Crude oil is a liquid mixture of hydrocarbons - molecules made of primarily hydrogen and carbon Oil formed during the Carboniferous Period (between 359.2 and 299 mya), just like coal
What is Oil?
Natural gas is a gaseous mix of hydrocarbons - mainly methane (CH4) It formed at the same time and through the same processes as crude oil, but was subjected to higher heat and pressure, resulting in more complete decomposition of the organic matter in the marine sediment Natural gas is trapped underground within porous rock layers that can sometimes also hold water and oil Natural gas is primarily used to produce heat and electricity
What is Natural Gas?
Most oil and gas deposits can be traced back to shallow seas in the Mesozoic Era (251 - 65 mya) - just after the Carboniferous period of the Paleozoic Era
Where did oil and gas form?
Oil and gas deposits are now richest in Saudi Arabia, Canada, Russia, and Venezuela
How does the formation of coal differ from the formation of oil and natural gas?
- Coal formed before oil + natural gas
- Coal formed from wood, while oil and natural gas formed from marine phytoplankton and zooplankton
- Natural gas and oil are both fossil fuels, while coal is not
- Coal formed relatively recently, while gas and oil take millions of years
Given what we know about coal, oil, and natural gas: Why are these resources considered "non-renewable"?
Oil and natural gas are both extracted through drilling Since oil and gas are sometimes found in the same deposit, they are often extracted at the same time In 1997, a process called
Extraction
Which of the following is a correct statement about the environmental hazards associated with hydraulic fracturing ("fracking")?
- Fracking only poses risks to the immediate surroundings of the drill site
- Fracking impacts ground stability, but does not affect local groundwater
- Fracking fluid is mostly water and completely harmless to the environment
- Fracking can contaminate groundwater and may increase the frequency of earthquakes in areas near the drill site
Hydraulic fracturing was afforded many exemptions to important environmental laws developed to protect environmental and human health: Resource Conservation and Recovery Act - fracking fluid and wastewater are exempted from being classified as hazardous waste Safe Drinking Water Act - Fracking fluid can be injected below the water table Clean Air Act - Drilling operations are fully exempted from this law National Environmental Policy Act - Environmental impact studies are not required before drilling
Fracking and Legislation
Oil and natural gas are both transported globally by pipeline, tanker truck, and supertanker ship Transportation is required both to move products between extraction sites and refineries, and from refineries to homes or commercial sale points
Transportation of Oil and Natural Gas
Exit Ticket: Why is it important to reduce our reliance on fossil fuels? Provide examples that reference both environmental and human health impacts.