Chapter 7 Fundamentals of Energy

Fossil Fuels and Nuclear Energy

Oil and Natural Gas

Oil and Natural GasPetroleum or crude oil, is not a single chemical compound

Liquid petroleum, or oil, comprises a variety of liquid hydrocarbon compounds, which are made up of long molecular strings of carbon and hydrogen

There are also a variety of gaseous hydrocarbons, collectively called natural gas, of which the compound methane (CH4) is the most common

How is Petroleum Created? Most geologists believe that crude oil and natural gas are the product of compression and heating of ancient organic materials over long geological time

According to this theory, oil is formed from the preserved remains of prehistoric zooplankton and algae which have settled to the ocean bottom and are buried in large quantities under anaerobic conditions (no oxygen)

How is Petroleum Created? Over geological time this organic matter, mixed with mud, is buried under heavy layers of sediment

As burial continues, the pressure and the temperature both increase, and chemical changes begin to occur

The large, complex organic molecules are slowly broken down into long chains of hydrocarbon molecules, which have the consistency of asphalt

How is Petroleum Created? Specifically, the organic molecules change into a waxy material known as kerogen

With time and if the kerogen is subjected to increased pressure and heat, it is further changed into liquid and gaseous hydrocarbons in a process known as catagenesis

How is Petroleum Created?

A Texas Oilman would say, the petroleum “matures”

It successively changing from “heavy” long hydrocarbon molecules into “light” simple gas and oil molecules

The thick liquids become progressively thinner and more valuable or “sweeter” because it requires less processing at the oil refinery

How is Petroleum Created?

Most of the maturation process occurs between 50o to 100o C (120o to 210o F)

At higher temperatures the hydrocarbon converts to methane gas

The Time Factor

The amount of time it takes to create petroleum is not precisely known

However, petroleum is not found in rock that is younger than 1 or 2 million years old

So, this is a slow process which takes million of years

This means that we are using up oil much much faster than it can be replaced by nature

We have essentially a finite supply of oil, then it will be gone

Oil and Gas Migration

We want to extract the oil

But the majority of the petroleum source rocks are fine-grained sedimentary rocks of low permeability

The petroleum is spread throughout the rock and it is hard and uneconomical to extract large quantities of oil or gas quickly

Oil and Gas Migration

To become economical, two things need to happen:

The gas and/or oil must migrate out of the source rocks into more permeable rocks, which is called the reservoir rock

And eventually, a large quantity must become concentrated and confined into a petroleum trap beneath an impermeable layer called a cap rock

Types of Petroleum Traps

(A) A simple fold trap (B) fossilized coral reef (C) fault trap (D) salt dome

Hydrocarbon Uses

A given oil field may contain a variety of hydrocarbon compounds and these different compounds have different uses

Oil, gas and methane can all be found together

Enhanced Oil Recovery

Some of the first oils wells were gushers, where the oil behaved like water in an artesian well

Extracting oil using no techniques beyond pumping is called primary recovery

This will only remove part of the oil deposit, usually a third or much less

However, on the average, two-thirds of the oil is left in the ground

There are many secondary recovery techniques that allow addition oil to be extracted

When flow falls off, water can be pumped into the reservoir rock, filling empty pore space and buoying up more oil

Or you can pump in steam

Or explosives can be set off in the oil zone, fracturing the rock and increasing permeability

Or carbon dioxide gas can be pumped in

Enhanced Oil Recovery

Secondary recovery can allow up to an additional 40% of the known oil reserves to be extracted

All of these secondary recovery methods add to the cost of oil extraction

Enhanced Oil Recovery

U.S. Energy Consumption The U.S. produces a staggering amount of energy per year, and about 80% of that energy currently comes from the fossil fuels coal, natural gas and oil

U.S. Energy Consumption The U.S. is the number one consumer of energy in the world and that consumption is rising

We now use 100 quadrillion of BTUs per year

BTU

In the United States, the term BTU (British Thermal Unit) is used to describe the energy content of fuels

A BTU is defined as the amount of heat required to raise the temperature of one pound of water by one degree Fahrenheit

143 BTU is required to melt a pound of ice

BTU One quadrillion BTU is:

1,000,000,000,000,000 BTU

That is a 1 followed by 15 zeros

It would take over 31 million years to count to a quadrillion at the rate of one number per second

But we are talking about 100 quadrillion

Supply and Demand

Oil is commonly discussed in quantities of barrels, where one barrel equal 42 gallons

Worldwide, over 500 billion barrels of oil has been consumed

Unfortunately, half of that consumption occurred over the past 25 years

The estimated proven oil reserves are about 1 trillion barrels

Or about 50 years at the current rate of use

Proven World Oil Reserves 2008Crude oil reserves in billions of barrels as of June 2008

