Exploration Seismic: Key to Achieving Net Zero Emission Goals in Australia. An Advanced Technology that is Being Overlooked

As the world strives to combat climate change and reduce greenhouse gas emissions, the concept of "net zero emissions" has gained immense importance. Net zero emissions occur when a country's total greenhouse gas emissions are balanced by removing an equivalent amount of greenhouse gases from the atmosphere, either through natural processes or technological interventions. Achieving net zero emissions is a critical step in limiting global warming and its adverse effects on the planet.

The Australian government, like many other nations, has international obligations to address climate change and achieve net zero emissions by taking significant actions to reduce carbon emissions and explore carbon removal options. Seismic methods can play a crucial role in achieving net zero objectives.

Historical Development of Exploration Seismic and Its Key Role in Discovering Deep Oil and Gas Resources.

Seismic exploration has been instrumental in the discovery of vast oil and gas reserves worldwide. This technique involves generating and recording sound waves that travel through the subsurface layers of the Earth. By analyzing the reflected waves, Geophysicists can create detailed images of subsurface structures, identifying potential oil and gas reservoirs. Over the years, seismic methods have evolved from simple two-dimensional (2D) surveys to advanced three-dimensional (3D) surveys. 2D seismic involves generating sound waves along a single line, while 3D seismic utilizes a spread of sensors on the earth's surface to create a comprehensive 3D image of the subsurface. Seismic methods can be categorized into active source and passive source techniques. Active source seismic involves artificially generating sound waves using specialized equipment like vibrators or weight drops. In contrast, passive source seismic relies on naturally occurring seismic waves, such as those produced by earthquakes or ocean waves.

End Products of Seismic Methods

The end products of exploration seismic methods include detailed subsurface images and data that reveal the geological structures, stratigraphy, and potential reservoirs beneath the Earth's surface. These images have traditionally assisted exploration companies in locating oil and gas resources, reduced drilling risks and environmental impacts, and used in optimizing resource extraction.

Application of Seismic Methods in Critical Mineral Resource Exploration

In recent years, seismic methods have extended their application beyond oil and gas exploration to the search for critical mineral resources. Critical minerals are essential for various high-tech industries, including renewable energy technologies, electronics, and batteries.

Australia, being rich in critical mineral reserves, has been always active in adopting seismic methods for deeper mineral exploration but these efforts have often been hampered by the costs and complexity of using this technology. Nevertheless, seismic surveys can aid in detecting subsurface structures, identifying potential deposits, and ensuring the sustainable extraction of these valuable resources.

Traditional geophysical methods in mineral exploration and their limitations

The application of potential geophysical methods in mineral exploration in Australia is widespread and has played a crucial role in the discovery and assessment of various mineral resources across the country. Potential geophysical methods, also known as passive geophysical methods, are techniques that measure natural variations in physical properties, such as gravity, magnetic, and electrical fields, to infer subsurface geological structures and potential mineral deposits. Here's how these methods are extensively used in mineral exploration in Australia:

1. Gravity Surveys: Gravity surveys are widely applied in mineral exploration to map variations in subsurface density, which can indicate the presence of different rock types, faults, and ore bodies.
2. Magnetic Surveys: Magnetic surveys are used to detect variations in the Earth's magnetic field caused by magnetic minerals in rocks. Magnetic methods are particularly effective in exploring iron ore, nickel, and other magnetic mineral deposits.
3. Electrical and Electromagnetic (EM) Surveys: Electrical and EM methods are applied in mineral exploration to detect variations in the electrical conductivity of subsurface materials. Conductive minerals, such as sulfides and graphite, can be indicators of valuable mineral deposits.
4. Induced Polarization (IP) Surveys: IP surveys are a specialized form of electrical geophysics that measures chargeability variations in the subsurface. IP is highly valuable for base metal exploration, as it can highlight disseminated sulfides associated with ore bodies.
5. Radiometric Surveys: Radiometric surveys measure natural radioactivity from rocks and minerals. These surveys are particularly useful for uranium exploration and are commonly utilized in regions with uranium potential.

