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Reverse Circulation

Fast sample return. Broader coverage.

Reverse circulation drilling returns representative rock-chip samples to surface for geological analysis. It supports exploration programs where drilling speed, cost per metre and broad coverage are central to the objective.

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Our Approach

Built around sample quality, coverage and site conditions

We align the rig, compressor capacity, drill string, sampling setup and field support to the geology, target depth, site access and sampling objectives of each program.

Reverse Circulation Programs

Efficient drilling and representative chip-sample collection support preliminary exploration, geological analysis and broader program coverage.

Configured for the Project

Ground conditions, depth, access and project requirements guide the drilling approach, equipment configuration and field support.

What We Bring

Reverse Circulation capabilities

Our RC capabilities combine experienced crews, engineered equipment and flexible configurations to support demanding exploration programs.

Sample Return

Dual-wall drilling and planned air capacity return rock chips through the inner tube for separation, collection and analysis.

Diverse Fleet

Our reverse circulation fleet includes multiple rig sizes, depth capacities up to 4,000 feet (1,219 metres), winterization options and skid, track, buggy and truck mounting configurations. All-terrain rigs support access to greenfield exploration sites.

Engineered Equipment

Our in-house engineers customize, upgrade and retrofit RC rigs for safety, flexibility and productivity. Equipment is field-tested for compliance, reliability and uptime.

Rod Handling

We continue to upgrade our RC fleet with rod-handling technology that reduces manual interaction and supports safer field operations.

How Reverse Circulation Works

From hole to sample

Reverse circulation drilling uses compressed air and a dual-wall drill string to return rock chips from the bit face to the surface. The material moves through the sampling system for separation and collection, producing representative chip samples for geological analysis.

Illustrated reverse circulation drilling process from bit and dual-wall drill string through cyclone, splitter and sample collection

The controlled return path keeps the sample moving directly from the hole to the collection point, supporting consistent sample handling across the program.

RC Methods and Field Setup

Equipment and field execution aligned to the program

We configure the drilling system and field support around the geology, depth, access and sampling objectives of each program. The rig, compressor, drill string and sampling setup work together to maintain sample return and support efficient field execution.

Reverse circulation drill string and equipment

Method

Dual-wall drilling

The drill string carries compressed air down the annular space and returns rock chips to surface through the inner tube.
Compressor and air support equipment for reverse circulation drilling

Method

Air and compressor support

Air capacity is planned around drilling depth, formation conditions and the sample-return requirements of the program.
Drilling samples prepared for field analysis

Method

Sample handling

Cyclone separation, collection, labeling and field handling support consistent sample control from the hole to analysis.
Mobile reverse circulation drilling rig

Method

Mobile configurations

Skid, track, buggy, truck-mounted, winterized and all-terrain configurations support varied access and operating conditions.

Our RC fleet includes multiple rig sizes and depth capacities up to 4,000 feet (1,219 metres), supported by in-house engineering, equipment upgrades and rod-handling technology.

Our Technical Expertise

Ground conditions, techniques and tooling

Our locally trained and certified reverse circulation crews bring extensive knowledge of ground conditions, drilling techniques and tooling. They use that experience to align the drilling approach and rig configuration to the project objectives and site conditions.

Experienced RC Crews

Local crews apply practical knowledge of the ground, techniques and tooling to deliver consistent field execution.

Local Talent, Global Strength

Local teams are backed by cross-regional expertise, equipment, services, performance metrics and reporting from across Boart Longyear.

Our Experience

Reverse Circulation expertise

Our people, equipment and operating practices support safe, reliable RC programs. Progressive safety programs, field-designed innovations and risk-management processes help our teams work consistently across project locations.

Up to 4,000 Feet

RC fleet depth capacity up to 4,000 feet (1,219 metres).

Experienced Crews

Locally trained and certified RC crews backed by global technical expertise and equipment.Wedges, motors and survey tools selected around the required correction.

Safety + ReliabilityCoordinated Execution

Field-designed safety innovations, world-class training programs and equipment tested for compliance and reliable performance.Locally trained and certified RC crews backed by global technical expertise and equipment.

Project highlights

Drilling within site constraints

Explore a municipal water-well project where drilling configuration and noise control shaped the approach.

Electric Rotary Drilling Meets 65 dBA Residential Noise Limit

Boart Longyear used an electric/hydraulic rotary drilling system and site controls to complete a municipal water well in a residential area while meeting a 65 dBA noise limit.
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Our Capabilities

Related Capabilities

Explore related drilling capabilities that may support your program.

Surface Coring

Recover continuous geological core with equipment and methods configured around the target, terrain and recovery requirements.

Sonic Drilling

Recover relatively undisturbed samples through difficult ground using controlled resonant energy and casing control.

Related Resources

Case studies and resources

Explore examples of our drilling expertise in action.

Reverse Circulation Drilling: When Timely Sample Return Matters

A practical overview of reverse circulation drilling, sample return, and early exploration decisions.
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Drilling Methods Overview

An overview of Boart Longyear drilling methods and where they may apply across exploration, underground, production, water, and specialized work.
Explore Resource

Rotary Drilling: Applications and Site Considerations

An overview of rotary drilling applications, hole requirements, equipment considerations, and operating conditions.
Explore Resource

From Ground to Sample

From field conditions to the right RC setup

Tell us the project objectives, ground conditions, site access and drilling requirements. We can help align the RC approach, equipment and field support to the work.

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