Flow control apparatus and method

Abstract

A fluid flow control apparatus for use in a mid-string location in a pipe string being run into a well has an open fluid flow route to the annulus above the apparatus to provide more flow area for upwardly moving fluid. Flow up the upper pipe string bore is resisted to reduce fluid overflow from the top of the pipe string. Fluid flow down the pipe string bore closes the fluid channel between the lower pipe string bore and the upper annulus and blows out a pipe bore flow resisting element for free down flow of fluids in the pipe string bore.

1. Apparatus for use down hole in a pipe string, when running pipe strings into a well, for management of surge pressure and the resulting fluid flow, the apparatus comprising:
 a) a body to function as a serial pipe string element, with means  threaded connections at each end to connect to continuing pipe string elements, having a generally central bore and first and second ports to conduct fluid through the apparatus wall;  
 b) a removable flow inhibiting element, in said generally central bore situated to fluidly separate said first and second ports, removable by fluid down-flow in said generally central bore;  
 c) a movable element in said generally central bore, responsive to downward flow of fluid in said generally central bore to close said second ports to outwardly directed flow;  
 d) a check  valve in said generally central opening arranged to cooperate with said first ports to resistively admit flow to said generally central bore and prohibit flow from said generally central bore through said first ports.  
 
     
     
       2. The apparatus of  claim 1  wherein said movable element is a piston and carries said removable flow inhibiting element. 
     
     
       3. The apparatus of  claim 2  wherein said piston carries a flexible tubular element arranged to cover said second ports to prevent the flow from the generally central bore and to deform to resist but admit the flow into the generally central bore. 
     
     
       4. The apparatus of  claim 2  wherein said removable flow inhibiting element is a rupture disc that breaks when stressed by a selected range of pressure. 
     
     
       5. The apparatus of  claim 2  wherein said removable flow inhibiting element is an elastomer element that is forced through a hole when stressed by a selected range of pressure. 
     
     
       6. The apparatus of  claim 1  wherein said check  valve is a flexible tubular element arranged to cover said first ports to prevent outflow and to deform to resist but admit inward flow. 
     
     
       7. A method for control of fluids displaced from a well during the running in of a first tubular string, to be installed in the well, the first tubular string suspended by a connecting adapter from a second, working, tubular string, the method comprising the steps:
 a) providing a flow path for fluids displaced from the well;  
 b) said flow path including the bore of the first tubular string, first ports through a wall of the adapter to the well annulus, some distance along the annulus, second ports through a wall of the adapter to the bore of the second tubular string, and upward in both bore and annulus of the second tubular string, thus reducing surge pressure in the well;  
 c) placing a down flow responsive removable occlusion means  between said first and second ports during assembly of said tubular strings;  
 d) placing check  valve equivalents to prohibit flow from the bore of the adapter to the well annulus;  
 e) placing a down flow responsive movable element in said adapter to activate a check  valve equivalent to cooperate with the first ports to prohibit flow through the first ports to the annulus;  
 f) pumping fluid down the working pipe string bore to blow out the occlusion means ; and  
 g) finishing the well servicing operation.  
 
     
     
       8. A method for running tubular string into an earth wellbore containing fluids, wherein the flow of fluids from the interior of the wellbore to the earth's surface follows two paths, a first path through the center bore of said tubular string, and a second path being the annulus at least partially surrounding the exterior of said tubular string, comprising the steps of:
   a )  running the tubular string into the earth wellbore;        b )  allowing the fluids in the second path to reach a given vertical level; and        c )  controlling the fluids in the first path to be at a vertical level at or below the vertical level of the fluids in said second path, said controlling step comprising the diverting of the fluids in said first path through a side wall at least partially surrounding said first path into the second path.      
     
     
       9. The method according to  claim 8 , wherein said tubular string comprises an installation string and a working string.  
     
     
       10. The method according to  claim 8 , wherein the tubular string includes a removable flow element positioned within the center bore of the tubular string.  
     
     
       11. The method according to  claim 10 , wherein said removable flow element is a rupture disc.  
     
     
       12. The method according to  claim 11 , including the additional steps of pumping fluid from the earth's surface through the center bore of said tubular string to rupture or otherwise deform said rupture disc, and continuing, as desired, to pump such fluid from the earth's surface down through said tubular string.  
     
     
       13. A method for running tubular string into an earth wellbore containing fluids, wherein the flow of fluids from the interior of the wellbore to the earth's surface follows two paths, a first path through the center bore of said tubular string, and a second path being the annulus at least partially surrounding the exterior of said tubular string, comprising the steps of:
   a )  running the tubular string into the earth wellbore, wherein said tubular string includes a removable flow element positioned within the center bore of the tubular string;        b )  diverting the well fluids located in said center bore beneath the removable flow element, to said second path and then re - diverting a portion of said fluid back from said second path into said first path at a location within the center bore of said tubular string above said removable flow element;        c )  allowing the fluids in the second path to reach a given vertical level; and        d )  controlling the fluids in the first path to be at a vertical level at or below the vertical level of the fluids in said second path.      
     
     
       14. The method according to  claim 13 , wherein said tubular string comprises an installation string and a working string.  
     
     
       15. The method according to  claim 14 , wherein said removable flow element is a rupture disc.  
     
     
       16. The method according to  claim 15 , including the additional steps of pumping fluid from the earth's surface through the center bore of said tubular string to rupture or otherwise deform said rupture disc, and continuing, as desired, to pump such fluid from the earth's surface down through said tubular string.  
     
     
       17. A method for running tubular string into an earth wellbore containing fluids, wherein the flow of fluids from the interior of the wellbore to the earth's surface follows two paths, a first path through the center bore of said tubular string, and a second path being the annulus at least partially surrounding the exterior of said tubular string, comprising the steps of:
   a )  running the tubular string into the earth wellbore; and        b )  controlling the relative vertical levels of the fluids in said first and second paths to prevent the fluid in the first path from overflowing onto the rig floor located at the earth's surface, said controlling step comprising the diverting of the fluids in said first path through a side wall at least partially surrounding said first path into the second path.      
     
     
       18. The method according to  claim 17 , wherein said tubular string comprises an installation string and a working string.  
     
     
       19. The method according to  claim 17 , wherein the tubular string includes a removable flow element positioned within the center bore of the tubular string.  
     
     
       20. The method according to  claim 19 , wherein said removable flow element is a rupture disc.  
     
     
       21. The method according to  claim 20 , including the additional steps of pumping fluid from the earth's surface through the center bore of said tubular string to rupture or otherwise deform said rupture disc, and continuing, as desired, to pump such fluid from the earth's surface down through said tubular string.  
     
     
       22. The method according to  claim 8 , wherein said controlling step further comprises the re- diverting of at least a portion of said fluids back from said second path into said first path.    
     
     
       23. The method according to  claim 17 , wherein said controlling step further comprises the re- diverting of at least a portion of said fluids back from said second path into said first path.