geo 304 midterm 2

what are the conventional fossil fuels

coal, oil and gas

what are the unconventional fossil fuels

tar sands and heavy oil, oil shale (shale gas), coalbed methane and methane hydrate

what is the carbon cycle

CO2 + H2O + sunlight = plant material, when you bury plant material into the ground everything gets separated and the water squeezes out of the plants which leads to coal formation

What are the setting conditions and necessary organic material for the formation of coal

swampy/wetland environment, anoxic (oxygen-poor) water, deep burial under sediments

what does anoxic water composition do

prevent decomposition of plant material

what are the stages of coal formation

peat, lignite, bituminous, anthracite

what is peat coal

similar to dirt, makes thick smoke (has lowest energy content) and most water is squeezed out and has hydrogen/oxygen removed

what is lignite coal

soft brown coal

what is bituminous coal

high energy content of soft coal and only has a internal difference with anthracite

what is anthracite coal

metamorphic hard coal, shiny and dust free and has high energy content (underwent metamorphism and has an internal arrangement)

what is the majority type of coal we use today

Bituminous coal

What is the significance of Pangea and carboniferous era

had massive coal formation, significant atmospheric changes and led to the origin of fossil fuels

what is surface mining

A method of mining mineral deposits located on or near the surface of the earth. Done in the USA and more safe and has a better recovery of coal (90%). Has more consequences to land and enviorement

What is room and pillar mining?

removing large open rooms between the intact pillars

what is strip mining

removal of overburden along one trench then mining coal from bottom of a trench and depositing the overburden from next trench to previous trench

where does contour mining happen

in hilly areas

what is contour mining

following coal seam and mining around the perimeter of hill

what is mountain top mining

removal of actual mountain top to get to the coal bed. has possibility of releasing carcinogenic chemicals and is a clean water act violation

what is underground mining

Mining under the ground with miners under the ground and not just machines

what are the risks of underground mining

expensive, dangerous, possibility of explosive and poisonous gasses, requires access through elevators and shafts, needs ventilation

what is a stope

part of the mine that is actually being mined and removed

what do underground mines have

shafts vertically and adits opening up to the surface

where does hydrocarbon formation happen

on shallow ocean floor or lakebed

what is the order of hydrocarbon formation from liquid to vapor

biogenic methane, kerogen "on the way" stage, oil generation, oil and gas generation, thermogenic gas generation + C-residuum = natural gas of methane

what are the depositional setting requirements

not be able to decompose, no hydrocarbons can be generated and requires anoxic enviorement

what is hydrocarbon formation burial depth

2-3km burial depth

what is diagenesis

conversion of sediment into rock and occurs at surface to few 100m deep (50 Celcius), microbial activity releases abundant biogenic gas

what is catagenesis

happens deeper than diagenesis and is the conversion of organic material (like kerogen) into hydrocarbons. occurs at 50-150 Celcius and down to 4km deep

what is catagenesis also known as

cracking

what is cracking

the breakdown of big pieces into smaller pieces

what is organic material cracked into

kerogen, then liquid petroleum, and thermogenic gas forms during cracking of organic molecules

what is the different hydrocarbon names

petroleum, crude oil, natural gas

what is the formula for methane

CH4

what is the formula for liquid/gas form

CxH2x+2

what is the state of matter for methane

gas

what is ethane formula

C2H6

what is propane formula

C3H8 (can also be kept in liquid but preferes vapor state)

what is butane formula

C4H10

what is pentane formula

C5H12

what is hexane formula

C6H14

what is heptane formula

C7H16

what is octane formula

C8H18

what is nonane formula

C9H20

what is decane formula

C10H22

what are the more thicker viscous liquids/big enough molecules

tar, apsalt, bitumen

what is viscosity

the resistance to flow

what are the 3 names for methane

methane, natural gas, CH4

What is a source rock?

