Presenting to: GCCSIGroundwater Thematic Working GroupInitial WorkshopCanberra, 3 May, 2011

Groundwater and CO2CRC- Insights from the Otway Project and Monitoring Activities

Allison HortleSenior Researcher, Petroleum HydrogeologyCooperative Research Centre for Greenhouse Gas Technologies (CO2CRC) © CO2CRC

All rights reserved

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

Concept of the CO2CRC Otway Project

Supercritical CO2 from Buttress-1

80% CO2 : 20% CH4

Fluid Sampling Field Lab.

Monitoring at the CO2CRC Otway site

δ

Schematic Stratigraphic Column of Otway Basin

Waarre Aq.

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

Groundwater Monitoring Stations• 24 Port Campbell

Limestone• 3 Dilwyn Aquifer• 5 Pre-injection

sampling trips• 4 Post-injection

sampling trips

Monitoring groundwater levels

• Install downhole pressure and temperature sensors

• Provide real-time measurements of fluctuations in water levels

• Bi-annual downloads

Screen

Datalogger

Waterlevel

Steel Cable

Cable permanently installed

Cap

5-10m

Field Sampling• At each site, pumped water was monitored

for:–pH, Eh, EC, DO and temperaturethrough 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

Pt Campbell Groundwater Composition

Water levels in the Dilwyn Confined Aquifer

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

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?

Groundwater Monitoring

• Standard practice, inexpensive, off-the shelf tools

• Provide real-time measurements of fluctuations in water levels and temperature and conductivity

• Still produce large amounts of data

Screen

Datalogger

Waterlevel

Steel Cable

Cable permanently installed

Cap

5-10m

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

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-, SO4

2-, Br-, NO3-, PO43-

(Anions), TOC, TIC, pH, Alkalinity, VOC, dC13.

http://bittooth.blogspot.com/2010/03/carbon-sequestration-sites-and-their.html

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

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

CO2CRC Participants

Established & supported under the Australian Government’s Cooperative Research Centres Program

Supporting Partners: The Global CCS Institute | The University of Queensland | Process Group | Lawrence Berkeley National Laboratory | Government of South Australia | CANSYD Australia

Naylor area Pre-production potentiometric surface

Onshore Otway Basin: declining pressure with time

Naylor-1 Croft-1

Presenter

Presentation Notes

The site of the project is in the otway basin in victoria, near the town of Waarrnambool, at the end of the great ocean road. The area is predominantly rural, mostly dairy farms, with little forestation. There is a major river, the Curdies River east of the project. It is also a region of significant oil and gas reservoirs with production beginning in 1986. This was a significant impact on the project as the locals were familiar with oil company activities. This mostly, but not always good. There are also natural accumulations of CO2 here, two of these are shown here, Boggy Creek, which produces food grade c02 and the Buttress Field, which was acquired by the CRC and provides the co2 for the project. This figure also has the injector well, crc-1, which was drilled by the crc and the monitoring well Naylor-1

0

2

4

6

8

10

12

1/10/00 13/02/02 28/06/03 9/11/04 24/03/06Date

Dep

th (m

etre

s)

BORE 141239BORE 141240BORE 141241

Hydrographs from the Unconfined Aquifer

~3.5m

Reduced Water Levels in Deep Bores (relative to AHD)

0

5

10

15

20

25

30

35

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

Date

Dep

th (m

etre

s)

BORE 84288BORE 84290BORE 84291BORE 85937BORE 85942

Long-term Monitoring of Deep Aquifer

Pump test

Test impacts

Groundwater Resources in Victoria