1
How are fossil fuels formed, and why are they considered nonrenewable resources? Where are current proven oil and natural gas reserves found, and what is meant by “peak oil”?
INFOGRAPHICS 19.1, 19.2, AND 19.3
What is the correct definition of fossil fuel proven reserves?
Humanmade storage areas for emergency supplies of fossil fuels
Areas where there are known stores of untapped fossil fuels held in reserve for the future
Known sources of fossil fuels that are both economically and technologically recoverable
Sources of fossil fuels that have not yet been discovered but that geologists have predicted to exist
C
The world will reach “peak oil” when:
we have managed to find and tap all oil reserves.
oil production reaches its highest levels and then starts to decline.
we develop techniques to extract oil without environmental damage.
oil can be extracted from all hard-to-reach sources.
B
If oil and natural gas are formed from once-living organisms, why are they considered to be nonrenewable resources?
They are considered nonrenewable because we use them much faster than they are made.
2
How are conventional oil and natural gas extracted? How is crude oil refined and used?
INFOGRAPHICS 19.4 AND 19.5
True or False: On average, 95% to 100% of the oil in a conventional oil reserve can be extracted by using primary, secondary, and tertiary techniques.
FALSE
Examine Infographic 19.5. According to the data, which of the following has the highest boiling point?
Jet fuel
Gasoline
Naphtha
Fuel oil
D
Describe the process of conventional oil extraction, including primary production, secondary production, and tertiary production.
Conventional oil is found underground beneath several layers of rock, and may have layer of natural gas above it. A well is drilled into the oil. Initially, a small amount of oil (5% to15% of what is in the reservoir) flows freely up the pipe because it is released from the pressure of the overlying rock: this is referred to as primary production. To force out additional oil, wells are drilled near to the oil reservoir and water is pumped underground to increase the pressure on the oil reservoir, allowing the oil to be pumped to the surface: this is secondary production and can extract 20-40% of the reservoir’s oil. Eventually, as the supply of oil declines, steam or carbon dioxide are pumped underground to further increase pressure: this is tertiary production which may extract 15% of the oil in the reserve.
3
What are some of the environmental costs of finding, extracting, and using oil and natural gas from conventional reserves?
INFOGRAPHIC 19.6
True or False: If we internalized all the costs of finding, extracting, and using oil, the prices of fuel and petroleum-based products would go up.
TRUE
Burning any fossil fuel generates air pollution, but the fossil fuel that releases the least amount of air pollution when burned is:
coal.
oil.
natural gas.
tar sands oil.
C
Compare the environmental impacts of finding, extracting, and using oil and rank these steps in terms of environmental damage and threats to human well-being. Which step would you address first in an effort to reduce the impact of finding, extracting, and using oil? Why?
Oil exploration can disrupt wildlife and habitats. Extraction can also disrupt wildlife and habitats but generally has a greater impact than the exploration stage. If it occurs near populated areas it can also negatively impact communities, especially if there is an accident. Burning the fossil fuels creates air pollution that is linked to health problems, ecosystem damage, and climate change. “Ranking” answers will vary depending on the weight given to the different impact. Extraction probably exceeds exploration in terms of environmental damage and disruption. If the health or environmental impacts of air pollution are considered worse than the impacts of extraction, then burning might be ranked as the one that causes the most damage.
4
What unconventional sources of oil and natural gas exist, and how are they extracted?
INFOGRAPHICS 19.7 AND 19.8
Why is the United States so interested in extracting tight oil from shale deposits?
It has abundant supplies.
These deposits are easier to extract than conventional oil supplies.
Shipping tight oil is easier and safer than shipping conventional crude oil.
Tight oil deposits are not contaminated with methane.
A
Which unconventional oil currently being commercially produced has the lowest EROEI and the highest carbon footprint?
Tight oil
Tar sands oil
Crude oil
Kerogen shale
B
Explain the process of fracking. Why is fracking used for some oil and natural gas reserves and not others?
In fracking, a well is bored to the level of the shale deposit containing the oil or gas and then is horizontally drilled another mile or so. Steel pipe is placed in the well bore and encased in concrete. Explosive charges are set off in the horizontal well bore to fracture the rock formation then a mixture of water, sand and chemicals is pumped in under high pressure to flush out the oil and gas. The fracking fluid also comes back up; if it is not reused, it must be disposed of as a hazardous waste, usually via injection deep into the ground at a nearby site. Fracking is used to access deep deposits of oil and natural gas that are widely dispersed in impermeable rock formations and can’t be extracted with a normal oil/gas well.
5
What are the trade-offs of pursuing unconventional oil and natural gas sources? What role do you think these resources should play in meeting future energy needs?
INFOGRAPHIC 19.9
True or False: Fracking uses a lot of water, but the wastewater produced is either recycled and used again or purified and pumped back into aquifers.
FALSE
Some homeowners suspect that methane-contaminated water is linked to nearby fracking wells. If this is true, what is the likely source of this contamination?
Leaky pipes near groundwater supplies or improperly handled fracking fluid
The initial drilling of the well
Installation of the well pipes and concrete casings
Detonation of explosive charges in the horizontal sections of the well
A
Distinguish between the actions a country might take when pursuing energy independence versus energy security.
A country that seeks energy independence wants all of its energy supplies to come from its own area but a country that seeks energy security is trying to ensure it has access to reliable and affordable energy supplies — this could include domestic sources but could also include reliable import partners and steps taken to reduce the amount of energy needed in the first place (energy conservation to decrease demand).
Since conventional sources of fossil fuels are running out, do you think accessing our abundant unconventional fossil fuels is the best path the United States or the world can take for energy security? Explain.
Answers will vary. Students may advocate using more or less of these fuels for various reasons but with current technology, these unconventional sources will not provide additional fuel for more than a few decades so they will not provide energy security for the long-term. We would still need to work toward transitioning to alternate fuels and different ways of using energy. We might choose to use them as a bridge fuel to buy time for the transition to alternate fuels, but there are not enough of these fuels to provide our energy needs indefinitely. We might choose to limit our use of these fuels since the environmental impacts of these fuels make them a very risky choice.
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