Martin J Blunt Department of Earth Science and Engineering, Imperial College London Two hundred barrels left: an analysis of population growth, oil reserves.

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: