Drilling efficiency evaluation

Abstract

A method comprises measuring, at a surface of a wellbore during drilling of the wellbore, at least one drilling operational parameter and determining at least one at-bit model parameter, at a drill bit used for drilling the wellbore, based on the at least one drilling operational parameter measured at the surface of the wellbore. The method comprises determining a drilling efficiency based on the at least one at-bit model parameter.

1 . A method comprising:
 measuring, at a surface of a wellbore during drilling of the wellbore, at least one drilling operational parameter;   determining at least one at-bit model parameter, at a drill bit used for drilling the wellbore, based on the at least one drilling operational parameter measured at the surface of the wellbore; and   determining a drilling efficiency based on the at least one at-bit model parameter.   
     
     
         2 . The method of  claim 1 , further comprising:
 transforming the at least one drilling operational parameter to at least one scaled drilling operational parameter based on transformation of the drill bit to an equivalent singular blade at unit length.   
     
     
         3 . The method of  claim 1 ,
 wherein determining the at least one at-bit parameter, at the drill bit used for drilling the wellbore, based on the at least one drilling operational parameter measured at the surface of the wellbore comprises:
 creating a bit-rock interaction model. 
   
     
     
         4 . The method of  claim 3 ,
 wherein determining the at least one at-bit parameter, at the drill bit used for drilling the wellbore, based on the at least one drilling operational parameter measured at the surface of the wellbore comprises:
 performing the following during drilling of the wellbore,
 monitoring, during drilling of the wellbore, whether the bit-rock interaction model is changing based on the at least one drilling operational parameter; and 
 in response to the bit-rock interaction model changing, adjusting the bit-rock interaction model based on changes to the at least one drilling operational parameter. 
 
   
     
     
         5 . The method of  claim 1 , wherein the at least one drilling operational parameter comprises at least one of weight on bit, rotations per unit of time of the drill string, or a flow rate of a drilling mud. 
     
     
         6 . The method of  claim 1 , wherein the at least one at-bit parameter comprises at least one of weight on bit, torque on bit, or depth of cut. 
     
     
         7 . The method of  claim 1  further comprising:
 modifying at least one operational attribute of the drilling of the wellbore based on the drilling efficiency, wherein the at least one operational attribute of the drilling of the wellbore comprises at least one of weight on bit, rotations of a drill string used for drilling the wellbore per unit of time, or a flow rate of a drilling fluid flowing in the wellbore. 
 
     
     
         8 . The method of  claim 3 , further comprising:
 determining at least one of different drilling regimes, a founder point, or a limiter point based on the bit-rock interaction model; and   classifying the drilling of the wellbore based on the at least one of the different drilling regimes, the founder point, or the limiter point; and   determining a current weight on bit (WOB) of the drilling of the wellbore;   comparing the current WOB of the drilling of the wellbore to at least one of the founder point or the limiter point;   calculating a performance index for drilling the wellbore based on the comparing; and   modifying an operation of the drilling of the wellbore based on the different drilling regimes and based on the performance index.   
     
     
         9 . The method of  claim 8 , further comprising:
 performing a postmortem analysis of the drilling of the wellbore based on previously recorded at least one drilling operational parameter.   
     
     
         10 . The method of  claim 9 , further comprising:
 using the postmortem analysis to inform decisions on drilling of a different wellbore to be drilled, in response to determining that at least one condition of the wellbore and the different wellbore are the same or substantially the same.   
     
     
         11 . The method of  claim 10 , further comprising:
 logging, into a database, at least one of the informing of decisions on the drilling of the different wellbore, the at least one drilling operational parameter measured during drilling of the wellbore, and the performance index calculated for the drilling of the wellbore; and   assessing overall metrics of effectivity of automated decision making with respect to the drilling efficiency.   
     
     
         12 . The method of  claim 1 , further comprising:
 tracking and classifying, over a defined depth of the drilling of the wellbore, the drilling efficiency; and   displaying the tracking and classifying, over the defined depth of the drilling of the wellbore, of the drilling efficiency in a form of at least one of a bar chart, a stacked bar chart, or a histogram.   
     
     
         13 . A non-transitory, computer-readable medium having instructions stored thereon that are executable by a processor, the instructions comprising:
 instructions to measure, at a surface of a wellbore during drilling of the wellbore, at least one drilling operational parameter;   instructions to determine at least one at-bit parameter, at a drill bit used for drilling the wellbore, based on the at least one drilling operational parameter measured at the surface of the wellbore; and   instructions to determine a drilling efficiency based on the at least one at-bit parameter.   
     
     
         14 . The non-transitory, computer-readable medium of  claim 13 , wherein the instructions comprise,
 instructions to transform the at least one drilling operational parameter to at least one scaled drilling operational parameter based on transformation of the drill bit to an equivalent singular blade at unit length.   
     
     
         15 . The non-transitory, computer-readable medium of  claim 13 ,
 wherein the instructions to determine the at least one at-bit parameter, at the drill bit used for drilling the wellbore, based on the at least one drilling operational parameter measured at the surface of the wellbore comprises:
 instructions to create a bit-rock interaction model. 
   
     
     
         16 . The non-transitory, computer-readable medium of  claim 15 ,
 wherein the instructions to determine the at least one at-bit parameter, at the drill bit used for drilling the wellbore, based on the at least one drilling operational parameter measured at the surface of the wellbore comprise:
 instructions to perform the following during drilling of the wellbore,
 instructions to monitor, during drilling of the wellbore, whether the bit-rock interaction model is changing based on the at least one drilling operational parameter; and 
 in response to the bit-rock interaction model changing, instructions to adjust the bit-rock interaction model based on changes to the at least one drilling operational parameter. 
 
   
     
     
         17 . An apparatus comprising:
 a processor; and   a computer-readable medium having instructions stored thereon that are executable by the processor to cause the processor to,
 measure, at a surface of a wellbore during drilling of the wellbore, at least one drilling operational parameter; 
 determine at least one at-bit parameter, at a drill bit used for drilling the wellbore, based on the at least one drilling operational parameter measured at the surface of the wellbore; and 
 determine a drilling efficiency based on the at least one at-bit parameter. 
   
     
     
         18 . The apparatus of  claim 17 , wherein the instructions comprise instructions executable by the processor to cause the processor to,
 transform the at least one drilling operational parameter to at least one scaled drilling operational parameter based on transformation of the drill bit to an equivalent singular blade at unit length.   
     
     
         19 . The apparatus of  claim 17 ,
 wherein the instructions executable by the processor to cause the processor to determine the at least one at-bit parameter, at the drill bit used for drilling the wellbore, based on the at least one drilling operational parameter measured at the surface of the wellbore comprises:
 instructions executable by the processor to cause the processor to create a bit-rock interaction model. 
   
     
     
         20 . The apparatus of  claim 19 ,
 wherein the instructions executable by the processor to cause the processor to determine the at least one at-bit parameter, at the drill bit used for drilling the wellbore, based on the at least one drilling operational parameter measured at the surface of the wellbore comprise instructions executable by the processor to cause the processor to,
 perform the following during drilling of the wellbore,
 monitor, during drilling of the wellbore, whether the bit-rock interaction model is changing based on the at least one drilling operational parameter; and 
 in response to the bit-rock interaction model changing, adjust the bit-rock interaction model based on changes to the at least one drilling operational parameter.