Lecture Notes

The Fossil Fuels:
Lecture #4
HNRT 228 Spring 2013
Energy and the Environment
Why is the term, FOSSIL FUEL used for coal,
oil, gas and lignite?
Because they all contain fossils.
Because they were once food sources for
things that are now fossils.
Because they are derived from living
matter of a previous geological age.
Because of their energy per unit of mass.
Because Prof. Geller said so.
Recall Exercise: Draw a flow map showing
the flow of energy transformations in a
car from starting vehicle to driving. You
should have 5 different types of energy.
Energy Transfer
Oil Exploration and Extraction
Oil is a fossil fuel
formed from the remains of plants and
 died in ancient seas around 300
million years ago
Biota such as plankton fall to the bottom
of the sea and decay
form sedimentary layers
little or no oxygen present
 microorganisms break down the
remains into carbon-rich
organic material mixes with the
sediments to form fine-grained shale,
or source rock
sedimentary rocks layer generate heat
and pressure
 distilled organic material forms
crude oil and natural gas
oil flows from the source rock and
accumulates in thicker, more porous
limestone or sandstone known as
reservoir rock.
When the Earth’s crust moves, the oil and
natural gas is trapped in reservoir rocks,
which are between layers of impermeable
rock (cap rock– usually granite or marble)
iClicker Question
Oil is a fossil fuel formed from the remains of
plants and animals which
formed on another planet billions of
years ago
formed on Earth a few billion years ago
formed on Earth in the past few
thousand years
died on another celestial object around
300 million years ago
died in ancient seas on Earth around
300 million years ago
iClicker Question
Oxygen is required in the formation of oil
in the sedimentary layers
– A
– B
The Search for Oil
Oil companies usually contract
out the search for oil to
exploration geophysicists
Exploration geophysicists utilize
surface features
surface rock
reservoir rock
satellite images
gravity meters
hydrocarbon sniffers
sometimes called electronic
seismometers [most common
technique used]
 shock waves developed
 reflections interpreted
Oil exploration methods are still
only about 10 percent successful
in producing useful well
iClicker Question
What is the name of a scientist who
explores for oil?
– A
oil scientist
– B
exploration geophysicist
– C
petroleum physicist
– D
All of the above
– E
Only A and B above
Once a Site is Selected
Getting the land ready:
The area is surveyed to
determine its boundaries.
Environmental studies are said
to be done.
The land is cleared and then
access roads are built.
Water is drilled if there are no
natural sources available.
A reserve pit is dug to dispose
of rock cuttings and mud. It is
lined with plastic to “protect”
the environment only if the
area is considered to be
“ecologically sensitive.”
Making way for the rig:
Several holes are dug to
make way for the rig
and main hole
A rectangular pit
(cellar) is dug around
the location of the
drilling hole. (This
provides a workspace)
The crew drills a main
Additional holes are dug
to the side to store
iClicker Question
Which of the following instruments is
(are) used to help discover oil?
– A
– B
– C
electronic noses
– D
All of the above (A,B and C)
– E
Only A and B above
Setting Up the Rig
Once the land is ready, several holes are dug to make way for the rig and main
hole. A rectangular pit, called a cellar, is dug around the location of the
actual drilling hole. The cellar provides a workspace around the hole. The
crew then drills a main hole. The following diagram shows how a rig is set.
Directions on drilling
Place drill bit, collar and drill pipe
in the hole
Attach the Kelly (six-sided pipe that
transfers rotary motion to the turntable and
drill string) and turntable
Begin drilling
As drilling progresses, circulate
mud through the pipe and out of
the bit to float the rock cutting
out of the hole
Add new sections (joints) of drill
pipes as the hole gets deeper.
Remove the drill pipe, collar and
bit when the pre-set depth is
anywhere from a few hundred
to a couple thousand feet
Photo courtesy Institute of Petroleum
Confirming the Presence of Oil
After the pre-wet depth is
reached, the workers run and
cement the casing –pipe
sections into the hole to
prevent it from collapsing.
Drilling continues in stages.
When the rock cuttings from
the mud reveal the oil sand
from the reservoir rock, they
may have reached the final
depth. At this point, they
remove the drilling apparatus
from the hole and perform
several tests to confirm the
presence of oil. These tests
are Well logging, Drill-stem
testing, and Core samples.
Photo courtesy Phillips Petroleum Co.
Rotary workers trip drill pipe
iClicker Question
What is a typical drill depth for an oil
– A
Several hundred feet
– B
1000 feet
– C
Several thousand feet
– D
All of the above
– E
Only A and B above
Extracting the Oil
Once the well is completed,
the operators must start the
flow of oil into the well. For
limestone reservoir rock, acid
is pumped down the well and
out the perforations. For
sandstone reservoir rock, a
special blended fuel containing
proppants (i.e. material
suspended in water) is pumped
down the well and out the
perforations. The pressure
from this fluid makes small
fractures in the sandstone
that allow oil to flow into the
well, while the proppants hold
these fractures open. Once
the oil is flowing, the oil rig is
removed from the site and
production equipment is set up
to extract the oil from the
http://science.howstuffworks.com/oil-drilling4.htm 16
iClicker Question
Which of the following is (are) used to
confirm the presence of oil in a well?
– A
Core samples
– B
Well logging
– C
Drill stem testing
– D
All of the above
– E
Only A and B above
Crude oil to Refineries
Oil fields and offshore oil
rigs generally have hundreds
of wells with flow lines that
carry crude oil to the lease
tanks. The crude oil flows
from the wells to the unseen
lease tanks via the flow lines,
where it is accumulated,
sampled and measured prior
to further transportation via
other connecting pipelines.
