Flow Rate From Displacement Unit Piston Position

Abstract

A method to detect flow rate from a displacement unit entailing locating the displacement unit in a fluid path, monitoring a piston position in the displacement unit for a stroke direction change, starting a timer upon a stroke direction change, monitoring at least one check valve position for an alteration of position, stopping the timer upon the alteration of position, calculating a time between the stroke direction change and the alternation of position, calculating a volume of the displacement unit and calculating the flow rate from the displacement unit by dividing the volume of the displacement unit by the calculated time.

What is claimed is: 
     
         1 . A method to detect flow rate from a displacement unit, comprising:
 measuring a compressibility of a downhole fluid;   calculating a dead volume for the displacement unit;   measure a hydrostatic pressure for the displacement unit;   measure a flowing pressure of the downhole fluid at a sand face;   calculating a rate of displacement unit volume change; and   calculating a time required to compress the displacement unit from the rate of displacement unit volume change.   
     
     
         2 . The method according to  claim 1 , wherein the time required to compress the displacement unit is: 
       
         
           
             
               Time 
               = 
               
                 
                   
                     
                       
                         V 
                         1 
                       
                       · 
                       
                          
                         
                           C 
                            
                           
                             ( 
                             
                               
                                 P 
                                 2 
                               
                               - 
                               
                                 P 
                                 1 
                               
                             
                             ) 
                           
                         
                       
                     
                     - 
                     
                       V 
                       1 
                     
                   
                   Q 
                 
                 . 
               
             
           
         
       
     
     
         3 . A method to detect flow rate from a displacement unit, comprising:
 locating the displacement unit in a fluid path;   monitoring a piston position in the displacement unit for a stroke direction change;   starting a timer upon a stroke direction change;   monitoring at least one check valve position for an alteration of position;   stopping the timer upon the alteration of position;   calculating a time between the stroke direction change and the alternation of position;   calculating a volume of the displacement unit; and   calculating the flow rate from the displacement unit by dividing the volume of the displacement unit by the calculated time.   
     
     
         4 . The method according to  claim 1 , wherein the displacement unit is located in a wellbore. 
     
     
         5 . The method according to  claim 3 , wherein the displacement unit is located in a wellbore.