| WEAR PATTERNS - Origin | |||
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| New | Optimum wear | Convex Lack of fluid circulation |
O.D. Loss Vibrations drilling in undersized hole |
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Concave Excesive penetration rate |
I.D. Loss Overfeeding unconsolidated formation |
Excesive diamond exposure Soft matrix for formation drilled |
Polished diamond Hard matrix for formation drilled |