COLLIE HUBPresentation

Groundwater Issues

3 May 2011

THE CONCEPT

COLLIE HUB•Integrated industrial CO2 geosequestration system•Storage within an identified area• Red mud sequestration 300,000 + tpa (Alcoa)• 2.4 mtpa Perdaman CO2• Potential for up to 7 mtpafor future power generation

HOW IT WILL WORK

Target formations

• The target injection formation is the Lesueur Sandstone with a top depth of approximately 1300 metres.

• The depths of injection will be approximately 2000 and 2500 metres.

• The Eneabba Formation will be the upper, “sealing” formation

• Modelling shows the CO2 just reaching the base Eneabba

CO2 Injectivity andDynamic Capacity

OPTION 1Single well

w/ dual completion

OPTION 2Multiple well

w/ single completion• Injection rate range:

• Base Myalup & top Wonnerup: 0.2 – 1 Mt/a/completion

• Mid Myalup: 0.3 – 1 Mt/a/completion• Total: 0.9 – 1.7 Mt/a/well

• CO2 contained volume (cumulative after 40 yrs of injection) :

• Base Myalup & top Wonnerup: 110 - 150 Mt • Mid Myalup: 90 – 150 Mt• Total injection range: 200 – 260 Mt

• Maximum pressure buildup of ~ 50 bar occurred across Darling fault, in Myalupand Wonnerup. Fault is still stable.

Dynamic Simulations

• Target injection (40 yrs): 6 injectors• Completion consideration to optimize

injection volume and manage containment risk:• Proximity to faults and well spacing• Rock quality distribution• Reservoir dip

• Two potential injection zones identified:

• Base Myalup/Top Wonnerup with lower containment risk

• Mid Myalup with higher injectivitypotential and higher containment risk due to the proximity to Eneabba:

• Smaller injection intervals away from the Base Eneabba

• Injection constraints: frac-pressureDarling Fault

Injection Intervals

Distance, m

Dis

tanc

e, m

Distance, m

1000 yrs

1000 yrs

CO2 Containment and Trapping Mechanism• CO2 reaches base of Eneabba at

250 yrs• After shut-in, up dip• After 100 years shut-in:

• mobile gas from 77% to 35%

• After 1000 years shut-in:• Mobile gas: 10%• Residual / immobile gas: 60%• Dissolved gas: 30%

• * residual saturation 10-40%

Trapping mechanism in Base Scenario

Fault Seal Analysis

•Fault Seal Analysis of bounding faults in the study area (Petrel):

• Darling Fault – main bounding fault (considered sealing)

• 4NS• 8EW

•Fault / Fracture Reactivation• faults stable up to 110 bar

overpressure

11

GSWA Harvey 1

Preparation Phase 2010 – 2012Pre-Competitive

• Further technical investigation of the Lesueur;

• Commenced a community & stakeholder consultation process

• Establishment of necessary legislative measures, approvals and easements; and

• Development of the proposed commercial structure and arrangements to facilitate the development.

Groundwater Analysis

• The main Perth domestic water supply aquifer is the Yarragadee Formation.

• The area chosen is on a structural high where the Yarragadee has been eroded off.

• Main water supply from irrigation and superficial formations.

• The Cockleshell Gully Fm is saline• The Leederville Fm mainly saline.• Lesueur Sst is a confined saline aquifer

This section eroded off

New Seismic: note unconformity

COLLIE HUB AND WATER

Primary aim is not to isolate potential groundwater sources either above or below the injection depth

• How will we ensure aquifers above injection zone are protected?

• How will CO2 injection alter the water chemistry and rock chemistry?

Upper Aquifers• Leederville Fm – 1.5km above injection formation

• Eneabba Fm consists of siltstones, mudstones and other “barrier” formations – need more data to prove this up in the area.

• Need to set up monitoring regime with tracers, monitoring bores etc

• Refine modelling with new data from seismic andGSWA Harvey 1 well.

Water Chemistry• Sampling program

using MDT (Modularformation DynamicsTester)

• Core geochemistryXRD, SEM, Hyloggeranalyses

Conclusions

• Collie Hub Project aware of resource conflict issues generally and groundwater specifically

• Already taken steps to avoid Perth’s main groundwater source, the Yarragadee Fm

• Data paucity means more acquisition necessary

• Planning team for future work includes DoW• Monitoring essential

Thank you