|Credit: University of Southampton|
Researchers from the University of Edinburgh have joined fellow academics from the University of Southampton and the National Oceanography Centre (NOC) to investigate the risk of leaks from carbon dioxide (CO₂) storage reservoirs situated beneath the seabed.
The NERC-funded Characterisation of Major Overburden Leakage Pathways above Sub-sea floor CO₂ Storage Reservoirs in the North Sea (CHIMNEY) project will explore chimney-like structures in North Sea sediments that could be possible pathways for the transfer of fluids and gases up to the sea floor.
As part of the four-year project, researchers will undertake major fieldwork to study a chimney structure in the North Sea, where they will carry out a unique geophysical experiment to determine its internal structure. Theory and practice developed by scientists at the University of Edinburgh will play a key role in this work.
Oil and gas reservoirs and saline aquifers are the preferred CO₂ storage location of most European nations. However, a key element in the safety of such storage is to fully understand the risks of any leakage. The project aims to develop better techniques to locate these sub-seafloor structures and determine the permeability of the pathways so that they can be better constrained and quantified.
Dr Mark Chapman, Principal Investigator at the University of Edinburgh, said:
This is an exciting project based around a novel broadband marine seismic experiment, which we will carry out in the North Sea next summer. Seismic velocities in the Earth vary with both frequency and direction; this is known as frequency-dependent anisotropy. Theory which we’ve developed in Edinburgh over the last ten years shows that these frequency-dependent effects are linked to fractures and permeability – key properties for carbon capture and storage. We’ve designed a unique seismic survey, which will measure velocities over sufficient angles and frequencies to allow proper application of our theories. We hope that this work will allow us to characterise permeability above potential CCS sites.
The project will also work closely with GEOMAR, in Germany; the Lawrence Berkeley National Laboratory, in California; CGG, in the UK; and Applied Acoustics, in the UK.
Project details can be found here.