Rate of penetration prediction and uses thereof

Abstract

System and methods are disclosed herein for rate of penetration (ROP) predictions and uses thereof. A ROP model representing a rate at which a drill bit can penetrate one or more formation layers can be computed based on a mechanical efficiency and bit wear model representing drill bit wear of the drill bit. In some examples, the ROP model can be combined with a geomechanical model representing the one or more formations to generate a drilling performance model that can represent (or predict) drilling efficiencies of the drill bit with respect to the one or more formations. Potential well trajectories through the one or more formations can be formed using the drilling performance model and one or more candidate well trajectories be selected from the potential well trajectories, for example, for use in formation drilling.

The invention claimed is: 
     
         1 . A computer implemented method comprising:
 computing, by a processor, a mechanical efficiency for a drill bit;   computing, by the processor, a bit wear model representing drill bit wear of the drill bit; and   generating, by the processor, a rate of penetration (ROP) model representing a rate at which the drill bit will penetrate one or more formation layers based on the mechanical efficiency and the bit wear model.   
     
     
         2 . The computer implemented method of  claim 1 , wherein said computing comprises:
 predicting, by the processor, a first rate of penetration (ROP) due to mechanical specific energy (MSE) for the drill bit;   predicting, by the processor, a second ROP due to MSE and hydraulic energy using the first ROP for the drill bit; and   predicting, by the processor, a third ROP due to bit wear using the second ROP for the drill bit, the third ROP being used for computing the mechanical efficiency.   
     
     
         3 . The computer implemented method of  claim 2 , further comprising deciding, by the processor, whether the third ROP equals a recorded ROP representative of ROP due to bit wear on the drill bit over a drilling distance. 
     
     
         4 . The computer implemented method of  claim 3 , wherein said deciding comprises a determining, by the processor, whether the recorded ROP increases with a weight on bit (WOB) indicative of an amount weight applied to the drill bit over the drilling distance. 
     
     
         5 . The computer implemented method of  claim 4 , further comprising:
 modifying, by the processor, a WOB parameter used for predicting the third ROP in response to determining that the recorded ROP does not increase with the WOB over the drilling distance; and   repeating, by the processor, the predicting of the third ROP and the deciding steps until the third ROP matches the recorded ROP over a given drill distance.   
     
     
         6 . The computer implemented method of  claim 1 , further comprising generating, by the processor, a geomechanical model representing the one or more formations. 
     
     
         7 . The computer implemented method of  claim 6 , wherein said generating the ROP model comprises:
 computing, by the processor, a confined compressive strength (CCS) for the one or more formations in the geomechanical model, wherein the CCS is computed for a number of sections or intervals of each formation; and   predicting, by the processor, a ROP due to mechanical specific energy (MSE) and hydraulic energy using a computed CCS for each formation section in the geomechanical model, wherein the ROP due to MSE and hydraulic energy is representative of a ROP produced by a new version of the drill bit through a respective formation section.   
     
     
         8 . The computer implemented method of  claim 7 , wherein the ROP model is generated based on the ROP computed for each formation section in the geomechanical model. 
     
     
         9 . The computer implemented method of  claim 6 , wherein said generating the ROP model further comprises:
 predicting, by the processor, a bit dull grade using the bit wear model for each formation in the geomechanical model, wherein the bit dull grade is predicted for a number of sections or intervals of each formation; and   predicting, by the processor, a ROP due to bit wear using the predicted bit dull grade for each formation section in the geomechanical model, wherein the ROP due to bit wear is representative of a ROP produced by a worn version of the drill bit through a respective formation section.   
     
     
         10 . The computer implemented method of  claim 9 , wherein the ROP model is generated based on the ROP due to bit wear computed for each formation section in the geomechanical model. 
     
     
         11 . The computer implemented method of  claim 6 , further comprising combining, by the processor, the geomechanical model and the ROP model to provide a drilling performance model with a ROP for formation sections of the geomechanical model. 
     
     
         12 . The computer implemented method of  claim 11 , further comprising outputting, by the processor, well trajectory data identifying a potential well trajectory through the drilling performance model. 
     
     
         13 . The computer-implemented method of  claim 12 , wherein said outputting comprises:
 identifying, by the processor, candidate formation layers from the one or more formation layers using a baseline well trajectory inserted in the drilling performance model, the candidate formation layers having candidate formation sections;   identifying, by the processor, one or more regions defined by a subset of candidate formation sections of the candidate formation sections in the drilling performance model that the baseline well trajectory intersects;   inserting, by the processor, one or more potential well trajectories into the drilling performance model that intersects the one or more regions; and   identifying, by the processor, a candidate potential well trajectory from the one or more potential well trajectories.   
     
     
         14 . The computer-implemented method of  claim 13 , further comprising:
 calculating, by the processor, an updated confined compressive strength (CCS) for each candidate formation of the subset of candidate formations sections forming the one or more regions; and   calculating, by the processor, an updated ROP for each candidate formation of the subset of candidate formations based on the updated CCS, the candidate potential well trajectory being identified based on an evaluation of the updated ROP calculated for each candidate formation of the subset of candidate formations sections.   
     
     
         15 . The computer implemented method of  claim 1 , further comprising evaluating, by the processor, an effective porosity and for each candidate formation of the subset of candidate formations sections along the one or more potential well trajectories to identify the candidate potential well trajectory, wherein the well trajectory data is provided in response to the evaluating. 
     
     
         16 . A system comprising:
 memory to store machine-readable instructions;   one or more processors to access the memory and execute the machine-readable instructions, the machine-readable instructions causing the processor to:
 identify one or more regions defined by formation sections that a baseline well trajectory intersects in a drilling performance model, wherein the drilling performance model is generated based on a rate of penetration (ROP) model, the ROP model being generated based on a mechanical efficiency for a drill bit, and a bit wear model representing drill bit wear of the drill bit; 
 insert potential well trajectories into the drilling performance model that intersects one or more regions of the drilling performance model; and 
 output well trajectory data identifying a candidate well trajectory of the inserted potential well trajectories for drilling by the drill bit. 
   
     
     
         17 . The system of  claim 16 , further comprising an output device, the machine-readable instructions further causing the processor to output the drilling performance model on the output device with the candidate trajectory well based on the well trajectory data. 
     
     
         18 . The system of  claim 16 , wherein the machine-readable instructions further cause the processor to combine a geomechanical model representing one or more formations and the ROP model to provide the drilling performance model with a ROP for formation sections of the geomechanical model. 
     
     
         19 . A computer-implemented method comprising:
 generating, by the processor, a rate of penetration (ROP) model representing a rate at which the drill bit will penetrate one or more formation layers based on a precomputed mechanical efficiency and bit wear model;   receiving, by the processor, a geomechanical model representing the one or more formations;   combining, by the processor, the geomechanical model and the ROP model to provide a drilling performance model with a ROP for the one or more formations; and   outputting, by the processor, well trajectory data identifying a well trajectory through the drilling performance model representative of a potential trajectory through the one or more formations.   
     
     
         20 . The computer-implemented method of  claim 19 , wherein said outputting comprises:
 identifying, by the processor, candidate formation layers from the one or more formation layers using a baseline well trajectory inserted in the drilling performance model, the candidate formation layers having candidate formation sections;   identifying, by the processor, one or more regions defined by a subset of candidate formation sections of the candidate formation sections in the drilling performance model that the baseline well trajectory intersects;   inserting, by the processor, one or more candidate well trajectories into the drilling performance model that intersects the one or more regions; and   identifying, by the processor, the well trajectory from the one or more candidate well trajectories.