Note that the Middle East has more oil than the entire rest of the world combined

Major World UsersLike other resources, petroleum sources are very unevenly spread around the world

For example, high-tech, densely-populated Japan has no oil, and must import 100% of the oil it needs

Imported oilMore than half of the oil consumed by the U.S. has been imported

Principle sources were Saudi Arabia, Venezuela, Canada and Mexico

Imported oilIn 1973, the U.S. dependence on foreign oil became a major political and strategic military concern, when OPEC shut off oil supplies

OPECThe Organization of Petroleum Exporting Countries (OPEC) is a cartel of twelve countries made up of Algeria, Angola, Ecuador, Iran, Iraq, Kuwait, Libya, Nigeria, Qatar, Saudi Arabia, the United Arab Emirates and Venezuela

OPECOPEC nations control two-thirds of the world's oil reserves and currently produce 36% of the world's oil, affording them considerable control over the global market

Strategic Petroleum Reserve

The Strategic Petroleum Reserve was established in 1977 to store about 550 million barrels of oil for military & emergency use

This was equal to a 115 day supply for 1977

Strategic Petroleum Reserve

As of January 22, 2009, the current inventory was 702.8 million barrels

This equates to 33 days of oil at current daily US consumption levels of 21 million barrels a day

U.S. Oil Supplies

The U.S. originally had about 10% of all the world’s oil supply

The U.S. has consumed over 200 billion barrels of oil

U.S. Oil Supplies

We currently consume about 7 billion barrels a year

For the past three decades we have been discovering new oil in the U.S. as fast as we were consuming

But...

Declining Yields

For land or offshore, the average yield from producing wells in the U.S. is declining, from a peak of 18.6 barrels per well per day in 1972 to 10.9 barrels in 2000

Declining YieldsThe total daily amount of oil produced in the U.S. has been steadily declining and is predicted to continue to decline

Hubbert’s Peak

M. King Hubbert was an oil man who predicted in 1956 that oil production would follow a bell curve

He was ostracized by the entire oil industry

The main counter argument was that we were just beginning to use modern exploratory methods and we simply had no idea how much oil existed on Earth

The “sky was not falling!”

He was right. Well kind of....

Hubbert’s Peak

Future Oil Prospects

Many people think that as oil prices soar, there will be increased exploration and discovery of new reserves

There is a finite amount of petroleum in the ground and we have found most of it

Two-thirds of new exploratory wells come up dry

The days of the gushers are over

Future Oil ProspectsIt is now very expensive to drill an exploratory oil well on land

It cost typically $2 to $20 million dollars per well

Future Oil ProspectsThe costs for drilling offshore are substantially higher, easily over $100 million and up

Drilling oils wells in the deep, abyssal plains of the open ocean may cost billions per well

U.S. Natural Gas UseThe supply and demand picture for natural gas is similar to that for oil

Natural gas provides about 25% of the energy used in the U.S.

Until recently, it was believed that the U.S. has 200 trillion cubic feet of proven reserves

And we import 15% of our natural gas

Natural Gas Reserves 2004Natural gas reserves are more widely distributed

Natural Gas Reserves 2008The Western Hemisphere, especially the United States, contains substantial proven reserves of natural gas

Burning Gas at the Well Head

Note the bright lights in the Gulf

Very Deep Natural Gas

At these depths, all petroleum molecules have been broken down into natural gas

The gas is under tremendously high pressure and is typically dissolved into fluids such as saline brines

The gas occurs in “oil shale”

Deep exploratory wells have recently discovered that tremendous natural gas reserves exist at depths of several thousand feet

Oil ShaleOil shale is a generic name for rock that contains petroleum

Oil shale is a misnomer

The rock does not have be shale, it can be any of a variety of sedimentary rocks, such as sandstone or limestone

There is actually so little oil in oil shale that it is useless

Rather, the potential fuel in oil shale is natural gas

Distribution of Oil Shale The U.S. has what is believed to be the second largest known oil shale deposits in the entire world (China may be first)

In the long run, this could provide a staggering amount of natural gas

Marcellus Shale The Marcellus Shale is a type of oil shale that is found through out the Eastern United States along the Appalachian Mountain range

It is estimated to contain 500 trillion cubic feet of natural gas

This could meet U.S. energy needs for a very long time

One of the extraction problems is that the Marcellus Shale ranges from 3000 to 9000 feet in depth below the surface

Marcellus Shale

FrackingRecent advances in horizontal drilling techniques and hydraulic fracturing (called fracking) have made removing natural gas from the Marcellus Shale both possible and economic

Ban Hydraulic Fracturing

Facebook.com “Arguments against hydraulic fracturing center around the extent to which fracturing fluid used far below the earth's surface might pollute fresh water zones, contaminate surface or near-surface water supplies, impact rock shelf causing seismic events or lead to surface subsidence...”

