2.5 - Deep Water Oil Extraction Flashcards
1
Q
How is fracking done?
A
- Bell bore (hole) drilled through layers of sediment
- to a depth of 2000-3000m
- then horizontal drilling for 1.5km through shale rock formation
- to a depth of 2000-3000m
- Perforation gun is fired, creating holes in rock layer
- Fracking fluid is pumped through well at high pressure
- cracks shale rock, gas + oil escapes through fractures
2
Q
What concerns are there with fracking?
A
- wells are supposed to be encased in steel and concrete or prevent fracking fluid from leaking out
- if not done well, fluid can leak into groundwater
- methane can also leak out with fluid
- is a problem as methane is a potent GHG
- can create localised earthquakes
- wastewater can contain radioactive substances and heavy metals
3
Q
What is the fracking fluid made of?
A
- 90% water
- on average a pit 3-6 million gallons of water
- rest is made up of concentrated additives:
- acids
- friction reducing compounds
- sand and clay
- allows for fissures to remain open, even after pressure is released allowing for extraction
4
Q
How does fracking create earthquakes?
A
- cracking of rocks can result in failure lines being introduced
- grow and spread over time
- may result in brittle rocks failing causing earthquakes
5
Q
What methods are used to exploit tar/oil sands?
A
- If bitumen is within 75m of surface, it is open pit mined
- clears a large amount of land
- only 20% of tar sands are found here
- Bitumen below 75m is extracted using in situ/underground methods
6
Q
How does open pit mining work?
A
- clumps of oil sands are taken to crushers to be broken up
- is mixed with heated water to separate the bitumen from sand
- sent for further processing
7
Q
How does in situ extraction work?
A
- two sets of parallel horizontal wells are dug
- steam is pumped underground through one set of horizontal wells
- this liquifies the bitumen underground, causing oil to collect in second well
- bitumen is then pumped to surface through second set of horizontal wells
- extracted bitumen is then upgraded to have similar properties to oil
- refined to create petroleum products
8
Q
What downsides are there with open pit mining?
A
- is guaranteed to remove vegetation
- can interfere with land belonging to indigenous groups
9
Q
How many drilling wells are in the Gulf of Mexico?
A
- 3400
- reach more than 150m below sea level
- drilling rigs can be moved, are not fixed
10
Q
Who owned Deepwater Horizon?
A
- TransOcean
- leased to BP to drill in US waters
- was a semi-submersible rig
11
Q
What is the price of deepwater oil?
A
- $50 per barrel
- vs $2> for Middle Eastern oil
12
Q
What happened to the Deepwater Horizon?
A
- oil rig exploded as methane gas was released
- collapsed and sank into Gulf of Mexico
- 11 killed
- 17 injured
13
Q
How much oil was released by Deepwater Horizon?
A
- 4.2 million gallons
- resulted in 8,332 species (marine animals and birds) becoming at risk
- continuous leak for 87 days
14
Q
What was the economic cost of Deepwater Horizon?
A
- massive impact on Louisiana’s $2.4bn fishing and coastal tourism industry
- TransOcean received $401m from insurance companies
- BP were fined up to $20bn
15
Q
What are the economic costs of deepwater oil extraction?
A
- technical complexity can result in high costs of extraction
- costs are carried over to price of deepwater oil which may make it uncompetitive with conventional oil and gas
- especially when oil price is very variable
- disputed areas such as the Arctic can lead to political conflict
- this also may have economic costs such as investment in military power to exert control over claimed areas
