Correlation of accelerated laboratory testing to actual field performance is essential in the successful development of polycrystalline diamond cutters (PDCs) and diamond-bearing elements for down-hole applications. A laboratory-scale drill rig apparatus for the investigation of diamond-bearing and drag bit cutter performance has recently been completed. The laboratory-scale test rig is capable of producing rotary speeds from 40 to 1500 rpm, normal forces up to 165 kN, torque up to 1900 Nm, and rates of penetration up to 67 m/hr. Drilling tests to evaluate PCD cutters can be conducted using a controlled normal force or controlled rate of penetration. Test methods have been developed to enable accurate comparisons of PCD inserts to be made, typically in one day or less. PCD bit testing shows that we can clearly differentiate cutting efficiency and wear rates based upon changes in the material properties of the PCD inserts. The test rig can also be utilized to measure wear rates and frictional forces in diamond thrust bearings. Full-scale PCD bearing experiments indicated that the bearings were capable of much higher loading than previously thought. Correlation between laboratory results and actual field performance will also be discussed. Article by J. Lund, C. Cooley, J. Gonzalez, and T. Sexton.
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