Fast screening of hydraulic fracture and reservoir models conditioned to production data

Abstract

A method involves obtaining a measured drainage function for a well and obtaining a set of drainage models, wherein each drainage model includes a reservoir model and a fracture model. The method also includes, for each drainage model, forming a predicted drainage function based, at least in part, on the drainage model, and determining a misfit value based, at least in part, on the predicted drainage function and the measured drainage function. The method further includes determining a set of candidate drainage models based, at least in part, on the misfit value for each drainage model, wherein each candidate drainage model comprises a candidate reservoir model and a candidate fracture model.

What is claimed: 
     
         1 . A method, comprising:
 obtaining a measured drainage function for a well;   obtaining a set of drainage models, wherein each drainage model comprises a reservoir model and a fracture model;   for each drainage model:
 forming a predicted drainage function based, at least in part, on the drainage model, and 
 determining a misfit value based, at least in part, on the predicted drainage function and the measured drainage function; and 
   determining a set of candidate drainage models based, at least in part, on the misfit value for each drainage model, wherein each candidate drainage model comprises a candidate reservoir model and a candidate fracture model.   
     
     
         2 . The method of  claim 1 , wherein forming a predicted drainage function comprises simulating a connected volume using a fast marching method solution to an eikonal equation. 
     
     
         3 . The method of  claim 1 , further comprising determining, for each candidate model, a preferred drainage model based on a reduction of the misfit value caused by perturbing of the candidate fracture model. 
     
     
         4 . The method of  claim 3 , further comprising performing full-physics pressure-transient/rate-transient simulation using the preferred drainage model. 
     
     
         5 . The method of  claim 1 , wherein determining the set of candidate drainage models comprises comparing the misfit value of each drainage model with a tolerance value. 
     
     
         6 . The method of  claim 5 , wherein the tolerance value is a predetermined value. 
     
     
         7 . The method of  claim 5 , wherein the tolerance value is selected based on a range of the misfit values. 
     
     
         8 . The method of  claim 3 , wherein determining, for each candidate model, a preferred drainage model based on a reduction of the misfit value comprises applying a machine learning network. 
     
     
         9 . The method of  claim 4 , wherein performing full-physics pressure-transient/rate-transient simulation comprises determining an uncertainty for the drainage model. 
     
     
         10 . The method of  claim 1 , wherein the fracture model comprises a plurality of fracture models each describing one of a plurality of hydraulic fractures intersecting the well. 
     
     
         11 . The method of  claim 1 , wherein the well comprises one or more wells. 
     
     
         12 . The method of  claim 1 , further comprising:
 determining a spacing of hydraulic fractures in an adjacent well; and   generating hydraulic fractures at the spacing.   
     
     
         13 . A non-transitory computer-readable medium storing instructions, the instructions, when executed on a processor, comprising functionality for:
 receiving a measured drainage function for a well;   obtaining a set of drainage models, wherein each drainage model comprises a reservoir model and a fracture model;   for each drainage model:
 forming a predicted drainage function based, at least in part, on the drainage model, and 
 determining a misfit value based, at least in part, on the predicted drainage function and the measured drainage function; and 
   determining a set of candidate drainage models based, at least in part, on the misfit value for each drainage model, wherein each candidate drainage model comprises a candidate reservoir model and a candidate fracture model.   
     
     
         14 . The non-transitory computer-readable medium of  claim 13 , wherein forming a predicted drainage function comprises simulating a connected volume using a fast marching method solution to an eikonal equation. 
     
     
         15 . The non-transitory computer-readable medium of  claim 13 , further comprising determining, for each candidate model, a preferred drainage model based on a reduction of the misfit value caused by perturbing of the candidate fracture model. 
     
     
         16 . The non-transitory computer-readable medium of  claim 15 , further comprising performing full-physics pressure-transient/rate-transient simulation using the preferred drainage model. 
     
     
         17 . A system, comprising:
 a well testing system, to determine a measured drainage function; and   a computer processor, configured to:
 receive a measured drainage function for a well; 
 obtain a set of drainage models, wherein each drainage model comprises a reservoir model and a fracture model; 
 for each drainage model:
 form a predicted drainage function based, at least in part, on the drainage model, and 
 determine a misfit value based, at least in part, on the predicted drainage function and the measured drainage function; and 
 
 determine a set of candidate drainage models based, at least in part, on the misfit value for each drainage model, wherein each candidate drainage model comprises a candidate reservoir model and a candidate fracture model. 
   
     
     
         18 . The system of  claim 17 , wherein the computer processor is further configured to:
 determine a spacing of hydraulic fractures in an adjacent well; and   generate hydraulic fractures at the spacing.   
     
     
         19 . The system of  claim 17 , wherein the computer processor is further configured to determine, for each candidate model, a preferred drainage model based on a reduction of the misfit value caused by perturbing of the candidate fracture model. 
     
     
         20 . The system of  claim 19 , wherein the computer processor is further configured to perform full-physics pressure-transient/rate-transient simulation using the preferred drainage model.