Tubular slug reducer

Abstract

The flow line 10, 12, 30 is provided for reducing axial separation of different density fluids passing through the flow line, such as gas and liquids. The flow line is provided with one or more grooves 16, 18, 32, 34, 36, 40 in the wall of the flow line and radially outward of a generally cylindrical bore of the tubular. Each of the one or more grooves forms a spiral along the axial length of the flow line, thereby swirling fluid passing through the flow line and causing lighter fluid to move toward a center of the flow line due to a created vortex and heavier fluid to move toward a radially outer portion of the flow line.

1 . A flow line for reducing axial separation of different density fluids passing through the flow line, comprising: 
 the flow line having a generally cylindrical bore with a bore internal diameter and one or more grooves in a wall of the flow line and radially outward of the generally cylindrical bore, the one or more grooves each forming a spiral along an axial length of the flow line, thereby swirling fluid passing through the flow line and causing lighter fluid to move toward a center of the flow line due to a created vortex and heavier fluid to move toward a radially outer portion of the flow line.    
   
   
       2 . A flow line as defined in  claim 1 , wherein each of the one or more grooves has a radial groove depth of from 2% to 25% of a wall thickness of the flow line.  
   
   
       3 . A flow line as defined in  claim 1 , wherein each of the one or more grooves has a groove depth of from 7% to 12% of a wall thickness of the flow line.  
   
   
       4 . A flow line as defined in  claim 1 , wherein each of the one or more grooves has a circumferential groove width flow line from 2% to 50% of the bore internal diameter.  
   
   
       5 . A flow line as defined in  claim 1 , wherein each of the one or more grooves has a circumferential groove width from 5% to 25% of the bore internal diameter.  
   
   
       6 . A flow line as defined in  claim 1 , wherein each of the one or more grooves is formed along a substantial portion of an axial length of one or more interconnected tubular members.  
   
   
       7 . A flow line as defined in  claim 1 , wherein each of the one or more grooves is formed along a substituted portion of an axial length of one or more couplings each interconnecting two tubular members.  
   
   
       8 . A flow line as defined in  claim 1 , wherein each of the one or more grooves has radially inner and radially outer edges each with the radius of from 10% to 40% of a radial depth of the groove.  
   
   
       9 . A flow line as defined in  claim 1 , wherein the flow line includes two or more grooves circumferentially spaced at a substantially uniform circumferential spacing about the flow line.  
   
   
       10 . A tubular for reducing axial separation of liquid slugs and gas slugs passing through the tubular in a well, comprising: 
 the tubular having a generally cylindrical bore with a bore internal diameter and one or more grooves in a wall of the tubular and radially outward of the generally cylindrical bore, the one or more grooves each forming a spiral along an axial length of the tubular, thereby swirling fluid passing through the tubular and causing gas to move toward a center of the tubular due to a created vortex and liquid to move toward a radially outer portion of the tubular.    
   
   
       11 . A tubular as defined in  claim 10 , wherein the tubular is one of a production tubular and a drill pipe.  
   
   
       12 . A tubular as defined in  claim 10 , wherein each of the one or more grooves has a radial groove depth of from 2% to 25% of a wall thickness of the flow line.  
   
   
       13 . A tubular as defined in  claim 10 , wherein each of the one or more grooves has a circumferential groove width flow line from 2% to 50% of the bore internal diameter.  
   
   
       14 . A tubular as defined in  claim 10 , wherein each of the one or more grooves is formed along a substantial portion of an axial length of one or more interconnected tubular members.  
   
   
       15 . A tubular as defined in  claim 10 , wherein each of the one or more grooves is formed along a substantial portion of an axial length of one or more couplings each interconnecting two tubular members.  
   
   
       16 . A tubular as defined in  claim 10 , wherein each of the one or more grooves has radially inner and radially outer edges each with the radius of from 10% to 40% of a radial depth of the groove.  
   
   
       17 . A method of reducing axial separation of different density fluids passing through a flow line having a generally cylindrical line with a bore internal diameter, comprising: 
 forming one or more grooves in a wall of the flow line and radially outward of the generally cylindrical bore, the one or more grooves each forming a spiral along an axial length of the flow line, thereby swirling fluid passing through the flow line and causing lighter fluid to move toward a center of the flow line due to a created vortex and heavier fluid to move toward a radially outer portion of the flow line.    
   
   
       18 . A method as defined in  claim 17 , wherein each of the one or more grooves is formed by providing one or more radially outward projections on a mandrel, the flow line moving axially over the mandrel while rotating to form the one or more grooves.  
   
   
       19 . A method as defined in  claim 17 , wherein each of the one or more grooves has a radial groove depth of from 2% to 25% of a wall thickness of the flow line; and 
 each of the one or more grooves has a circumferential groove width flow line, from 2% to 50% of the bore internal diameter.    
   
   
       20 . A method as defined in  claim 17 , wherein each of the one or more grooves has radially inner and radially outer edges each with the radius of from 10% to 40% of a radial depth of the groove.