After 10 years of Sonic Drilling - "when (or why) should I use a Sonic Drilling?"

"When (or why) should I use a Sonic Drilling?"....

Here’s the short answer from my perspective:

✅ When “undisturbed” samples in alluvial or sedimentary formations are critical to project success and may be required at significant depths.
✅ Where site-specific lithology makes conventional methods unreliable or ineffective.
✅ In uncertain conditions where success hinges on a rig's flexibility to adapt to unknown conditions—especially on very remote sites or projects with high timeline risks.
✅ Where hands-free drilling is a site requirement for safety or compliance. Sonic rigs are more easily equiped with automated systems.

There are many instances where a sonic rig is NOT required (or practical) and a conventional rig and methodology will certainly achieve the project outcomes cheaper and more efficiently.

From environmental investigations to geotechnical and mining projects, sonic rigs address critical challenges with sample recovery in tough ground conditions.

At Legion Drilling, our sonic rigs have become indispensable for projects like landfill investigations, mine waste assessments, tailings management, seep groundwater monitoring and dam evaluations. With the right tools and expertise, we’ve turned client challenges into successful outcomes.

Benefits of Sonic Drilling Rigs

With over a decade of experience as a Sonic drilling company in Australia, Legion has continues to develop this capability due to the following advantages:

1. Continuous Sampling to Total Bore Depth
   Sonic rigs deliver high-quality continuous core samples in all ground conditions, ensuring detailed subsurface profiling.

2. Large-Diameter Sampling
   Capable of sampling diameters exceeding 200mm, Sonic rigs are ideal for bulk sampling projects.

3. Versatility Across Formations
   A single drilling string accommodates varying formations and conditions, eliminating the need for multiple techniques.

4. Instrument Installation Inside Temporary Casings
   Sonic drilling helps prevent cross-contamination with the use of casing and simplifies the installation of instruments like piezometers and inclinometers.

5. Improved Efficiency and Sample Recovery

   • High sample recovery rates (near 100%) with minimal soil disturbance.

   • Reduced sample-to-waste ratio compared to other methods.

6. Multi-Functionality
   Sonic rigs are equipped with high-speed rotary motors, allowing for diamond core tails, SPT testing making them a powerful option for Geotechnical drilling in challenging conditions. At time we will run full face bits for speed with air or water where sections of the vertical profile are unimportant. In hard rock it possible to utilise down hole hammers.

Applications of Sonic Drilling

Sonic drilling is a game-changer for the following projects:

• Landfill Investigations: Obtain undisturbed samples to analyze waste composition and potential contaminant migration. Use drilling fluids and temporary casing to minimise exposure to noxious or flammable gases in the work zone.

• Mine Waste and Tailings Dams: Assess stability and subsurface conditions with confidence. Low pressure track mounted machines make accessing challenging sites possible.

• Environmental Drilling: Ensure reliable, uncontaminated samples for soil property and contaminant pathway analysis. Collect intact samples at greater depths than direct push sampling.

• Geotechnical Drilling: Provide precise subsurface data for foundation design and construction projects, great for continuous sampling and testing through sands and gravels. Cherry on top is a diamond tail using the high speed rotation head fitted Legion sonic machines.

• Mineral Exploration: High volume and high recovery sampling in alluvial and sedimentary formations.

Continuous Innovation with Sonic Drilling Technology

Legion Drilling is exploring new methods to enhance the capabilities of Sonic rigs, such as using air and water with full-face bits to boost production in more accomodating formations. These advancements aim to outperform traditional techniques like mud rotary and air hammer drilling in formations where production is prioritized over sampling.

Challenges and Maintenance of Sonic Rigs - Why is sonic more expensive?

Despite their numerous advantages, Sonic drilling rigs come with challenges, including:

• Size and Complexity: Sonic rigs and their support vehicles require substantial space and specialized maintenance.

• Maintenance Requirements: The intricate Sonic drill heads demand skilled technicians for upkeep.

• Cost - The power requirements result in large complex machines that are expensive to purchase and expensive to maintain. Technical assistance is limited in Australia with only a few “experts” available with the knowledge to assist contractors.

To address these challenges, Legion Drilling has invested heavily in its workshop team and maintenance infrastructure, ensuring these machines operate efficiently for every project.

With a proven track record and ongoing innovations, Legion Drilling's Sonic rigs are at the forefront of environmental, geotechnical, and mining applications. Whether your project involves landfill investigations, mine waste drilling, or tailings dam assessments, our Sonic rigs deliver unmatched precision, reliability, and efficiency.