Long before “digital mining” became an industry-wide term, drilling engineers were already exploring how operational data could provide much more than information about machine performance.
A paper presented at Exploration 97 by P. de Groulard examined how recording drilling parameters as a function of depth could support mineral exploration, mine development and drilling optimization.
The principle remains powerful: every metre drilled generates data about both the drilling process and the ground being drilled.
From Drilling Performance to Geological Information
The combination of destructive drilling and continuous recording of drilling parameters can help identify changes between geological units encountered by the bit.
According to the paper, drilling data can be used to support the detection of geological boundaries and anomalous zones. In exploration drilling, this can provide additional information about formations where core drilling alone may not give sufficient spatial coverage.
The value comes from monitoring how the drill responds to changing ground conditions.
Among the parameters highlighted in the study are:
- Instantaneous Advance Speed (IAS) – or penetration rate, an indicator of drillability rather than a direct measurement of rock hardness.
- Tool Pressure (TP) – useful for monitoring the regularity of drilling operations.
- Injection Pressure (IP) – can provide information about changes in formation behaviour and fluid losses.
- Torque (TQ) – reflects the work required to rotate the drilling tool and can indicate variations in ground heterogeneity.
- Rotation Speed (RPM) – provides additional information that can complement torque measurements.
- Instantaneous Drilling Time (TIME) – essentially the inverse of penetration speed and particularly useful where drilling rates are low.
- Reflected Vibration (VIBRALIM) – represents energy reflected by the formation and can provide additional information related to ground hardness.
Other measurable parameters mentioned include strike pressure, hold pressure, drilling-fluid flow rate and drilling-fluid temperature.
Together, these measurements create a much richer picture of what is happening underground.
Three Major Areas of Application
The paper identifies three main ways drilling-parameter monitoring can create value.
1. Geological Exploration
Changes in drilling response can help distinguish geological units and identify anomalous areas.
In unexplored ground, this information may help define the boundaries of potentially mineralized horizons. In more advanced exploration, drilling parameters can complement core drilling and increase the density of available subsurface information.
This is especially valuable because the information is collected continuously while drilling is already taking place.
2. Mine Development Planning
Drilling records can also support operational planning.
Information such as drilling start and finish times, drilled depth, drilling incidents and hole orientation can provide a detailed operational history for each hole.
The paper also highlights potential benefits for underground development, including improved control of drilling operations and better identification of geotechnical changes as tunnelling progresses.
3. Drilling Optimization
Perhaps the most immediate operational benefit is the ability to understand how drilling equipment interacts with different ground conditions.
Monitoring penetration rate, torque, pressure and other parameters can help operators adjust machine settings, manage drilling depth and reduce unnecessary tool wear.
Instead of treating drilling parameters only as machine-control values, they can become part of the decision-making process.
The Bigger Opportunity: Data Already Generated by the Drill
One of the most interesting ideas in this 1997 paper is that valuable geological information does not always require an entirely separate measurement process.
The drilling system itself is continuously interacting with the rock.
Penetration rate changes. Torque changes. Pressure changes. Vibration changes.
Each response contains information.
The challenge is to capture those signals consistently, relate them to depth and interpret them correctly.
Nearly three decades later, the basic concept remains highly relevant to mineral exploration: drilling is not only a way to reach the geology — it is also a way to measure it.
For exploration companies looking to improve efficiency and extract more value from drilling campaigns, drilling-parameter data represents an important additional layer of geological and operational intelligence.
Source: P. de Groulard, Drilling Parameters and Their Application in Mining and Exploration, Proceedings of Exploration 97: Fourth Decennial International Conference on Mineral Exploration, 1997, pp. 721–722.
