Sonic drilling is an advanced drilling technology that uses high-frequency oscillation (typically 50–150 Hz) to deliver near-100% continuous core recovery, exceptional speed, and significantly reduced investigative waste.

A powerful oscillator in the sonic head generates resonant energy, transmitting precise axial oscillation through the drill string to the bit and casing. This oscillation fluidizes surrounding materials, reduces friction dramatically, and enables smooth penetration through virtually any formation — from soft soils to hard rock — while minimising sample disturbance and maintaining high sample integrity.

In suitable formations (especially unconsolidated soils), sonic drilling often advances with minimal or no drilling fluids. The core sample is captured inside the inner barrel for recovery, while displaced material from the bit face is largely compacted or reorganized into the borehole walls by the oscillating action. Any excess emerges as limited spoils at the surface around the borehole collar — resulting in significantly reduced waste compared to conventional rotary methods that rely on full fluid circulation.

This makes sonic drilling ideal for exploration, geotechnical, environmental, groundwater, and tailings investigations across Australia, where speed, sample quality, and low site impact are priorities.

Sonic Legion delivers this cutting-edge technology as a specialist subsidiary of Legion Drilling.

Sonic drilling offers several key advantages over conventional methods, particularly in challenging or variable formations:

• Near-100% continuous core recovery — even in unconsolidated, saturated, layered, or mixed soils and overburden, providing reliable geological data.

• Exceptional speed — often 3–5 times faster penetration in overburden due to reduced friction from high-frequency oscillation.

• Minimal disturbance and high sample integrity — preserves stratigraphy and sample quality for accurate analysis in geotechnical, environmental, and exploration work.

• Significantly reduced investigative waste — material is largely compacted into borehole walls or recovered as core, with limited spoils at surface and often minimal or no drilling fluids in suitable formations.

• Versatility — effective through cobbles, boulders, tailings, landfill debris, weathered rock, and more, with options for angled drilling and casing advancement.

• Low site impact — ideal for sensitive environmental sites, tailings dams, and infrastructure projects.

These benefits make sonic drilling highly efficient for mining, geotechnical, environmental, groundwater, and tailings applications.

Sonic Legion provides Australia's leading sonic drilling services as a specialist subsidiary of Legion Drilling.

While powerful, sonic drilling has some limitations to consider:

• Higher upfront cost — equipment, tooling, and trained operators are more expensive than conventional rotary or auger methods, though often offset by faster completion and reduced waste disposal.

• Potential heat generation — prolonged dry advancement can heat the bit in hard or consolidated formations, sometimes requiring minimal fluids for cooling or limiting run lengths.

• Formation-specific performance — excels in unconsolidated/overburden but may need adjustments (e.g., limited fluids) in dense rock or abrasive materials.

• Noise and vibration — the high-frequency oscillation can produce noticeable noise and localised vibration, though modern rigs minimise this.

• Not always the lowest-cost option — in very simple, soft formations where basic methods suffice, sonic may be over-specified.

Sonic drilling shines where high recovery, speed, and low impact are critical — often proving more cost-effective overall in complex sites.

Sonic Legion optimises rig selection and techniques to address these factors for Australian projects.

Sonic rigs are most productive and useful in challenging or high-value applications where speed, recovery, and minimal site impact matter most:

• Difficult overburden/unconsolidated formations — layered soils, saturated sands, cobbles, boulders, tailings, landfill debris, or heaving materials where conventional methods stall or lose recovery.

• High-recovery needs — geotechnical investigations, tailings dam assessments, environmental site characterisation, groundwater monitoring, or exploration requiring continuous, high-integrity cores.

• Waste-sensitive or remote sites — reduced spoils and often minimal fluids make it ideal for contaminated land, mine waste, or environmentally protected areas.

• Time-critical projects — rapid advancement (up to metres per hour faster) for deep monitoring wells, infrastructure foundations, or large-scale sampling.

• Versatile transitions — dual-head rigs allow seamless shift to diamond coring in bedrock.

Sonic rigs deliver peak productivity in complex Australian conditions — from mine sites and tailings to urban environmental assessments.

Sonic Legion's fleet excels in these scenarios nationwide.

