DRILL BIT AND DESIGN METHOD FOR OPTIMIZING DISTRIBUTION OF INDIVIDUAL CUTTER FORCES, TORQUE, WORK, OR POWER

• US 20090166091A1
• Filed: 07/03/2008
• Published: 07/02/2009
• Est. Priority Date: 08/31/1998
• Status: Active Grant

• Current Assignee: Halliburton Energy Services Incorporated (Halliburton Company)
• Original Assignee: Halliburton Energy Services Incorporated (Halliburton Company)
• Inventors: Chen, Shilin, Matthews, Oliver, Clayton, Robert I.
• Granted Patent: US 8,437,995 B2
• Time in Patent Office: Days
• US Class Current: 175/195
• CPC Class Codes: E21B 10/08 Roller bits E21B10/26 takes precedence; roller core bits E21B10/06; characterised by wear resisting parts E21B10/50
• CPC Class Codes: E21B 10/16 characterised by tooth form or arrangement

Abstract

A design process and resulting bit structure is provided for drill bits wherein cutter geometries on the face of the bit are tailored to optimize the distribution of one or more of forces, torque, work, or power of each cutter relative to other cutters. Balanced are the forces, torque, work, or power generated by each cutter in respect to other cutters that are working within the same region of cut, so that all cutters within the same region of cut are generating sufficiently comparable forces, torque, work, or power. In this manner all of the cutters on the bit may share as closely as possible the work and loads required to penetrate the subterranean rock. The design process produces a bit structure in which each cutter is doing similar levels of work or creating similar levels of force, torque, or power relative to other cutters within the same region of cut on the bit, within specified ranges of design criteria.

Claims

1. A method for designing a drill bit, comprising:

defining a cutting structure for the bit and applying the defined cutting structure to a simulated formation for producing generated values of at least one cutter parameter of force, torque, work, or power by cutters of the structure;

determining whether the generated values of the at least one cutter parameter meet one or more design criteria for optimizing the distribution of generated values for individual cutters relative to other cutters within a region or among regions of the bit; and

redefining the cutting structure until the one or more distribution design criteria are met.

2. The method of claim 1 wherein the one or more distribution design criteria comprises a relatively low total variance in the average change in value of the at least one cutter parameter for a cutter and its radially trailing and leading cutters.

3. The method of claim 2 wherein the relatively low total variance is less than five percent when using the ratio of average change in parameter to average parameter.

4. The method of claim 1 wherein the one or more distribution design criteria comprises a relatively low total variance in the average change in value of the at least one cutter parameter for a cutter and its radially trailing cutter.

5. The method of claim 4 wherein the relatively low total variance is less than five percent when using the ratio of average change in parameter to average parameter.

6. The method of claim 1 wherein the one or more distribution design criteria comprises a relatively low total lateral bit moment imbalance for the bit.

7. The method of claim 1 wherein the one or more distribution design criteria comprises a total lateral bit moment imbalance for the bit of less than four percent of the value of the torque on bit.

8. The method of claim 1 wherein the one or more distribution design criteria comprises a total variance in the average of the values of the at least one cutter parameter for the region of the bit of less than one hundred percent.

9. The method of claim 1 wherein the region of the bit comprises at least one of the face of the bit, the entire bit, an individual blade of the bit, selected blades of the bit, profile segments of the bit, quadrants of the bit, or other spatial divisions of the bit.

10. The method of claim 1 wherein the method is implemented utilizing one or more computer programs.

11. A method for designing a drill bit, comprising:

defining a cutting structure for the bit and applying the defined cutting structure to a simulated formation for producing generated values of at least one cutter parameter of force, torque, work, or power by cutters of the structure;

determining whether the summation of generated force values of the defined cutting structure produce a net imbalance force for the bit that meets one or more design criteria, and redefining the cutting structure until the one or more net imbalance force design criteria are met; and

determining whether the generated values of the at least one cutter parameter meet one or more design criteria for optimizing the distribution of generated values for individual cutters relative to other cutters within a region of the bit; and

redefining the cutting structure until the one or more distribution design criteria are met.