Potential geophysical methods have proven to be invaluable tools in mineral exploration, especially for targeting shallow and near-surface deposits. However, they do have some limitations, particularly when applied to deep earth and under-cover exploration which are regarded as the main challenge in future exploration endeavors where the deposits are expected to be found at large depths. Here are the main constraints of potential geophysical methods in these scenarios:

1. Depth of Penetration: One of the primary limitations of potential geophysical methods is their reduced depth of penetration in deep earth exploration. As depth increases, the signals measured by these methods become weaker, making it challenging to image targets at significant depths.
2. Resolution: The resolution of potential geophysical methods is generally low and tends to decrease more with depth. As the signals propagate through the subsurface, they interact with various geological layers, which can smoothen the data and reduce the ability to detect smaller or closely spaced targets.
3. Regolith Effect: The presence of regolith can significantly impact the measurements and interpretations of potential geophysical methods. The conductive and magnetic properties of regolith materials can mask or interfere with signals from subsurface targets, leading to ambiguous or misleading results.
4. Lack of Direct Detection: Potential geophysical methods are indirect techniques, meaning they infer subsurface information based on measured physical properties.
5. Interference and Noise: In highly mineralized areas or regions with complex geological structures, potential geophysical methods can suffer from interference and noise, which may obscure or distort the target signals.
6. Limited Sensitivity to Certain Minerals: Some mineral deposits may have weak responses to potential geophysical methods due to their specific physical properties. For example, some non-magnetic minerals might not be effectively detected using magnetic surveys.
7. Inaccessible Areas: Potential geophysical methods rely on data acquisition at the surface or from airborne platforms, which can be challenging or restricted in certain terrains or environments. For example, dense forests, swamps, or urban areas may limit the feasibility of data collection.

Advancements in Seismic Methods for Deep and Under Cover Mineral Exploration

In contrast to potential geophysical methods, seismic methods offer several advantages for deep and under cover mineral exploration:

1. No Limit in the Depth of Investigation: Seismic waves can penetrate deep into the Earth's crust, an important factor that determines our ability to search deeper levels.
2. High-Resolution Results: Seismic surveys produce detailed images with high-resolution data, allowing for accurate identification of potential mineral deposits at various depths.
3. Non-Invasive Methods: Seismic techniques are non-intrusive methods, minimizing environmental impact compared to extensive drilling campaigns.
4. Unaffected by Regolith Cover: Seismic waves can bypass regolith cover, providing a clear view of the subsurface under this layer, even in regions with thick cover.

Role of Seismic Methods in Achieving Net Zero Emission Goals

Beyond their main application in finding critical mineral reserves, seismic methods can assist in achieving net zero emission goals in many other ways:

1. CO2 Geo-Sequestration: CO2 geo-sequestration involves capturing and storing CO2 emissions from industrial processes and power plants in deep geological formations, preventing their release into the atmosphere. Seismic surveys are instrumental in assessing the suitability of potential storage sites, mapping subsurface structures, and ensuring the secure containment of CO2 to prevent its leakage.
2. Finding Geothermal Reserves: Seismic methods are also valuable in the exploration of geothermal energy resources. Geothermal energy harnesses the Earth's heat to generate electricity, providing a clean and sustainable energy source. Seismic surveys help in identifying subsurface geothermal reservoirs and assessing their potential for energy production in various ways that are very similar to those used in discovering and developing hydrocarbon reserves.
3. Windfarm Site Characterization: Seismic methods are increasingly applied in windfarm site characterization to assess the subsurface conditions and suitability of the location for wind energy development. Windfarm site characterization involves understanding the geological and geotechnical properties of the site to optimize the design and construction of wind turbines, access roads, and other infrastructure. Seismic techniques provide valuable information that helps developers make informed decisions during the planning and development stages of a wind energy project.
4. Assessing Leakage from Earth's Natural Gas Reserves: Seismic methods can be utilized to detect and assess potential leakage in Earth's natural gas reserves. By identifying and mitigating leaks, methane emissions can be minimized, helping to reduce the overall carbon footprint.
5. Monitoring Subsurface Changes Due to Climate Change: Seismic methods can be employed to monitor and study the impact of climate change on the subsurface, such as changes in permafrost stability or sea-level rise effects on coastal geology. Understanding these changes can aid in adapting to climate change impacts and planning sustainable infrastructure.
6. Assessing Geological Storage Potential for Hydrogen: Seismic surveys can be utilized to evaluate geological formations for hydrogen storage, supporting the development of hydrogen as a clean energy carrier and helping to decarbonize various sectors, including industry and transportation.

