Downhole motor sensing assembly and method of using same

Abstract

A downhole sensing assembly for sensing motor parameters of a downhole motor positionable in a wellbore penetrating a subterranean formation is provided. The downhole motor has a stator and a rotor rotatable within the stator. The sensing assembly includes at least one rotor extension operatively connectable to the rotor and movable therewith, at least one marker positionable about the rotor extension, and at least one motor sensor positionable about a downhole tool and operatively coupled to the marker to detect movement of the marker whereby motor parameters, such as rotational speed of the motor, are detectable.

1 . A downhole sensing assembly for sensing motor parameters of a downhole motor positionable in a wellbore penetrating a subterranean formation, the downhole motor having a stator and a rotor rotatable within the stator, comprising:
 at least one rotor extension operatively connectable to the rotor and movable therewith;   at least one marker positionable about the at least one rotor extension; and   at least one motor sensor positionable about a downhole tool and operatively coupled to the at least one marker to detect movement of the at least one marker whereby motor parameters comprising rotational speed of the downhole motor are detectable.   
     
     
         2 . The downhole sensing assembly of  claim 1 , wherein at least one of the rotor extension, the at least one marker and the at least one motor sensor is positioned outside of the downhole motor. 
     
     
         3 . The downhole sensing assembly of  claim 1 , wherein the at least one marker is integral with the at least one rotor extension. 
     
     
         4 . The downhole sensing assembly of  claim 1 , wherein the at least one marker is operatively connectable to the at least one rotor extension. 
     
     
         5 . The downhole sensing assembly of  claim 1 , wherein the at least one rotor extension comprises a rotor catch. 
     
     
         6 . The downhole sensing assembly of  claim 1 , wherein the at least one rotor extension comprises a rod threadedly connectable to an end of the rotor. 
     
     
         7 . The downhole sensing assembly of  claim 1 , wherein the at least one rotor extension extends from an uphole end of the rotor. 
     
     
         8 . The downhole sensing assembly of  claim 1 , wherein the at least one rotor extension extends from the rotor and into a sub adjacent to the downhole motor. 
     
     
         9 . The downhole sensing assembly of  claim 1 , wherein the at least one rotor extension comprises a handle with a plurality of members extending therefrom, the plurality of members integral with the at least one marker. 
     
     
         10 . The downhole sensing assembly of  claim 1 , wherein the at least one marker is integral with the at least one rotor extension. 
     
     
         11 . The downhole sensing assembly of  claim 1 , wherein the at least one marker is operatively connectable to the at least one rotor extension. 
     
     
         12 . The downhole sensing assembly of  claim 1 , wherein the at least one rotor extension comprises one of an integral and a modular body. 
     
     
         13 . The downhole sensing assembly of  claim 1 , wherein the at least one rotor comprises an upper portion and a lower portion threadly connectable to the at least one rotor, the at least one marker positionable about the lower portion. 
     
     
         14 . The downhole sensing assembly of  claim 1 , wherein the at least one marker comprises a magnet generating a magnetic field detectable by the at least one motor sensor. 
     
     
         15 . The downhole sensing assembly of  claim 1 , wherein the at least one motor sensor comprises at least one of a magnetic, electromagnetic, proximity, optical, electro-magnetic, acoustic, fluxgate, magneto-resistive, magnetometer, and Hall Effect sensor. 
     
     
         16 . The downhole sensing assembly of  claim 1 , further comprising at least one downhole sensor comprising at least one of a temperature, pressure, vibration, force, and gyroscope sensor. 
     
     
         17 . A drilling system for drilling a wellbore in a subterranean formation, the drilling system comprising:
 a downhole motor positionable in a downhole drilling tool disposable in the wellbore, the downhole motor comprising a stator and a rotor;   a downhole sensing assembly, comprising:
 at least one rotor extension operatively connectable to the rotor and movable therewith; 
 at least one marker positionable about the at least one rotor extension; and 
 at least one motor sensor positionable about the downhole drilling tool and operatively coupled to the at least one marker to detect movement of the at least one marker whereby motor parameters comprising rotational speed of the downhole motor are detectable. 
   
     
     
         18 . The drilling system of  claim 17 , further comprising at least one of a surface unit and a downhole unit operatively connected to the downhole sensing assembly. 
     
     
         19 . The drilling system of  claim 17 , further comprising telemetry operatively coupling the surface unit and the downhole sensing assembly. 
     
     
         20 . The drilling system of  claim 17 , further comprising a top sub operatively connected to the downhole motor, and wherein at least one of the at least one rotor extension, the at least one marker and the at least one motor sensor are positioned in the top sub. 
     
     
         21 . A method of sensing parameters of a motor of a downhole tool positionable in a wellbore penetrating a subterranean formation, the motor comprising a stator and a rotor, the method comprising:
 providing the motor with a downhole sensing assembly, the downhole sensing assembly comprising:
 at least one rotor extension operatively connectable to the rotor and movable therewith; 
 at least one marker positionable about the at least one rotor extension; and 
 at least one motor sensor positionable about the downhole tool and operatively coupled to the at least one marker to detect movement of the at least one marker; 
   detecting the at least one marker with the at least one marker sensor.   
     
     
         22 . The method of  claim 21 , further comprising determining downhole parameters comprising revolutions per minute of the motor based on the detecting. 
     
     
         23 . The method of  claim 21 , further comprising determining downhole parameters with at least one downhole sensor. 
     
     
         24 . The method of  claim 21 , further comprising selectively adjusting drilling based on at least one of drilling parameters determined from the detecting, downhole parameters determined with the at least one downhole sensor, and known parameters. 
     
     
         25 . The downhole assembly of  claim 1 , wherein the at least one marker comprises a magnet, and wherein the at least one rotor extension comprises a rotor catch, the at least one magnet positionable in the rotor catch.