Induction loop cementing progress detection

Abstract

A wellbore fluid inductance monitor is disclosed, which operates at an end of a tubular in a wellbore. The wellbore fluid inductance monitor comprises an inductor in an electrical circuit. A magnetically doped portion of wellbore fluid, which may be a hydraulic fluid or cement slurry, is introduced into the wellbore during a reverse cementing or other cementing operation. The magnetically doped portion of wellbore fluid contains a dopant that alters at least one of a magnetic permeability and conductivity. The wellbore fluid inductance monitor detects the proximity magnetically doped portion of wellbore fluid based on altered electrical characteristics of the inductor. Based on the detection, the wellbore fluid inductance monitor triggers a wellbore operation which is detectable at a cementing controller and the cementing operation can be stopped or otherwise completed based on the determination that the cement slurry has reached the end of the tubular.

What is claimed is: 
     
         1 . An apparatus comprising:
 an electrical circuit comprising at least one inductor at an end of a tubular;   a processor; and   a machine-readable medium having instructions stored thereon that are executable by the processor to cause the apparatus to,
 monitor measures of inductance of the electrical circuit for a change; 
 determine if a change in the measures of inductance has exceeded a sensitivity threshold; and 
 based on the determination that the change in the measures of inductance has exceeded the sensitivity threshold, trigger a wellbore operation corresponding to a cementing operation. 
   
     
     
         2 . The apparatus of  claim 1 , wherein the electrical circuit is separated from a wall of the tubular a soft magnetic material. 
     
     
         3 . The apparatus of  claim 1 , wherein the end of a tubular comprises the terminal three sections of the tubular. 
     
     
         4 . The apparatus of  claim 1 , wherein the measure of inductance comprises at least one of a current measurement, a voltage measurement, and a frequency measurement. 
     
     
         5 . The apparatus of  claim 1 , wherein the electrical circuit is integrated into a shoe. 
     
     
         6 . The apparatus of  claim 1 , wherein the tubular is at least one of a casing, a liner, a drill string, and coiled tubing. 
     
     
         7 . An apparatus comprising:
 a tubular associated with a wellbore;   an electrical circuit comprising at least one inductor at an end of the tubular;   a processor; and   a machine-readable medium having instructions stored thereon that are executable by the processor to cause the apparatus to,
 monitor measures of inductance of the electrical circuit for a change; 
 determine if a change in the measures of inductance has exceeded a sensitivity threshold; and 
 based on the determination that the change in the measures of inductance has exceeded the sensitivity threshold, trigger a wellbore operation corresponding to a cementing operation. 
   
     
     
         8 . The apparatus of  claim 7 , wherein the electrical circuit is located at a first location of the tubular, and wherein the wellbore operation comprises terminating a fluid flow through the tubular at a second location of the tubular.