FOSSIL FUELS: OIL AND
NATURAL GAS (+
UNCONVENTIONAL SOURCES)
Filip Černoch
ESS411 – Environmental aspects of energy
Exploration and production of oil
 Onshore
 Limited impacts – considerable experience, physically limited
possibility of spillage
 Impacts similar to mining operations in non-energy industry –
land use, water and air pollution, dust, noise, transportation
damages of habitats.
 Long history of regulation in the EU and USA
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Exploration and production of oil
Offshore
 Complicated technology increases the risk of accidents and
consequent damages due to the hostile environmental conditions
 Worse impacts of oil spillages (1m3 = spillage up to 1km2)
 Increase in a number of off-shore installations accompanied by
more stringent regulation (2010 Gulf of Mexico - Directive
2013/30/EU on safety of offshore oil and gas operations)
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 Klasická ropa, liší se schopností migrovat v hornině.
 IEA: konvenční ropa: směs uhlovodíků, existující za normálních povrchových
podmínek v kapalném skupenství (vzlínání), nekonvenční ropa je ta, kterou je
třeba získávat za pomocí nekonvenčních technologií, protože v přirozeném
stavu ji nelze (bez zahřívání či ředění) těžit.
 Těžká a velmi těžká ropa
 Bitumen (ropné písky)
 Kerogen (břidličná ropa)
 Ropa z velkých hloubek, biopaliva, ropa získávána konverzí uhlí a zemního
plynu (Fischer-Tropschova syntéza).
 Hranice jsou prostupné.
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Unconventional oil
 = produced or extracted using techniques other than the
conventional (oil well) methods.
 Conventional crude: mineral oil consisting of a mixture of
hydrocarbons of natural origin, exists in liquid form under normal
surface temperatures and pressure, unconventional oil: to be
extracted non-conventional technology is needed, in natural state
(without heating or diluting) couldn´t be extracted.
 Oil sands
 Tight oil
 Oil shale
 Oil produced from coal
 …
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Oil sands, tight oil, oil shale…
 Consistency – extremely dense and viscous, almost solid.
 High level of sulphur and metals (nickel, vanadium).
 Venezuela – Orinoco Belt (1200 bn. barrels = approximately equal
the world´s reserves of lighter oil, 200 billion barrels technically
recoverable)
 Alberta, Canada – reserves of 1700 -250 bn. barrels (11 % of
world oil reserves, 3rd on the world), 99 % oil sands. Export
around 2 mil. barrels/day.
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Producing techniques
 In – situ mining (Oil shale-kerogen). Injecting hot fluids (or steam) into the rock
formation, shale oil is recovered through vertical wells. Increased water and
energy (natural gas) consumption. 2-4 barrels of water/1 barrel of oil, 70-90%
could be recycled. Steam-Assisted Gravity Drainage (SAGD)
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Producing techniques
 Open pit (ex-situ) mining (max 70m) (oil sand-bitumen, also shale
oil). Excavation, when sand is cooped out by power shovels, carried
away, then hot water is used to separate bitumen from the sand. Then
it is refined. 8-10 barrels of water/1 barrel of oil, 40 – 70% could be
recycled. About 2 (but up to 4) tons of material/1 barrel of oil. 1,5x
more GHG then in case of conventional crude oil.
 EROI cca 5:1
 http://www.youtube.com/watch?v=YkwoRivP17A
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Shale gas
 Natural gas (= clean fuel) trapped within shale formations.
 Fracking – combination of horizontal drilling and hydraulic
fracturing.
 High consumption of water, 0,5-2% of injected liquid represents
added chemicals.
 One well – 280 000 hl of water.
 2-4 hectares/1 drilling pad (= up to 30 wells), 3-6km between pads.
 Transport – one well/700-2000 trucks (during installation one car
every 4 minutes)
 Methane leackages, earthquakes.
 https://www.youtube.com/watch?v=Ag9GUogWEa0
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Shale gas
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EROEI of different sources of energy
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Oil in the beginning of oil business 100
Oil in Texas around 1930 60
Oil in the Middle East 30
Other oil 10-35
Natural gas 20
High quality coal 10-20
Low quality coal 4-10
Water power plants 10-40
Wind power plants 5-10
Shale oil 5
PV power plants 2-5
Nuclear energy 4-5
Oil sands max. 3
Shale oil max. 1,5
Biofuels (in Europe) 0,9 - 4
Transport of oil
 Dominated by marine transport (2/3 of world production vs. 1/3
transported by pipelines)
 Liquid bulk carriers (tankers) – 77% of all tankers transport crude,
33 % oil and chemical products.
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Transport of oil
 One of the biggest threats in ship transportation – accident and oil
spill. Intentional accidents (terorism, piracy), unintentional
(accident, collision,, running ashore, failure of the ship).
 Risk is significantly higher in highly frequent areas – in 1995-2005
in Turkish Straits 269 accidents.
 To stop VLCC or ULCC tanker 14 minutes and 3km are needed.
 In 70s there were 25,2 leaks annually, in 80s 9,3 leaks, in 90s 7,8 and
after 2000 3,4 leaks annually.
 But with increasing capacity of tankers the oil spills are more
severe with increasing environmental impacts.
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Oil accidents
 Exxon Valdez – 3/1989 at Alaska, 37 000 tons of oil leaked. Impacts still visible.
 Deep Water Horizon – 2010, at Louisiana. Oil spill almost 10 000 km2.
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Cleanup and recovery
 Bioremediation – use of microorganisms or biological agents
(bacterias) to break down oil
 Controlled burning – air pollution
 Dispersants – to dissipate oil slick.
 Wath and wait.
 Solidifying – changing the physical state of spilled oil from liquid to
a semi-solid.
 Skimming
 = usually no more than 20% of oil is re-captured.
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