When: Wednesday 26 April at 13:00 (Oslo time)
Who: Dr. Tom Bultreys, assistant professor at Ghent University and recipient for the Interpore-PoreLab award for young researchers 2019
Title: New developments in micro-CT-based imaging of flow in porous media: 3D X-ray micro-velocimetry and to pore-to-core imaging experiments
X-ray micro-CT is an important technique to the behavior of fluids in porous media in three dimensions and at micrometer-scale resolutions. However, a number of important challenges have remained, notably studying pore-scale dynamic processes and bridging the gap between the pore- and the core-scale. In this talk, I will address recent developments on these issues at Ghent University.
First, I will present how the development of fast micro-CT has led to 3D velocimetry, and show how it can be applied to measure flow field fluctuations triggered by Haines jumps in unsteady drainage experiments. The resulting data gives unique insight into the non-equilibrium energy dynamics during multiphase flow.
Next, I will discuss imaging experiments targeting pore-scale multiphase flow dynamics in REV-scale rock samples. Previous pore-scale imaging studies on fluctuations in the fluid distributions (intermittency or ganglion dynamics) were limited to small samples with mm-scale diameters and volumes on the order of ~ 0.5 cm3. Here, we image steady-state co-injection experiments on a one-inch diameter core plug sample, with nearly two orders of magnitude larger volume (21 cm3), while maintaining a pore-scale resolution. Our observations differ markedly from those reported for mm-scale samples, suggesting that viscous forces may play a role in the cm-scale fluid distribution even at very low Ca, dampening intermittent pathway flow. This is important to translate findings from pore-scale studies to measurements of continuum properties typically performed on larger samples, and ultimately to field-scale models.