Pulsing Apparatus for Downhole Use

Abstract

A pulsing apparatus for use in a conduit through which is flowing a liquid. The pulsing apparatus includes a housing in which is positioned a valve generally at the inlet of the housing, the valve controlling flow of fluid down a central passageway of the housing. There is also flow through an annulus of the housing formed in part by at least one rotor and one stator, the rotor rotating in response to fluid flow impinging on the vanes of the rotor. There is a second valve provided in the lower end of the housing through which flow can be intermittently interrupted to cause pressure pulses in the mud flow and hence in the conduit in which the pulsing apparatus is disposed, the second valve being operatively connected to the rotor.

What is claimed is: 
     
         1 . A downhole pulsing apparatus comprising:
 an elongate tubular housing having a first end and a second, there being an axial fluid flow pathway through said housing;   a first valve disposed proximal said first end of said housing to at least partially control the flow of fluid through said housing, said first valve having a valve inlet and a valve outlet;   at least one vaned stator having a plurality of circumferentially spaced, angled first vanes to direct fluid entering said first end of said housing in a spiral pattern;   at least one vaned rotor rotatably mounted in said housing below said at least one stator, said rotor having a central fluid passageway in fluid communication with the outlet of said valve, said rotor having a plurality of circumferentially spaced, angled second vanes rotatable with said rotor, flow from said stator impinging on said rotor vanes resulting in rotation of said first rotor;   a second valve mounted in said housing, said second valve having first and second valve members, each of said valve members having first and second axial flow openings, respectively, said first valve member being rotatable around a longitudinal axis through said housing, said second valve member being fixed, rotation of said first valve member varying the alignment of said first and second openings between a minimum open area and a maximum open area to provide a an intermittently varying flow and pressure exiting said second end of said housing.   
     
     
         2 . The pulsing apparatus of  claim 1 , wherein said first valve member is operatively connected to said first rotor for rotation therewith. 
     
     
         3 . The pulsing apparatus of  claim 1 , wherein there are a plurality of said rotors. 
     
     
         4 . The pulsing apparatus of  claim 3 , wherein there are a plurality of stators, respective ones of said rotors being positioned below respective ones of said stators. 
     
     
         5 . The pulsing apparatus of  claim 4 , wherein said first valve member of said second valve is operatively connected to the rotor most proximal said second end of said housing. 
     
     
         6 . The pulsing apparatus of  claim 1 , wherein said first valve comprises an annular valve body, said annular valve body defining said valve inlet, and a valve element mounted in said valve housing, said valve element comprising a valve plug connected to a compression spring, said valve plug substantially preventing fluid flow into said valve inlet when said spring is in a relaxed position, fluid flowing through said housing acting on said valve plug to compress said spring and increase the flow through said valve inlet. 
     
     
         7 . The pulsing apparatus of  claim 6 , wherein said valve plug is conically shaped. 
     
     
         8 . The pulsing apparatus of  claim 1 , wherein said at least one rotor comprises a first central core portion in surrounding relationship to said central passageway and a first outer sleeve, a first rotor annulus being formed between said first central core portion and said first outer sleeve, said second vanes being disposed between and interconnected to said first central core portion and said first outer sleeve. 
     
     
         9 . The pulsing apparatus of  claim 8 , further comprising a plurality of angled ports in open communication with said central passageway and said first rotor annulus. 
     
     
         10 . The pulsing apparatus of  claim 8 , wherein said first central core portion of said at least one rotor is connected to a second rotor for rotation therewith, said second rotor comprising a second central core portion and a second outer sleeve, a second rotor annulus being formed between said second central core portion and said second outer sleeve, the vanes of said second rotor being disposed in said second rotor annulus. 
     
     
         11 . The pulsing apparatus of  claim 8 , wherein said central core portion includes an axially extending shaft portion and said second rotor has an axially extending bore for receipt of said shaft. 
     
     
         12 . The pulsing apparatus of  claim 11 , wherein said shaft is connected to said second central core portion by a pin received in registering holes in said shaft and said second central core portion. 
     
     
         13 . The pulsing apparatus of  claim 6 , wherein said valve body has a generally cylindrical portion and a generally frustoconical portion, said frustoconical portion defining said valve inlet. 
     
     
         14 . The pulsing apparatus of  claim 1 , wherein said second axial flow opening in said second valve member is generally crescent-shaped when viewed in plan view. 
     
     
         15 . The pulsing apparatus of  claim 14 , wherein said generally crescent-shaped opening forms the mouth of a passageway extending through said second valve member, said second valve member comprising a disc-shaped plate having an upper surface proximal said first valve member, said passageway through said second valve member having a chamfered lip portion extending from said upper surface into said passageway, said lip portion extending for a portion of the periphery of said crescent-shaped opening. 
     
     
         16 . The pulsing apparatus of  claim 1 , wherein said first valve member comprises a second disc shaped plate.