Geological survey drilling: Why do they do it?

Dr Richard Blewett PSM is currently a Director of a junior private company Weethalle Gold and a consulting services company GeoSystems Consulting Pty Ltd.

Prior to these roles, Richard was the General Manager of the Minerals Systems Branch at Geoscience Australia (up to 2021). He was responsible for leading GA’s minerals science, including carriage of the minerals component of the AUD 225 million Exploring for the Future program, and the promotion of Australia as an attractive investment destination for minerals exploration. Richard wrote the National Mineral Exploration Strategy, the Resources Data Strategy and was co-author of the UNCOVER strategy. He was Chief Editor of Shaping a Nation: A Geology of Australia.

The national agency Geoscience Australia (GA) works collaboratively with State and Northern Territory geological survey organizations (GSOs) on many areas of geoscience, including drilling. This article aims to expand on some of their minerals-related drilling activities and will also briefly include other use cases.

The roles of each GSO vary, but all of them aim to attract private investment in mineral and energy exploration, and to some extent groundwater, through the provision of ‘pre-competitive’ data and information. The GSOs are not explorers as such; their primary role is to lower technical risk through conducting regional framework studies involving geological, geophysical, and geochemical mapping.

The scale of GSO work varies from continent-wide to individual map sheet areas, and even smaller areas such as mineral districts and deposits when needed. The GSO aims to map and understand systems rather than make a discovery, although many GSOs have made notable discoveries in the past when that was their role.

The discovery itself is the role of industry. But mineral exploration companies can only acquire new data within tenements, which range from hundreds to only a few thousand square kilometers in area. As a result, companies may often lack a broader framework. It’s like having a detailed map of a single tree without understanding the entire forest. The role of the GSOs is to provide a map of that ‘forest’.

In parallel, as resources become more difficult to find, the need to step out into more deeply covered and remote areas grows. Drilling is increasingly becoming a key activity for the GSOs as they attempt to validate mineral system models, especially from these remote and poorly understood greenfield regions.

Brief history of government drilling

The Australian Government and its colonial predecessor have been involved in geological investigations for minerals, energy, and water from at least the early 1800s. From the 1920s, the Australian Government was encouraging oil exploration with financial support, tax breaks, and access to geological data and resources. The oil companies shared their data and stored their samples with the Bureau of Mineral Resources (BMR), now Geoscience Australia, where these samples remain today. Even though the search was for oil, the government had the foresight to add a condition that basement cores were to be provided. These samples are now valuable material for understanding the basement geology of large basins like the Great Artesian Basin.

The development push after the Second World War led to pioneering geological investigations and exploration from the GSOs. BMR was active in mineral exploration, as well as in the systematic geological mapping efforts. Some of the notable discoveries involved drilling.

The BMR owned drill rigs primarily for stratigraphic drilling purposes or for shot holes for seismic surveying. Most government drilling was focused on Australia’s sedimentary basins. Deep holes were drilled to obtain stratigraphic data, as well as reference samples for further analysis. The data was used to understand the depth dimension of the basin stratigraphy and to identify petroleum sources, reservoirs, and traps. Several GSOs had an engineering geology function in the past and utilized geotechnical drilling for site investigations.

Government-backed drilling ranged in scale from mega offshore rigs (through collaboration with the International Ocean Drilling Programme), and large petroleum rigs with blow-out prevention (CO₂ storage characterization), to the typical mineral and water rigs. Ageing equipment and challenging budgets meant that eventually a decision was made to outsource drilling to the private sector.

Throughout the 1990s and 2000s, government drilling was limited, at least in the minerals domain. GSOs were heavily focused on improving geophysical coverages and their interpretation to remap the country. In the process of this, they started to uncover new questions asked by geophysics that could only be answered with drilling.

My first involvement with drilling as a government geologist was writing it into the National Mineral Exploration Strategy in 2012. This provided the ‘mandate’ to drill as there were dissenters internally saying that drilling was the role of industry.

The 2012–15 Stavely project in Victoria was the first of the reborn GSO drilling projects. It was a GA-GSV collaboration with research teams from Deep Exploration Technologies CRC (DET CRC), which was developing new technologies including a Lab-at-Rig® and other sensors, as well as the coiled tube system. The GSOs were pragmatic about allowing researchers to perfect their kit as they understood the long-run benefit to Australia if new tech was commercialized.

This style of project continued to the Thomson Orogen (2014–17), with GA partnering with GSNSW and GSQ, and in the Coompana region in the far southwest of South Australia with GSSA. The scientific insights and success of these projects were a catalyst for the National Drilling Initiative (NDI), which is operational today. The NDI is led by the GSOs (except GSQ) and is a theme of the DET CRC’s successor—the research program MinEx CRC (started in 2017).

The NDI has completed six projects across South Australia, Northern Territory, New South Wales and Western Australia, with many more in planning stages. It is clear from the map that targeting the frontier regions distant from the known mineral camps is a government focus, and that drilling plays a key part in the investigations.

