1. Drill for 5 minutes with initially selected proper WOB and moderate RPM (60~100r/min) and record the ROP (as shown in the table below).
2. Moderately inctease WOB and keep the same RPM and drill under this WOB for 5 minutes and again record the RPO (as shown in the table below).
3. Decrease WOB b the same extent and tepeat step 2.
4. Find the WOB in the tow groups of test than can yield highest ROP.
5. Properly change RPM under optimal WOB and record the ROP (as shown in the table below).
6. Select the RPM at the highest ROP.
7. Set the drilling parameter at the best combination:60KN RPM: 120r/min