Sour crude oil
Encyclopedia
Sour crude oil is crude oil
containing the impurity sulfur
. It is common to find crude oil containing some impurities. When the total sulfur level in the oil is > 0.5 % the oil is called "sour".
The impurities need to be removed before this lower quality crude can be refined into petrol, thereby increasing the cost of processing. This results in a higher-priced gasoline than that made from sweet crude oil
. Thus sour crude is usually processed into heavy oil
such as diesel and fuel oil
rather than gasoline to reduce processing cost.
The majority of the sulfur in crude oil occurs bonded to carbon atoms, with a small amount occurring as elemental sulfur in solution and as hydrogen sulfide
gas. Sour oil can be toxic and corrosive, especially when the oil contains high levels of hydrogen sulfide. At low concentrations the oil has the smell of rotten eggs, but at high concentrations the inhalation of hydrogen sulfide is instantly fatal. At higher concentrations, the hydrogen sulfide can damage the olfactory nerve
, rendering the gas effectively odorless and undetectable, while paralyzing the respiratory system. If exposure is not fatal, its effects on the human body are similar to that of Gulf War Syndrome
including chronic fatigue, headaches, dizziness, skin problems, memory problems, birth defects, and a host of breathing problems such as asthma. Sour crude oil needs to be stabilized by having hydrogen sulfide gas (H2S) removed from it before being transported by oil tankers for safety reasons.
Since sour crude is more common than sweet crude
in the U.S. Gulf of Mexico
, Platts
has come out in March 2009 with a new sour crude benchmark (crude oil) oil marker called "Americas Crude Marker (ACM)". Dubai Crude
(and Oman Crude) both sour crude oils have been used as a benchmark (crude oil) oil marker for Middle East
crude oils for some time.
Major producers of sour crude oil:
North America
: Alberta
(Canada
), U.S. Gulf of Mexico
and Mexico
.
South America
: Venezuela
, Colombia
and Ecuador
.
Middle East
: Saudi Arabia
, Iraq
, Kuwait
, Iran
, Syria
and Egypt
.
Petroleum
Petroleum or crude oil is a naturally occurring, flammable liquid consisting of a complex mixture of hydrocarbons of various molecular weights and other liquid organic compounds, that are found in geologic formations beneath the Earth's surface. Petroleum is recovered mostly through oil drilling...
containing the impurity sulfur
Sulfur
Sulfur or sulphur is the chemical element with atomic number 16. In the periodic table it is represented by the symbol S. It is an abundant, multivalent non-metal. Under normal conditions, sulfur atoms form cyclic octatomic molecules with chemical formula S8. Elemental sulfur is a bright yellow...
. It is common to find crude oil containing some impurities. When the total sulfur level in the oil is > 0.5 % the oil is called "sour".
The impurities need to be removed before this lower quality crude can be refined into petrol, thereby increasing the cost of processing. This results in a higher-priced gasoline than that made from sweet crude oil
Sweet crude oil
Sweet crude oil is a type of petroleum. Petroleum is considered "sweet" if it contains less than 0.5% sulfur, compared to a higher level of sulfur in sour crude oil. Sweet crude oil contains small amounts of hydrogen sulfide and carbon dioxide. High quality, low sulfur crude oil is commonly used...
. Thus sour crude is usually processed into heavy oil
Heavy oil
Heavy oil may refer to:*Fuel oil that contains residual oil left over from distillation.*Heavy crude oil, viscous crude oil.*Coal tar creosote, a wood preservative and waterproofing agent....
such as diesel and fuel oil
Fuel oil
Fuel oil is a fraction obtained from petroleum distillation, either as a distillate or a residue. Broadly speaking, fuel oil is any liquid petroleum product that is burned in a furnace or boiler for the generation of heat or used in an engine for the generation of power, except oils having a flash...
rather than gasoline to reduce processing cost.
The majority of the sulfur in crude oil occurs bonded to carbon atoms, with a small amount occurring as elemental sulfur in solution and as hydrogen sulfide
Hydrogen sulfide
Hydrogen sulfide is the chemical compound with the formula . It is a colorless, very poisonous, flammable gas with the characteristic foul odor of expired eggs perceptible at concentrations as low as 0.00047 parts per million...
gas. Sour oil can be toxic and corrosive, especially when the oil contains high levels of hydrogen sulfide. At low concentrations the oil has the smell of rotten eggs, but at high concentrations the inhalation of hydrogen sulfide is instantly fatal. At higher concentrations, the hydrogen sulfide can damage the olfactory nerve
Olfactory nerve
The olfactory nerve, or cranial nerve I, is the first of twelve cranial nerves. It is instrumental in the sense of smell. Derived from the embryonic nasal placode, the olfactory nerve is capable of regeneration.-Anatomy:...
, rendering the gas effectively odorless and undetectable, while paralyzing the respiratory system. If exposure is not fatal, its effects on the human body are similar to that of Gulf War Syndrome
Gulf War syndrome
Gulf War syndrome or Gulf War illness describes a medical condition that affected veterans and civilians who were near conflicts during or downwind of chemical weapons depot demolition, after the 1991 Gulf War. A wide range of acute and chronic symptoms have included fatigue, musculoskeletal...
including chronic fatigue, headaches, dizziness, skin problems, memory problems, birth defects, and a host of breathing problems such as asthma. Sour crude oil needs to be stabilized by having hydrogen sulfide gas (H2S) removed from it before being transported by oil tankers for safety reasons.
