Unconventional Fossil Fuels
Tar Sands
Oil Shale
Shale Gas
Deepwater Oil
Tar Sands
- Also known as oil sands.
- These are naturally occurring mixtures of sand, clay, water and a dense viscous form of petroleum called bitumen.
- Canada has 73% of known global stocks.
- Tar sands have to be mined and then injected with steam to make the tar less viscous so that it can be pumped out.
Oil Shale
Deposits of organic compounds called kerogen in sedimentary rocks that have not undergone sufficient pressure, heat or time to become conventional oil. The USA has 77% of known global reserves.
Either mined or shale is ignited so that the light oil fractions can be pumped out.
Shale Gas
Usually methane in coal seams, or natural gas trapped in fractures and pores of sandstones and shales.
Fracking: pumping water and chemicals forces out the gas
Deepwater Oil
As accessible reserves (e.g. North Sea oil) run out, prospecting companies have to look into deeper ocean waters with greater risks and costs, e.g. the Gulf of Mexico and Brazil’s off-shore reserves.
Drilling takes place from ocean rigs; already underway in the Gulf of Mexico and Brazil
Unconventional Fossil Fuels – Why use them?
‘Peak Oil’ has been predicted for many years – this is when oil production will reach a global peak, before declining sharply.
As conventional fossil fuels (oil, gas and coal) reach an end, the search for other sources has intensified.
Unconventional fossil fuels are becoming more viable, particularly as areas such as Canada and USA discover its reserves.
At the same time, geopolitics can make access to resources difficult, or cause the prices of oil and gas to increase, making unconventional fuels like shale gas more economically viable.
Three examples of the exploitation of unconventional fossil fuels
Canadian tar sands
US shale gas
Brazilian deepwater oil
Canadian tar sands
- There are numerous deposits of tar sands in the world, but the biggest are in Canada and Venezuela.
- Exploiting the Canadian deposits on a commercial scale started in 1967 and has focused on the province of Alberta, most notably the Athabasca area.
- Currently, tar sands produce about 40 per cent of Canada’s oil output.
- The 2015 fall in the global price of oil had a depressing impact on the tar sands industry because extracting bitumen is relatively expensive, largely because of the high energy input.
- The exploitation of tar sands is not without its environmental costs, such as the scale of the strip mining, which requires the clearance of large areas of taiga.
US shale gas
- In 2000, shale gas provided one per cent of the USA’s gas supply.
- In 2015 it was nearly 25 per cent. Most of that increased production is due to the growing use of hydraulic fracturing (fracking) to release oil and gas from underground formations that are otherwise too difficult to drill.
- The most important shale gas fields have been found in the states of New York, Pennsylvania, Texas and West Virginia.
- Fracking for oil in the USA is now a key determinant of US oil security and has an increasing influence on the global oil price.
- Environmental concerns associated with fracking include possible contamination of groundwater by the chemicals in the pumping fluid and surface subsidence.
- Fracking is known to produce airborne pollutants such as methane, benzene and sulphur dioxide.
- There are also reports of ‘fraccidents’, such as mysterious animal deaths and industrial explosions.
Brazilian deepwater oil
- The discovery of huge oil deposits far off the Brazilian coast in 2006 was hailed as one of the biggest oil finds ever.
- Brazil is one of the leading emerging economies and badly needs oil and gas.
- The deepwater oil came on stream in
2009. - By 2020, Petrobras (the state oil company) aims to raise production to 500,000 barrels of oil a day.
- Since the 2006 discovery, the once scenic coast between Rio de Janeiro and São Paulo has been disfigured by refineries and the bases that serve the oil and gas fields more than 200 km offshore.
- Apart from this, and the serious pollution of the coastal waters, there are concerns about the risky nature of drilling so far offshore.
- The rigs are beyond the range of most helicopters, and access by ship is made hazardous by the prevailing rough seas.
- The rigs are drilling more than 2,000 m below the surface of the sea and then many more thousands of metres below the seabed.
- The deposits lie below a thick layer of salt.
- The oil and gas reservoirs contain huge amounts of toxic, flammable and explosive gases.
