PDC Drill Bits Manufacturing process

1. Manufacturing Process of Polycrystalline
Diamond Compact(PDC) bits
Name- Abhijeet Chodankar

2. Outline
• Introduction
• Main Parts of PDC bits
• Manufacturing Process
• Conclusion
• References

3. Polycrystalline Diamond Compact
• aggregates tiny, inexpensive, manmade diamonds into relatively large, intergrown
masses of randomly oriented crystals that can be formed into useful shapes called
diamond tables
• Hardest material
• Bonds with tungsten carbide materials that can be brazed (attached) to bit bodies
• Random structure found in bonded synthetic diamond performs better in shear

4. Diamond table
• Diamond grit is sintered with tungsten carbide and metallic binder to form a
diamond-rich layer
• wafer-like in shape and thick because diamond volume increases wear life
• Thickness- (2 to 4)mm
• Tungsten carbide substrate- 0.5 inches high
• Diamond table and substrate make up a cutter
Sintering is the process of compacting and forming a solid mass of material by
heat and/or pressure without melting it to the point of liquefaction

5. Major Parts of PDC Drill Bit
• Polycrystalline Diamond cutter
• Matrix crown
• Fluid nozzles
• API pin connection or Shank
• Blank

7.  Polycrystalline Diamond cutter
• Extremely durable
• Shears the rock formation
• Different sizes and shapes
 Matrix Crown
• Material: Matrix of powdered metal
• PDC cutters and fluid nozzles are housed

8.  Fluid Nozzles
• Nozzles are placed inside the crown during manufacturing.
• Purpose: flush the debris away from the open spaces of the bit
 API pin connection or Shank
• Connection between drill bit and drill string
• Material: Steel
 Blank
• Part of the bit which connects the crown to the shank
• Material- Steel (AISI 1018 steel )
• Matrix material of the crown cannot be welded so the blank is very
important

9.  Matrix
• very hard, rather brittle composite material comprising tungsten carbide grains
metallurgically bonded with a softer, tougher, metallic binder.
• resistant to abrasion and erosion
• Withstands high compressive loads
• heterogeneous
Drawbacks
• low resistance to impact loading

10.  Steel
• Higher Strength and higher ductility
• Homogeneous material
• Complex bit profiles and hydraulic designs are easy to construct
• Rebuilt a number of times because worn or damaged cutters can be replaced easily
Drawbacks
• quickly fails by abrasion and erosion

11. Why Steel is the better material choice for crown material?
• Higher Toughness
• Taller/Thinner blades
• Larger junk slot area and face fluid volume
• More Hydraulic efficiency
• Improved PDC Cutter location accuracy

12. Steps in manufacturing of PDC drill bits
1) Ordering of the PDC Drill Bit
• SAP program
 Order is placed for the PDC bits.
 used to keep track of the progress of bit assembly, lot numbers, heat codes of raw materials such as steel and matrix
powder
 contains the Bit Assembly Master, Specification Drawings and the router packet
• Router packets
 Series of bar codes scanned when certain materials are used or tasks are performed
 Overall checklist of the manufacturing process of the PDC drill bits
2) Designing of the PDC Drill bits
• Software like Geoscience, SPOT, Pro-Engineering Design and CAM, ANSYS, CATIA are used in the design
and analysis of drill bits

13. Geoscience
Analysis
Drilling and
Wear
Simulation
Propose
Existing Bit
Design
Pro-Engineering CAD
( Computer Aided
Design)
CFD Analysis
Pro-Engineering
CAM
(Computer
Aided
manufacturing)
Bit run and Geoscience Post
Run analysis
Successful
design and
analysis of
PDC bit
Important Steps in the manufacturing of PDC drill Bits

14. Bit Assembly Master
• Direction manual for building a bit

15. Milling operation
Milling is the machining process of using rotary cutters to remove material from a workpiece advancing (or
feeding) in a direction at an angle with the axis of the tool
Turning operation
Turning is the process of machining external, or internal cylindrical. and conical surfaces in which the part is
rotated as the tool is held. against it on a machine called a lathe
 Basic difference between Milling and Turning operation
• Milling operation
Job is fixed and tool is rotating
• Turning operation
Job is rotating and tool is fixed

