Transcript CO2 Storage in Deep Saline Aquifers

Geologic Storage of CO2: Leakage
Pathways and Environmental Risks
Michael A. Celia, Catherine A. Peters, and
Stefan Bachu
Princeton University
and
Alberta Geological
Survey
May 2002
CO2 Injection and Trapping Mechanisms
Injection Well
Confining Layer(s)
Supercritical
CO2
~800 m
Dissolved CO2
Precipitated Carbonate Minerals
Stratigraphic
Trapping
Solubility
Trapping
Hydrodynamic
Trapping
Mineral
Trapping
Research Questions
• How effective are the
various trapping
mechanisms?
• Today: Solubility
trapping
• What is the likelihood and
magnitude of CO2 leakage?
• Today: Abandoned wells
• What are the
environmental impacts of
CO2 leakage?
• Today: Mammoth Mtn,
and groundwater quality
Simulation of Injection of Supercritical CO2
CO2 injection
= 20 kg/s
• TOUGH2 Simulator
• Radial symmetry
• Isothermal conditions
790 m
Brine
• Confining layer
permeability of 0.1 mD
CO2
• Target formation
porosity 10% and
permeability of 100 mD.
10 m
50 m
Simulation of Injection of Supercritical CO2
CO2 injection combined
with injection of brine
above the confining layer
After 4 years of CO2
injection
Mass of CO2/Volume [kg/m3]
Mass of CO2/Volume [kg/m3]
Depth [m]
Depth [m]
Qbrine = 40 kg/s
Radial distance [m]
Radial distance [m]
Simulation of Injection of CO2
Dissolved in Water
• After 1 year
• After 50 years
Mass of CO2/Volume [kg/m3]
Mass of CO2/Volume [kg/m3]
Total Mass CO2 injected
= 3.1x107 kg
Total Mass CO2 injected
= 1.2x109 kg
seal
seal
Leakage
Pathways and
Trapping
Mechanisms
Atmosphere
Surface
Ecosystems
Potable Water
fractures,
faults, wells
Localized vertical migration
Confining Layer(s)
Injected
Carbon Dioxide
lateral
migration
year abandoned
1998
1989
1980
1971
1962
1953
1944
1935
1926
1917
1908
1883
5000
4500
4000
3500
3000
2500
2000
1500
1000
500
0
number of wells
Leakage Pathways:
Abandoned Wells in the Alberta Basin
Simulation of leakage through a single
abandoned well
Depth [m]
• Permeability of a
typical well cement
~ 10-17 m2
• Permeability of a
medium sand
~ 10-10 m2
Rate of CO2 Leakage [kg/s]
4
3
2
1
0
1.00E-17
1.00E-15
1.00E-13
1.00E-11
Permeability [m^2]
1.00E-09
Potential Effect on GW Quality
groundwater
flow
drinking-water
aquifer
CO2 leakage
Pb2+concentration, mol/L
1.2E-07
10 yr.
9.0E-08
8 yr.
6.0E-08
6 yr.
4 yr.
3.0E-08
2 yr.
deep brine aquifer
0.0E+00
-50
50
150
distance, m
250
Mammoth
Mountain
• On the Long Valley Caldera in eastern California
• Soil gas surveys revealed CO2 concentrations as
high as 95%. (CO2 concentrations > 10% toxic
to humans.)
Changes in Metal Uptake in Plants
Mn 1989
Ambient soil CO2
2001
Zn
Ca
Elevated soil CO2
Ca
2001
1989
Mn
Zn
c
b
Acknowledgements
• Funding from BP and Ford.
• Equations of State: R. Bruant
• TOUGH2 Simulations: A. Guswa, S. Gasda
• Leakage Estimates: A. Duguid
• Groundwater Simulations: P. Jaffe, S. Wang
• Mammoth Mountain: S. Myneni, S.J. White