Welcome to the next PoreLab lecture!
Who: Prescelli Annan, doctoral student at the Swiss Seismological Service (SED), ETH Zurich, Switzerland.
Prescelli is using numerical modelling to cross-correlate datasets varying in scale from lab to field, in the context of CO2 sequestration. Her Ph.D. is part of the SMILE project (MultidiSciplinary and MultIscale approach for coupLed processes induced by geo-energies) as part of the European Doctoral Network on Geo-energy.
When: Wednesday 2 October at 13:00 (Norway time)
Where: The lecture will be in person in the common room at PoreLab in Trondheim, and will be streamed in the Kelvin room (PoreLab Oslo). From anywhere else, you will be able to join via the following Zoom link:
https://uio.zoom.us/j/65837085049?pwd=WjZianUyN3FJa2liQkxBbzQrOCtGdz09
Title: Multi-scale study into the structural control on fluid-rock interactions in caprocks and reservoir rocks for geological CO2 storage
Abstract: This research will involve a series of laboratory and field experiments to investigate the complex interactions between reactive pore fluids and the rock matrix in caprocks and reservoir rocks, which are crucial for effective GCS. We will employ a multiscale approach, integrating laboratory experiments with field studies at the Mont Terri Underground Rock Laboratory. A key focus is on understanding how fractures influence pore structure modification and fluid transport. Specifically, we aim to investigate fracture-limited transport processes during CO₂-saturated fluid injections in both controlled laboratory conditions and field settings.
In the laboratory, CO₂ exposure experiments of intact core samples will replicate in situ salinity, pressure and temperature levels using a batch reactor system equipped with continuous pH monitoring. Characterisation of the mechanical and physical properties of the basalt and claystone samples will be conducted before and after CO₂-rich seawater exposure, using X-ray computed tomography (XRCT) of cores to provide 3D insights across various rock types and better understand controls to rock alteration. We aim to confine the impact of CO₂ exposure on the hydromechanical properties of basalt and claystone, and hope to provide this dataset to other modelling studies. Applications of this research will help interpret results from geophysical field campaigns and assist storage reservoir management strategies.
Scaling this to the decameter scale, we investigate the injection of CO₂-saturated brine into a fault zone within Opalinus Claystone at Mont Terri —an analogue caprock. This contributes to a more comprehensive understanding of fluid injection on fault reactivation and up-fault leakage, as well as the mechanisms of claystone fracture self-sealing. Here we target leakage processes at shallow depths, important to CO₂ storage security, and will investigate remediation methods to deploy in the case of leakage.