Sonic Legion, as the dedicated sonic subsidiary of Legion Drilling, stands out as Australia's leading provider through proven expertise, modern fleet, and client-focused delivery:

• Extensive experience - over a decade of specialist sonic operations across all states, tackling mine sites, tailings, landfills, infrastructure, and environmental projects.

• Advanced fleet - six high-capacity, crawler-mounted sonic rigs (including Geoprobe and Comacchio models) with dual-head capabilities for seamless diamond coring and options for hands-free rod loading to enhance safety.

• Mining compliance - rigs fully compliant with major operators (BMA, Rio Tinto, QAL, Glencore) for safe, reliable work on mine sites and tailings facilities.

• Nationwide coverage - depots in Brisbane, Townsville, Sydney, and Darwin ensure fast mobilisation and lower logistics costs.

• Safety and innovation - focus on hands-free systems, high sample integrity, and minimal impact aligns with industry best practices.

• In-house Maintenance - we have a crew of dedicated technicans trained and experienced in re-building 4 sonic head designs. This ensures when issues occur rigs are back up and running asap unlike companies who rely on 3rd paty support which is very hard to access in Australia.

Clients choose Sonic Legion for consistent results, technical excellence, and trusted service in Australia's toughest conditions.

Sonic drilling rigs are available through specialist contractors across Australia, with Sonic Legion (part of Legion Drilling) offering one of the most comprehensive and accessible fleets:

• East Coast and beyond — rigs based in Brisbane, Townsville, Sydney, and Darwin for rapid deployment nationwide.

• Mine sites, tailings, and infrastructure - compliant rigs ready for remote or regulated sites, including major mining operations.

• Project scale - high-capacity sonic rigs suitable for deep investigations, large programs, or quick-response work.

Contact Sonic Legion directly via www.soniclegion.com.au or www.legiondrilling.com.au to discuss availability, mobilisation, and tailored solutions for your location and requirements. Our team ensures fast, reliable access to sonic drilling across Australia.

Yes - Sonic Legion (Legion Drilling) operates fully mining-compliant sonic drilling rigs tailored for Australian mine sites and related projects.

Our fleet includes high-capacity, crawler-mounted sonic rigs compliant with stringent requirements from major operators such as BMA, Rio Tinto, QAL, Glencore, Yancoal, Whitehavan, Peabody, and many others. These rigs support geotechnical assessments, tailings dam investigations, mine waste characterisation, groundwater monitoring, and exploration - all while meeting site safety, environmental, and operational standards.

With depots in key mining regions across (including Darwin for NT access), we provide fast mobilisation and reliable performance on active mine sites and tailings facilities. Contact us to confirm compliance details for your specific operation.

Yes - hands-free (or automated) rod loading systems are available and in use on sonic rigs, significantly improving safety by reducing manual handling.

Sonic Legion (Legion Drilling) has equipped multiple rigs with advanced hands-free rod loading options, including systems like the Geoprobe SRC30DT sonic rod carrier. These allow virtually hands-free rod handling for most operations, accommodating sufficient rods for deep projects (e.g., 100m+) and supporting varied casing sizes.

This innovation minimises risks, enhances efficiency, and aligns with stringent mining and safety requirements. Four of our rigs also feature dual heads for added versatility. Sonic Legion leads in safe, modern sonic drilling solutions across Australia

Yes (Sometimes), in many suitable formations-especially unconsolidated soils, overburden, and softer materials, sonic drilling can advance effectively with minimal or no drilling fluids.

The high-frequency oscillation fluidizes the material at the bit face, allowing the casing to penetrate while most displaced soil is compacted or reorganized into the borehole walls. Any excess emerges as limited spoils at the surface, resulting in significantly reduced investigative waste compared to conventional rotary methods.

In harder, denser, or abrasive formations, limited fluids (air, water, or additives) are often introduced for bit cooling, lubrication, or cuttings removal to maintain performance and extend run lengths.

Sonic Legion optimises fluid use based on specific site conditions to deliver high sample integrity and efficiency. We recommend not making assumptions about fluid use and ensuring there is flex-ability depending on early results.