drill- off test"- selection of weight on bit and rotary speed
TRANSCRIPT
![Page 1: Drill- off Test"- Selection of Weight on Bit and Rotary Speed](https://reader035.vdocuments.us/reader035/viewer/2022070515/587855a11a28ab68198b7269/html5/thumbnails/1.jpg)
Drill- off Test"- Selection of Weight on Bit and
Rotary Speed
![Page 2: Drill- off Test"- Selection of Weight on Bit and Rotary Speed](https://reader035.vdocuments.us/reader035/viewer/2022070515/587855a11a28ab68198b7269/html5/thumbnails/2.jpg)
When to carry out Drill- Bit Test:
• Drill-bit test needs to be done at the start of bit run
• On encountering a new formation• If there is a reduction in ROP
![Page 3: Drill- off Test"- Selection of Weight on Bit and Rotary Speed](https://reader035.vdocuments.us/reader035/viewer/2022070515/587855a11a28ab68198b7269/html5/thumbnails/3.jpg)
Step 1
Maintaining a constant RPM, WOB (near maximum available)
![Page 4: Drill- off Test"- Selection of Weight on Bit and Rotary Speed](https://reader035.vdocuments.us/reader035/viewer/2022070515/587855a11a28ab68198b7269/html5/thumbnails/4.jpg)
Step 2
Record the time required to drill a weight increment for example: 2000 kg
![Page 5: Drill- off Test"- Selection of Weight on Bit and Rotary Speed](https://reader035.vdocuments.us/reader035/viewer/2022070515/587855a11a28ab68198b7269/html5/thumbnails/5.jpg)
Step 3
Length of pipe drilled during step 2 is needs to be recorded
![Page 6: Drill- off Test"- Selection of Weight on Bit and Rotary Speed](https://reader035.vdocuments.us/reader035/viewer/2022070515/587855a11a28ab68198b7269/html5/thumbnails/6.jpg)
Step 4
From step 2 & 3, the drilling rate in meter per hour has to be calculated.
![Page 7: Drill- off Test"- Selection of Weight on Bit and Rotary Speed](https://reader035.vdocuments.us/reader035/viewer/2022070515/587855a11a28ab68198b7269/html5/thumbnails/7.jpg)
Step 5
Step 2 & 3 are repeated at least four times. The last test should be at the
same value as first.
![Page 8: Drill- off Test"- Selection of Weight on Bit and Rotary Speed](https://reader035.vdocuments.us/reader035/viewer/2022070515/587855a11a28ab68198b7269/html5/thumbnails/8.jpg)
Step 6
Penetration rate versus bit weight is plotted.
![Page 9: Drill- off Test"- Selection of Weight on Bit and Rotary Speed](https://reader035.vdocuments.us/reader035/viewer/2022070515/587855a11a28ab68198b7269/html5/thumbnails/9.jpg)
Step 7
The bit weight which produced the fastest ROP is selected.
![Page 10: Drill- off Test"- Selection of Weight on Bit and Rotary Speed](https://reader035.vdocuments.us/reader035/viewer/2022070515/587855a11a28ab68198b7269/html5/thumbnails/10.jpg)
Step 8
ROP versus RPM is plotted and the RPM which resulted in the fastest ROP is
selected. This is the optimum rotary speed.
![Page 11: Drill- off Test"- Selection of Weight on Bit and Rotary Speed](https://reader035.vdocuments.us/reader035/viewer/2022070515/587855a11a28ab68198b7269/html5/thumbnails/11.jpg)
Step 9
These values for RPM and WOB obtained will result in optimum ROP for
the particular formation and bit type.