Variable Throat Venturi Flow Meter

Abstract

An apparatus for performing a well test operation includes a closed chamber testing system having a downhole flow control device. In some embodiments, a method of performing a well test operation includes performing a well test operation with a closed chamber testing system having a downhole flow control device and estimating the reservoir properties based on pressure and flow data measured during the well test operation.

1 . A variable throat Venturi flow meter comprising:
 an upstream pipe section having a substantially constant upstream cross-sectional area;   a throat section having a variable throat cross-sectional area that is smaller than the upstream cross-sectional area; and   a plurality of section-varying elements adapted to temporarily vary the throat cross-sectional area to allow a downhole tool to pass through the throat section.   
     
     
         2 . The variable throat Venturi flow meter of  claim 1 , further comprising:
 a tapered section connecting the upstream pipe section and the throat section.   
     
     
         3 . The variable throat Venturi flow meter of  claim 1 , further comprising:
 an upstream port disposed in the upstream pipe section and in communication with a first pressure sensor; and   a throat port disposed in the throat section and in communication with a second pressure sensor.   
     
     
         4 . The variable throat Venturi flow meter of  claim 1 , further comprising:
 a differential pressure sensor disposed in the throat section.   
     
     
         5 . The variable throat Venturi flow meter of  claim 1 , wherein the plurality of section-varying elements comprise spring blades arranged to vary the throat cross-sectional area in response to axial force. 
     
     
         6 . The variable throat Venturi flow meter of  claim 5 , further comprising:
 a viscous fluid or material disposed behind the plurality of spring blades.   
     
     
         7 . The variable throat Venturi flow meter of  claim 5 , further comprising:
 a density/viscosity sensor disposed in the throat section.   
     
     
         8 . The variable throat Venturi flow meter of  claim 2 , wherein the plurality of section-varying elements comprise at least two rotatable inserts configured to vary the throat cross-sectional area by rotating between an open position and a closed position. 
     
     
         9 . The variable throat Venturi flow meter of  claim 2 , wherein the plurality of section-varying elements comprise at least two revolving inserts disposed in a rotatable sleeve. 
     
     
         10 . The variable throat Venturi flow meter of  claim 1 , wherein the throat cross-sectional area varies in response to a command signal. 
     
     
         11 . The variable throat Venturi flow meter of  claim 10 , wherein the command signal is one of a pressure signal and an electrical signal. 
     
     
         12 . A downhole flow testing system comprising:
 a command module; and   a variable throat Venturi flow meter disposed in a wellbore, the variable throat Venturi meter comprising:
 an upstream pipe section having a substantially constant upstream cross-sectional area; 
 a throat section having a variable throat cross-sectional area that is smaller than the upstream cross-sectional area; 
 a plurality of section-varying elements adapted to temporarily vary the throat cross-sectional area to allow a downhole tool to pass through the throat section; and 
 a controller system configured to receive open and close signals from the command module.