Seismic methods are being overlooked in the context of climate goals.

Several factors contribute to the perception that seismic methods are being overlooked in the context of achieving net zero goals:

1. Focus on Renewables: The renewable energy sector, particularly solar and wind power, has received significant attention in the global race towards achieving net zero goals. This and the association of seismic methods with fossil fuel extraction in the past have overshadowed the fact that seismic methods can fast-track our efforts towards the net zero goal.
2. Limited Awareness: The full potential and applications of seismic methods in various net zero initiatives may not be widely known or understood. There might be a lack of awareness among policymakers, investors, and the general public about the benefits of seismic techniques in addressing climate change.
3. Funding Priorities: Investment and funding decisions are often influenced by the prominence and perceived urgency of specific technologies or solutions. Seismic research and applications might not receive the same level of funding compared to more well-established or heavily promoted alternatives.
4. Perceived Complexity: Seismic methods may be viewed as more complex and technically challenging compared to other exploration or monitoring techniques. As a result, some stakeholders may opt for simpler or more familiar methods, even if they might not be as effective in specific scenarios.
5. Regulatory and Policy Frameworks: The absence of favorable regulatory and policy frameworks can also contribute to the underutilization of seismic methods. If existing policies do not incentivize or support the adoption of these techniques, they might not be prioritized in net zero strategies.
6. Public Perception and Environmental Concerns: Seismic methods, particularly active source techniques involving explosions or vibrators, can raise environmental and public concerns. The perception of seismic surveys as potentially disruptive or harmful to the environment may lead to hesitancy in their widespread adoption.
7. Data Accessibility and Integration: Utilizing seismic data effectively requires proper integration with other datasets and advanced processing infrastructure. Challenges in data sharing, integration, and interpretation may hinder the seamless incorporation of seismic methods into net zero initiatives.

Supporting and Advancing Research in Critical Mineral Exploration Using Seismic Methods

To advance research in critical mineral exploration and in various other aspects of utilization of exploration seismic towards climate-related goals, the Australian government and universities can play crucial roles. They can:

1. Establish Funding Initiatives: By providing financial support for research projects focused on seismic exploration for critical minerals, CO2 geo-sequestration, and geothermal reserve discovery and development. The government can encourage innovation and collaboration among researchers and industry experts.
2. Foster Industry-Academia Partnerships: Widening collaborations between universities and mining companies can facilitate the exchange of knowledge and expertise, leading to more efficient exploration techniques and technologies.
3. Develop Educational Programs: Universities can design specialized geophysics courses and programs that equip the new generation of geophysicists with the skills needed to effectively use seismic methods for future explorations and climate related activities.

Conclusion

Exploration seismic is a powerful tool that has significantly contributed to the discovery of oil, gas, critical minerals, and geothermal reserves. Seismic methods are crucial in monitoring and verifying proper storage of the injected CO2 during CO2 geosequestration projects in carbon capture and storage (CCS) initiatives. The ability to probe the Earth's subsurface at greater depths with high-resolution and minimal environmental impact makes these methods indispensable for sustainable resource exploration and accelerating our efforts towards other climate goals.

Australia, with its abundance of critical mineral reserves and commitment to addressing climate change, can lead the way in supporting research and education in seismic methods for critical mineral exploration and other key aspects of climate change. By harnessing the potential of seismic technologies, Australia can ensure a greener, more sustainable future while securing its valuable mineral resources for generations to come.

Mehdi Asgharzadeh

[email protected]