Wear indicator

• US 20050154568A1
• Filed: 12/10/2004
• Published: 07/14/2005
• Est. Priority Date: 03/13/2000
• Status: Abandoned Application

• Current Assignee: Smith International Incorporated (Schlumberger NV)
• Original Assignee: Smith International Incorporated (Schlumberger NV)
• Inventors: Huang, Sujian J.
• Application Number:
  US11/009,971
• Publication Number:
  US 20050154568A1
• Time in Patent Office: Days
• US Class Current: 703/7
• CPC Class Codes: E21B 10/16 characterised by tooth form or arrangement

Abstract

A method for designing a roller cone drill bit comprising selecting initial bit design parameters, selecting initial earth formations parameters, selecting initial drilling parameters, simulating drilling a selected earth formation, determining stress on at least one of the group of cutting element, cone, and drill bit, determining velocity of at least one of the group of cutting element, cone, and drill bit, calculating wear, varying at least one of the bit design parameters and repeating the simulating and the calculating until the wear meets a selected criterion. The method further comprises normalizing said calculated wear, and converting said normalized wear into a visual representation.

Claims

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

selecting initial bit design parameters;

selecting initial earth formation parameters;

selecting initial drilling parameters;

simulating drilling a selected earth formation;

determining stress on at least one from the group of cutting element, cone, and drill bit;

determining velocity of at least one from the group of cutting element, cone, and drill bit;

calculating wear; and

varying at least one of the bit design parameters and repeating the simulating, the determining stress, the determining velocity, and the calculating until the wear meets a selected criterion.

2. The method of claim 1, wherein the initial bit design parameters comprise at least one of cutting element count, cutting element height, cutting element geometrical shape, cutting element spacing, cutting element orientation, cone axis offset, cutting element material, cutting element location, cone diameter profile, and bit diameter.

3. The method of claim 1, wherein the initial earth formation parameters comprise a hardness of the formation.

4. The method of claim 1, wherein said initial bit design parameters form part of a computer aided design file.

5. The method of claim 1, wherein said initial drilling parameters comprise weight on bit.

6. The method of claim 1, wherein said initial drilling parameters comprise rotational speed of a bit.

7. The method of claim 1, further comprising normalizing said calculated wear.

8. The method of claim 1, wherein the calculating wear is the linear wear of at least one of the group of cutting element, cone, and drill bit.

9. The method of claim 1, wherein the varying at least one of the bit design parameters and repeating the simulating and the calculating until the wear meets a selected criterion is repeated until an optimized roller cone drill bit design is achieved.

10. The method of claim 1, further comprising converting said normalized wear into a visual representation.

13. A drill bit designed by the method of claim 1.

12. The method of claim 12, wherein the visual representation is a graphical display of the drill bit showing said normalized linear wear.

11. The method of claim 12, wherein the visual representation is in tabular form.