Methods for modeling, displaying, designing, and optimizing fixed cutter bits
In one aspect, the invention provides a method for modeling the performance of a fixed cutter bit drilling an earth formation. In one embodiment, the method includes selecting a drill bit and an earth formation to be represented as drilled, simulating the bit drilling the earth formation, displaying the simulating, and adjusting at least one parameter affecting the performance. The method of design is used to make a fixed cutter drill bit. In another embodiment the method includes numerically rotating the bit, calculating bit interaction with the earth formation during the rotating, and determining the forces on the cutters during the rotation based on the calculated interaction with earth formation and empirical data.
1. A method for designing a fixed cutter drill bit, comprising:
simulating dynamically the fixed cutter drill bit drilling a first section of a wellbore, wherein the dynamically simulating comprises using at least one datum of a first iteration of the simulation in a subsequent iteration of the simulation and wherein the simulating dynamically takes into account individual cutting elements of the fixed cutter drill bit contacting the formation;
graphically displaying a three-dimensional representation of individual cutting elements of the fixed cutter drill bit contacting formation for at least a portion of the simulating of the first section;
simulating dynamically the fixed cutter drill bit drilling a second section of the wellbore;
graphically displaying a three-dimensional representation of individual cutting elements of the fixed cutter drill bit contacting formation for at least a portion of the simulating of the second section;
adjusting a value of at least one design parameter for the fixed cutter drill bit according to the three-dimensional graphical display, wherein the graphical display includes displays of cutter forces, blade forces, cut area, and wear flat area for cutters on any blade of the fixed cutter drill bit; and
repeating the simulating, displaying and adjusting to change a simulated performance of the fixed cutter drill bit.
2. The method of claim 1 , wherein the first and second sections of the wellbore comprise different types of formation.
3. The method of claim 1 , further comprising graphically displaying at least one fixed cutter drill bit design parameter.
4. The method of claim 1 , wherein the adjusting is based at least in part on a lateral force response.
5. The method of claim 1 , wherein the adjusting is based at least in part on a lateral acceleration response.
6. The method of claim 1 , wherein the adjusting is performed to increase the time a bit rotates around its center.
7. The method of claim 1 , wherein the adjusting is performed to increase at least one of bit durability and rate of penetration.
8. The method of claim 1 , wherein the adjusting is performed to match the fixed cutter bit with a rotary steerable system.
9. The method of claim 1 , further comprising:
displaying a sensitivity plot of the simulated fixed cutter drill bit.
10. A system comprising:
a processor;
a memory operatively connected to the processor; and
instructions stored in the memory and executable by the processor to:
a. input fixed cutter drill bit design parameters;
b. simulate dynamically drilling an earth formation in accordance with the input drill bit design parameters to obtain at least one performance characteristic, wherein the simulating dynamically comprises graphically displaying in three dimensions individual cutting elements of the fixed cutter drill bit contacting formation for at least a portion of the simulating of the first section;
c. graphically display in three dimensions the at least one of the performance characteristic;
d. adjust a drill bit design parameter in accordance with the at least one of the performance characteristics displayed in three dimensions;
e. simulate drilling an earth formation in accordance with the input drill bit design parameters adjusted in accordance with step (d) to obtain adjusted performance characteristics;
f. graphically display in three dimensions at least one of the adjusted performance characteristics, wherein the graphical display includes displays of cutter forces, blade forces, cut area, and wear flat area for cutters on any blade of the fixed cutter drill bit;
g. output a fixed cutter drill bit design comprising an optimized drill bit design parameter.
11. The method of claim 10 , wherein the graphically displaying comprises displaying a three-dimension representation of the drill bit drilling the earth formation.
12. The method of claim 10 , wherein the optimized drill bit design parameter is based on a preferred performance characteristic.
13. The method of claim 12 , wherein the fixed cutter bit design is optimized for bit durability.
14. The method of claim 12 , wherein the fixed cutter bit design is optimized for rate of penetration.
15. The method of claim 12 , wherein the fixed cutter bit design is optimized for directional drilling.
16. The method of claim 10 , wherein the performance characteristic comprises a torsional vibration.
17. The method of claim 10 , wherein the simulating comprises a time-based response.
18. The method of claim 10 , further comprising instructions to:
input bottom-hole assembly component parameters.
19. The method of claim 10 , wherein the instructions to simulate dynamically account for a response of the bottom-hole assembly.