Multiscale whole systems modelling and analysis for CO2 capture, transport and storage.

Lead Research Organisation: British Geological Survey
Department Name: Energy & Marine Geoscience

Abstract

The UK has challenging green house gas (GHG) reduction targets. It is believed that carbon capture and storage (CCS) will play a critical role in the energy systems of the future, in part to support the decarbonisation objective and in part to provide grid flexibility in a future system including a large fraction of less responsive low carbon energy systems (e.g. nuclear baseload and intermittent wind). The proposed research methodology is based on multiscale modelling. This involves the development of fit-for-purpose models of the individual components which describe phenomena that operate over different length and time scales and which support integration and data exchange across scales. Located at the end of the CCS chain, the performance of the geological CO2 storage site has implications for many other parts of the CCS infrastructure. For instance, how easily the store accepts injected CO2 will govern in part the number of wells required and wellhead design. The pressure of fluids already present in a store, and how this pressure is connected, will be a factor in how much CO2 the store will ultimately hold. Each potential CO2 storage site may be defined by a set of geological and geotechnical parameters. Variation in these parameters and their interaction at different scales results in each site being unique. As one of the objectives of this proposal BGS will construct a series of injection and storage models that will reflect the widely differing characteristics of a CO2 storage complex and test how variations in key parameters for each model affect the whole CCS system. Accurate characterisation of a realistic set of CO2 stores will be a crucial component in the construction of the whole systems model. Several types of geological storage mechanisms, typical of offshore UK oil and gas fields and saline aquifers, will be identified to reflect the different storage options that may be available in future CCS projects. Using actual examples, each potential storage site will be mapped and characterised. Static storage capacity will be calculated and will account for the limiting effect of pressure build-up in the reservoir and possible mitigation options. A 3D model of each site will be constructed and populated with relevant geological and geotechnical information derived from existing accessible datasets, interpretations and published information. Use will be made of data and results from other relevant CCS studies including CASSEM and the Scottish Regional Study. Where specific in situ information is unobtainable, data from analogues will be utilised. The results will be used in Work Packages 1 and 5 of this bid.
 
Description This is the first time that detailed 3D models of potential CO2 storage reservoirs have been constructed with the functionality of being able to represent the storage reservoir in different parts of an offshore sedimentary basin. They have direct relevance to the study of CO2 plume migration in the sub-surface and have the potential to continue to contribute to future research in this area. This work demonstrates that it is possible to build 3D earth models from publically available information that provide useful tools to further understand and measure CO2 injection and storage performance; the models may also have applicability in other fields of research. Papers published so far, that utilise these models in flow modelling software, have generated results that show them to be useful tools in the study of CO2 storage.

Through this project BGS has developed the methodology and confirmed the approach to building complex 3D models using publically available data. For example the use of relatively old data from the Forties and Nelson hydrocarbon fields has been used to construct a complex model of a turbidite submarine fan system, one that can be transposed to different parts of the system, enabling comparison of results.
Exploitation Route BGS has written a Research Report detailing the building and attribution of the three 3D models of potential CO2 stores. The report is undergoing internal peer review procedure at present. The report will be freely accessible to all and we will be endeavouring to make all three models available for download and use by other researchers or interested parties. The models and accompanying report provide a platform for further research, by both academic and other interested parties, into the predictive movement of CO2 through these sedimentary systems.
Sectors Education,Energy,Environment