Detector for Distinguishing Phases in a Multiphase Fluid Mixture

Abstract

A detector ( 1 ) is used distinguishing a phase from a multiphase fluid mixture. The detector comprises: an optical probe ( 2 ) for optically distinguishing one of the phases from the multiphase fluid mixture, the optical probe having a tip ( 20 ) in contact with the multiphase fluid mixture, and a detector cell ( 3 ) arranged to be coupled to a multiphase fluid mixture flowing line (L) and to the optical probe ( 2 ). The detector cell ( 1 ) further comprises: an internal flowing line ( 4 ) arranged so that the phases of the multiphase fluid mixture flowing in the internal flowing line are driven-on by capillarity effect, and a bore ( 5 ) coupled to the internal flowing line for positioning the optical probe in the detector cell so that the multiphase fluid mixture flows substantially around the tip ( 20 ) of the optical probe.

1 . A detector for distinguishing a phase from a multiphase fluid mixture, the detector comprising:
 an optical probe for optically distinguishing one of the phases from the multiphase fluid mixture, the optical probe having a tip in contact with the multiphase fluid mixture, and   a detector cell arranged to be coupled to a multiphase fluid mixture flowing line (L) and to the optical probe,   
     wherein the detector cell further comprises:
 an internal flowing line arranged so that the phases of the multiphase fluid mixture flowing in the internal flowing line are driven-on by capillarity effect, and 
 a bore coupled to the internal flowing line for positioning the optical probe in the detector cell so that the multiphase fluid mixture flows substantially around the tip of the optical probe. 
 
   
   
       2 . A detector for distinguishing a phase from a multiphase fluid mixture according to  claim 1 , wherein the internal flowing line has an internal diameter (ID) substantially corresponding to a capillary tube diameter. 
   
   
       3 . A detector for distinguishing a phase from a multiphase fluid mixture according to  claim 1 , wherein the internal flowing line has an internal diameter ranging from 0.5 mm to 20 mm. 
   
   
       4 . A detector for distinguishing a phase from a multiphase fluid mixture according to  claim 1 , wherein the internal flowing line and the bore of the detector cell forms a Y having a first, a second and a third branch, the first and second branch being formed by the internal flowing line and the third branch being formed by the bore of the detector cell. 
   
   
       5 . A detector for distinguishing a phase from a multiphase fluid mixture according to  claim 4 , wherein the first and second branch are perpendicular. 
   
   
       6 . A detector for distinguishing a phase from a multiphase fluid mixture according to  claim 4 , wherein the first and second branch are in-line. 
   
   
       7 . A detector for distinguishing a phase from a multiphase fluid mixture according to  claim 4 , wherein the third branch is perpendicular to the second branch. 
   
   
       8 . A detector for distinguishing a phase from a multiphase fluid mixture according to  claim 1 , wherein the optical probe is coupled to the bore of the detector cell through a compression fitting. 
   
   
       9 . A detector for distinguishing a phase from a multiphase fluid mixture according to  claim 1 , wherein the optical probe comprises a sapphire rod having a bi-cone shaped tip, the optical probe being connected to an electronic module though an optical fiber. 
   
   
       10 . A transferring arrangement, for transferring a single phase from a sampling bottle comprising a multiphase fluid mixture to a shipping bottle, the transferring arrangement comprising:
 a flow line (L) coupling the sampling bottle to the shipping bottle, and   a pumping arrangement for transferring a fluid from the sampling bottle to the shipping bottle,   a detector for distinguishing a phase from a multiphase fluid mixture, the detector comprising:
 an optical probe for optically distinguishing one of the phases from the part of the multiphase fluid mixture, the optical probe having a tip in contact with the fluid transferred from the sampling bottle to the shipping bottle, 
 a detector cell arranged to be coupled to the flow line (L) and to the optical probe and comprising an internal flowing line and a bore coupled to the internal flowing line, 
 the bore positioning the optical probe in the detector cell so that the part of the multiphase fluid mixture flows substantially around the tip of the optical probe. 
   
   
   
       11 . A hydrocarbon well testing arrangement, for testing a well that produces a multiphase fluid mixture flowing though a main line, the arrangement comprising:
 a derivation line coupled to the main line for deriving a part of the multiphase fluid mixture,   a detector for distinguishing a phase from a multiphase fluid mixture, the detector comprising:
 an optical probe for optically distinguishing one of the phases from the part of the multiphase fluid mixture, the optical probe having a tip in contact with the part of the multiphase fluid mixture, 
 a detector cell arranged to be coupled to the derivation line and to the optical probe and comprising an internal flowing line and a bore coupled to the internal flowing line, 
 the internal flowing line being arranged so that the phases of the part of the multiphase fluid mixture flowing in the internal flowing line are driven-on by capillarity effect, 
 the bore positioning the optical probe in the detector cell so that the part of the multiphase fluid mixture flows substantially around the tip of the optical probe. 
   an acquisition device connected to the detector.   
   
   
       12 . A hydrocarbon well flowrate measurement arrangement, for measuring a flowrate of a phase of a multiphase fluid mixture flowing though a main line of a hydrocarbon well, the arrangement comprising:
 a derivation line coupled to the main line for deriving a part of the multiphase fluid mixture,   at least two detectors for distinguishing a phase from a multiphase fluid mixture, each detector being connected in serial along the derivation line, each detector comprising:
 an optical probe for optically distinguishing one of the phases from the part of the multiphase fluid mixture, the optical probe having a tip in contact with the part of the multiphase fluid mixture, 
 a detector cell arranged to be coupled to the derivation line and to the optical probe and comprising an internal flowing line and a bore coupled to the internal flowing line, 
 the internal flowing line being arranged so that the phases of the part of the multiphase fluid mixture flowing in the internal flowing line are driven-on by capillarity effect plugs and rings in the internal flowing line, 
 the bore positioning the optical probe in the detector cell so that the part of the multiphase fluid mixture flows substantially around the tip of the optical probe. 
   an acquisition device connected to the detectors, the acquisition device:
 receiving from each detector a signal which level is characteristic of the phase flowing around the tip, 
 performing a cross correlation of the received signals, 
 determining a transit time of each phase from one detector to the other, and 
 computing a measurement representative of the flow rate in the main line.