Government incentives and support

Governments boost attempts to increase economic growth through resource discovery. They realize that drilling leads to discovery and therefore provide incentives for it. These incentives have existed for over a century, requiring minimal government spending and, at the same time, attracting significant industry investment into exploration and discovery.

The South Australian government energized the game in 2005 with their innovative Plan for Accelerating Exploration (PACE) scheme. It is underpinned by AUD 700 million in private mineral exploration, helping at least 15 significant discoveries at a rate of 20:1 in private-to-public spending (Economics Consulting Services, 2014).

Currently all the GSOs (except GA) have some form of a drilling incentive. The Australian Government previously offered the Junior Minerals Exploration Incentive (JMEI) to encourage investment in greenfields mineral exploration. The incentive provided a tax offset to Australian investors for a junior company’s exploration costs, including drilling.

The West Australian Exploration Incentive Scheme (EIS) is the largest co-investment scheme. Economic modeling for 2009–20 concluded that the EIS delivered a 31:1 ratio in private-to-public spending (Fogarty, 2021). The Exploration Drilling Program component of the EIS is open for applications twice a year and offers up to a 50% refund for innovative exploration drilling projects. Securing a grant is highly competitive and only the technically best applications are successful.

A very beneficial component of all these schemes is the transparency of results to all. After short confidentiality periods, the core and analysis (often done by the GSOs themselves) are published, which adds enormously to common knowledge. This extra knowledge lowers the technical risk for all, which encourages further investment.

Government drill core libraries and databases

It breaks one’s heart to see hard-won drill core scattered in the bush. Millions of holes have been drilled in Australia, but only a tiny fraction of the collected material is retained for the long term. GSOs have a crucial role as sample custodians. They all have major core and physical sample libraries that store their own, as well as industry material.

South Australia has an impressive facility in a disused former car factory. They store samples as old as 130 years! Western Australia has two facilities. Geoscience Australia have an entire building attached to the main office building where millions of samples and cores are stored from onshore and, importantly, offshore Australia, as well as Australian Antarctic Territory and other neighboring countries. All the samples are accessible for further study.

Handling and storing core and samples is expensive. But physical samples like drill core are enduring, with many being studied and restudied years later as new techniques become available or new questions are being asked. The smart explorer regularly visits their state or GA facility to study rocks from their and others’ tenements. I know of several investment decisions being made on drill core library material.

In addition, all GSOs (except GA and GSV) have the latest core loggers contributing data to the National Virtual Core Library, which is the world’s largest drill core mineralogical database.

Databases are a core business for a GSO—sorry for the pun. Each GSO has a database of drilling within their state/territory, some with millions of records. The information available on each drillhole is extensive: assays, geochemistry, lithology descriptions and logs, drilling parameters. Many records link to the source reports submitted by the company to the regulator, or the reports if they were government holes. Australia is blessed to have all this information freely available. It is a point of difference compared to many competitor jurisdictions.

Future of geological survey drilling

All governments have a form of net-zero commitment and a desire to develop the critical minerals needed to achieve it. They are also keen to support the METS (Mining Equipment, Technology, and Services) sector where innovative drilling technologies are being developed.

Australia is blessed with a remarkable geological endowment, including many of the critical minerals. GSOs will be central to improving the knowledge base of these systems and will continue to play a pull-through role in helping technology development through the ‘valley of death’. For the GSOs, the drill bit is very much becoming the 21ˢᵗ century geopick.

Conclusion

Drilling is fundamental for the necessary validation and the scientific test of a mineral system model, geochemical or geophysical anomaly or interpretation. Despite the millions of drill holes across Australia, there are still numerous geological units identified in geophysics data that are unknown geologically and not penetrated by a drill hole. Drilling will always be needed, and it is the role of the GSOs to provide the necessary geological framework for it at ever increasing levels of detail and sophistication.

Working as a drilling contractor for a GSO can be a rewarding experience. You know that your hard work and skill as a driller is much appreciated and that your cores will be ‘squeezed’ for as much additional information as possible and the material will be cared for in perpetuity. They won’t end up on the dump or on the edge of a paddock!

Each hole has been carefully planned in terms of science, with the objective of making a difference to our knowledge. The difference can be revolutionary in ways that change the perception of a region’s prospectivity, lead to new discoveries and to a more prosperous Australia.

Drilling and the resultant knowledge gained from it are increasingly becoming a key component in the pre-competitive service provided by the GSOs. It can make the difference between a major company investing in Australia, or not.

References

Economics Consulting Services (2014). The Evaluation of the Plan for Accelerating Exploration (PACE): Prospectivity, Programs, Promotion and People (Report Book 2014/00014). Department for Manufacturing, Innovation, Trade, Resources and Energy, South Australia, Adelaide.

Fogarty, JJ (2021). An Economic Assessment of the Exploration Incentive Scheme: 10 years from 2009 to 2020, Prepared for the Department of Mines, Industry Regulation and Safety: Geological Survey of Western Australia, 48p.

For more information: Get in touch with Richard on LinkedIn

Read more about the MinEx CRC initiative on p. 14 in Coring Magazine’s Issue 31, or on our website here.