Apparatus for generating pulses in fluid during drilling of wellbores

Abstract

In one aspect, an apparatus for use in a drilling assembly is disclosed that in one embodiment includes a flow control device that further includes: a fluid flow path having an inlet and an outlet; an electromagnetic circuit that includes a closing member made from a soft magnetic or magnetic material as a part of the electromagnetic circuit, wherein the closing member moves from a first open position to a second closed position to close the fluid flow path to produce a pressure pulse in a fluid flowing through the fluid flow path when the electromagnetic circuit is formed.

The invention claimed is: 
     
       1. A method of producing a pressure pulse in a fluid flow path of a downhole tool, the method comprising:
 energizing a magnetic member separated by a gap from a movable member in the fluid flow path to form a magnetic flux in the gap, the movable member including a closing member; 
 moving the movable member in response to the magnetic flux to close the gap; and 
 engaging the closing member with an inlet of the fluid flow path, pursuant to the closing the gap, to produce the pressure pulse. 
 
     
     
       2. The method of  claim 1 , wherein the engaging includes moving the closing member axially to engage the inlet of the fluid flow path. 
     
     
       3. The method of  claim 1 , wherein moving the movable member further comprises rotating the movable member about an axis. 
     
     
       4. The method of  claim 1 , wherein the movable member is magnetic. 
     
     
       5. The method of  claim 1  wherein the closing member is non-magnetic. 
     
     
       6. The method of  claim 1 , further comprising energizing the magnetic member at a location of the downhole tool outside of the fluid flow path. 
     
     
       7. The method of  claim 1 , wherein the movable member includes an extension member having flow paths therethrough and the extension member moves in response to the magnetic flux to close the gap. 
     
     
       8. The method of  claim 1 , further comprising de-energizing the magnetic member and supplying a fluid under pressure to the fluid flow path to move the movable member to open the gap. 
     
     
       9. The method of  claim 1 , wherein producing the pressure pulse transmits a signal related to a parameter of interest provided by a sensor of the downhole tool. 
     
     
       10. An apparatus for use in a downhole tool, comprising:
 a movable member in a fluid flow path of the downhole tool, the movable member including a closing member; and 
 a magnetic member that is separated from the movable member by a gap, the magnetic member energizable to form a magnetic flux in the gap that moves the movable member to close the gap, wherein moving the movable member to close the gap engages the closing member with an inlet of the fluid flow path to produce a pressure pulse. 
 
     
     
       11. The apparatus of  claim 10 , wherein the closing member is configured to move axially to engage the inlet of the fluid flow path. 
     
     
       12. The apparatus of  claim 10 , wherein the movable member is configured to rotate about an axis to close the gap. 
     
     
       13. The apparatus of  claim 10 , wherein the movable member is magnetic. 
     
     
       14. The apparatus of  claim 10 , wherein the closing member is non-magnetic. 
     
     
       15. The apparatus of  claim 10 , wherein the magnetic member is outside of the fluid flow path. 
     
     
       16. The apparatus of  claim 10 , wherein the movable member includes an extension member having flow paths therethrough and the magnetic flux moves the extension member to close the gap. 
     
     
       17. The apparatus of  claim 10 , wherein the movable member is configured to move to open the gap pursuant to a fluid under pressure being supplied to the fluid flow path and the magnetic member being de-energized. 
     
     
       18. The apparatus of  claim 10 , wherein the downhole tool further includes a sensor that provides signals relating to a parameter of interest and a circuit that processes the signals to generate the parameter of interest, wherein the closing member engages the inlet to produce pulses to transmit the parameter of interest through a fluid in the fluid flow path.