Subsurface Storage Projects

Development of Machine Learning techniques to improve assessment of the subsurface for Sustainable Energy Solutions based on legacy geophysical and geological data sets

Local authorities such as City Councils need to assess cost-effectively and quickly the suitability of the subsurface for a variety of subsurface low carbon solutions such as thermal storage, heat extraction from mine water, energy storage using e.g. gravity or compressed air etc.. To be able to do this, they have neither the time nor the money to commission major geophysical and geological data acquisition campaigns. This research theme aims to develop a novel way to utilize existing data sets to the fullest. Using machine learning (ML) techniques we will train our system using high resolution geophysical datasets of known geo-assets to develop strategies to augment existing lower resolution geophysical data sets. For example, high resolution datasets from coal measures in the Glasgow region could be used to inform assessment of other coal measure areas in the UK that have lower resolution geophysical and geological datasets.

Academic lead – Dr Phil Livermore

Assessing the geothermal potential of abandoned coalfields in the Yorkshire region: a clean source of energy

Flooded mine workings can provide ambient temperature storage while energy generation through geothermally heated mine water can be utilised in district heating schemes to produce clean and renewable heat energy. However, most mine workings are currently abandoned, and not considered as significant in supporting UK’s transition to low-carbon energy solutions. The urban area of Leeds and the Selby mine ~35 km to the east have such legacy mine workings while local authorities and businesses are interested in the potential of their use. Thus, these areas are ideally suited for an in-depth study.
Depending on the students’ interest, research can be directed towards one or a number of research themes:
– estimation of geothermal energy potential of selected areas utilizing available mine records, their associated geological data and archive seismic reflection profiles augmented with targeted geophysical and geological data acquisition. It may also be possible to conduct new geophysical surveys (including seismic refraction and resistivity methods, possibly extending to distributed acoustic sensing) to enrich the interpretation of the site.
– subsequent assessment of the long-term sustainability of the source as well as optimal use of available geothermal energy based on local demand and supply
– investigation of the stability of the mines and open cavities to assessed the risk of possible eventual collapse and consequent ground-surface movements such as the development of sinkholes, micro-earthquakes or groundwater impacts. Geophysical data analysis and experimental physical testing of representative samples at University labs may provide additional data.
The ultimate goal is to provide local authorities with a scientifically well founded set of recommendations.
We anticipate to work with external collaborators such as City Councils/BGS for studies in this research area.

Academic lead – Dr Chrysothemis Paraskevopoulou

Investigating the movement of CO2 in heterogeneous material

The commitment to NetZero by 2050 necessitates large scale CO2 sequestration in the subsurface. For safe CO2 sequestration and design of its storage in the subsurface the behaviour of CO2 movement in the subsurface and its interaction with the host rocks needs to be monitored with high accuracy both in time and space. Whereas CO2 injection would result in larges changes in reflected seismic amplitudes, an increase in seismic attenuation could partially mask that effect and lead to incorrect estimates for CO2 in place. In this research theme we will use seismic datasets and develop novel processing and inversion methods to investigate the effect of attenuation on mapping of CO2 movement in the subsurface and the effect on CO2 in-place estimates. 

Academic lead – Dr Sjoerd de Ridder

Characterization of sedimentary heterogeneity in giant saline aquifers to assess suitability for long-term underground CO2 storage

This project will determine the suitability of giant subsurface saline aquifers for the safe and long-term storage of CO2. Very large storage volumes within unclosed Triassic saline aquifers of the UK have the potential to contribute significantly to the solution of what is the most pressing problem faced by the world today: how to dramatically reduce emissions of greenhouse gas to the atmosphere. The successful candidate will use techniques in sedimentary facies analysis, structural geology, basin analysis, petrophysics and reservoir modelling to investigate the role of lithological heterogeneity in determining injectivity of CO2 into aquifers and the ability of low-permeability seal units to act as barriers to the upward movement of CO2. Although depleted UK oil and gas reservoirs are attractive short-term targets for CO2 storage because their geological character is known, their storage capacities are limited. Much larger saline aquifers must additionally be utilised if the majority of carbon produced by the UK’s large point source emitters (e.g., cities, power stations) is to be sequestered effectively over coming decades. Triassic saline aquifers of the UK Southern North Sea, East Irish Sea Basin and adjacent onshore areas, with their favourable porosity and permeability character and their stratigraphical juxtaposition to seals, can potentially store significantly more CO2 than the combined capacity of the regions’ depleted hydrocarbon fields. This project will undertake a combined outcrop and subsurface characterisation of the Triassic Bunter and Ormskirk Sandstone formations (and lateral equivalents), two of the largest UK saline aquifers considered as potentially suitable for long-term CO2 storage. The size, shape, frequency and degree of interconnectivity of sedimentary geobodies will be characterised. Results will quantify net CO2 storage potential, will predict injectivity within different sedimentary successions, will predict flow migration pathways, and will assess the ability of aquifers to retain CO2 over long time scales. Fluvial, Eolian & Shallow-Marine Research Group (http://frg.leeds.ac.uk/)

Academic lead – Professor Nigel Mountney