martin j blunt department of earth science and engineering, imperial college london two hundred...
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Martin J Blunt
Department of Earth Science and Engineering, Imperial College London
Two hundred barrels left:an analysis of population growth, oil reserves and carbon dioxide emissions
Big question?
Volatile oil prices
Financial crisis
Rising food prices
Growing population
Peak oil
Global warming
Where are we heading?
World population
dt
dP
Pg
1
http://www.census.gov/ipc/www/idb/worldpop.html
Growth rates
Population growth
Growth rate as a function of population
US population to the present day
US population growth rate
Swedish population
Swedish population growth rate
Population of Saudi Arabia
Growth rate for Saudi Arabia
Population of Rwanda
Growth rate for Rwanda
Global population growth rates fit to linear models
K
Pr
dt
dP
Pg 1
1
Logistic equation
K is carrying capacity
Logistic equation
Population projections
Green line – my estimateOther lines and crosses: more detailed estimates from the UN, US Census Bureau and the World Bank
Hubbert analysis of oil production
N
N
US oil production to 1960
US oil production to 1960
US oil production – data and prediction
US oil production to 1960
Hubbert analysis for world oil production
K
Cr
dt
dC
Cg 1
1
http://www.bp.com/centres/energy/
Hubbert prediction – peak in 2010!
Total volume of discoveries worldwide, 1900-2004
From Tertzakian, 2006; based on Harper, 2003
Comments
Oil is integral to our society – think of something that doesn’t use oil in its manufacture or distribution.
We are not about to run out of oil, but it is a precious resource.
So what will happen?
Fossil fuels and global warming
What is the greenhouse effect?
What does it have to do with carbon dioxide?
What has carbon dioxide to do with the oil industry?
Are we likely to damage the climate?
Should we be worried?
Don’t listen to opinions – work this out for yourselves.
What determines climate?
Radiative heat transfer from the sun (which is influenced by orbital mechanics, solar variations)Flow of warm and cold water in the oceanFlow of warm and cold air in the atmosphereReflection of sunlight back to spaceGreenhouse gasesFeedbacks (much more about this later)
Source: Lamb & Singleton, Earth Story, Princeton U. Press, 1998
(ORNL 1997)
Carbon exchange with the environment
Atmospheric CO2 concentration
- Last glacial maximum to present
Radiation energy balance
Source: IPCC Third Assessment Report, 2001
Greenhouse gases
Water is the most important GHG.
CO2, CH4, N2O and CFCs are other important GHGs.
Sulfur emissions (aerosol precursors have also risen).
Surface ocean pH has declined by 0.1 due to dissolving CO2.
Source: IPCC Third Assessment Report, 2001
The Earth is a greenhouse planet
The combination of solar irradiance and greenhouse effect determines the mean surface temperatures of Mars, Earth and Venus. In the absence of the natural greenhouse effect, the average surface temperature of Earth would be -19oC.
- 63oC 15oC 452oC
Average Surface Temperatures
Mars Earth Venus
Source: C.T. Bowman, Mechanical Engineering, Stanford
Source: IPCC, “Climate Change 2001: The Scientific Basis, Cambridge Univ. Press, UK (2001)
Source: IPCC, “Climate Change 2001: The Scientific Basis, Cambridge Univ. Press, UK (2001)
How much carbon dioxide?
Concentration in the atmosphere
Fossil fuel reserves
Population growth
How much oil per person?
Carbon dioxide concentrations
What can we do?
We do still need the oil industry.
Yes, we will continue to use fossil fuels – like it or not.
There is only one technology that can save us…..?
Carbon capture and storage
How much can be stored?
920 Gt – 45% of emissions to 2050 in oil and gas fields.
400-10,000 Gt in aquifers 20-500% of emissions to 2050
IEA estimates.
700 Gt in North Sea alone (DTI) ≈CO2 produced by all UK population for >50 years
Critical point of CO2 is 31oC and 72 atm (7.2 MPa).
CO2 will be injected deep underground at supercritical conditions (depths greater than around 800 m).
CO2 is relatively compressible; density less than water,
similar to oil.
Low viscosity – around10% of that of water.
Carbon dioxide properties
Current emissions are around 30 Gt CO2 per year (8.5 Gt carbon).
Say inject at 10 MPa and 40oC – density is 600-700 kgm-3.This is around 108 m3/day or around 700 million barrels per day.
Current oil production is around 85 million barrels per day.
Huge volumes – so not likely to be the whole story, but could contribute 1-2 Gt carbon/yr….
Costs: 1-2p/KWh for electricity for capture and storage; £25-60 per tonne CO2 removed – Shackley and Gough, 2006.
Could help fill the UK emissions gap in 2020.
Some numbers
North Sea storage
Large capacity in mature oil and gas fields.
Oil and gas field relatively small traps in much larger aquifers.
Engineering challenge to construct the capture, transport and injection infrastructure.
Most current infrastructure would need to be replaced.
Trapping background
How can you be sure that the CO2 stays underground?
Dissolution, chemical reaction, cap-rock and capillary trapping.
Capillary trapping is rapid (decades): CO2 as pore-scale bubbles surrounded by water.
host rock
Pore-scale CO2 trapping
CO2 bubbles
Design of CO2 storage
Injector
Producer
SPE 10 reservoir model, 1,200,000 grid cells (60X220X85), 7.8 Mt CO2 injected.
Qi et al., SPE 109905
A case study on a highly heterogeneous field representative of an aquifer below the North Sea:
Inject brine and CO2 together and then use chase brine to trap CO2
1D results are used to design a stable displacement
Simulations are used to optimize trapping
3D results for aquifer storage
Mobile CO2 saturation
Z
170m
X3200m
Y
2280m
Trapped CO2 saturation
X3200m
Y
2280m
Z
170m
20 years of water and CO2 injection followed by 2 years of water injection in realistic geology
95% of CO2 trapped after 4 years of water injectionQi et al., SPE 109905
Conclusions and thanks
Do your own analysis!
Many students and post-docs and research funders: