Application of the New IADC Dull Grading System for Fixed Cutter Bits

Abstract

ABSTRACT This paper describes a recently developed standardized system for dull grading natural diamond, PDC, and TSP (Thermally Stable Polycrystalline diamond) bits, otherwise known as fixed cutter bits. The new system is consistent with the recently revised dull grading system for roller bits. It describes the condition of the cutting structure, the primary (with location) and secondary dull characteristics, the gauge condition, and the reason the bit was pulled. Examples of all commonly seen dull characteristics of fixed cutter bits are given. In addition, several worn fixed cutter bits are dull graded using the system.