Real-time fluid monitoring and classification using downhole spectrometer measurements

Abstract

The disclosed techniques relate to fluid monitoring and classification techniques that include a method that includes acquiring, via a spectral analysis module of a sampling system of a downhole well tool, spectral data for an unknown reservoir fluid received by the sampling system of the downhole well tool from a geological formation; determining, via the one or more processors, a fluid type of the unknown reservoir fluid in the sampling system of the downhole well tool based at least in part on projections of the spectral data for the unknown reservoir fluid onto at least the first two eigenvectors of spectral data of known fluids stored in a spectral database; and generating, via the one or more processors, a downhole well operation decision based on the determined fluid type of the unknown reservoir fluid in substantially real-time while the sampling system of the downhole well tool receives the unknown reservoir fluid.

1 . A method, comprising:
 acquiring, via a spectral analysis module of a sampling system of a downhole well tool, spectral data for an unknown reservoir fluid received by the sampling system of the downhole well tool from a geological formation;   determining, via the one or more processors, a fluid type of the unknown reservoir fluid in the sampling system of the downhole well tool based at least in part on projections of the spectral data for the unknown reservoir fluid onto at least the first two eigenvectors of spectral data of known fluids stored in a spectral database; and   generating, via the one or more processors, a downhole well operation decision based on the determined fluid type of the unknown reservoir fluid in substantially real-time while the sampling system of the downhole well tool receives the unknown reservoir fluid.   
     
     
         2 . The method of  claim 1 , comprising:
 training, via the one or more processors, fluid monitoring and classification (FMC) algorithms based on reference fluid types of spectral measurements stored in the spectral database; and   determining, via the one or more processors, the fluid type of the unknown reservoir fluid based at least in part on the trained FMC algorithms.   
     
     
         3 . The method of  claim 2 , wherein training, via the one or more processors, the FMC algorithms comprises determining the eigenvectors of the spectral data of the known fluids stored in the spectral database. 
     
     
         4 . The method of  claim 1 , comprising:
 continuously monitoring, via the spectral analysis module of the downhole well tool, changes in the spectral data for a subsequent reservoir fluid during a downhole well operation;   determining, via the one or more processors, a fluid type of the subsequent reservoir fluid based at least in part on the subsequent projections of the spectral data; and   adjusting, via the one or more processors, the downhole well operation decision based on the determined fluid type of the subsequent reservoir fluid.   
     
     
         5 . The method of  claim 1 , comprising automatically adjusting, via the one or more processors, a downhole well operation in accordance with the downhole well operation decision. 
     
     
         6 . The method of  claim 1 , comprising determining, via the one or more processors, the fluid type of the unknown reservoir fluid in the sampling system of the downhole well tool based at least in part on projections of the spectral data for the unknown reservoir fluid onto only the first two eigenvectors of the spectral data of the known fluids stored in the spectral database. 
     
     
         7 . The method of  claim 6 , wherein determining the fluid type of the unknown reservoir fluid comprises utilizing cross-plots of the projections of the first and second eigenvectors of the spectral data relative to their positions on a unit-circle of 1. 
     
     
         8 . The method of  claim 7 , comprising:
 determining, via the one or more processors, a gas-oil-ratio (GOR) of the unknown reservoir fluid based on angles formed by the projections of the first and second eigenvectors of the spectral data; and   determining, via the one or more processors, the fluid type of the unknown reservoir fluid based at least in part on the determined GOR.   
     
     
         9 . The method of  claim 1 , wherein determining the fluid type of the unknown reservoir fluid comprises categorizing the unknown reservoir fluid as one of: black oil, volatile oil, gas condensate, wet gas, and dry gas. 
     
     
         10 . A system, comprising:
 a spectral analysis module configured to acquire spectral data for an unknown reservoir fluid received by a sampling system of a downhole well tool from a geological formation; and   a data processing system configured to:
 determine a fluid type of the unknown reservoir fluid in the sampling system of the downhole well tool based at least in part on projections of the spectral data for the unknown reservoir fluid onto at least the first two eigenvectors of spectral data of known fluids stored in a spectral database; and 
 generate a downhole well operation decision based on the determined fluid type of the unknown reservoir fluid in substantially real-time while the sampling system of the downhole well tool receives the unknown reservoir fluid. 
   
     
     
         11 . The system of  claim 10 , wherein the data processing system is configured to:
 train fluid monitoring and classification (FMC) algorithms based on reference fluid types of spectral measurements stored in the spectral database; and   determine the fluid type of the unknown reservoir fluid based at least in part on the trained FMC algorithms.   
     
     
         12 . The system of  claim 11 , wherein training the FMC algorithms comprises determining the eigenvectors of the spectral data of the known fluids stored in the spectral database. 
     
     
         13 . The system of  claim 10 , wherein the spectral analysis module is configured to continuously monitor changes in the spectral data for a subsequent reservoir fluid during a downhole well operation, and wherein the data processing system is configured to:
 determine a fluid type of the subsequent reservoir fluid based at least in part on the subsequent projections of the spectral data; and   adjust the downhole well operation decision based on the determined fluid type of the subsequent reservoir fluid.   
     
     
         14 . The system of  claim 10 , wherein the data processing system is configured to automatically adjust a downhole well operation in accordance with the downhole well operation decision. 
     
     
         15 . The system of  claim 10 , wherein the data processing system is configured to determine the fluid type of the unknown reservoir fluid in the sampling system of the downhole well tool based at least in part on projections of the spectral data for the unknown reservoir fluid onto only the first two eigenvectors of the spectral data of the known fluids stored in the spectral database. 
     
     
         16 . The system of  claim 15 , wherein determining the fluid type of the unknown reservoir fluid comprises utilizing cross-plots of the projections of the first and second eigenvectors of the spectral data relative to their positions on a unit-circle of 1. 
     
     
         17 . The system of  claim 16 , wherein the data processing system is configured to:
 determine a gas-oil-ratio (GOR) of the unknown reservoir fluid based on angles formed by the projections of the first and second eigenvectors of the spectral data; and   determine the fluid type of the unknown reservoir fluid based at least in part on the determined GOR.   
     
     
         18 . The system of  claim 10 , wherein determining the fluid type of the unknown reservoir fluid comprises categorizing the unknown reservoir fluid as one of: black oil, volatile oil, gas condensate, wet gas, and dry gas. 
     
     
         19 . A method, comprising:
 acquiring, via a spectral analysis module of a sampling system of a downhole well tool, spectral data for an unknown reservoir fluid received by the sampling system of the downhole well tool from a geological formation;   training, via one or more processors, fluid monitoring and classification (FMC) algorithms based on reference fluid types of spectral measurements stored in the spectral database to determine eigenvectors of spectral data of known fluids stored in a spectral database;   determining, via the one or more processors, a fluid type of the unknown reservoir fluid in the sampling system of the downhole well tool based at least in part on projections of the spectral data for the unknown reservoir fluid onto at least the first two eigenvectors of the spectral data of the known fluids stored in the spectral database and based at least in part on the trained FMC algorithms; and   generating, via the one or more processors, a downhole well operation decision based on the determined fluid type of the unknown reservoir fluid in substantially real-time while the sampling system of the downhole well tool receives the unknown reservoir fluid.   
     
     
         20 . The method of  claim 19 , comprising automatically adjusting, via the one or more processors, a downhole well operation in accordance with the downhole well operation decision.