method for detecting a pipe coupling, comprising:
 moving a pipe coupling detector along the interior of a pipe disposed in a wellbore;   conducting an output of the coupling detector to a signal detector, the signal detector generating a pulse in response to detection by the coupling detector of a pipe coupling in the wellbore;   conducting output of the signal detector to an acoustic telemetry transmitter; and   causing the transmitter to impart an acoustic signal to an instrument conveyance device in response to output of the signal detector.   
   
   
       10 . The method of  claim 9  further comprising detecting the acoustic signal proximate the Earth's surface from the conveyance device. 
   
   
       11 . The method of  claim 10  wherein the detecting the acoustic signal comprises measuring acceleration of the conveyance device. 
   
   
       12 . The method of  claim 9  wherein the conveyance device comprises slickline 
   
   
       13 . The method of  claim 9  wherein the conveyance comprises coiled tubing. 
   
   
       14 . The method of  claim 9  wherein the coupling detector comprises a magnetic casing collar locator. 
   
   
       15 . The method of  claim 9  further comprising detecting the acoustic signal proximate the Earth's surface and processing the signal substantially in real time to determine positions of casing collars in the wellbore.