PDC or tricone in HDD? May the best bit win!

Horizontal Directional Drilling
Written By Omer Ahmad

PDC (polycrystalline diamond compact) bits and tricones have advanced over the years. The market is constantly changing and adapting - to new and improved materials and designs. 

 
 

PDC’s and tricone’s have pros and cons for the HDD environment. 

Advantages of a PDC:

PDC bits don’t require significant weight on bit to support the cutting action. A PDC bit will drill fast and shear the rock, rather than grinding and crushing. Whether this is more effective than a tricone will depend on the ground, your equipment, and experience using the tooling.

PDCs:

  • Are fast cutting in the right formation

  • Have no moving parts 

  • Shear rock through scraping action

  • Have a long life

  • Have higher rates of penetration

PDCs may cost more than tricones, but they last longer when used in their optimal conditions.

Advantages of a tricone:

Tricones have been around a long time, and have been the traditional go to bit - when needing to deal with harder conditions requiring an AT style rig or mud motor. Tricones work by grinding and crushing, with its three roller cones.

Tricones:

  • Are a familiar tool that drillers understand how to use to best effect

  • Work well in inconsistent ground conditions

  • Have a lower cost

  • Are hard hitting

  • Are very versatile

  • Have more control with torque and weight

If you are able to source a tricone built specially for HDD, it will have extra gauge protection, which helps reduce wear on the shirtail on the bottom of the hole.

Ground conditions in Australia:

PDC

  • Consolidated ground

  • Sandstones

  • Clay

  • Soft sands

Tricones

  • hard rock

  • unconsolidated ground

  • abrasive ground

Ground conditions in New Zealand:

PDC

  • East Coast Bays formation

  • Consolidated hard formation

Tricones

  • Basalt

  • Gravel and unconsolidated formations

  • Hard rock with fissures

There are advantages and disadvantages to both tricones and PDCs; with geology, drilling fluids and rig capacity all coming into consideration. With a combination of a good drilling fluid system, lubricated bits, and a smooth operator at the helm - winner winner chicken dinner!

For help in determining the right bit for your HDD project, please talk to one of our Sales Managers. Blick stocks a leading range of tricones and PDCs, and partners with M-I SWACO for drilling fluids.

 
 
Omer Ahmad

Omer is Blick’s newest addition, and has already educated the team on Bush Chook protocol.

As our Sales Manager in Perth, Omer is focused on building our presence on the west coast in the mineral coring, waterwell, HDD, oil & gas and tunnelling markets.

Omer comes from a drilling industry background, and is ready to help our WA customers do a great job.

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