1. Improving our understanding of fluid transport in rocks – CO 2 sequestration Tim Senden Department of Applied Mathematics Research School of Physics and Engineering

2. Underground storage of CO 2 has been proposed as a means of mitigating climate change through ghg emissions. Several major challenges to address –Volume of CO 2 that can be stored within a given geological formation –Proximity to CO 2 source (powerplant, gas field) –Long term storage security (e.g. leakage rate must be less than 0.01% per year) Introduction

3. CO 2 -rock interactions are a source of uncertainty in assessment of CO 2 storage viability –Change injectivity (porosity, permeability etc) –May alter seal rock integrity –Mineral trapping / contaminant liberation … but supercritical CO 2 is an unusual beast!! Facts: Above 31°C and 73 atm (not uncommon in reservoirs/aquifers); ½ as dense as water, and 1/10 th as viscous but flows like a liquid. while it does not mix with water is does react to make the water acidic it dissolves in hydrocarbons.

4. Saline aquifer Sleipner (Norway) Globally ubiquitous Need to ensure security to avoid groundwater contamination (true for any lithology) Mineral trapping small volumetrically but potentially important (changes to flow properties) Image source: Statoil So how to study this troublesome fluid in microscopic pores within rock?

5. The X-ray micro-Tomography Facility Micro-focus X-ray source Rock specimen Double helical trajectory means very high fidelity data from micron to centimeter scale

6. Physical ParametersReservoir Descriptors Electrical ConductivityOil Saturation Dielectric PermittivityWater Saturation NeutronGas Saturation Borehole PressurePorosity Sound VelocityPermeability NMR Response Gamma-ray x-section Capillary Pressure How does fluid permeability correlate to other observables ? We must manage our hydrocarbon resources efficiently Instead of a single data point we can extract 100’s from a single core

7. 1 mm 3 sandstone showing simulated flow lines

8. Triaxial cell 8 – 25 mm cores Beryllium cell Axial strain < 1000 atm Confining pressure < 100 atm No creep over 8 hr Designed for scCO 2 at present using analogue fluids Simulation Experiment

9. Mardie Green Sand – Barrow Is, WA Courtesy of Rowan Romeyn (Hons. student). Native stateAfter exposure to CO 2 equivalent Using analogue fluids

10. ANU/UNSW spin-off Christoph Arns ** Tomaso Aste Holger Averdunk Gareth Crook Andrew Fogden Abid Ghous Stephen Hyde Anthony Jones Alexandre Kabla * VizLab ANUSF ** UNSW Vanessa Robins Rowan Romeyn Mohammad Sadaatfar Arthur Sakellariou Tim Sawkins Adrian Sheppard Rob Sok Michael Turner Trond Varslot Paul Veldkamp The Digicore Consortium has included; Saudi Aramco, ExxonMobil, Shell, Chevron, BP, Total, Schlumberger, Baker Hughes, Abu Dhabi Onshore, Maersk, Petronas, PetroBras, Japan Oil & Gas, ONGC (India), BHP, BG, Conoco Philips, FEI, Digitalcore Andrew Kingston Munish Kumar Mark Knackstedt Shane Latham Evgenia Lebedeva Ajay Limaye * Jill Middleton Glenn Myers Val Pinczewski ** Since 2000 Since 2006 Since 2009

11. Australian National Low Emissions Coal Research and Development (ANLEC) In partnership with Digitalcore and ANU received a multi-million dollar grant to develop methods to investigate CO 2 – rock interactions in Australian aquifers. 3 years. Building an open access data repository, visualisation and simulation platform for tomographic data 2011