Capturing most severe failure regions around borehole in analytical poroelastic analysis

Abstract

A method for performing a borehole operation is disclosed. The method includes determining a characteristic diffusion time that corresponds to an undrained response period or a non-monotonic pore pressure dissipation phase of a porous medium surrounding a borehole, determining, based on a pre-determined failure criterion, a critical time of the borehole that corresponds to when a failure of the porous medium occurs within the characteristic diffusion time, identifying a failure region of the failure occurring at the critical time of the borehole, and performing, based on at least the identified failure region, the borehole operation.

What is claimed is: 
     
         1 . A method for performing a borehole operation, comprising:
 determining a characteristic diffusion time that corresponds to an undrained response period or a non-monotonic pore pressure dissipation phase of a porous medium surrounding a borehole;   determining, based on a pre-determined failure criterion, a critical time of the borehole that corresponds to when a failure of the porous medium occurs within the characteristic diffusion time;   identifying a failure region of the failure occurring at the critical time of the borehole; and   performing, based on at least the identified failure region, the borehole operation.   
     
     
         2 . The method of  claim 1 ,
 wherein the borehole is an existing borehole,   wherein the failure that occurred during previous drilling of the borehole results in a potential borehole breakout event, and   wherein the borehole operation comprises a maintenance operation to mitigate the potential borehole breakout event.   
     
     
         3 . The method of  claim 1 , further comprising:
 determining, based on at least the identified failure region, an adjusted mud weight with respect to time,   wherein the borehole operation is performed further based on the adjusted mud weight with respect to time.   
     
     
         4 . The method of  claim 1 ,
 wherein the borehole is a planned borehole to be drilled,   wherein the failure is predicted to occur during a drilling operation of the planned borehole to result in a potential borehole breakout event, and   wherein the borehole operation comprises the drilling operation that is performed based on drilling parameters and equipment that are selected to mitigate the potential borehole breakout event.   
     
     
         5 . The method of  claim 4 , further comprising:
 specifying, based on the identified failure region, the drilling parameters and the equipment of the drilling operation.   
     
     
         6 . The method of  claim 1 ,
 wherein the pre-determined failure criterion comprises one of Mohr-Coulomb criterion, Drucker-Prager criterion, Hoek-Brown criterion, and Modified Lade criterion.   
     
     
         7 . The method of  claim 1 , wherein performing the borehole operation comprises preventing a borehole breakout induced problem of tight hole or stuck pipe. 
     
     
         8 . A data gathering and analysis system, comprising:
 a computer processor; and   memory storing instructions, when executed, causing the computer processor to:
 determine a characteristic diffusion time that corresponds to an undrained response period or a non-monotonic pore pressure dissipation phase of a porous medium surrounding a borehole; 
 determine, based on a pre-determined failure criterion, a critical time of the borehole that corresponds to when a failure of the porous medium occurs within the characteristic diffusion time; 
 identify a failure region of the failure occurring at the critical time of the borehole; and 
 perform, based at least on the identified failure region, a borehole operation. 
   
     
     
         9 . The data gathering and analysis system of  claim 8 ,
 wherein the borehole is an existing borehole,   wherein the failure that occurred during previous drilling of the borehole results in a potential borehole breakout event, and   wherein the borehole operation comprises a maintenance operation to mitigate the potential borehole breakout event.   
     
     
         10 . The data gathering and analysis system of  claim 8 , instructions, when executed, further causing the computer processor to:
 determine, based on at least the identified failure region, an adjusted mud weight with respect to time,   wherein the borehole operation is performed further based on the adjusted mud weight with respect to time.   
     
     
         11 . The data gathering and analysis system of  claim 8 ,
 wherein the borehole is a planned borehole to be drilled,   wherein the failure is predicted to occur during a drilling operation of the planned borehole to result in a potential borehole breakout event, and   wherein the borehole operation comprises the drilling operation that is performed based on drilling parameters and equipment that are selected to mitigate the potential borehole breakout event.   
     
     
         12 . The data gathering and analysis system of  claim 11 , instructions, when executed, further causing the computer processor to:
 specify, based on the identified failure region, the drilling parameters and the equipment of the drilling operation.   
     
     
         13 . The data gathering and analysis system of  claim 8 ,
 wherein the pre-determined failure criterion comprises one of Mohr-Coulomb criterion, Drucker-Prager criterion, Hoek-Brown criterion, and Modified Lade criterion.   
     
     
         14 . The data gathering and analysis system of  claim 8 , wherein performing the borehole operation comprises preventing a borehole breakout induced problem of tight hole or stuck pipe. 
     
     
         15 . A well system comprising:
 a rig for drilling a borehole; and   a data gathering and analysis system comprising functionality for:
 determining a characteristic diffusion time that corresponds to an undrained response period or a non-monotonic pore pressure dissipation phase of a porous medium surrounding a borehole; 
 determining, based on a pre-determined failure criterion, a critical time of the borehole that corresponds to when a failure of the porous medium occurs within the characteristic diffusion time; 
 identifying a failure region of the failure occurring at the critical time of the borehole; and 
 performing, using the rig and based at least on the identified failure region, a borehole operation. 
   
     
     
         16 . The well system of  claim 15 ,
 wherein the borehole is an existing borehole,   wherein the failure that occurred during previous drilling of the borehole results in a potential borehole breakout event, and   wherein the borehole operation comprises a maintenance operation to mitigate the potential borehole breakout event.   
     
     
         17 . The well system of  claim 15 , the data gathering and analysis system further comprising functionality for:
 determining, based on at least the identified failure region, an adjusted mud weight with respect to time,   wherein the borehole operation is performed further based on the adjusted mud weight with respect to time.   
     
     
         18 . The well system of  claim 15 ,
 wherein the borehole is a planned borehole to be drilled,   wherein the failure is predicted to occur during a drilling operation of the planned borehole to result in a potential borehole breakout event, and   wherein the borehole operation comprises the drilling operation that is performed based on drilling parameters and equipment that are selected to mitigate the potential borehole breakout event.   
     
     
         19 . The well system of  claim 18 , the data gathering and analysis system further comprising functionality for:
 specifying, based on the identified failure region, the drilling parameters and the equipment of the drilling operation.   
     
     
         20 . The well system of  claim 15 ,
 wherein the pre-determined failure criterion comprises one of Mohr-Coulomb criterion, Drucker-Prager criterion, Hoek-Brown criterion, and Modified Lade criterion, and   wherein performing the borehole operation comprises preventing a borehole breakout induced problem of tight hole or stuck pipe.