Oil pipelines are considered
to be a closed system since
the chemicals theoretically
don’t touch the environment,
however leaks in the system
do occur. Also, oil tankers
bring oil to refineries and as
was the case in the Exxon
Valdez disaster, the
environment suffers
Photo Courtesy
tremendously from oil
Environmental Disasters
Tanker Oil Spills
Graphic courtesy of http://www.itopf.com/information-services/data-and-statistics/statistics/#major
iClicker Question
What is the name of the suspension used
to keep fractures in rock open and allow
oil to flow?
– A
– B
fracture suspension
– C
– D
– E
Fractional Distillation
Heat the mixture of two or more substances with
different boiling points to a high temperature. Heating is
usually done with high-pressure steam to temperatures
of about 1112 degrees Fahrenheit/600 degrees Celsius
The mixture boils, forming vapor (gases): most
substances go into the vapor phase.
The vapor enters the bottom of a long column (fractional
distillation column) that is filled with trays or plates.
The vapor rises in the column
As the vapor rises through the trays in the column, it
When a substance in the vapor reaches a height where
the temperature of the column is equal to the substances
boiling point, it will condense to form a liquid.
The trays collect the various liquid fractions
The collected liquid fractions may pass to condensers,
which cool them further, and then go to storage tanks or
go to other areas for further chemical processing.
Further chemical
processing is required to
make various products
– gasoline, lubricating
oils, kerosene, jet fuel,
heating oil, chemicals
for plastics and other
It is possible to change
one fraction into another
through three methods
– cracking, unification,
and alteration.
Cracking takes large
hydrocarbons and breaks
them into smaller ones
iClicker Question
The process by which components in a
chemical mixture are separated according
to their different boiling points, is called
– A
– B
– C
– D
Fractional distillation
– E
Fractional fractionating
Unification is the process
where smaller hydrocarbons
are combined to make larger
ones. The main unification
process is called catalytic
reforming and uses a catalyst
to combine low weight
naphtha into aromatics which
are used in making chemicals
and in blending gasoline.
Alteration: The structures
of molecules in one fraction
are rearranged to produce
another. Commonly this is
done using alkylation- low
molecular weight compounds
are mixed in the presence of
a catalysts such as
hydrofluoric acid or sulfuric
Distilled and chemically processed fractions are treated to:
remove impurities by passing the fractions through the
A column of sulfuric acid
An absorption column filled with drying agents to remove
Sulfur treatment and hydrogen-sulfide scrubbers to remove
sulfur and sulfur compounds
Products From Refined Oil Refraction
gasoline of various
grades, with or without
lubricating oils of various
weights and grades (e.g.
10W-40, 5W-30)
kerosene of various
jet fuel
diesel fuel
heating oil
chemicals of various
grades for making
plastics and other
Oil, Gasoline, Polymers, and Plastics are moved around to
the marketplace in trucks, trains, ships and via pipelines
Tanker trucks hold
around 9,000 gallons
of gasoline
Tanker ships hold
around 1.26 million
barrels of oil
It would take 14 and a
quarter tanker ships
to carry all the oil
that the U.S consumes
in one day
The U.S alone has over
200,000 miles of oil
Photo courtesy of chevron.com
Oil Transportation Issues
Numerous cases of land, ocean and lake spills of
petroleum have occurred all over the world,
causing the irregular operation of petroleum
pumping, fluid transport, tank storage, plant and
refinery, and maritime and truck transport
Spills and leaks of petroleum and refined
products have been detected from: overflowing
tanks, leaking extraction and pumping stations,
ocean tankers and tank trucks.
Petroleum and derivatives have spilled into lakes,
the ocean, and land areas surrounding industry
Loaded tank trucks have overturned, spilling
diesel and gasoline fuel on roads and highways.
iClicker Question
Which of the following are not petroleum
derived products?
– A
– B
– C
jet fuel
– D
– E
None of the above
Gas Stations Leak
Methyl tertiary butyl ether (MTBE) -- a gasoline additive
has been detected in wells, lakes and underground aquifers
across the country
In California (with ~27 million vehicles and over 9,500 gas
stations) MTBE has contaminated some 10,000 shallow
groundwater sites, including 1,000 in the San Francisco Bay
Area. It has been found in dozens of state lakes and
reservoirs, including Shasta, Tahoe and Donner in the north
and Castaic, Pyramid and Perris in the south.
The U.S. Geological Survey has found MTBE in more than a
quarter of the nation's shallow urban wells, as well as in
streams, lakes, rain and snow.
Researchers have found that MTBE can cause cancer in
animals, and they believe it is a potential carcinogen in
human beings.
In South Lake Tahoe, leaks at underground gas station
tanks have caused the water district to close 12 of 34 wells.30
World Oil Consumption
Products Consumed from Oil
Oil Waste
Carbon dioxide is released to the atmosphere
when oil is burned.
Petroleum derived plastics are dumped into
landfills, if not recycled, and can seep into the
soil over time.
An oil well can produce at least 1,500 tons of
toxic drilling muds which are dumped into rivers,
streams and soils.
Wastewater from petrochemical industries can
contain hazardous chemicals.
The average refinery generates 10,000 gallons a
day of waste that contain toxic chemicals known
to cause cancer, birth defects, or breathing
Refineries create an added burden of pollution in
the areas within which they reside.