- Many observers are wondering what will happen if there is an accident, such as occurred at the Deepwater Horizon rig in the Gulf of Mexico in 2010.
Players in the harnessing of unconventional fossil fuels:
Exploration companies
Environmental groups
Affected communities
Governments
Exploration companies
- These are not always the major players, such as Shell, Exxon or Petrobas.
- There is a large amount of subcontracting to companies specialising in exploration, such as Halliburton.
- Ultimately, though, the big energy companies have to bear the financial risks associated with finding and opening up new energy reserves.
- But their searches are in the context of oil and gas, rather than the wider search for completely new (i.e. renewable) sources of energy.
Environmental groups
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It is very evident that exploitation of all unconventional fossil fuels has adverse impacts on the environment, which protest groups such as Greenpeace have done much to publicise. They are there to monitor the progress and their campaigns are well articulated.
Affected communities
The tendency is to focus on the negative impacts that energy production has on nearby communities. including various forms of pollution, disturbance of traditional ways of life, and so on. However, there are also benefits: job opportunities, inflows of investment and improved services. So, the role of such communities should not always be to object to each and every development.
Governments
The role of governments is a tricky one. Most governments wish to be seen as caring for the environment. Equally, for strategic reasons, they have a responsibility to ensure and improve energy security. Appealing to many governments is the fact that it is the private sector taking the financial risks associated with the search for new sources of energy.
TWh =
Terawatt hours
1 TW = 1 trillion watts
The UK’s Changing Energy Mix
The UK government is very mindful of the need to become energy secure and to play its part in reducing global emissions.
Oil and natural gas provide nearly 80% of the UK’s primary energy in 2021, with petrol being used by transport and most of the gas used to generate electricity.
There is some good news though:
Today we consume less energy than we did in 1970, despite the population increase of some 6.5 million – mainly due to a changing economy, moving away from industry.
The UK is now more efficient, both in producing energy and using it.
Household uses 12% less energy while industry uses 60% less – however this has been offset by transport as there’s been a big increase in vehicles and flights.
four different ways the UK hopes to reduce its reliance on fossil fuels
Increasing renewable energy – especially wind and solar
Developing a new generation of nuclear power stations, e.g. Hinkley Point C.
Reduce energy use through technologies such as LED light bulbs.
Recycling energy which would normally be wasted.
Alternative Resources
In order to drastically reduce enhanced climate change, we need to seek alternative resources away from fossil fuels.
Recyclable
Renewable
recyclable
Reprocessed energy
Examples:
Nuclear power
Heat recovery systems
Renewable
These are continuous flows of nature and can be constantly re-used.
Examples:
Biomass Wave and tidal
HEP Wind
Solar Wind
heat recovery systems
- Heat recovery systems work by drawing on that potentially valuable warm air or water in a property and getting it to work just a little bit harder for us.
- Normally, air circulates around an office, becomes stale and is replaced by colder air that it is warmed up by the ventilation system.
- What happens to that already warm, stale air?
- It simply gets expelled into the atmosphere.
- Heat recovery systems don’t replace the need for a boiler or other technology to heat your radiators but it does help them work more efficiently by recycling that warm air ensuring that you get the most out of it.
- A heat recovery system can work via a ventilation system which is positioned at the top of the building.
- Rather than just draw the stale air out and replace it with new stuff, it first of all works to draw the heat from the outgoing air and passes it to the air which is coming in.
The UK energy mix
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- The UK government is very mindful of the need to become energy secure and to play its part in reducing global carbon emissions.
- when it comes to primary energy consumption, while there has been a complete shift away from a direct use of coal, the reliance on oil and natural gas seems to have settled at a rather high level, providing close to 80 per cent of the UK’s primary energy.
- Much of the petroleum is used by transport and most of the natural gas is used to generate electricity.
- Forecasts suggest that this is unlikely to change much in the near future.
- The electricity is in fact ‘primary electricity’ generated by renewable (hydro, wind, solar, photovoltaic and geothermal) and recyclable (nuclear) energy.
