First published in ADIA June 2026 edition
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Directional core drilling has built its reputation on deep exploration targets, where conventional coring tends to drift outside tolerance as depth increases. The technology is now finding a steadier role in mine services, where geology teams want the same trajectory control on grade control, infill and underground resource definition programs.

For drilling contractors, the relevant questions are practical. How doesdirectional coring change the operational model on site, who carries responsibility when the tool is in the hole, and how does the commercial caseactually stack up against conventional coring. Hamish Haliday, General Manager Australia for Aziwell, says the conversation needs to move away from a cost-per-metre frame.

“Fewer holes, fewer total metres, and far less re-drilling when targets are missed.”
 — Hamish Haliday, Aziwell

“Fewerholes, fewer total metres, and far less re-drilling when targets are missed,”Hamish explains to Australasian Drilling. “When you price in avoided metres, time, pad clearing and rehabilitation costs, permitting and approval delays,directional drilling often delivers a stronger return than conventional coringfor projects with complex, deeper or tighter target constraints.”

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Branching from the mother hole

The operational pull of directional coring sits in the branch holes. Aziwell's AZIDRILL system allows multiple holes to be branched from a single mother hole, removing the need to move the rig, build new pads, or realign between holes.

Ona mine services program, that changes the maths in obvious ways. Padconstruction, site clearing, mobilisation between collars and the downtime that goes with each move all come out of the contractor's budget. Where deepertargets and tighter spacing make those moves more frequent, the savingscompound.

The trajectory control itself addresses a problem most deep coring contractors will recognise. Conventional coring drifts off intended trajectory in adverse geological conditions, and the re-drills, re-collars and pad extensions thatfollow eat into program margin.

“By having the ability to understand and adjust toolface direction at the end of each core run, you can almost entirely eliminate wandering hole and the need tore-drill,” Hamish says. “This in turn saves on reclearing of sites or extending drill pads to allow to move and recollar.”

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Nospecial rig, no special adapters

AZIDRILL runs in almost the same configuration as a standard core barrel.

“AZIDRILL swaps in for a conventional core barrel with no special adapters, extra space, or dedicated gear,” Hamish says. “If the rig can run a standard core barreleffectively, it can run AZIDRILL the same way.”

For contractors responding to mine services tenders, that means directionalcapability can be added to a scope without rig modification or dedicatedequipment. The HQ barrel weighs around 80kg, which Hamish notes will usuallyrequire some form of mechanical aid to lift into the mast and into vehicles fortransport, but otherwise the same operating constraints apply as a conventionalcoring program.

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In thehole only when it needs to be

One of the more important operational details for contractors sits in how the tool is actually used on a program. AZIDRILL is only in the hole when a correctionor a steered section is required. Once the desired bend rate is achieved andthe hole is tracking on target, the contractor pulls the tool and continuesunder conventional coring parameters.

That has two consequences worth understanding. First, the contractor's drillers run the rig the way they normally would for the bulk of the program, with directional capability stepping in only at defined points. Second, Aziwell's operating model means a single tool and crew can be deployed across multiplerigs concurrently.

“We can utilise our service on three, four or even five different rigs moving between holes,” Hamish says. “We are constantly monitoring the data that thedrilling contractors are getting back from their survey results and if neededwe will let them know if they are wandering off target and suggest running backin for a correction to get the hole back on target before it gets to a pointwhere the hole may be lost or a correction may cause so much dog leg in thehole that the rod string would be in danger.”

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Where responsibility sits

Theresponsibility question is the one most contractors will need to answer beforepricing directional capability into a tender. Hamish frames it in terms drilling and oil and gas readers will recognise.

“The drilling contractor is the one who will be operating the rig. We are a third-party tool hand essentially. It's a similar model to that of Sperry, BakerHughes, Weatherford, if we are going to reference oil and gas,” he says. “Weprovide the tooling and the systems to plan and track the borepath. We aremonitoring and advising of our preferred and allowable tolerances at all timeswhile the contracting party is operating.”

