Drilling is one of the biggest line items in your exploration budget. How can you tell if you’re really getting the best value from every metre drilled and every dollar spent?
Choosing the right drilling contractor matters - balancing cost, production, and sample quality. But to truly understand how your project is performing, you need metrics that fit your specific goals. Metrics that shine a light on what’s really happening underground, on your rig, and in your budget.
In this article, we explore practical drilling metrics that help you:
Understand contractor performance Predict budget outcomes Decide if you want to rehire a contractor Let’s dig in.
Tracking costs Cost per Metre (CPM) CPM is the classic way to measure spend versus progress. You calculate it by dividing total drilling costs over a period by the metres drilled in that same time.
For example: If your drillers invoiced $100,000 for 2,000 metres, your cost per metre is $50.
You can also use CPM to estimate future spend by comparing planned versus actual metres drilled.
Heads-up: This metric can be misleading if it combines different drilling methods. For example, mixing auger and diamond drilling into a single cost per metre skews your results.CPM per rig Breaking CPM down by rig helps you see cost efficiency on a deeper level.
It lets you compare rigs of the same type, track trends over time, and avoid misleading averages.
This is especially helpful when you’re working with multiple contractors or rig types.
What’s a "good" CPM? There’s no simple answer. Cost depends on your budget, rig type, drilling depth, extra contractor services, and more.
Watching your CPM over time helps you spot trends and check if you’re staying on budget. If costs start creeping up, having this visibility means you can investigate before it becomes a bigger problem.
Some contractors might share insights to help you get more from your rig and budget. But the most important thing is knowing your numbers well enough to ask the right questions.
Keep in mind: cost is only part of the story. Balancing cost with productivity and quality metrics - based on what’s most important for your project - gives you a clearer picture.
Measuring productivity Metres per Shift (MPS) MPS measures how many metres your rig drills in a shift. It’s a simple way to track output, but it doesn’t tell you what happens during that time.
A rig drilling 100 metres in a shift might look efficient until you realise it sat idle half that time waiting on a geologist.
On its own, MPS doesn’t reveal where time goes or what’s slowing progress. To understand why, you need to dig deeper.
Driller efficiency This metric shows the percentage of available shift time actually spent drilling.
Driller Efficiency = Drilling Time / Available Drill Time
For example: In a 12-hour shift with a 30-minute safety meeting, 11.5 hours are available to drill. If the drill was active for 9 hours, efficiency is about 78%.
Efficiency helps compare how drillers use their time - but it doesn’t measure drilling quality.
Metres per Available Hour (MPAH) This tells you how much drilling happens during the time the rig could actually be drilling.
Metres per Hour = Metres Drilled / Available Hours to Drill
If metres per hour drops, it often points to bottlenecks like unexpected maintenance, slow sample collection, or delays in rod delivery.
Tracking this over time reveals patterns - shifts that regularly underperform or formations that slow progress. This metric helps you spot issues early and address them before they add up.
Assessing quality Core recovery and sample bag weight A faster penetration rate might boost metres per shift but can harm sample quality. In RC drilling, drilling too quickly risks losing fines or damaging the sample.
Tracking sample recovery alongside penetration rate helps you:
Spot when fast drilling causes poor core recovery or sample loss Link drilling settings (like bit type or speed) with sample quality changes Decide when slowing down or changing methods preserves important geological data Core recovery, sample loss, and bag weights can create a tolerance range tailored to your program.
We’ve previously explored the relationship between sample quality and drilling data , and the risks of storing it all in spreadsheets.
Finding the ROI sweet spot for your operation There’s no one-size-fits-all benchmark for “good” drilling performance. Every project is different.
Your ideal results depend on factors like budget, ground conditions, rig type, and what matters most: speed, cost, or sample quality
The real insight comes from seeing how these metrics interact. For example:
Is shift time used well, or is standby time cutting into performance? Are you likely to overspend based on current costs and metres left? Would slower drilling with higher-quality samples make sense? Looking at metrics in context - not just numbers - helps you make smarter trade-offs and decisions. Over time, you’ll build a clear performance picture that guides contractor choice, planning, and getting the most from every drilling dollar.
Let CorePlan do the heavy lifting Manually tracking these metrics takes time.
CorePlan’s drill operations software automates the work. It
Ingests plods from any contractor Calculates key metrics automatically Tracks costs, productivity, and quality over time Reconciles invoices against contract rates Spend less time wrangling data, more time making confident decisions.
👉 Explore the CorePlan platform or book a demo to see it in action.
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