Unless your horizontal directional drilling (HDD) crews are working in in tough rock conditions regularly, investing in a dedicated rock drilling solution like a dual rod machine, air hammer or mud motor system may not be the most economical tooling solution for your needs. Instead, you may want to consider equipping your team with a versatile HDD tooling package, like the Vermeer Armor® drilling system, that has multiple drill bit options to be productive in a wide range of conditions. This rock-focused drilling system features a premium, sideload housing assembly, numerous drill bits designed for whatever rock formations you may encounter, and extras, including swivels, pullback mounts and bent sub adapters.

According to Jason Zylstra, product manager for Lifecycle at Vermeer, the Vermeer Armor system is a good fit for drilling in ground conditions ranging from hard pack soils to rock up to 10,000 pounds per square inch (68.9 MPa). “The system has several bit options that can be easily and quickly swapped out as soil conditions change,” he explained. “Also, the housing is constructed with dual water ports that can deliver up to 70 gallons per minute (265 Lpm) at 800 fluid pressure per square inch (48.3 bar) of mud flow to effectively carry cuttings out of the bore. The system’s performance, as well as a robust exterior design that uses a single roll pin to secure the sonde lid to the housing instead of bolts, gives contractors dependable performance on challenging bores.”

Drill bit options

On many bores, ground conditions can change quickly — one bore may start in soft soils and then change to a more solid formation or cobble. It’s projects like these where the Vermeer Armor system can improve a crew’s efficiency because they can swap between a range of bits by removing a single pin, instead of dealing with a threaded, torqued connection. Each bit in the Armor system has been designed to perform efficiently in specific conditions, and you can build your system one bit at a time or all at once.

For working in hard packed soil, gravel or cobble, you’ll want to consider using a Lance™ Original or Lance Pro bit. These bits have a scoop design to aid with steering and limit wandering in challenging ground conditions. The Lance Pro bit offers continuous carbide coverage across the front to help extend the wear life. Both bits include a heavy-duty quick pullback hook for smaller diameter installations.

Lance bits also perform well in cobble/broken formations, but for solid formations you may want to consider a Gauntlet™ bit. These bits are designed for use in soft to medium rock, shale and caliche up to 10,000 pounds per square inch (68.9 MPa) while maintaining excellent steering capabilities. There are also Gauntlet bit bolt-on options with a pullback hook.

The single roller cone bit is designed to deliver versatility in cobble and broken formations. As it works through the ground, the cone's rotation helps smooth out the entire drill string and reduce torque spikes. For additional versatility in mixed and solid rock conditions, the API bent sub adapter offers compatibility with any API thread tri cone or PDC bit.

“All of the possible configurations with the Vermeer Armor system help ensure a better tooling match for whatever current ground conditions are,” Zylstra explained. “And, as any drill operator knows, having the right drill bit in challenging ground conditions can make a world of difference.”

Rebuildable drill bits

Challenging, rocky soils are tough on bits, and through a rebuild program offered by Vermeer you can extend the life of Lance bits, and Gauntlet bits. It’s an easy-to-use program that can help reduce your out-of-pocket tooling expenses and help you get more from your rock tooling.

“To have a bit rebuilt, Armor system owners simply need to contact their local Vermeer dealer to send the bit or housing to the Vermeer manufacturing facility in Pella, Iowa,” said Zylstra. “It will then be analyzed to confirm it can be rebuilt to factory specifications — most bits can be rebuilt several times. The whole process happens quickly, so we can get the rebuilt tooling back out in the field working. It’s just one more reason why the Vermeer Armor system is a great and economical rock drilling solution.”

Threaded Options

The Vermeer Armor drilling system is a complete system for challenging bores, but Vermeer now offers its popular Gauntlet and Lance Pro bits on the threaded Armor Direct API connection platform. Since these models are threaded, you won’t have the ability to quickly swap out bits like you would with the single roller pin design and the bits aren’t able to be rebuilt. However, threaded Gauntlet and Lance Pro bits are productive and economical options when you’re working in tough conditions that outmatch plate bits.

For more information about the Vermeer Armor drilling system, talk to your local Vermeer dealer or explore our Armor inventory.