ESL Basic Facts
ESL Lesson 1
Oil in Our Every Day Life
ESL Lesson 2
The History of Mining
ESL Lesson 3
Economic growth
ESL Lesson 4
Delivery Systems
ESL Lesson 5
Cities and Population Movement
ESL Lesson 6
Recycling
ESL Lesson 7
Rubber
ESL Lesson 8
Farming
What is crude oil?
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Crude oil - petroleum directly out of the ground - is a remarkably (amazingly) varied substance,
both in its use and composition (what it is made out of). It can be a straw-colored liquid or tar-
black solid. Red, green and brown hues (colors) are not uncommon. In addition, not all crude oils
behave in the Hollywood manner (do the same thing) shooting into the air (gusher), some flow
about as well as cold peanut butter.
Several historical factors (events at that time in history) changed that. The kerosene lamp, invented in 1854, ultimately created the first large-scale demand for petroleum. Kerosene first was made from coal, but by the late 1880s most was derived (made from) from crude oil (black oil from the ground). Petroleum was used mostly for its yield (total given amount) of kerosene until the turn of the century (100 year period). Gasoline was burned off, and bitumen and asphalt (the heavier parts of crude oil) were discarded (thrown away). But gradually becoming more important were the incandescent light (electric light bulb) and the internal combustion engine (motor engine). The incandescent light relied (depended) on oil-fired generating plants, the internal combustion engine on gasoline.
Geologists generally agree that crude oil was formed (made) over millions of years from the remains of tiny aquatic (water) plants and animals that lived in ancient seas. But petroleum owes its existence (is around because) largely (mostly) to one-celled marine (seawater) organisms. As these organisms died, they sank to the sea bed (sea floor). Usually buried with sand, mud and gravel, they formed a layer that eventually turned to sedimentary rock (sandstone and shale for example). The process (steps to make something happen) repeated itself, one layer covering another. Then, over millions of years (1,000,000), the seas withdrew (went away). In lakes and inland seas, a similar (almost the same) process took place with deposits formed of non-marine (fresh water or dry land) vegetation (plants). Bacteria broke down the trapped preserved plants and tiny organisms, molecule by molecule, into substances (matter) rich in hydrogen (H) and carbon (C) (hydrocarbons). Increased pressure (pushing force) and heat from the weight of the rock layers above caused the organic remnants (leftover plants and tiny organisms), ever so slowly (extremely slowly) to transform (change into), into crude oil and natural gas. The oldest oil-bearing rocks (oil inside the rock) date back more than 600 million years, the youngest about 1 million. However, most oil fields have been found in rocks between 10 million and 270 million years old.
Sub-surface (below the ground) temperature, which increases with depth (the deeper it is the hotter it is), is a critical factor (one of the most important parts) in the creation of oil. Petroleum hydrocarbons (crude oil and natural gas) rarely (hardly ever) are formed at temperatures less than 150 degrees Fahrenheit and generally (usually) are destroyed at temperatures greater than (above) 500 degrees. Most hydrocarbons are found at "moderate" (medium) temperatures ranging from 225 to 350 degrees.
Some crudes (crude oils) from Louisiana and Nigeria are similar because both were formed in similar (same type of) marine environments. In parts of the Far East, crude oil generally (usually) is waxy, black or brown, and low in sulfur. It is similar to crudes found in central Africa because both were formed from non-marine sources. In the Middle East, crude oil is black but less waxy and higher in sulfur. Crude oil from Western Australia can be a light, honey-colored liquid, while that from the North Sea typically is a waxy, greenish-black liquid.
Sweet and Sour Crude
Not all the black gooey stuff that comes out of the ground is the same. Crude oil produced by different fields differs in viscosity (how thick or thin an oil is) and sulfur content (percentage of natural element Sulfur in the oil). The more viscous (thicker and slow flowing) crudes are called "heavier," and those with higher sulfur content are called "sour" as opposed to low-sulfur called "sweet" and thin easy flowing called “light” crude. The heavier and more sour the crude, the more difficult and expensive it is to turn into usable refined products (finished oil product). The price of oil you usually hear quoted is the price of a “light”, “sweet” grade like West Texas Intermediate, Saudi and Middle Eastern types and Brent Sea.
One factor (cause) contributing (adding to) to the dramatic increase (remarkable increase) in the price is a decrease (decline) in the supply of light, sweet crude. The higher quality crude supplies of course get used up first (because it produces a lot of gasoline per barrel), so the world is now increasingly reliant (depending more and more on) on a lower quality product. Over the last five years, the average API gravity of non-OPEC oil production has decreased (crude being pumped is increasingly "heavy") and the sulfur content has increased (crude is increasingly "sour").
Crude oil is classified as Light, Medium/Intermediate or Heavy, according to its measured API gravity. API measures the specific gravity of liquids less dense (lighter) than water. Does oil pour like honey, thick or does it pour like water, thin? Light crude oil is defined as having an API gravity higher than 31.1 °API Medium/Intermediate oil is defined as having an API gravity between 22.3 °and 31.1 °API Heavy crude oil is defined as having an API gravity below 22.3 °API. Oil which will not flow at normal temperatures or without dilution (thinning out with other substance) is named bitumen and the API gravity is generally less than 10 °API. Bitumen derived from (coming from) the oil sands deposits in the Alberta, Canada area has an API gravity of around 8 °API. It is 'upgraded' (made thinner with heat and other chemicals) to an API gravity of 31 °API to 33 °API and the upgraded oil is known as synthetic oil (syncrude).
OPEC's 2005 August Oil Market Report calculates (estimates) that global production of light, sweet crude actually declined between 2000-2004, and peak oil has already passed, at least as far as light, sweet crude is concerned.
The third critical (most important) ingredient is refining capacity (what type of oil and the amount of oil that can be made into other products). British Petroleum (BP) reported that global refinery capacity increased by 1.8 million barrels a day between 2001 and 2004, while global crude production was up 5.3 mbd. Additionally, not enough of this capacity (size and amount) is able to process the increasingly (more and more) heavy and sour crude supplies.
Energy Information Administration (EIA) August 21, 2005 Report
Continue to: Classification of Different Types of Crude Oil
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Hubbert Peak Theory
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Oil Reserves by Country
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Energy Return on Energy Invested (EROEI)
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What is Crude Oil
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Classification of Different Types of Crude Oil
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What is in a Barrel of Crude Oil
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