"If the bit ain't Turning..."

When drilling, time is money. Every idle hour on a rig means lost revenue for contractors, wasted costs for mining teams, and missed deadlines. As the saying goes: "If the bit ain’t turning, no one’s earnin’.”

To keep things moving and profitable, both mining companies and drilling contractors need to understand exactly how rig time is being spent. That’s where Time Usage Models come in.

What is a Time Usage Model (TUM)?

A Time Usage Model is a framework that breaks down how a rig spends its time during a shift. It's not just about drilling time (bit-on-bottom). It includes everything from actual drilling to standby, maintenance, and even delays.

Think of it like a time budget. But instead of allocating dollars, you're allocating hours. It helps you see where time is being spent and where improvements can be made.

When done right, a Time Usage Model lets you:

Measure rig utilisation
Benchmark rig performance
Identify bottlenecks and inefficiencies

Why are Time Usage Models matter?

For Mining Companies:

Control costs: Know exactly what you’re paying for and why.
Improve planning: Spot delays early, refine schedules, and allocate resources better.
Hold contractors accountable: A shared model sets clear expectations and makes billing transparent.

For Drilling Contractors:

Prove your value: Use hard data to show you're efficient and productive.‍
Improve performance: Spot areas to train crews or fix repeat issues.‍
Boost profitability: Less downtime = more billable hours.

How to build a Time Usage Model

1. Define your categories

Start with clear categories that cover the main types of drilling activity. Here’s a common breakdown:

Time Activities Categorisation

Active Time

Rig is available and running.

Active (Drilling): Bit-on-bottom time – the rig is actively drilling.
Active (Productive): Non-drilling activities related to the drilling process (e.g. casing, tripping).
Active (Non-Productive): Rig is running but not progressing the hole (e.g. rig moves, stuck rods).

Standby: Operational or External

Rig is available but not running.

Standby (Operational): Downtime within the crew’s control (e.g. lunch breaks, training).
Standby (External): Downtime outside the crew’s control (e.g. weather delays, site access).

Maintenance Time

Rig is mechanically unavailable.

Maintenance (planned): The drill rig is unavailable for work, but according to the plan. Scheduled maintenance goes under this category.
Maintenance (unplanned): The drill rig is unavailable for work when we need it to be. This is also called breakdown
‍

Category	Description	Examples
Active (Drilling)	This category exclusively captures the time the drill bit is actively penetrating the ground.	Drilling time only, always.
Active (Productive)	This encompasses all activities directly related to drilling, where the rig is operational but not actively drilling.	Reaming, casing, tripping (raising or lowering the drill string), connecting rods, conducting downhole surveys.
Active (Non-Productive)	This includes activities where the rig is operational but not directly contributing to drilling progress.	Rig moves, freeing stuck pipe, addressing minor equipment issues, non-drilling related delays (e.g., waiting for supplies).
Standby (Operational)	The rig is available but not running due to planned breaks or activities within the crew's control.	Lunch breaks, safety meetings, pre-shift checks, crew training.
Standby (External)	The rig is available but unable to operate due to factors outside the crew's control.	Weather delays, waiting for site access, client-requested stoppages, safety stand-downs.
Maintenance (Planned)	Scheduled maintenance activities that require the rig to be shut down.	Regular servicing, preventative maintenance, inspections, replacing worn components.
Maintenance (Unplanned)	Unexpected downtime due to equipment failures or breakdowns.	Engine problems, hydraulic leaks, broken drill string components, electrical issues.
Other	This is an optional category and we don’t recommend using this one unless absolutely necessary.	ideally minimal entry

2. Assign activities

List out the typical activities that happen on-site and be as specific as possible. The more detail, the better. Then, map each activity to the category it belongs to based on your time model.

Example:

Connecting drill rods → Active (Productive)
Waiting for client instruction → Standby (External)
Replacing drill bit (planned) → Maintenance (Planned)

3. Customise for contracts

Consistent data capture is key. Choose a method that suits your site:

Digital Plods: Logged on tablets at the rig
Rig Monitoring Systems: Automated sensor data (e.g. engine hours, pressure)
Manual Time Logs: Paper-based logs filled out by the crew. Still common, but more prone to errors and harder to work with.

4. Implement a Data Capture System

Reliable and consistent data capture is the foundation of a successful Time Usage Model. Choose a method that suits your operational needs and technology capabilities:

Digital Plods: Electronic drilling logs captured on tablets or ruggedised devices at the rig.
Rig Monitoring Systems: Automated data collection from sensors on the rig, tracking parameters like engine hours, drilling depth, and pressures.
Manual Time Logs: Paper-based logs filled out by the drill crew, although this method is more prone to errors and less efficient.

5. Analyse and Optimise

Once you're capturing data, it’s time to look at the trends.
What’s dragging performance down?
Where’s the non-productive time stacking up?

Example: Analysing Rig Utilisation in CorePlan

Below, we see CorePlan’s Rig Utilisation charts with the time usage breakdown. The primary purpose of the Rig Utilisation chart is to benchmark your rigs and compare their overall performance.

Rig Utilisation Hours Chart on CorePlan

At a glance, we see that Rig GDD22 is far more efficient and effective when it comes to its shift time. It has a greater percentage of time spent on actual drilling and other "active" hours compared to the other rigs listed.

Meanwhile, the opposite is happening with Rig GRC20, where more time is spent on Unplanned Maintenance (usually, time classified as 'Breakdown' is placed in this category) - which would be a cause for concern as it's an indicator of potential revenue loss.

(In a nutshell: the more blue, the better)

This offers a clear way to determine which rigs are performing well and which ones need attention.

Navigating the Grey Areas of Categorisation

Sometimes it's challenging to categorise a time activity definitively. Should refuelling be under Operational Standby, Non-productive Active time, or perhaps even Planned Maintenance? How about daily pre-starts, how should they be classified?

Ultimately, it’s up to you how you want to split it up, and you can even place them under different categories for different cost contracts.

The Power of CorePlan

By implementing a well-defined Time Usage Model and leveraging the power of data, you can gain control over your operations, boost efficiency, and enhance profitability. Whether you're a mining company seeking to optimise exploration or a drilling contractor striving for operational excellence, a Time Usage Model is your key to unlocking success.

CorePlan's drilling management platform streamlines data capture, automates time usage calculations, and provides powerful visualisations to help you analyse and optimise your drilling operations. With CorePlan, you can easily:

Create and customise Time Usage Models.
Track and analyse time usage across rigs, crews, and projects.
Identify bottlenecks and implement improvements.
Benchmark performance across rigs, projects and more

Download the checklist here

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Time usage models explained

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