p6 Flashcards
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
A
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.