organic material such as phytoplankton and algae deposited into muddy sedimentary rocks (such as shale)

what is reservoir rock

a rock that has a porosity and permeability to transmit fluids. it is where petroleum migrates

what is caprock

an impermeable rock layer that forms the seal on top of an oil or gas reservoir and prevents petroleum from rising farther up

what is a trap

brings and transports oil in one concentrated spot

what is the correct order of oil depost formation

1- source rock

2- reservoir rock

3- caprock

4- trap

what are the characteristics of an anticline

arch shaped, easy to find, rock layers dipping off to the east, has horizontal layers

what is the most desirable shape for a trap

a anticline

how do you indicate something is an anticline

if there is a back and forth dipping pattern

what are the other types of traps

fault trap, salt dome trap, and stratigraphic/unconformity trap

what is a fault trap

A geological formation where oil and gas collect in tilted strata adjacent to a fault. It has reservoir rock surrounded by impermeable layers

what is a salt dome trap

A trap formed when deeply buried salt flows upward, deforming overlying strata. forms in mezozoic areas and has much lower density

where do salt dome traps form

underground, 1km-2km deep

why doesn't oil flow through salt or dissolve

because it's impermeable

what is a stratigraphic/unconformity trap

an erosion in surface that represents missing time based on deposition occurring

what is a shot point

a pulse of energy being released into the earth

what is a reflector

a change in one rock type to another

what does oil expoloration look for

energy to go down into the earth, hit a change in conditions and have enough energy to have a reflection of thumped energy off of rock layers

what do you get with oil exploration

a series of pulses of energy from 1 shot point to 40 geophones

what is primary recovery

oil coming to surface by actual reservoir pressure (is around 25%)

what is secondary recovery

used after reservoir pressure drops too low (on average 25%)

what are the timings of major oil productions in USA

- Pennsylvania 1859 (Titusville and Oil creek)

- Texas 1901 (Spindletop)

- California 1920s (Signal Hills)

- ALaska 1988

what is ANWR

Arctic National Wildlife Refuge

what is the amount of oil in ANWR

around 10 billion barrels, 15 month supply

what is the amount of oil the USA uses every year

7.6 billion barrels

what is the deepwater horizion

the oil spill that happened in Louisiana in 2010 and spilled into the Gulf of Mexico and affects are still happening today

vertical drilling

most drilling was done this way until 1990's because it was the most profitable and best way to get resources they needed

directional drilling

more expensive than vertical drilling but it is less expensive than starting a new well

what led to directional drilling

in the 1990's companies created drill bits that have control over direction and speed, can drill vertically and then rotate 90 degrees

what can directional drilling do

cut through multiple reservoir layers at a time

what is hydraulic fracturing

the use of breaking down rocks with the use of fluid or water under pressure

what are the environmental risks for hydraulic fracturing?

methane emissions, water depletion, groundwater contamination, wastewater disposal, uses small amounts of explosives

what does fracturing fluids do

it goes into the wells and finds and pushes it into the cracks of the rock to open up a pathway for gas to migrate out

what is marcellous shale

natural gas shale bed part of the Appalachian mountains. it is 7,000ft deep underground and doesn't get exposed to the top besides a few isolated spots around the edges

what is the history of new york policy DEC

no new hydraulic wells are allowed to be made and there can only be work done on the current wells as of 2015

what is the issue in NYS with hydraulic fracturing and marcellous shale

the hydraulic fracturing and Marcellus shale are right next to each other so in order to get to the Marcellus shale it would impact 8+ million people

what are the natural gas sources

thermogenic and biogenic gas

bridge fuel

lowers up to half of CO2 emissions compared to burning coal; use of natural gas means inevitable leaks of natural gas in the athmosphere

what is tar sands/heavy oil

largest molecule hydrocarbon. has missing cap and trap layers (sometimes one or the other, sometimes both)

what is Oil shale (shale gas)

rocks that have been mined or heated to extract oil. there is no reservoir layer for hydrocarbons to move so it stays in the shale and has low energy return

what is coal bed seems

areas where there are coal seems and only the methane is taken out and the coal is left behind

what is methane hydrate

methane that is trapped in a slushy ice cage and is in the ocean floor sediments. it wouldn't become oil or gas deposits but some organic material that breaks down into methane