16. Steps in Manufacturing of PDC Drill bits (Powdered Metal Infiltration Casting Method)
1. Milling and Turning operation on Matrix and Blank
2. Plotting Phase
3. Loading Phase
4. Furnacing phase
5. Cooling Phase
6. Breakout phase
7. Crown Machining phase
8. Welding and Brazing phase
9. Final Machining
10. Inspection, Painting and Packing

17.  Matrix Crown
• Manufactured using molds
• Material- Graphite bar
• Types of Molds:
a) Milled Mold Assembly- Junk slots already milled
b) Milled Junk Slot- junk slots need to plotted
 API Pin Connection -Manufactured using steel bars
 Blank
• Material- Steel bars (AISI 1018)
• Hole in the center of steel bar lowers the milling and turning time

19.  Plotting phase
• PDC cutter, nozzle and junk slots displacements are plotted.
• Slots for nozzles, PDC cutter pockets, junk slots and bore tubes are formed
from the sand molds and are glued into the graphite crown mold
• Graphite nozzle displacements are filled with sand and baked before they are
put into the crown mold
• Size of the tubes depends on the size of the bit to be manufactured

20.  Loading Phase
• Mold is loaded with tungsten carbide matrix powder
• Mold is packed by vibrating the assembly
• Funnels are attached and loaded with matrix binder material
• Flux powder is added to the binder – acts as anti-oxidant which aids in binder flow

21.  Furnacing phase
• Preheat the furnace to specified temperature. This temperature depends on
binding material and the bit size.
• Furnace drops in temperature when it is opened to put the bit assembly inside.
• Recovery time
Time taken by furnace to reach the proper temperature
• Baking time (Soak time) doesn’t start until the furnace temperature has
recovered.
• Bit assembly soaked at 2100 0F (minimum temperature)
• Soak time depends on the size of the bit

23. Cooling Phase
• Bit assembly is cooled on a cooling plate
• Water is pumped through this cooling plate at different pressures and flow
rates depending on the size of bit manufactured.

24.  Breakout Phase
• Remove the funnels carefully to avoid the breakage of funnels
• Bit is removed using an electric hoist
• Mold is removed using electric hoist and rubber mallet
• Remove the displacements such as graphite, sand clay and ceramic using a
chisel. Silica displacements are removed shot blasting the bit
 Crown Machining Phase
• Crown is machined
• Threads are added to the crown

25.  Welding Phase
• Shank is attached and wrapped in insulation to control its temperature.
• Bit is preheated in preparation for welding
• Post Weld Heat Treating - Bit is heated for 15 minutes at 1050 oF
 Brazing Phase
• Brazing is a metal joining process in which two or more metal items are joined together by
melting and flowing filler metal into the joints, the filler metal is having lower melting points
than the adjoining metals
• Filler metal flows into the gap by capillary action
• Filler metal is brought slightly above its melting temperature and is protected by flux
• This filler flows over the base metal and is cooled to join the workpieces together.
• Filler metal- Aluminium-Silicon, Copper, Bronze, Brass

26. • Installation of PDC cutters- Cutters are preheated and placed in bath of molten flux
• Bit is heated again to around 1140oF
• PDC cutter sockets are heated by torch to brazing temperatures.
• Braze alloy is applied before the PDC cutters are set. The braze alloy is applied again after
the PDC cutters are set.

27. • After the PDC cutters are set, dry flux is applied in order to freeze the cutters in place.
 Final Machining
• The shank is ground to the specified diameter and the weld is machined off
 Inspection, Painting and Packing
• The bit goes through its final inspection, painted and shipped off to the customer.

28. References
1) Manufacturing System of Polycrystalline Diamond Compact Bits: Student-
Glenn J Compliment,
2) https://www.youtube.com/watch?v=_8BzrVLPFKQ
3) www.petrowiki.org
4) http://www.varelintl.com/es/content/includes/varel_fixed_cutter_drill_bits.pdf
5) https://en.wikipedia.org/wiki/Brazing