Posted by: mmeazaw | April 25, 2010

is that possible a crude petroleum move from one country to another with its original state?

In its strictest sense, petroleum includes only crude oil, but in common usage it includes both crude oil and natural gas. Both crude oil and natural gas are predominantly a mixture of hydrocarbons. Under surface pressure and temperature conditions, the lighter hydrocarbons methane, ethane, propane and butane occur as gases, while the heavier ones from pentane and up are in the form of liquids or solids. However, in the underground oil reservoir the proportion which is gas or liquid varies depending on the subsurface conditions, and on the phase diagram of the petroleum mixture.

An oil well produces predominantly crude oil, with some natural gas dissolved in it. Because the pressure is lower at the surface than underground, some of the gas will come out of solution and be recovered (or burned) as associated gas or solution gas. A gas well produces predominately natural gas. However, because the underground temperature and pressure are higher than at the surface, the gas may contain heavier hydrocarbons such as pentane, hexane, and heptane in the gaseous state. Under surface conditions these will condense out of the gas and form natural gas condensate, often shortened to condensate. Condensate resembles gasoline in appearance and is similar in composition to some volatile light crude oils.

The proportion of hydrocarbons in the petroleum mixture is highly variable between different oil fields and ranges from as much as 97% by weight in the lighter oils to as little as 50% in the heavier oils and bitumens.

The hydrocarbons in crude oil are mostly alkanes, cycloalkanes and various aromatic hydrocarbons while the other organic compounds contain nitrogen, oxygen and sulfur, and trace amounts of metals such as iron, nickel, copper and vanadium. The exact molecular composition varies widely from formation to formation but the proportion of chemical elements vary over fairly narrow limits as follows:

Composition by weight

Element Percent range
Carbon 83 to 87%
Hydrogen 10 to 14%
Nitrogen 0.1 to 2%
Oxygen 0.1 to 1.5%
Sulfur 0.5 to 6%
Metals less than 1000 ppm

Four different types of hydrocarbon molecules appear in crude oil. The relative percentage of each varies from oil to oil, determining the properties of each oil.

Composition by weight

Hydrocarbon Average Range
Paraffins 30% 15 to 60%
Naphthenes 49% 30 to 60%
Aromatics 15% 3 to 30%
Asphaltics 6% remainder

Most of the world’s oils are non-conventional.

Crude oil varies greatly in appearance depending on its composition. It is usually black or dark brown (although it may be yellowish or even greenish). In the reservoir it is usually found in association with natural gas, which being lighter forms a gas cap over the petroleum, and saline water which, being heavier than most forms of crude oil, generally sinks beneath it. Crude oil may also be found in semi-solid form mixed with sand and water, as in the Athabasca oil sands in Canada, where it is usually referred to as crude bitumen. In Canada, bitumen is considered a sticky, tar-like form of crude oil which is so thick and heavy that it must be heated or diluted before it will flow.Venezuela also has large amounts of oil in the Orinoco oil sands, although the hydrocarbons trapped in them are more fluid than in Canada and are usually called extra heavy oil. These oil sands resources are called unconventional oil to distinguish them from oil which can be extracted using traditional oil well methods. Between them, Canada and Venezuela contain an estimated 3.6 trillion barrels (570×10^9 m3) of bitumen and extra-heavy oil, about twice the volume of the world’s reserves of conventional oil.

Petroleum is used mostly, by volume, for producing

fuel oil and gasoline (petrol), both important primary energy

sources.84% by volume of the hydrocarbons present in petroleum is converted into energy-rich fuels (petroleum-based fuels), including gasoline, diesel, jet, heating, and other fuel oils, and liquefied petroleum gas.[8] The lighter grades of crude oil produce the best yields of these products, but as the world’s reserves of light and medium oil are depleted, oil refineries are increasingly having to process heavy oil and bitumen, and use more complex and expensive methods to produce the products required. Because heavier crude oils have too much carbon and not enough hydrogen, these processes generally involve removing carbon from or adding hydrogen to the molecules, and using fluid catalytic cracking to convert the longer, more complex molecules in the oil to the shorter, simpler ones in the fuels.

Due to its high

energy density, easy transportability and relative abundance, oil has become the world’s most important source of energy since the mid-1950s. Petroleum is also the raw material for many chemical products, including pharmaceuticals, solvents, fertilizers, pesticides, and plastics; the 16% not used for energy production is converted into these other materials. Petroleum is found in porousrock formations in the upper strata of some areas of the Earth‘s crust. There is also petroleum in oil sands (tar sands). Known reserves of petroleum are typically estimated at around 190 km3 (1.2 trillion(short scale)barrels) without oil sands,[9] or 595 km3 (3.74 trillion barrels) with oil sands.[10] Consumption is currently around 84 million barrels (13.4×10^6 m3) per day, or 4.9 km3 per year.


Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s