Multiple inserts of different geometry in a single row of a bit
A method for designing a roller cone drill bit having a plurality of cutting elements in a row. The method includes defining a pitch pattern for the plurality of cutting elements such that a first group of adjacent cutting elements are arranged in a first pitch and a second group of adjacent cutting elements are arranged in a second pitch in the row; evaluating the pitch pattern of the plurality of cutting elements in the row; and modifying at least one of the plurality of cutting elements, based on the evaluating the pitch pattern of the plurality of cutting elements.
1. A method for designing a roller cone drill bit having a plurality of cutting elements arranged in a row, comprising:
defining a pitch pattern for the plurality of cutting elements such that a first group of adjacent cutting elements are arranged in a first pitch and a second group of adjacent cutting elements are arranged in a second pitch in the row;
evaluating the pitch pattern of the plurality of cutting elements in the row; and
modifying at least one of the plurality of cutting elements, based on the evaluating of the pitch pattern of the plurality of cutting elements.
2. The method of claim 1 , wherein the evaluating comprises simulating the bit.
3. The method of claim 1 , wherein the evaluating comprises determining a bottomhole hit location for at least one of cutting elements in the row.
4. The method of claim 1 , wherein the evaluating comprises determining a bottomhole hit pattern for the pitch pattern of the plurality of cutting elements in the row.
5. The method of claim 1 , further comprising:
identifying at least one cutting element located at or near a pitch break.
6. The method of claim 5 , wherein the modifying comprises modifying the at least one cutting element located near the pitch break.
7. The method of claim 6 , wherein the modifying comprises adding a bulk to the at least one cutting element located near the pitch break.
8. The method of claim 7 , wherein the bulk is added to a leading side of the cutting element.
9. The method of claim 1 , wherein the evaluating comprises determining a force on at least one cutting element in the pitch pattern.
10. The method of claim 9 , wherein the evaluating further comprises:
determining a stress on at least one cutting element in the pitch pattern.
11. The method of claim 10 , wherein the modifying comprises providing a relieved portion on at least one of the cutting elements in response to the determined stress.
12. The method of claim 1 , wherein the modifying comprises providing a relieved portion on at least one of the cutting elements.
13. The method of claim 1 , wherein the evaluating comprises determining a dull condition of the drill bit based on the pitch pattern of the plurality of cutting elements in the row.
14. The method of claim 1 , wherein the modifying comprises changing a cutting element in more than one row of the drill bit.
15. The method of claim 14 , wherein the more than one row includes at least a gage row and a heel row.
16. The method of claim 1 , wherein the modifying comprises changing a geometric location of at least one of the cutting elements.
17. The method of claim 1 , wherein the modifying comprises placing the plurality of cutting elements in a staggered row.
18. The method of claim 17 , wherein at least two of the cutting elements in the staggered row have different diameters.
19. The method of claim 1 , wherein at the modifying comprises disposing at least two of the plurality of cutting elements to form a band.