Transcript ECI_2 - Australian National University

Improving our understanding of fluid transport
in rocks – CO2 sequestration
Tim Senden
Department of Applied Mathematics
Research School of Physics and Engineering
Introduction
• Underground storage of CO2 has been proposed
as a means of mitigating climate change through
ghg emissions.
• Several major challenges to address
– Volume of CO2 that can be stored within a given
geological formation
– Proximity to CO2 source (powerplant, gas field)
– Long term storage security (e.g. leakage rate must be
less than 0.01% per year)
• CO2-rock interactions are a source of
uncertainty in assessment of CO2 storage
viability
– Change injectivity (porosity, permeability etc)
– May alter seal rock integrity
– Mineral trapping / contaminant liberation
… but supercritical CO2 is an unusual beast!!
Facts: Above 31°C and 73 atm (not uncommon in reservoirs/aquifers);
• ½ as dense as water, and 1/10th 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.
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Saline aquifer
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Sleipner (Norway)
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Globally ubiquitous
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Need to ensure security
to avoid groundwater
contamination (true for
any lithology)
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Mineral trapping small
volumetrically but
potentially important
(changes to flow
properties)
So how to study this troublesome fluid in microscopic pores within rock?
Image source: Statoil
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
We must manage our hydrocarbon resources efficiently
Physical Parameters
Reservoir Descriptors
Electrical Conductivity
Dielectric Permittivity
Neutron
Borehole Pressure
Sound Velocity
NMR Response
Gamma-ray x-section
Capillary Pressure
Oil Saturation
Water Saturation
Gas Saturation
Porosity
Permeability
Instead of a single
data point we can
extract 100’s from
How does fluid permeability correlate to other observables ?
a single core
1 mm3 sandstone showing simulated flow lines
Simulation
Experiment
Triaxial cell
•8 – 25 mm cores
•Beryllium cell
•Axial strain < 1000
atm
•Confining pressure <
100 atm
•No creep over 8 hr
•Designed for scCO2
at present
using analogue fluids
Mardie Green Sand – Barrow Is, WA
Native state
Using analogue fluids
After exposure to CO2 equivalent
Courtesy of Rowan Romeyn (Hons. student).
Since 2000
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Since 2006
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
Since 2009
ANU/UNSW spin-off
Christoph Arns **
Tomaso Aste
Holger Averdunk
Gareth Crook
Andrew Fogden
Abid Ghous
Stephen Hyde
Anthony Jones
Alexandre Kabla
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Andrew Kingston
Munish Kumar
Mark Knackstedt
Shane Latham
Evgenia Lebedeva
Ajay Limaye *
Jill Middleton
Glenn Myers
Val Pinczewski **
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Vanessa Robins
Rowan Romeyn
Mohammad Sadaatfar
Arthur Sakellariou
Tim Sawkins
Adrian Sheppard
Rob Sok
Michael Turner
Trond Varslot
* VizLab ANUSF
Paul Veldkamp
** UNSW
2011 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 CO2 – rock interactions in Australian
aquifers. 3 years.
Building an open access data repository, visualisation
and simulation platform for tomographic data