Method and apparatus for monitoring a downhole tool

Abstract

A telemetry system and method configured to communicate a wellbore parameter such as fluid composition, temperature, and pressure. In one embodiment, a plurality of tracers is stored downhole, and each of the tracers represents a different value of the wellbore parameter. After measuring the wellbore parameter, the measured value is correlated to one or more of the plurality of tracers that is equivalent to the measured value of the downhole parameter. The one or more tracers representing the measured value are then released from their respective containers to travel upstream. A sensor located upstream may detect the one or more tracers, which are then correlated back to obtain the measured value of the wellbore parameter. In another embodiment, ratiometric amounts of the tracers may be used to represent additional values of the wellbore parameter.

1 . A method of communicating a wellbore parameter from a downhole tool, comprising:
 providing a plurality of tracers for representing a value of the wellbore parameter;   measuring the wellbore parameter using a sensor;   correlating the wellbore parameter to a value represented by one or more of the plurality of tracers;   releasing the one or more of the plurality of tracers to travel upstream;   detecting presence of the one or more of the plurality of tracers; and   determining the wellbore parameter from the detected one or more of the plurality of tracers.   
     
     
         2 . The method of  claim 1 , wherein each of the plurality of tracers is assigned a different value. 
     
     
         3 . The method of  claim 1 , wherein each of the plurality of tracers comprises a chemical. 
     
     
         4 . A system for communicating a wellbore parameter from a downhole tool, comprising:
 a plurality of tracers for representing a value of the wellbore parameter;   a plurality of containers for storing the plurality of tracers;   a first sensor for measuring the wellbore parameter;   a downhole controller configured to correlate the wellbore parameter to one or more of the plurality of tracers and configured to release the one or more of the plurality of the tracers;   an second sensor for detecting presence of the one or more of the plurality of tracers; and   an uphole controller configured to determine the wellbore parameter from the detected one or more of the plurality of tracers.   
     
     
         5 . The system of  claim 4 , wherein each of the plurality of tracers is assigned a different value. 
     
     
         6 . The system of  claim 4 , wherein each of the plurality of tracers comprises a chemical. 
     
     
         7 . The system of  claim 4 , wherein the container is pressurized. 
     
     
         8 . The system of  claim 4 , wherein the first sensor is located downhole and the second sensor is located uphole. 
     
     
         9 . A method of communicating a wellbore parameter from multiple downhole tools, comprising:
 associating a first set of tracers to a first downhole tool;   associating a second set of tracers to a second downhole tool, wherein the first and second set of tracers represent a value of the wellbore parameter;   measuring the wellbore parameter using a sensor of the first downhole tool;   correlating the wellbore parameter to a value represented by one or more of the first set of tracers;   releasing the one or more of the first set of tracers to travel upstream;   detecting presence of the one or more of the first set of tracers;   determining the wellbore parameter from the detected one or more of the first set of tracers; and   determining the one or more of the first set of tracers was sent from the first downhole tool.   
     
     
         10 . The method of  claim 9 , wherein each of the first set of tracers is assigned a different value. 
     
     
         11 . The method of  claim 9 , wherein each of the first set of tracers comprises a chemical. 
     
     
         12 - 22 . (canceled) 
     
     
         23 . A method of communicating a wellbore parameter from a downhole tool, comprising:
 providing a plurality of tracer chemicals, whereby a code comprising a plurality of code elements correlates to a release of a single tracer chemical or a unique combination of a subset of the plurality of tracer chemicals to a specific value or a range of values of the wellbore parameter;   measuring a value of the wellbore parameter using a sensor;   ascribing the measured value to a code element;   releasing one or more of the plurality of tracer chemicals corresponding to the code element;   detecting the presence of the one or more of the plurality of tracer chemicals; and   determining the specific value or range of values of the measured wellbore parameter from the detection of the one or more of the plurality of tracer chemicals.   
     
     
         24 . The method of  claim 23 , wherein ascribing the measured value to a code element is performed downhole. 
     
     
         25 . The method of  claim 23 , wherein detecting the presence of one or more of the plurality of tracer chemicals is performed at a surface of the wellbore. 
     
     
         26 - 29 . (canceled) 
     
     
         30 . A method of communicating a wellbore parameter from a downhole tool, comprising:
 providing a plurality of tracers for representing a value of the wellbore parameter;   measuring the wellbore parameter using a sensor;   correlating the wellbore parameter to a value represented by a ratiometric amount of one or more of the plurality of tracers;   releasing the ratiometric amount of one or more of the plurality of tracers to travel upstream;   detecting presence of the ratiometric amount one or more of the plurality of tracers; and   determining the wellbore parameter from the detected ratiometric amount of one or more of the plurality of tracers.   
     
     
         31 . The method of  claim 30 , further comprising releasing a calibration dosage of the plurality of tracers. 
     
     
         32 . The method of  claim 30 , wherein each ratiometric amount of the plurality of tracers is assigned a different value. 
     
     
         33 . The method of  claim 30 , wherein each of the plurality of tracers comprises a chemical. 
     
     
         34 . The method of  claim 30 , wherein each tracer is released from a container storing the tracer. 
     
     
         35 . The method of  claim 34 , further comprising opening the container using a mechanical actuator. 
     
     
         36 - 44 . (canceled)