UT & Fracking

News Sentinel [Dec. 2, 2012] “The University of Tennessee plans to drill for natural gas in its research forest in Morgan and Scott counties, a proposal that would allow UT to lease its land to an oil and gas company and the study the environmental impacts of hydraulic fracturing...”

U.S. Natural Gas Reserves

In the past four years, the United States has increased its production of natural gas by 27%

By 2020, the United States is expected to be the number one producer of natural gas in the entire world

Burning Ice

Methane clathrate, also called methane hydrate or methane ice, is a solid form of water that contains a large amount of methane trapped within its crystal structure

Burning IceAbout 10 years ago, it was discovered that extremely large deposits of methane clathrate occur under sediments on the ocean floors, usually along the coastlines

Burning Ice

The size of these oceanic deposits is staggering

For example, it has been estimated that over 1 quadrillion cubic feet of methane ice lies offshore of North and South Carolina alone

There is more methane ice than all other fossil fuels combined

Burning Ice

Methane is a far more efficient greenhouse gas than carbon dioxide

The amount of methane locked in methane hydrates is estimated to be 3000 times more than is currently in the atmosphere

Can global warming melt these methane ice deposits?

This would profoundly increase the greenhouse effect

La Brea Tar Pits

The Rancho La Brea Tar pits are a famous series of natural tar (asphalt) pits in Los Angeles

La Brea Tar PitsPools of water covers the sticky tar, and for thousands of years, animals who tried to drink the water became trapped in the tar, creating a treasure trove of fossils

The predators who fed on the trapped prey, also became trapped

La Brea Tar PitsSince 1901, over one million bones of Pleistocene animals have been removed by paleontologists, including saber-toothed cat and giant sloth

Oil Spills on land

In general, oil spills on land are small and confined

Pipe line ruptures, train wreaks, tanker truck accidents and illegal waste dumping are the most common sources of spill

This spill in Siberia was burned off, but that creates airborne oil-smoke pollution

Casualty of Warfare

In July 2006, Israel attacked the Hezbollah in Lebanon

In the first week of the conflict, Israeli fighter planes struck the Jiyyeh power plant just south of Beirut

The attack set ablaze five oil tanks and caused a 110,000 gallon fuel oil spill along the eastern Mediterranean coast

Casualty of Warfare

A bad day at Beirut’s beaches

Casualty of Warfare

Because of the conflict, serious oil cleaning did not start until September, two months after the bombing

The biggest losers were the endangered green sea turtles that could not lay that year’s clutch of eggs along the Lebanon beaches

Casualty of Warfare

During the first Iraq war, Sadam had his retreating troops set over 800 oil wells in Kuwait on fire

Casualty of Warfare

The fires consumed an estimated six million barrels of oil daily

Their immediate consequence was a dramatic decrease in air quality, causing respiratory problems for many Kuwaitis

Casualty of WarfareThe sabotage of the oil wells also impacted the desert environment, which has a limited natural cleansing ability

Oil from the wells formed about 300 oil lakes that contaminated around 40 millions tons of sand and earth.

Oil and Water Don’t Mix

The news concentrates on major spills, but most oil spills are small, but in the course of a year, they can add up

The U.S. Coast Guard reports that there are about 10,000 oil spills in U.S. waters each year, totaling 15 to 25 million gallons

It is estimated that 600,000 tons of oil per year naturally escapes from permeable rocks into the oceans

Oil and Water Don’t Mix

When an oil spill occurs at sea, the oil, being less dense than water, floats

The lightest, most volatile hydrocarbons start to evaporate immediately, causing air pollution

Over several months, sunlight and bacteria action, can destroy up to 85% the oil, leaving thick asphalt lumps that can persist for many months

Oil and Water Don’t Mix

If a spill is small, it can be contained by floating barriers, and the oil skimmed off of the surface

Chalk, wood shavings and peat moss have been used to soak up oil

In big spills, detergent is added to the oil to speed up decomposition, but detergent is toxic to fish and birds

Oil and Animals Don’t Mix

Oil is toxic to marine life, causes water-birds to drown when their feathers become coated and decimates fish and shell fish populations

Oil and Animals Don’t Mix

Feathers can be cleaned of oil using soap and water, but it is very traumatic to the bird

The survival rate is low

IXTOC 1 Oil Well

Ixtoc I was an exploratory oil well platform in the Gulf of Mexico, about 600 miles south of Texas

On June 3, 1979, the well suffered a blowout and became the largest unintentional oil well spill in history

IXTOC 1 Oil Well

The oil caught on fire and the drilling platform collapsed

140 million gallons of oil spilled out into the Gulf

The well was finally capped on March 23, 1980