Water washing estimation and prediction from statistical relationships of gas compositions

Abstract

A computer-implemented method for estimating water washing parameters is described. The method includes estimating, using at least one hardware processor, a gas oil ratio (GOR) by deriving statistical relationships between gas composition ratios. The method includes calculating, using the at least one hardware processor, a C7 transformation ratio (Tr1) and present-day reservoir temperature (PDRT) based on the GOR. The method also includes creating, using the at least one hardware processor, a water washing intensity index based on the GOR, Tr1, and PDRT. Additionally, the method includes integrating, using the at least one hardware processor, the water washing intensity index with a gross depositional environment map, wherein a resulting integrated map is used to guide water washing of accumulations.

What is claimed is: 
     
         1 . A computer-implemented method for estimating water washing parameters, the method comprising:
 estimating, using at least one hardware processor, a gas oil ratio (GOR) by deriving statistical relationships between gas composition ratios;   calculating, using the at least one hardware processor, a C7 transformation ratio (Tr1) and present-day reservoir temperature (PDRT) based on the GOR;   creating, using the at least one hardware processor, a water washing intensity index based on the GOR, Tr1, and PDRT; and   integrating, using the at least one hardware processor, the water washing intensity index with a gross depositional environment map, wherein a resulting integrated map guides water washing of accumulations.   
     
     
         2 . The computer implemented method of  claim 1 , comprising obtaining gas compositions in real time, during drilling. 
     
     
         3 . The computer implemented method of  claim 1 , comprising obtaining gas compositions after drilling by analyzing rock samples obtained during drilling. 
     
     
         4 . The computer implemented method of  claim 1 , wherein integrating the water washing intensity index with the gross depositional map comprises an indicated water washing intensity index associated with a corresponding depositional environment of the integrated map. 
     
     
         5 . The computer implemented method of  claim 1 , wherein the statistical relationships are predetermined correlations between gas composition ratios and GOR. 
     
     
         6 . The computer implemented method of  claim 1 , wherein calculating Tr1 and PDRT based on the GOR comprises applying predetermined correlations to the GOR. 
     
     
         7 . The computer implemented method of  claim 1 , wherein the water washing intensity index quantifies an intensity of a water washing process as none, very slight, slight, moderate, or severe. 
     
     
         8 . An apparatus comprising a non-transitory, computer readable, storage medium that stores instructions that, when executed by at least one processor, cause the at least one processor to perform operations comprising:
 estimating a gas oil ratio (GOR) by deriving statistical relationships between gas composition ratios;   calculating a C7 transformation ratio (Tr1) and present-day reservoir temperature (PDRT) based on the GOR;   creating a water washing intensity index based on the GOR, Tr1, and PDRT; and   integrating the water washing intensity index with a gross depositional environment map, wherein a resulting integrated map guides water washing of accumulations.   
     
     
         9 . The apparatus of  claim 8 , comprising obtaining gas compositions in real time, during drilling. 
     
     
         10 . The apparatus of  claim 8 , comprising obtaining gas compositions after drilling by analyzing rock samples obtained during drilling. 
     
     
         11 . The apparatus of  claim 8 , wherein integrating the water washing intensity index with the gross depositional map comprises an indicated a water washing intensity index associated with a corresponding depositional environment of the integrated map. 
     
     
         12 . The apparatus of  claim 8 , wherein the statistical relationships are predetermined correlations between gas composition ratios and GOR. 
     
     
         13 . The apparatus of  claim 8 , wherein calculating Tr1 and PDRT based on the GOR comprises applying predetermined correlations to the GOR. 
     
     
         14 . The apparatus of  claim 8 , wherein the water washing intensity index quantifies an intensity of a water washing process as none, very slight, slight, moderate, or severe. 
     
     
         15 . A system, comprising:
 one or more memory modules;   one or more hardware processors communicably coupled to the one or more memory modules, the one or more hardware processors configured to execute instructions stored on the one or more memory models to perform operations comprising:   estimating a gas oil ratio (GOR) by deriving statistical relationships between gas composition ratios;   calculating a C7 transformation ratio (Tr1) and present-day reservoir temperature (PDRT) based on the GOR;   creating a water washing intensity index based on the GOR, Tr1, and PDRT; and   integrating the water washing intensity index with a gross depositional environment map, wherein a resulting integrated map guides water washing of accumulations.   
     
     
         16 . The system of  claim 15 , comprising obtaining gas compositions in real time, during drilling. 
     
     
         17 . The system of  claim 15 , comprising obtaining gas compositions after drilling by analyzing rock samples obtained during drilling. 
     
     
         18 . The system of  claim 15 , wherein integrating the water washing intensity index with the gross depositional map comprises an indicated a water washing intensity index associated with a corresponding depositional environment of the integrated map. 
     
     
         19 . The system of  claim 15 , wherein the statistical relationships are predetermined correlations between gas composition ratios and GOR. 
     
     
         20 . The system of  claim 15 , wherein calculating Tr1 and PDRT based on the GOR comprises applying predetermined correlations to the GOR.