The DETCRC has developed a small sensor and data logger, called the autonomous shuttle, that is pumped to the bottom of the drill hole where it protrudes beyond the tip of the diamond drill bit.

The shuttle measures the properties of the rocks surrounding the hole as the drill rods and bit are retrieved.

The autonomous shuttle – designed, built and tested by researchers at Curtin University and Perth company Globaltech – successfully recorded natural gamma radiation in a test hole. This shows it could differentiate between rock types.

To DETCRC chief executive Professor Richard Hillis, this may be the Holy Grail of exploration technologists.

“This means we can cost-effectively retrieve real-time data on the rock formations deep inside the earth,” he said.

“The natural gamma sensor used in the successful trial is the first of several sensors that will be deployed on the autonomous shuttle.

“With a suite of sensors, the shuttle could replace much drill core, saving time and analytical costs and permitting drilling techniques that are only half the cost of conventional diamond drilling at a time when Australian mining is feeling the pinch of high costs and declining commodity prices.”

The technology has been tested at the DETCRC’s Brukunga Drilling Research and Training Facility in the Adelaide Hills.

There, technologies can be tested against a fully cored and logged reference hole.

That facility opened last November and has already been the site of several successful field trials of emerging technologies.

One of the key researchers on the project, Globaltech’s Gordon Stewart, said the conventional process of analysing drill core was time-consuming and expensive.

“Mineral exploration holes are drilled to obtain information about the rocks at depth in the subsurface,” he said.

“Current methods require analysis of core or rock cuttings from the hole or they require the time and expense of mobilising a separate wireline crew to run sensors in the hole.

“Since it can be deployed by the drilling crew to obtain real-time information from a hole without the risk of the hole collapsing before it is analysed, the autonomous shuttle is a major international advance and offers significant cost savings.”

Hillis said the shuttle’s full sensing capability would dramatically increase productivity by avoiding delays of weeks or sometimes months when core is sent to laboratory for analysis.

“It will enable cheaper existing drilling methods to replace diamond drilling and open the door for next generation drilling technologies such as downhole motors and coiled tubing drilling,” he said.

Hillis said the breakthrough was just one of several techniques being developed at the DETCRC.