Predicting and reducing vibrations during downhole drilling operations

Abstract

Vibrations occurring during downhole drilling operations can be predicted and reduced according to some examples. One particular example includes a system that can receive drilling parameter values associated with a drilling operation involving drilling a wellbore through a subterranean formation using a drill string. The system can receive a depth value associated with the drilling parameter values. The system can provide the drilling parameter values as input to a drill string model to receive a critical speed prediction as output from the drill string model. The system can then generate a speed-depth mapping based on the critical speed prediction and the depth value. The speed-depth mapping can be used to avoid the critical speed at the depth in the wellbore, which may prevent a failure of the drill string resulting from associated vibrations.

1 . A system comprising:
 a processor; and   a memory including instructions that are executable by the processor for causing the processor to:
 receive a plurality of sets of drilling parameter values associated with a drilling operation involving drilling a wellbore through a subterranean formation using a drill string; 
 receive a plurality of depth values associated with the plurality of sets of drilling parameter values, each depth value corresponding to a particular set of drilling parameter values in the plurality of sets of drilling parameter values; 
 provide the plurality of sets of drilling parameter values as input to a drill string model to receive a plurality of critical speed predictions as output from the drill string model, each critical speed prediction being determined by the drill string model based on a respective set of drilling parameter values of the plurality of sets of drilling parameter values; 
 generate a plurality of speed-depth mappings based on the plurality of critical speed predictions and the plurality of depth values, each speed-depth mapping including (i) a respective critical-speed prediction from among the plurality of critical speed predictions and (ii) a respective depth-value associated with the respective set of drilling parameter values used by the drill string model to determine the respective critical-speed prediction; and 
 generate a graphical user interface including the plurality of speed-depth mappings for display on a display device, the plurality of speed-depth mappings in the graphical user interface being usable to reduce vibrations in the drill string at the plurality of depth values during the drilling operation. 
   
     
     
         2 . The system of  claim 1 , wherein the memory further includes instructions for the drill string model, and wherein the drill string model is configured to:
 generate a range of candidate bit speeds; and   for each candidate bit speed in the range of candidate bit speeds:
 determine a respective vibration response associated with the candidate bit speed; 
 determine if the respective vibration response exceeds a predefined threshold limit; and 
 flag the candidate bit speed as a critical speed if the respective vibration response is greater than or equal to the predefined threshold limit; or 
 flag the candidate bit speed as a non-critical speed if the respective vibration response is below the predefined threshold limit. 
   
     
     
         3 . The system of  claim 2 , wherein the drill string model is configured to determine the respective vibration response based on a damping effect of substance in the drill string. 
     
     
         4 . The system of  claim 2 , wherein the drill string model is configured to determine the respective vibration response based on one or more characteristics of a motor of the drill string. 
     
     
         5 . The system of  claim 4 , wherein the one or more characteristics include a lobe configuration of the motor. 
     
     
         6 . The system of  claim 1 , wherein the memory further includes instructions that are executable by the processor for causing the processor to receive the plurality of sets of parameter values from one or more sensors coupled to the drill string. 
     
     
         7 . The system of  claim 1 , wherein the memory further includes instructions that are executable by the processor for causing the processor to adjust a drilling parameter value associated with the drilling operation so as to prevent a drill bit of the drill string from rotating at a critical speed included in the plurality of critical speed predictions when the drill string is at a particular depth that is associated with the critical speed in the plurality of speed-depth mappings. 
     
     
         8 . A method comprising:
 receiving, by a processor, a plurality of sets of drilling parameter values associated with a drilling operation involving drilling a wellbore through a subterranean formation using a drill string;   receiving, by the processor, a plurality of depth values associated with the plurality of sets of drilling parameter values, each depth value corresponding to a particular set of drilling parameter values in the plurality of sets of drilling parameter values;   providing, by the processor, the plurality of sets of drilling parameter values as input to a drill string model to receive a plurality of critical speed predictions as output from the drill string model, each critical speed prediction being determined by the drill string model based on a respective set of drilling parameter values of the plurality of sets of drilling parameter values;   generating, by the processor, a plurality of speed-depth mappings based on the plurality of critical speed predictions and the plurality of depth values, each speed-depth mapping including (i) a respective critical-speed prediction from among the plurality of critical speed predictions and (ii) a respective depth-value associated with the respective set of drilling parameter values used by the drill string model to determine the respective critical-speed prediction; and   generating, by the processor, a graphical user interface including the plurality of speed-depth mappings for display on a display device, the plurality of speed-depth mappings in the graphical user interface being usable to reduce vibrations in the drill string at the plurality of depth values during the drilling operation.   
     
