Modeling pressure response of in-situ diverting acid flow

Abstract

Examples described herein provide for modeling pressure response of acid flow of an acid in a formation. An example method includes receiving data associated with acid stimulation of a formation and modeling the pressure response of the acid flow in the formation. Modeling the pressure response is based on a model which divides a domain into multiple zones, and modeling the pressure response includes modeling a length of a disturbance zone included in the multiple zones based on a function of: reaction kinetics associated with the acid and rock included in the formation; and an injection rate of the acid, a velocity of the acid, or both. The method includes performing the acid stimulation based on a stimulation parameter associated with the data and the acid stimulation or a modified stimulation parameter, responsive to determining whether the pressure response satisfies the pressure response threshold.

What is claimed is: 
     
         1 . A method for modeling pressure response of acid flow of an acid in a formation, the method comprising:
 receiving data associated with acid stimulation of a formation;   modeling the pressure response of the acid flow in the formation, wherein modeling the pressure response is based on a model which divides a domain into multiple zones, and modeling the pressure response comprises modeling a length of a disturbance zone comprised in the multiple zones based on a function of:
 reaction kinetics associated with the acid and rock comprised in the formation; and 
 an injection rate of the acid, a velocity of the acid, or both; 
   determining whether the pressure response satisfies a pressure response threshold; and   performing the acid stimulation based at least in part on a stimulation parameter associated with the data and the acid stimulation or a modified stimulation parameter, responsive to determining whether the pressure response satisfies the pressure response threshold.   
     
     
         2 . The method of  claim 1 , further comprising:
 responsive to determining that the pressure response fails to satisfy the pressure response threshold, modifying the stimulation parameter in association with adjusting the pressure response; and   performing the acid stimulation based at least in part on the modified stimulation parameter.   
     
     
         3 . The method of  claim 1 , wherein the acid comprises a self-diverting acid. 
     
     
         4 . The method of  claim 1 , wherein modeling the pressure response is based on a function of a consecutive series of flow disturbances in the disturbance zone causing pressure build up. 
     
     
         5 . The method of  claim 1 , wherein the pressure response is a function of an injected volume of the acid, a pore volume of the disturbance zone, and the velocity of the acid. 
     
     
         6 . The method of  claim 1 , wherein the pressure response comprises at least one of:
 first pressure response associated with a first zone of the multiple zones, the first zone comprising a wormhole formed in the formation in association with the acid stimulation;   second pressure response associated with a second zone of the multiple zones, wherein the second zone is adjacent the first zone; and   third pressure response associated with a third zone of the multiple zones, wherein the third zone is adjacent the second zone.   
     
     
         7 . The method of  claim 1 , further comprising:
 determining an acid concentration of the acid associated with the acid stimulation, wherein the acid concentration is associated with an end portion of a wormhole formed in association with the acid stimulation,   wherein modeling the pressure response is based at least in part on the acid concentration.   
     
     
         8 . The method of  claim 7 , further comprising:
 determining a second acid concentration of the acid, wherein the second acid concentration is associated with a location in the formation at which a viscosity level of the acid satisfies a threshold viscosity,   wherein modeling the pressure response is based at least in part on the second acid concentration.   
     
     
         9 . The method of  claim 1 , wherein modeling the pressure response comprises:
 determining, by applying the data associated with the acid stimulation to the model, a pore volume to breakthrough value associated with the formation,   wherein setting or modifying the stimulation parameter is based on the pore volume to breakthrough value.   
     
     
         10 . The method of  claim 1 , wherein modeling the pressure response is based at least in part on one or more dimensions of a wormhole formed in the formation in association with the acid stimulation. 
     
     
         11 . The method of  claim 1 , wherein modeling the pressure response is based at least in part on temperature information associated with the formation. 
     
     
         12 . The method of  claim 1 , wherein the model comprises a linear model. 
     
     
         13 . The method of  claim 1 , wherein the model comprises a radial model. 
     
     
         14 . The method of  claim 1 , wherein the data associated with the acid stimulation comprises:
 laboratory data; and   field data associated with one or more wellbore operations.   
     
     
         2 . A system for modeling pressure response of acid flow of an acid in a formation, the system comprising:
 a processing system configured to execute computer readable instructions, the computer readable instructions controlling the processing system to perform operations comprising:   receiving data associated with acid stimulation of a formation;   modeling the pressure response of the acid flow in the formation, wherein modeling the pressure response is based on a model which divides a domain into multiple zones, and modeling the pressure response comprises modeling a length of a disturbance zone comprised in the multiple zones based on a function of:
 reaction kinetics associated with the acid and rock comprised in the formation; and 
 an injection rate of the acid, a velocity of the acid, or both; 
   determining whether the pressure response satisfies a pressure response threshold; and   performing the acid stimulation based at least in part on a stimulation parameter associated with the data and the acid stimulation or a modified stimulation parameter, responsive to determining whether the pressure response satisfies the pressure response threshold.   
     
     
         16 . The system of claim  15 , wherein the computer readable instructions control the processing system to perform further operations comprising:
 responsive to determining that the pressure response fails to satisfy the pressure response threshold, modifying the stimulation parameter in association with adjusting the pressure response; and   performing the acid stimulation based at least in part on the modified stimulation parameter.   
     
     
         17 . The system of claim  15 , wherein the acid comprises a self-diverting acid. 
     
     
         18 . The system of claim  15 , wherein modeling the pressure response is based on a function of a consecutive series of flow disturbances in the disturbance zone causing pressure build up. 
     
     
         19 . The system of claim  15 , wherein the pressure response is a function of an injected volume of the acid, a pore volume of the disturbance zone, and the velocity of the acid. 
     
     
         20 . The system of claim  15 , wherein the pressure response comprises at least one of:
 first pressure response associated with a first zone of the multiple zones, the first zone comprising a wormhole formed in the formation in association with the acid stimulation;   second pressure response associated with a second zone of the multiple zones, wherein the second zone is adjacent the first zone; and   third pressure response associated with a third zone of the multiple zones, wherein the third zone is adjacent the second zone.