The CO2CRC Otway Project has established a groundwater monitoring network at its injection site in Victoria, Australia to track any impacts from CO2 injection and storage on local freshwater aquifers, with monitoring showing no changes to groundwater levels, composition, or quality between pre-and post-injection periods. The monitoring network utilizes standard tools like dataloggers to continuously measure water levels and temperatures in shallow and deep aquifers, with collected data demonstrating stable conditions and providing confidence that CO2 storage can safely co-exist with groundwater resources.

1. Groundwater and CO2CRC- Insights from
the Otway Project and Monitoring Activities
Allison Hortle
Senior Researcher, Petroleum Hydrogeology
Cooperative Research Centre Presenting to: GCCSI
for Greenhouse Gas Groundwater Thematic Working Group
Technologies (CO2CRC) Initial Workshop © CO2CRC
Canberra, 3 May, 2011 All rights reserved

2. M&V Goals
• To monitor the freshwater aquifers to demonstrate that they are
unaffected by the injection and storage of CO2
• To set-up a long term sentinel monitoring system
• To combine the hydrogeology and the geochemistry with the
atmospheric and soil gas program to develop a methodology for
an integrated surface and sub-surface monitoring system
• Create public confidence in “decarbonisation” technology and
demonstrate that this technology can co-exist with existing
exploitable resources

3. Concept of the CO2CRC Otway Project
Fluid Sampling
Field Lab.
Supercritical CO2 from
Buttress-1
80% CO2 : 20% CH4

4. Monitoring at the CO2CRC Otway site
δ

5. Schematic Stratigraphic Column of Otway
Basin
Port Campbell Limestone Aq.
• Unconfined to semi-confined
• Major local freshwater source; dairy,
irrigation, domestic, etc
Dilwyn Formation Aquifer
• Confined, freshwater
• Future urban water resource
• Limited current use
Waarre Aq.

6. Groundwater Monitoring Stations
• 24 Port Campbell
Limestone
• 3 Dilwyn Aquifer
• 5 Pre-injection
sampling trips
• 4 Post-injection
sampling trips

7. Monitoring groundwater levels
Cap
• Install downhole pressure and Cable permanently
temperature sensors installed
Steel Cable
• Provide real-time measurements
of fluctuations in water levels
Waterlevel
5-10m
• Bi-annual downloads Datalogger
Screen

8. Field Sampling
• At each site, pumped water was monitored
for:
–pH, Eh, EC, DO and temperature
through a flow cell until stable readings were
acquired
• A set of samples were field titrated for
alkalinity
• A set of samples were analysed for reduced
Fe2+ through the portable mass
spectrophotometer
• Sets were obtained for comparison of field and
lab results to determine if field processing is
necessary

9. Pt Campbell Groundwater Composition

10. Water levels in the Dilwyn Confined Aquifer

11. Outcomes to date
• Groundwater composition has not changed between pre- and
post- injection
• No evidence of any changes in water level or temperature
associated with CO2CRC activities
• All data has been given to landowners, consequently they are
still very supportive
• We have demonstrated that no change has occurred at any of
the monitoring stations – this is not the same as evidence of
containment

12. What is a monitoring network?
• Monitor pre-existing wells, both groundwater and petroleum
• Under what circumstances will these installations “see”
changes related to CO2?
• What volume, how far away from leak, what impacts?
• How do you define an acceptable detection limit? pH,
pressure, HCO3?

13. Groundwater Monitoring
Cap
• Standard practice, inexpensive, off-the Cable permanently
shelf tools installed
Steel Cable
• Provide real-time measurements of
fluctuations in water levels and
Waterlevel
temperature and conductivity
5-10m
Datalogger
• Still produce large amounts of data
Screen

14. Permanent Downhole Monitoring
• Becoming more standard in
oil & gas industry
• Real-time monitoring of
pressure, temperature and
possibly fluids
• Much better reservoir
management
• Drawbacks are costs and
longevity
• Large amounts of data are
produced, requiring complex
and time-consuming analyses
Schmidt, H.S., Nordtvedt, J-E., Nygaard, O. and Erskine, S., 2002, Reservoir management of gas
fields using permanent sensors, World Oil, April, 2002, Vol. 223, No. 4, http://www.worldoil.com/April-
2002-Reservoir-management-of-gas-fields-using-permanent-sensors.html

15. Cranfield, EOR, USA (SEACARB)
• PDS in injection interval, PT,
and
• AMZI: 120m above injection
zone, changes in pressure in
injection zone are not
apparent in AZMI
• Groundwater: geochemical
sampling of aquifers at 70-
100m; Ag, Al, As, Ba, Ca, Cd,
Cr, Cu, Fe, K, Mg, Mn, Mo, Na,
Pb, Se, Zn (Cations), F-, Cl-,
SO42-, Br-, NO3-, PO43-
(Anions), TOC, TIC, pH,
Alkalinity, VOC, dC13.
http://bittooth.blogspot.com/2010/03/carbon-sequestration-sites-and-their.html

16. Ketzin, Germany (CO2SINK)
• Atmospheric monitoring:
tunable diode laser system
for CO2 and methane
• Gas monitoring: surface
soil flux (20 stations),
methane @ 2 m (10 wells)
• Groundwater: 2
multisensor monitoring
wells
Wuerdemann, et al., 2010

17. Summary
• Groundwater can be monitoring using geochemistry or
pressure; pressure propagates further than CO2 plume
• Tools for monitoring groundwater pressures (heads) are
off-the-shelf, cheap, long-lived and effective for
monitoring changes in pressure, temperature and
activity
• Tools for monitoring reservoir interval pressures are
also off-the-shelf, but more expensive and longevity is
less than 10 years
• Continuous monitoring is possible, but expensive and
requires complex analysis combined with a very good
geological model and field history

18. CO2CRC Participants
Supporting Partners: The Global CCS Institute | The University of Queensland | Process Group | Lawrence Berkeley National Laboratory | Government of South Australia | CANSYD Australia
Established & supported under the Australian Government’s Cooperative Research Centres Program

19. Naylor area Pre-production potentiometric surface

20. Onshore Otway Basin: declining pressure with time
Naylor-1 Croft-1

22. Hydrographs from the Unconfined Aquifer
Date
1/10/00 13/02/02 28/06/03 9/11/04 24/03/06
0
2 ~3.5m
4
Depth (metres)
6 BORE 141239
BORE 141240
BORE 141241
8
10
12

23. Long-term Monitoring of Deep Aquifer
Reduced Water Levels in Deep Bores (relative to AHD)
Date
14/11/84 23/01/87 2/04/89 11/06/91 19/08/93 28/10/95 5/01/98 15/03/00 24/05/02 1/08/04 10/10/06 18/12/08
0
Pump test
5
BORE 84288
BORE 84290
10 BORE 84291
BORE 85937
Test impacts BORE 85942
15
Depth (metres)
20
25
30
35

24. Groundwater Resources in Victoria