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New High Strength and Faster Drilling Thermally Stable Polycrystalline (TSP) Diamond Cutters
Project Number

The goal of this project is to reduce drilling costs by increasing rates of penetration and bit life in medium-to-hard rock applications.


Technology International, Inc. 
Jet Propulsion Laboratory (JPL) – microwave brazing process development
Colorado School of Mines (CSM) – modeling, mechanical and metallurgical testing, and prototype manufacturing studies. 
General Electric Superabrasives (GE)
Sandia National Laboratory (SNL)
Hughes Christensen Diamond Bit 
Diamond Product International, Inc. (DPI) – sharing cost for TSP cutter laboratory wear, impact, and field drag bit testing.

Kingwood, Texas 77339


A significant way to increase the efficiency of drilling and decrease the costs associated with drilling gas wells is to use a drill bit that can withstand high penetration rates for long periods of time. Improvements in the longevity of the polycrystalline diamond cutting elements on drill bits will help realize these savings to the industry and potentially lower costs to the consumer.

ENDURUS(TM) Diamond Cutter
ENDURUS(TM) Diamond Cutter

This project will develop an advanced thermally stable polycrystalline (TSP) diamond drag bit capable of withstanding high penetration rates for longer periods resulting in increased drilling efficiency. These improvements will help industry realize cost savings and potentially lower natural gas costs to the consumer. The primary effort is to develop an improved method for attaching the TSP cutters to the tungsten-carbide bit substrate. The new technique must prove that improvements can be made in the attachment shear strength and TSP cutter impact strength.


The results of this project are expected to make a major contribution to reducing the number of trips needed for bit replacement due to the increased wear/fracture resistance of these TSP cutters. Smith International, a major bit manufacturer, has shown significant interest in commercializing bits using these cutters.

Accomplishments (most recent listed first)

New cutter designs have achieved a significant reduction in wear rate. The microwave brazing process has shown an ability to braze each of the conventional cutter diameters, 5 mm, 8 mm, 13 mm, and 19 mm. A prototype processing facility was installed at CSM to produce the quantity of cutters needed for field bit testing. Testing has proved that the new TSP manufacturing processes results in a 36% increase in fracture resistance over conventional TSP cutters and attachment shear strength over 50,000 psi. (345 MPa). Technology International tested the ENDURUS ™ TSP Cutters and hard rock drill bit designs at the Sandia National Laboratory and GE Superabrasives Cutter Wear Facilities. The cutters were also tested at the Gas Technology Institute (GTI) Catoosa test well. These tests indicate that by using ENDURUSTM TSP cutters in hard and abrasive rock, drill bit rate of penetration can be doubled; thus, well drilling costs can be reduced by about 15%, with overall drilling project cost savings of 7.5%. Additionally, hard rock drill bit tests using these cutters on a bit supplied by a major oil and gas company were performed at the TerraTek, Inc. Drilling Laboratory in Salt Lake City, Utah, to simulate deeper drilling conditions (approximately 13,000 ft.).

Current Status

and Remaining Tasks: 
Technology International has successfully developed a new microwave brazing process that results in a stronger, longer-lasting TSP bit. Additional testing of the hard rock bit at TerraTek, the Rocky Mountain Oilfield Testing Center (RMOTC), and other industry field locations is being pursued.

Project Start
Project End
DOE Contribution


Performer Contribution


Contact Information

Technology International - Robert Radtke (281-359-8520 or
NETL - William Gwilliam (304-285-4401 or

Additional Information

Final Report [PDF-2.21MB]

Pertinent Publications:
Robert P. Radtke, SPE Paper Number 90845, “Thermally Stable Polycrystalline Diamond Cutters for Drill Bits,” 2004, SPE Annual Conference and Exhibition, Houston, TX 27-29 Oct., 2004.

Robert Radtke, Richard Riedel and John Hanaway, “New Faster Drilling Longer Life Thermally Stable Diamond Drill Bit Cutters” Gas Tips.