Demand from the mining industry for the REFLEX EZ-GAMMA driller- operable, gamma logging tool, used in geological mapping, has markedly increased since its launch in October, states downhole instrumentation, data management and data analysis technologies provider REFLEX.

The REFLEX EZ-GAMMA tool is an intelligent, subsurface instrument used to determine lithology and geological correlation through the measurement of natural gamma radiation over the span of the borehole. The self-contained, natural gamma sensor continuously measures and records natural gamma counts in an internal memory for processing at the surface.

REFLEX Geosciences global product manager Dr Dave Lawie emphasises that the cost and performance efficiencies achieved by using the tool have resulted in the tool becoming a sought- after product, particularly at a time when the mining industry is under considerable cost pressures and needs to increase productivity across all operational platforms.

REFLEX will, therefore, demonstrate the tool and its related software solutions at the Investing in African Mining Indaba, which will run from February 8 to 11 at the Cape Town International Convention Centre.

While gamma data provides invaluable mapping and cross-hole correlation data for geologists, the traditional method of logging is too expensive to make it practical for general use, Lawie says.

He avers that, the use of the REFLEX EZ-GAMMA tool changes this, as drillers and on-site geologists can now accurately gamma-log drilling progress.

“The tool’s driller operability reduces delays and costs, as there is no need for a specialist service provider to operate the tool, or for costly logging trucks on site, while rig downtime, as a result of waiting for the logging trucks to arrive on site, is eliminated. The tool also provides near real-time information, allowing for decisions to be made immediately,” Lawie explains.

Moreover, the lower cost of gamma logging provides an opportunity for further logging, which has previously been too expensive an exercise.

Lawie explains that, with the REFLEX EZ-GAMMA, the drilling crew deploys the tool using the existing wireline, as the tool is memory-based and requires no active electrical connection.

In the field, a plot is made of the gamma response and logging speed on a portable device as the gamma tool is retrieved from the hole.

This allows for the geologist or driller, with a minimal amount of training, to simply assess whether or not the logging was successful, before pulling the rods and moving the rig.

The EZ-GAMMA software carefully guides the user through the logging process to ensure correct use of the tool. Additionally, the data is automatically uploaded to REFLEXHUB-IQ, where it can be viewed from anywhere as soon as the logging process is complete.

The EZ-GAMMA tool has been tested in iron-ore, uranium, coal and gold applications, in both diamond drilling and reverse circulation drilling. In all cases, the EZ-GAMMA has been operated by drilling crews with minimal training, says Lawie.

A key field trial of the tool was conducted at major gold producer KCGM’s Fimiston openpit gold mine, also known as the Super Pit, in Kalgoorlie, Australia, in September 2015.

The tool was used in the deepest diamond drill hole ever drilled in Australia at 3 011.5 m, Lawie says.

The REFLEX EZ-GAMMA was coupled with the REFLEX EZ-GYRO, a north-seeking gyroscopic survey instrument, and the REFLEXHUB-IQ, a cloud-based data system, to provide critical information on the hole position and lithology of the surrounding rock in near real time.

The combination provided significant efficiencies for KCGM, as gamma logging was completed without downtime delays and at minimal cost.

Lawie highlights that the tool is suitable for use in the coal, potash, uranium, gold, iron-ore and mineral sands sectors “and anywhere where additional data for geological correlation helps with interpretation and modelling”.

“The ability of the drilling contractors to obtain this gamma data for the resource companies with no additional resources required and at a fraction of the cost will make gamma logging far more attractive to resource companies,” he concludes.