Since sour crude is more common than sweet crude
Sweet Crude
Sweet Crude is a documentary film by Sandy Cioffi about Nigeria's oil-rich Niger Delta. The film premiered in April 2009 at the Full Frame Documentary Film Festival and has since screened at 30 film festivals around the world and has won numerous awards....
in the U.S. Gulf of Mexico
Gulf of Mexico
The Gulf of Mexico is a partially landlocked ocean basin largely surrounded by the North American continent and the island of Cuba. It is bounded on the northeast, north and northwest by the Gulf Coast of the United States, on the southwest and south by Mexico, and on the southeast by Cuba. In...
, Platts
Platts
Platts is a provider of energy and metals information and a source of benchmark price assessments in the physical energy markets. Platts was founded in Cleveland, Ohio in 1909 by Warren C...
has come out in March 2009 with a new sour crude benchmark (crude oil) oil marker called "Americas Crude Marker (ACM)". Dubai Crude
Dubai Crude
Dubai Crude is a light sour crude oil extracted from Dubai. Dubai Crude is used as a price benchmark or oil marker because it is one of only a few Persian Gulf crude oils available immediately. The other two main oil markers are Brent Crude and West Texas Intermediate.Dubai Crude is generally used...
(and Oman Crude) both sour crude oils have been used as a benchmark (crude oil) oil marker for Middle East
Middle East
The Middle East is a region that encompasses Western Asia and Northern Africa. It is often used as a synonym for Near East, in opposition to Far East...
crude oils for some time.
Major producers of sour crude oil:
North America
North America
North America is a continent wholly within the Northern Hemisphere and almost wholly within the Western Hemisphere. It is also considered a northern subcontinent of the Americas...
: Alberta
Alberta
Alberta is a province of Canada. It had an estimated population of 3.7 million in 2010 making it the most populous of Canada's three prairie provinces...
(Canada
Canada
Canada is a North American country consisting of ten provinces and three territories. Located in the northern part of the continent, it extends from the Atlantic Ocean in the east to the Pacific Ocean in the west, and northward into the Arctic Ocean...
), U.S. Gulf of Mexico
Gulf of Mexico
The Gulf of Mexico is a partially landlocked ocean basin largely surrounded by the North American continent and the island of Cuba. It is bounded on the northeast, north and northwest by the Gulf Coast of the United States, on the southwest and south by Mexico, and on the southeast by Cuba. In...
and Mexico
Mexico
The United Mexican States , commonly known as Mexico , is a federal constitutional republic in North America. It is bordered on the north by the United States; on the south and west by the Pacific Ocean; on the southeast by Guatemala, Belize, and the Caribbean Sea; and on the east by the Gulf of...
.
South America
South America
South America is a continent situated in the Western Hemisphere, mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere. The continent is also considered a subcontinent of the Americas. It is bordered on the west by the Pacific Ocean and on the north and east...
: Venezuela
Venezuela
Venezuela , officially called the Bolivarian Republic of Venezuela , is a tropical country on the northern coast of South America. It borders Colombia to the west, Guyana to the east, and Brazil to the south...
, Colombia
Colombia
Colombia, officially the Republic of Colombia , is a unitary constitutional republic comprising thirty-two departments. The country is located in northwestern South America, bordered to the east by Venezuela and Brazil; to the south by Ecuador and Peru; to the north by the Caribbean Sea; to the...
and Ecuador
Ecuador
Ecuador , officially the Republic of Ecuador is a representative democratic republic in South America, bordered by Colombia on the north, Peru on the east and south, and by the Pacific Ocean to the west. It is one of only two countries in South America, along with Chile, that do not have a border...
.
Middle East
Middle East
The Middle East is a region that encompasses Western Asia and Northern Africa. It is often used as a synonym for Near East, in opposition to Far East...
: Saudi Arabia
Saudi Arabia
The Kingdom of Saudi Arabia , commonly known in British English as Saudi Arabia and in Arabic as as-Sa‘ūdiyyah , is the largest state in Western Asia by land area, constituting the bulk of the Arabian Peninsula, and the second-largest in the Arab World...
, Iraq
Iraq
Iraq ; officially the Republic of Iraq is a country in Western Asia spanning most of the northwestern end of the Zagros mountain range, the eastern part of the Syrian Desert and the northern part of the Arabian Desert....
, Kuwait
Kuwait
The State of Kuwait is a sovereign Arab state situated in the north-east of the Arabian Peninsula in Western Asia. It is bordered by Saudi Arabia to the south at Khafji, and Iraq to the north at Basra. It lies on the north-western shore of the Persian Gulf. The name Kuwait is derived from the...
, Iran
Iran
Iran , officially the Islamic Republic of Iran , is a country in Southern and Western Asia. The name "Iran" has been in use natively since the Sassanian era and came into use internationally in 1935, before which the country was known to the Western world as Persia...
, Syria
Syria
Syria , officially the Syrian Arab Republic , is a country in Western Asia, bordering Lebanon and the Mediterranean Sea to the West, Turkey to the north, Iraq to the east, Jordan to the south, and Israel to the southwest....
and Egypt
Egypt
Egypt , officially the Arab Republic of Egypt, Arabic: , is a country mainly in North Africa, with the Sinai Peninsula forming a land bridge in Southwest Asia. Egypt is thus a transcontinental country, and a major power in Africa, the Mediterranean Basin, the Middle East and the Muslim world...
.