Variable Circulation Rate Sub for Delivering a Predetermined Straight through Flow

Abstract

A housing is integrated into a tubing string having a straight through passage and a lateral wall exist. Inside the passage is a flow responsive member with an applied preload force. Flow corresponding to a predetermined differential pressure in the housing will not move the valve member so all flow will go straight through in a downhole direction. As flow increases, the preload bias is overcome to align the passage through the housing and openings in the valve member with wall openings. As flow into the housing increases, more lateral wall opening area is aligned with the passage to increase circulation flow while holding through flow downhole constant. Dropping a ball on the valve member blocks through flow and allows opening of total bypass passages. The ball can be removed by blowing it through the seat or otherwise failing or disintegrating it.

We claim: 
     
         1 . A flow regulation device to a bottom hole assembly supported on a tubular string in a wellbore, comprising:
 a housing comprising a through passage and at least one lateral wall opening communicating with said passage;   a valve member biased in said passage by a first bias having a flow path therethrough directing up to a predetermined flow entering said housing to said bottom hole assembly, said valve member maintaining said predetermined flow to said bottom hole assembly in response to increases in flow to said housing above said predetermined flow by movement of said valve member against said bias to selectively open said at least one lateral wall opening to divert flow from said housing that in excess of said predetermined flow away from said bottom hole assembly.   
     
     
         2 . The device of  claim 1 , wherein:
 said first bias comprises at least one of a coiled spring, Belleville washers and a compressible fluid.   
     
     
         3 . The device of  claim 1 , wherein:
 said at least one lateral wall opening comprises a plurality of lateral wall openings arranged in axially spaced rows, wherein movement of said valve member against said first bias opens at least one of said rows.   
     
     
         4 . The device of  claim 1 , wherein:
 said valve member is movable into a configuration where no flow is directed to the bottom hole assembly by blocking said flow path in said valve member with a first object and shifting said valve member with said first object to selectively open at least one full recycle port in said housing.   
     
     
         5 . The device of  claim 4 , wherein:
 said at least one lateral wall opening is closed by said valve member when said at least one full recycle port is open.   
     
     
         6 . The device of  claim 5 , wherein:
 said at least one full recycle port is selectively closed by at least one second object thereby allowing pressure buildup on said first object to force said first and second objects through said flow path to enable said first bias to close said at least one full recycle port for resumption of said predetermined flow to the bottom hole assembly.   
     
     
         7 . The device of  claim 1 , wherein:
 said predetermined flow is adjustable with a preload applied to said first bias on said valve member.   
     
     
         8 . The device of  claim 3 , wherein:
 a second bias engages said valve member after all said axially spaced rows of said lateral wall openings are open.   
     
     
         9 . The device of  claim 8 , wherein:
 said second bias is stronger than said first bias.   
     
     
         10 . The device of  claim 1 , wherein:
 said at least one lateral wall opening comprises a plurality of circumferentially spaced axially elongated tapered lateral wall openings.   
     
     
         11 . The device of  claim 10 , wherein:
 said valve member is movable into a configuration where no flow is directed to the bottom hole assembly by blocking said flow path in said valve member with a first object and shifting said valve member with said first object to selectively open at least one full recycle port in said housing.   
     
     
         12 . The device of  claim 11 , wherein:
 said at least one full recycle port comprises a plurality of full recycle ports axially aligned with said tapered lateral wall openings.   
     
     
         13 . The device of  claim 12 , wherein:
 said recycle ports and tapered lateral wall openings are integrated into a continuous port.   
     
     
         14 . The device of  claim 1 , wherein:
 said valve member holding housing pressure in said passage at flow rates below said predetermined flow.