     
         9 . The method of  claim 8 , wherein the drill string model is configured to:
 generate a range of candidate bit speeds; and   for each candidate bit speed in the range of candidate bit speeds:
 determine a respective vibration response associated with the candidate bit speed; 
 determine if the respective vibration response exceeds a predefined threshold limit; and 
 flag the candidate bit speed as a critical speed if the respective vibration response is greater than or equal to the predefined threshold limit; or 
 flag the candidate bit speed as a non-critical speed if the respective vibration response is below the predefined threshold limit. 
   
     
     
         10 . The method of  claim 9 , wherein the drill string model is configured to determine the respective vibration response based on a damping effect of substance in the drill string. 
     
     
         11 . The method of  claim 9 , wherein the drill string model is configured to determine the respective vibration response based on one or more characteristics of a motor of the drill string. 
     
     
         12 . The method of  claim 11 , wherein the one or more characteristics include a lobe configuration of the motor. 
     
     
         13 . The method of  claim 9 , further comprising receiving the plurality of sets of parameter values from one or more sensors coupled to the drill string. 
     
     
         14 . The method of  claim 9 , further comprising adjusting a drilling parameter value associated with the drilling operation so as to prevent a drill bit of the drill string from rotating at a critical speed included in the plurality of critical speed predictions when the drill string is at a particular depth that is associated with the critical speed in the plurality of speed-depth mappings. 
     
     
         15 . A non-transitory computer-readable medium comprising program code that is executable by a processor for causing the processor to:
 receive a plurality of sets of drilling parameter values associated with a drilling operation involving drilling a wellbore through a subterranean formation using a drill string;   receive a plurality of depth values associated with the plurality of sets of drilling parameter values, each depth value corresponding to a particular set of drilling parameter values in the plurality of sets of drilling parameter values;   provide the plurality of sets of drilling parameter values as input to a drill string model to receive a plurality of critical speed predictions as output from the drill string model, each critical speed prediction being determined by the drill string model based on a respective set of drilling parameter values of the plurality of sets of drilling parameter values;   generate a plurality of speed-depth mappings based on the plurality of critical speed predictions and the plurality of depth values, each speed-depth mapping including (i) a respective critical-speed prediction from among the plurality of critical speed predictions and (ii) a respective depth-value associated with the respective set of drilling parameter values used by the drill string model to determine the respective critical-speed prediction; and   generate a graphical user interface including the plurality of speed-depth mappings for display on a display device, the plurality of speed-depth mappings in the graphical user interface being usable to manage vibrations in the drill string at the plurality of depth values during the drilling operation.   
     
     
         16 . The non-transitory computer-readable medium of  claim 15 , further comprising program code for the drill string model, and wherein the program code for the drill string model is executable by the processor for causing the processor to:
 generate a range of candidate bit speeds; and   for each candidate bit speed in the range of candidate bit speeds:
 determine a respective vibration response associated with the candidate bit speed; 
 determine if the respective vibration response exceeds a predefined threshold limit; and 
 flag the candidate bit speed as a critical speed if the respective vibration response is greater than or equal to the predefined threshold limit; or flag the candidate bit speed as a non-critical speed if the respective vibration response is below the predefined threshold limit. 
   
     
     
         17 . The non-transitory computer-readable medium of  claim 16 , wherein the drill string model is configured to determine the respective vibration response based on a damping effect of substance in the drill string. 
     
     
         18 . The non-transitory computer-readable medium of  claim 16 , wherein the drill string model is configured to determine the respective vibration response based on one or more characteristics of a motor of the drill string. 
     
     
         19 . The non-transitory computer-readable medium of  claim 18 , wherein the one or more characteristics include a lobe configuration of the motor. 
     
     
         20 . The non-transitory computer-readable medium of  claim 15 , further comprising program code that is executable by the processor for causing the processor to adjust a drilling parameter value associated with the drilling operation so as to prevent a drill bit of the drill string from rotating at a critical speed included in the plurality of critical speed predictions when the drill string is at a particular depth that is associated with the critical speed in the plurality of speed-depth mappings.