Liability splits along familiar lines. If the contractor operates outside Aziwell's recommended parameters and an issue follows, the responsibility sits with the operator. Mechanical failure or technician negligence on Aziwell's side sits with Aziwell. Adverse ground conditions not disclosed before running in hole sit with the principal, the same way they would on any other drilling contract.

For contractors, the practical takeaway is that directional capability does notchange the contracting model in any unfamiliar way. The tooling is third party.The rig operation stays with the contractor.

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Crewfootprint and site set-up

Aziwell's on-site presence is small. The typical setup is one Senior Tech per shift,  second Aziwell technician on shift only when a trainee is being brought through. Crews work a two weeks on, two weeks off rotation that can benegotiated to align with the contractor's roster on remote work.

The site set-up is similarly compact. A site workshop trailer of around 10m by 3msits at a laydown area for tool re-builds, reporting and borehole tracking. The rig itself only needs space for an LV. Hamish describes the package as one vehicle and one trailer with everything required to run a project.

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Wherethe case is strongest

The strongest case sits in hard rock, on deeper targets with tighter drill spacing,and where core samples have genuine geological value. That covers a large sliceof grade control and resource definition work in Australian mine services,particularly on narrow or steeply dipping structures where conventional coringtends to drift outside tolerance as depth increases.

Hamish is unusually direct about where the technology fits, which is useful for contractors trying to assess when to recommend it on a tender. In hard rock, AZIDRILL's rate of penetration and trajectory accuracy means a steered sectioncan be completed in a shorter time frame than a conventional motor and wedgeprogram, and the total directional metres required to land the target arereduced significantly. The exception sits where there is no requirement forcore in the target structure and the overburden geology is not relevant, forexample steering above a coal seam, where a traditional mud motor program canbe the more economical approach.

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Thecost-per-target argument

Aziwell positions as a premium service with a premium upfront cost. Hamish does not duck that but argues the line item belongs in a different column.

“It may look daunting at first,” he says. “However, we encourage our clients to look at a cost per target economy, rather than a cost per metre economy.”

For contractors, the framing is useful in two directions. It gives them a way to defend the line item when clients balk at the rate, and it gives them a way to push back internally on programs that are being scoped on cost-per-metre logic when the underlying target is the actual deliverable.

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Demand and capacity

Aziwell's Australian business has grown on the back of repeat work, with programs that start small with new clients tending to scale once the cost-per-target outcomes show up in the data. The company is currently booked out into mid-2027, which Hamish acknowledges limits its ability to respond to short-notice mobilisation requests.

Aziwell is continuing to develop new tools and workflows and is investing in industry reducation to lift familiarity with directional coring among geologists and program planners. Hamish expects the technology to become more standard in mine services as commodity demand pushes the industry to cut total metres drilled and target more precisely.

For drilling contractors, the practical question is narrower. On the next mine services program with deep targets, tight spacing, hard rock and a real need for core, is directional capability worth pricing in. On the operational model Hamish describes, the answer is increasingly yes.

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JAMIE WADE

At a Glance:

•     Runs in a standard core barrel. No bespoke rig requirements or adapters. HQ barrel is 80kg and usually requires mechanical aid for lifting.

•     Branch holes from a single mother hole. Removes pad moves, site prep and realignment time.

•     Toolace adjustment at the end of each core run. Reduces wandering hole, redrills and recollars.

•     In the hole only for corrections and steered sections. Contractor continues coring parameters between interventions.

•     One tool and crew can run across three to five rigs concurrently.

•     Crew on site: typically one Senior Tech per shift, with a second Aziwell technician on shift only when training a trainee. Two-on, two-off, negotiable rotation.

•     Site footprint: one workshop trailer at the laydown, one LV at the rig.

•     Responsibility model: third party tool hand, similar to oil and gas directional services. Operator failure sits with the contractor, mechanical failure with Aziwell, undisclosed ground conditions with the principal.

•     Commercial framing: cost per target, not cost per metre.

•     Capacity: currently booked into mid-2027.

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