Investigating the multiphase flow behaviour of CO2 and brine

Catriona Reynolds

Supervisors: Dr Samuel Krevor and Prof Martin Blunt

Funding: Project carried out under the auspices of the QCCSRC, PhD funded by Department of Earth Sciences Scholarship provided by EPSRC


The aim of this PhD project is to improve our qualitative understanding of the multiphase flow behaviour of the CO2-brine system in sandstones. Being able to predict how and where CO2 will move when injected into subsurface aquifers and how much CO2 can be trapped is vital to the design of CO2 storage sites.

 I measure relative permeability curves and quantify residual trapping in sandstones at reservoir conditions using a high pressure, high temperature circulation loop.  Experiments are performed at the centimetre scale to investigate the impact of geologic heterogeneities on CO2 flow and on the micron scale to improve our description of two phase flow in the pore space. Images are taken of the pore space during flow experiments using medical and micro X-ray CT scanners and using the Diamond Light Source synchrotron in order to resolve the CO2 distribution from spatially from 1 micron to 10 cm, and provide both static and time resolved images.

 The major findings of this PhD are:

  1. A systematic study of the influence of fluid properties and flow conditions on relative permeability and the interaction of CO2 flow with pore space heterogeneity (Figure 1).
  2. Relative permeability and trapping characterisation of potential CO2 storage sites in the UK and a current pilot CO2 storage site in Australia
  3. A new description of two-phase flow at the pore scale, using time resolved imaging


cat pic 1

Figure 1. Relative permeability curves measured under various flow conditions in a single rock sample.

cat pic 2

Figure 2. Nitrogen imaged during flow in the pore space of a sandstone. Separate ganglia are coloured by size.