System and method for remaining resource mapping

Abstract

A method for mapping remaining hydrocarbon resources in a subsurface reservoir, includes generating a pressure depletion map of the subsurface reservoir based on a pressure depletion dataset representing a pressure change in at least one well over a time interval, obtaining a hydrocarbon pore thickness map of the subsurface reservoir based on a hydrocarbon pore thickness dataset representing hydrocarbon pore thickness substantially at a beginning of the time interval, using the pressure depletion map and the hydrocarbon pore thickness map, generating a remaining resource map of the subsurface reservoir, for each of a plurality of infill wells located in the subsurface reservoir and operated during a portion of the time interval, determining an estimated ultimate recovery value, using each estimated ultimate recovery value with data from the remaining resource map for the locations of the infill wells to determine a correlation, and using the correlations and the remaining resource map, evaluating a location for a proposed infill well.

What is claimed is: 
     
         1 . A method for mapping remaining hydrocarbon resources in a subsurface reservoir, comprising:
 generating a pressure depletion map of the subsurface reservoir based on a pressure depletion dataset representing a pressure change in at least one well over a time interval;   obtaining a hydrocarbon pore thickness map of the subsurface reservoir based on a hydrocarbon pore thickness dataset representing a hydrocarbon pore thickness substantially at a beginning of the time interval;   using the pressure depletion map and the hydrocarbon pore thickness map, generating a remaining resource map of the subsurface reservoir;   for each of a plurality of infill wells located in the subsurface reservoir and operated during a portion of the time interval, determining an estimated ultimate recovery value;   using each estimated ultimate recovery value with data from the remaining resource map for the locations of the infill wells to determine a correlation; and   using the correlations and the remaining resource map, evaluating a location for a proposed infill well.   
     
     
         2 . A method as in  claim 1 , further comprising, estimating, for the proposed infill well location, a proportion of infill well production that represents accelerated production and a proportion of infill well production that represents incremental impact of the infill well, wherein the estimating is based on the remaining resource map and the correlations. 
     
     
         3 . A method as in  claim 2 , wherein the estimating is further used to generate contours of incremental reserves for the subsurface reservoir. 
     
     
         4 . A method as in  claim 2 , wherein an ensemble of estimates of incremental impact is generated. 
     
     
         5 . A method as in  claim 1 , wherein the estimated ultimate recovery value for each well is estimated based, at least in part, on measured pressure decline rate and cumulative production for each well. 
     
     
         6 . A method as in  claim 1 , wherein the estimated ultimate recovery value for each well comprises a range of estimated ultimate recoveries. 
     
     
         7 . A method as in  claim 1 , wherein the generating a pressure depletion map comprises generating high and low case pressure depletion maps. 
     
     
         8 . A system for mapping remaining hydrocarbon resources in a subsurface reservoir, comprising:
 a depletion map module configured and arranged to generate a pressure depletion map of the subsurface reservoir based on a pressure depletion dataset representing a pressure change in at least one well over a time interval;   a pore thickness map module configured and arranged to obtain a hydrocarbon pore thickness map of the subsurface reservoir based on a hydrocarbon pore thickness dataset representing hydrocarbon pore thickness substantially at a beginning of the time interval;   a remaining resource map module configured and arranged to use the pressure depletion map and the hydrocarbon pore thickness map, to generate a remaining resource map of the subsurface reservoir;   an estimated ultimate recovery module configured and arranged to, for each of a plurality of infill wells located in the subsurface reservoir and operated during a portion of the time interval, determine an estimated ultimate recovery value;   a correlation module configured and arranged to use each estimated ultimate recovery value with data from the remaining resource map for the locations of the infill wells to determine a correlation; and   an evaluation module configured and arranged to, using the correlations and the remaining resource map, evaluate a location for a proposed infill well.   
     
     
         9 . A non-transitory processor readable medium containing computer readable software instructions for performing the method comprising:
 generating a pressure depletion map of the subsurface reservoir based on a pressure depletion dataset representing a pressure change in at least one well over a time interval;   obtaining a hydrocarbon pore thickness map of the subsurface reservoir based on a hydrocarbon pore thickness dataset representing hydrocarbon pore thickness substantially at a beginning of the time interval;   using the pressure depletion map and the hydrocarbon pore thickness map, generating a remaining resource map of the subsurface reservoir;   for each of a plurality of infill wells located in the subsurface reservoir and operated during a portion of the time interval, determining an estimated ultimate recovery value;   using each estimated ultimate recovery value with data from the remaining resource map for the locations of the infill wells to determine a correlation; and   using the correlations and the remaining resource map, evaluating a location for a proposed infill well.