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The Fossil Fuels:Oil Lecture #4 HNRS 228 Energy and the Environment
Why is the term, FOSSIL FUEL used for coal, oil, gas and lignite?A Because they all contain fossils.B Because they were once food sources for things that are now fossils.C Because they are derived from living matter of a previous geological age.D Because of their energy per unit of mass.E 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 Sound (mechanical) Electrical Thermal Mechanical Electrical Chemical Electrical Light (Electromagnetic)
Oil Exploration and Extraction • Oil is a fossil fuel • formed from the remains of plants and animals • 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 compounds • 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) http://www.energyquest.ca.gov/story/chapter08.html
iClicker Question • Oil is a fossil fuel formed from the remains of plants and animals which • A formed on another planet billions of years ago • B formed on Earth a few billion years ago • C formed on Earth in the past few thousand years • D died on another celestial object around 300 million years ago • E 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 True • B False
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 entrapment satellite images gravity meters magnetometers hydrocarbon sniffers sometimes called electronic noses seismometers [most common technique used] shock waves developed reflections interpreted Oil exploration methods are still only about 10 percent successful in producing useful well http://science.howstuffworks.com/oil-drilling2.htm http://science.howstuffworks.com/oil-drilling1.htm
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
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.” 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 hole Additional holes are dug to the side to store equipment Once a Site is Selected Getting the land ready: Making way for the rig:
iClicker Question • Which of the following instruments is (are) used to help discover oil? • A seismometers • B magnetometers • 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. http://science.howstuffworks.com/oil-drilling2.htm
Drilling 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 reached • anywhere from a few hundred to a couple thousand feet Photo courtesy Institute of Petroleum http://science.howstuffworks.com/oil-drilling1.htm
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 pipehttp://science.howstuffworks.com/oil-drilling4.htm
iClicker Question • What is a typical drill depth for an oil well? • 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 well. http://science.howstuffworks.com/oil-drilling4.htm http://science.howstuffworks.com/oil-drilling4.htm
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 tremendously from oil production. Photo Courtesy http://response.restoration.noaa.gov/photos/exxon/exxon.html
Environmental Disasters Statistic courtesy of http://www.itopf.com/stats.html
iClicker Question • What is the name of the suspension used to keep fractures in rock open and allow oil to flow? • A crackant • B fracture suspension • C flowant • D fracturant • E proppant
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 cools. • 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 polymers 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 http://science.howstuffworks.com/oil-refining5.htm
iClicker Question • The process by which components in a chemical mixture are separated according to their different boiling points, is called • A Distillationism • B Fractionation • C Fractioning • 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 acid. http://science.howstuffworks.com/oil-refining5.htm http://science.howstuffworks.com/oil-refining5.htm
Distilled and chemically processed fractions are treated to: remove impurities by passing the fractions through the following:A column of sulfuric acidAn absorption column filled with drying agents to remove waterSulfur treatment and hydrogen-sulfide scrubbers to remove sulfur and sulfur compounds http://science.howstuffworks.com/oil-refining3.htm
Products From Refined Oil Refraction • gasoline of various grades, with or without additives • lubricating oils of various weights and grades (e.g. 10W-40, 5W-30) • kerosene of various grades • jet fuel • diesel fuel • heating oil • chemicals of various grades for making plastics and other polymers http://science.howstuffworks.com/oil-refining6.htm
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 pipelines 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 facilities. • 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 facilities. • 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 gasoline • B kerosene • C jet fuel • D plastics • 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.
World Oil Consumption http://people.hofstra.edu/geotrans/eng/ch5en
Products Consumed from Oil http://www.eia.doe.gov/kids/non-renewable/oil.html
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 problems. • Refineries create an added burden of pollution in the areas within which they reside.