12. The method of claim 11 further comprising:

determining whether the defined cutting structure produces a wear value for the bit that meets one or more design criteria and redefining the cutting structure until the one or more wear value design criteria are met.

13. The method of claim 11 wherein the one or more net imbalance design criteria comprises a total lateral imbalance force of less than four percent of the value of the weight on bit.

14. The method of claim 11 wherein the one or more distribution design criteria comprises a total variance in the average change in value of the at least one cutter parameter for a cutter and its radially trailing and leading cutters of less than five percent when using the ratio of average change in parameter to average parameter.

15. The method of claim 11 wherein the one or more distribution design criteria comprises a total variance in the average change in value of the at least one cutter parameter for a cutter and its radially trailing cutter of less than five percent when using the ratio of average change in parameter to average parameter.

16. The method of claim 11 wherein the one or more distribution design criteria comprises a total lateral bit moment imbalance for the bit of less than four percent of the value of the torque on bit.

17. The method of claim 11 wherein the region of the bit comprises at least one of the face of the bit, the entire bit, an individual blade of the bit, selected blades of the bit, profile segments of the bit, quadrants of the bit, or other spatial divisions of the bit.

18. The method of claim 11 wherein the at least one cutter parameter of force comprises one or more of axial force or drag force.

19. A method of balancing forces on a drill bit, comprising:

determining the forces on individual cutters of the bit by creating a representation of the bit geometry and applying the bit geometry to a simulated formation to produce force vectors for each cutter;

summing the force vectors for each cutter to produce a net force for the drill bit and modifying the bit geometry to achieve a net force that meets at least one selected design criteria; and

comparing the magnitude of produced force vectors for individual cutters with that of other cutters in a region of the bit, and modifying the bit geometry to achieve a comparison that more evenly distributes the magnitude of produced force vectors within the region to meet at least one selected design criteria.

20. The method of claim 19 further comprising:

summing the moment vectors for each cutter to produce a net moment for the drill bit and modifying the bit geometry to achieve a net moment that meets at least one selected design criteria.

21. The method of claim 19 wherein the force vectors for individual cutters comprise at least one of axial force or drag force.

22. The method of claim 19 wherein the region of the bit for comparing the magnitude of produced force vectors comprises at least one of the face of the bit, the entire bit, an individual blade of the bit, selected blades of the bit, profile segments of the bit, quadrants of the bit, or other spatial divisions of the bit.

23. The method of claim 19 wherein the comparing the magnitude of produced force vectors for individual cutters with that of other cutters comprises comparisons of at least one of the cutter to its radially trailing and leading cutters, the cutter to its radially adjacent cutter;

the cutter to multiple radially trailing and leading cutters.

24. A method of optimizing loads on a drill bit, comprising:

determining one or more load values on individual cutters of the bit by creating a representation of the bit geometry and applying the bit geometry to a simulated formation to produce load values for each cutter;

summing the one or more load values for each cutter to produce a net force for the drill bit and modifying the bit geometry to achieve a net force that meets at least one selected design criteria; and

comparing the one or more load values for individual cutters with that of other cutters in a region of the bit, and modifying the bit geometry to achieve a distribution of the magnitudes of the one or more load values for cutters relative to each other within the region to meet at least one selected design criteria.

25. A drill bit designed by defining a cutting structure for the bit and applying the defined cutting structure to a simulated formation for producing generated values of at least one cutter parameter of force, torque, work, or power by cutters of the structure;

determining whether the generated values of the at least one cutter parameter meet one or more design criteria for optimizing the distribution of generated values for individual cutters relative to other cutters within a region of the bit; and

redefining the cutting structure until the one or more distribution design criteria are met.

26. A drilling system, comprising:

a drill string which is connected to a bit; and

a rotary drive which rotates at least part of the drill string together with the bit; and

wherein the bit comprises a drill bit designed by defining a cutting structure for the bit and applying the defined cutting structure to a simulated formation for producing generated values of at least one cutter parameter of force, torque, work, or power by cutters of the structure;

determining whether the generated values of the at least one cutter parameter meet one or more design criteria for optimizing the distribution of generated values for individual cutters relative to other cutters within a region of the bit; and

redefining the cutting structure until the one or more distribution design criteria are met.