Formation elastic property evaluation using drilling data based on a bit-rock interaction model

Abstract

A method comprises obtaining drilling data of a drill bit while drilling a wellbore in a formation with the drill bit. The method comprises generating stress representatives and strain representatives via a bit-rock interaction model configured with parameters to map the drilling data. The method comprises determining one or more elastic properties of the formation based on the stress representatives and the strain representatives.

The invention claimed is: 
     
         1 . A method comprising:
 obtaining drilling data of a drill bit while drilling a wellbore in a formation with the drill bit;   generating stress representatives and strain representatives via a bit-rock interaction model configured with parameters to map the drilling data; and   determining one or more elastic properties of the formation based on the stress representatives and the strain representatives.   
     
     
         2 . The method of  claim 1 , wherein the drilling data includes any one or more of torque on bit, weight on bit, drill bit accelerations, rotations per minute, depth of cut, and rate of penetration. 
     
     
         3 . The method of  claim 1 , wherein the stress representatives are generated based on drill bit vibrations; and wherein the strain representatives are generated based on rate of penetration. 
     
     
         4 . The method of  claim 3 , wherein the drill bit vibrations are obtained via sensors proximate the drill bit including accelerometers, strain gauges, gyroscopes, magnetometers, or any combination thereof. 
     
     
         5 . The method of  claim 1 , wherein the one or more elastic properties of the formation are determined based on Hooke's law. 
     
     
         6 . The method of  claim 1  further comprising;
 obtaining reference elastic properties of the formation to be drilled by the drill bit; 
 calibrating the bit-rock interaction model with the reference elastic properties; and 
 outputting the parameters for the drilling data. 
 
     
     
         7 . The method of  claim 6  further comprising:
 inputting the drilling data and the parameters into the bit-rock interaction model to generate the stress representatives and the strain representatives. 
 
     
     
         8 . The method of  claim 1 , wherein the one or more elastic properties includes Young's modulus and Poisson's ratio. 
     
     
         9 . A system comprising:
 a drill bit configured to drill a wellbore in a formation;   a processor; and   a computer-readable medium having instructions stored thereon that are executable by the processor to cause the processor to,
 obtain drilling data of the drill bit while drilling the wellbore; 
 generate stress representatives and strain representatives via a bit-rock interaction model configured with parameters to map the drilling data; and 
 determining one or more elastic properties of the formation based on the stress representatives and the strain representatives. 
   
     
     
         10 . The system of  claim 9 , wherein the drilling data includes any one or more of torque on bit, weight on bit, drill bit accelerations, rotations per minute, depth of cut, and rate of penetration. 
     
     
         11 . The system of  claim 9 , wherein the stress representatives are generated based on drill bit vibrations; and wherein the strain representatives are generated based on rate of penetration. 
     
     
         12 . The system of  claim 11 , wherein the drill bit vibrations are obtained via sensors at the drill bit including accelerometers, strain gauges, gyroscopes, magnetometers, or any combination thereof. 
     
     
         13 . The system of  claim 9 , wherein the one or more elastic properties of the formation are determined based on Hooke's law. 
     
     
         14 . The system of  claim 9  further comprising;
 obtaining reference elastic properties of the formation to be drilled by the drill bit; 
 calibrating the bit-rock interaction model with the reference elastic properties; and 
 outputting, the parameters for the drilling data. 
 
     
     
         15 . A non-transitory, computer-readable medium having instructions stored thereon that are executable by a processor to perform operations comprising:
 obtaining drilling data of a drill bit while drilling a wellbore in a formation with the drill bit;   generating stress representatives and strain representatives via a bit-rock interaction model configured with parameters to map the drilling data; and   determining one or more elastic properties of the formation based on the stress representatives and the strain representatives.   
     
     
         16 . The non-transitory, computer-readable medium of  claim 15 , wherein the drilling data includes torque on bit, weight on bit, drill bit accelerations, rotations per minute, depth of cut, and rate of penetration. 
     
     
         17 . The non-transitory, computer-readable medium of  claim 15 , wherein the stress representatives are generated based on drill bit vibrations; and wherein the strain representatives are generated based on rate of penetration. 
     
     
         18 . The non-transitory, computer-readable medium of  claim 17 , wherein the drill bit vibrations are obtained via sensors at the drill bit including accelerometers, strain gauges, gyroscopes, magnetometers, or any combination thereof. 
     
     
         19 . The non-transitory, computer-readable medium of  claim 15  further comprising;
 obtaining reference elastic properties of the formation to be drilled by the drill bit; 
 calibrating the bit-rock interaction model with the reference elastic properties; and 
 outputting, the parameters for the drilling data. 
 
     
     
         20 . The non-transitory, computer-readable medium of  claim 19  further comprising:
 inputting the drilling data and the parameters into the bit-rock interaction model to generate the stress representatives and the strain representatives.