map marker United Kingdom | 15 July 2025
Reading Time : 4 min, 24 sec

There are no easy solutions to a problem as significant and urgent as climate change. But there are a range of mitigation measures, and for me, CCUS is one of the most exciting. 

CCUS involves capturing carbon dioxide (CO2) produced by industrial processes, at their point or origin, or directly from the atmosphere. The captured CO2 is used or ‘utilised’ in other processes, or transported to be injected into deep geological formations, such as depleted hydrocarbon reservoirs or saline aquifers. Although carbon capture technologies and commercial models can help kickstart this nascent industry, it is the rocks beneath our feet – and the geologists who study them – that are the key to locking away CO2. 

Professor Chris Jackson
Chris Jackson
Technical Director of Subsurface Storage
United Kingdom
Chris on site collecting geological data from sequences of rocks

Chris on-site colleting geological data from sequences of rocks.

Characterising potential carbon storage

But what sort of rocks are geologists looking for? Geological carbon storage requires a continuous layer of porous and permeable rock at a depth of 1-2.5 km, ideally sandwiched between two layers of impermeable rock. Compressed CO2 is then injected into the sponge-like spaces in the rock until the store is full. The impermeable rocks prevent it leaking out, and the CO2 is permanently sequestered deep below the surface.

The good news is that the UK has a wealth of suitable rock formations – enough, according to the British Geological Survey (BGS), to store 78 billion tonnes of CO2. That could allow us to geologically store CO2 for hundreds of years. And our long oil and gas heritage has left us with a rich archive of geological and geophysical data with which to characterise rock. 

All this enables geologists to accurately model the subsurface and the effect of injecting CO2. 

Enhancing industry and public understanding 

Modelling is important for reassuring the public that geological storage of carbon is safe and effective. People worry about induced seismicity – earthquakes that result from changing the stress state of rocks as CO2 is injected into them. FracMan®, WSP's pioneering discrete fracture network (DFN) software, helps address this concern and supports our clients in meeting their regulatory requirements. FracMan® allows us to model the existing subsurface geometry and structures, and what will happen when rocks are pressurised during CO2 injection, thus allowing us to understand the likelihood of fractures slipping and producing earthquakes. 

Of course, even advanced modelling can only help you so far. It’s developing more projects that will really enhance our understanding. There are currently around only 50 CCUS projects operating around the world (although just under 600 more are being developed), with most of these using depleted oil and gas reservoirs – very few are injecting into saline aquifers. But the industry is poised to ramp up development, with an estimated 400 new wells required each year between now and 2050 to achieve global climate ambitions. Geologists will learn from each of these new projects, updating our models, and helping the industry advance rapidly.

As independent experts, the geologists and engineers at WSP are well placed to do this. We’ve already led a team of specialists advising the UK government on CCUS, which included addressing issues such as how to characterise and monitor geological stores. And we remain focussed on bringing our scientific expertise to bear on making the right decisions for the right sites, whether we’re working with storage hosts, regulators or anyone else involved in the process.

Geological analysis of rock cores from beneath the sea to assess suitability for storing CO2

Offshore rock core analysis to assess CO₂ storage suitability.

Accelerating technological development 

Our geologists strive to stay at the cutting edge of their field. WSP’s Future Ready® innovation programme ensures we develop and share knowledge about emerging areas of geological carbon storage – including advances such as reactive trapping. This approach depends not on pore spaces in sponge-like rock, but on binding of CO2 and more specifically carbon (C) to the crystal structure of minerals within the rock. This process can be used where porous rock is rare, but where hard, crystalline, igneous rock, like basalt, formed during volcanic eruptions, is widespread. 

Although geologists have a good conceptual understanding of reactive trapping, it is harder to predict how CO2 will move through the rock and how much trapping will occur. As early trials and projects develop, geologists will be able to accelerate the industry’s understanding of the processes at work and provide more certainty to developers and investors. 

In a field that is developing rapidly, new problems will arise, and new processes must be developed to solve them. This is exactly what WSP geologists and engineers do: we deliver excellent science and engineering that advances the industry and builds public confidence in a technology that can help mitigate climate change. We’re unlocking the potential that lies beneath your feet.

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