First Break - Volume 42, Issue 10, 2024

The offshore Natal valley along the east coast of South Africa is a large, underexplored frontier region. Newly acquired seismic datasets not only reveal new play and lead opportunities, but also allow the application of limited AVO analysis. Legacy seismic data were acquired during the 1970s along the narrow continental shelf only. However, the 2013 and 2018 PGS datasets expanded across the continental, transitional and oceanic crustal domains. The available seismic datasets include the full stack (5–35°), near (5–16°) and far offset (27–38°). The latter was loaded, and addition trace calculations conducted, comprising of far minus near and far minus near multiplied by far. The new data not only adds new play opportunities to this frontier basin but also identifies four leads that produce a positive AVO response. While additional seismic data is required to test the viability of the leads and derive maximum benefit from AVO analysis, the results of this study assist in de-risking the leads and provide new optimism to the frontier Natal valley.

Carbon Capture and Storage (CCS) technology is recognised as an important contribution to mitigate climate changes, and monitoring of the injected carbon dioxide (CO2) is an important element of this technology to ensure that the CCS system operates within the required legal and regulatory standards. To be able to offer more flexible monitoring solutions, the potential of mini streamers for overburden and shallow CCS monitoring has been investigated. The results from a series of 2D and 3D mini-streamer operations across the Sleipner CO2 storage site are assessed and compared with conventional streamer seismic. The results show a clear enhancement in overburden imaging and higher detail at the CO2 plume level compared to conventional streamer seismic data. However, the mini streamers also come with limitations related to the acquisition configuration (for example limited fold, offset, etc.).

The necessary increase in carbon sequestration to reach national and global set targets requires significant geological and technological developments to play a role in the mitigation of climate impacts. Therefore, many options are currently being considered for permanent carbon removal.

In this article we discuss CO2 mineralisation within mafic and ultramafic rocks, where carbon is incorporated into the structure of the rock through the crystallisation of new, stable carbonate minerals. This technology potentially offers the means to store CO2 safely, rapidly and permanently in large quantities, but also requires minimal effort to verify and monitor after disposal. We present screening workflow outputs that enable the rapid, global and regional screening of sites that may be prospective for the storage of CO2 through mafic and ultramafic rock mineralisation, in the subsurface or at tailings in mine sites as examples.

How can we speed up the energy transition as part of our response to the climate change challenge? The essential tools for enabling rapid reductions in greenhouse gas emissions are well known, but implementing these vectors of decarbonisation is challenging, partly for economic reasons and partly due to social resistance. We argue that geoscientists have a critical role to play in meeting these challenges: (a) they need to engage technically to enable low-carbon emissions projects to proceed, and (b) they need to communicate and explain the risks and benefits of emerging projects to our society in a more effective way. After reviewing recent progress in reducing global CO2 emissions, we discuss societal responses, identifying some important biases in the social discourse concerning low-emission energy projects. We then present a simple summary of the physics of CO2 as greenhouse gas, to help dispel some typical misunderstandings and to support geoscientists in their discussions about climate change science. Finally, we outline the key role that geoscientists can play, drawing from specific examples in the fields of CO2 storage and marine monitoring.

In the past decade, there has been a remarkable growth in renewable energies in the state of Utah, adding new resources to the state’s traditional fossil fuels. Utah’s New Energy Corridor spans between the town of Delta and Cedar City in the Great Basin. This 140-mile stretch is home to a diverse array of clean energy projects, including hydrogen storage, geothermal plants, and wind and solar farms. With its favourable conditions including high geothermal gradiants, high solar irradiance, and a vast desert landscape, Utah’s New Energy Corridor will play a greater role in “coproduction” of renewable energies and clean energy technologies, and already offers field-scale analogs for similar energy transition projects in other parts of the world. The knowledge base and skillsets arising from the development of the new energies in Utah are also valuale contributions to energy science and engineering.