This blog was authored by Junyoung Hwang, Imperial College London.
My first UKCCSRC meeting was held at Cardiff University to discuss the past, present, and most importantly the future of Carbon Capture, Utilization, and Storage (CCUS). The meeting sessions presented a wide range of CCUS research areas, including the current retrofit technologies and CCUS applications in many locations in the UK. It was also interesting to hear from the delegates from the US Senate Committee on what is being discussed across the pond. The poster session was also a great opportunity to present my work to the CCUS community in the UK.
On the second day of the conference, parallel sessions were held on the main aspects of reducing the UK’s CO2 emission: capture, storage, and systems and policy. I attended the session on storage, the most relevant to the topic of my own PhD project. The rest of this blog is intended to deliver to the readers what I have learned from the five talks given by researchers that addressed various challenges in storing CO2 and the progress made to overcome them. The session on storage was led by Professor Stuart Haszeldine from the University of Edinburgh. My research project investigates the physical interaction of CO2 in nanoscale pores, so its contrast with the presented work focusing on larger scale responses of storage sites provided a new perspective.
Silvia De Simone from Imperial College London kicked off the session with a talk titled Simplified models for CO2 storage capacity assessment for large scale. She discussed the pressure response of injection sites upon CO2 storage using analytical solutions that compare well to numerical solutions, but require much less computing power. Silvia emphasized the need for assessing the pressure response as micro-seismic events may potentially occur beyond limiting pressure. With this model, Silvia investigated the effects of multiple parameters, such as CO2/water viscosity and permeability, on multiple site injection scenarios. By analyzing the sources of error of the model and correcting for them, Silvia derived a generalized model for designing and optimizing the site specifications and to estimate the maximum amount of injection.
Masoud Ahmadinia from the University of Coventry presented his work on CO2 plume prediction at the top surface using history matching techniques. The CO2 activity after storage must be monitored carefully to make sure that what is being put underground stays underground. My personal experience with outreach events also tells me that this is the most concerning element of CO2 storage to the public. Masoud looked into how the shape of cap rocks affect the movement of CO2 plume. By altering the cap rock shape to match the experimental seismic data, he was able to understand the extent of various parameters, such as aquifer size, permeability barriers, flow capacity, pore volume, and relative permeability.
Understanding the saturation behavior of CO2 in geologic formations is a significant component in monitoring carbon storage projects. In this context, Georgos Papageorgiou from the University of Edinburgh presented his work on modeling CO2 saturated anisotropic synthetic sandstone. The model describes the behavior of measured datasets including the observation of “patchy” saturation of CO2-brine mixture. Georgos showed that this “patchy” behavior is related to viscoelasticity and can be explained in terms of the fluid pressure.
Jim White from British Geological Survey presented a research project called Pre-ACT (Accelerating CCS Technologies), which aims to develop a protocol for conformance assessments of CO2 storage projects. Jim stressed the importance of collecting experimental data and developing a proper model to describe the observations to explore what controls subsurface anomalies and consequences of heterogeneity. With the conformance assessment tool, optimal monitoring plans and approaches can be derived. This allows correct decisions to be made based on assessment results.
The last presentation was given by Luke Jenkins from the University of Oxford on coupling CO2 plume evolution with large-scale pressure dissipation, to evaluate the storage capacity of aquifer formations that are controlled by the location of injected CO2 and pressure build-up caused by it. Luke presented and compared 1D and 2D models that couple CO2 migration and pressure dissipation. The presentation was followed by an interesting discussion on the use of the term ‘leakage’ and whether the term is appropriate to gain public acceptance as the word carries a negative connotation. The term ‘migration’ has been suggested to gain better public acceptance of CO2 storage.