Crude oil assay
Encyclopedia
A crude oil assay is essentially the chemical evaluation of crude oil feedstocks by petroleum
testing laboratories. Each crude oil type has unique molecular
, chemical
characteristics. No crude oil type is identical and there are crucial differences in crude oil quality. The results of crude oil assay testing provide extensive detailed hydrocarbon
analysis data for refiners, oil traders and producers. Assay data help refineries determine if a crude oil feedstock is compatible for a particular petroleum refinery or if the crude oil could cause yield, quality, production, environmental and other problems.
The assay can be an inspection assay or comprehensive assay. Testing can include crude oil characterization of whole crude oils and the various boiling range fractions produced from physical or simulated distillation by various procedures. Information obtained from the petroleum assay is used for detailed refinery engineering and client marketing purposes. Feedstock assay data are an important tool in the refining process.
Many oil companies have links to crude oil assays on their web pages. The assays are often on the pages with the field information.
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...
testing laboratories. Each crude oil type has unique molecular
Molecule
A molecule is an electrically neutral group of at least two atoms held together by covalent chemical bonds. Molecules are distinguished from ions by their electrical charge...
, chemical
Chemistry
Chemistry is the science of matter, especially its chemical reactions, but also its composition, structure and properties. Chemistry is concerned with atoms and their interactions with other atoms, and particularly with the properties of chemical bonds....
characteristics. No crude oil type is identical and there are crucial differences in crude oil quality. The results of crude oil assay testing provide extensive detailed hydrocarbon
Hydrocarbon
In organic chemistry, a hydrocarbon is an organic compound consisting entirely of hydrogen and carbon. Hydrocarbons from which one hydrogen atom has been removed are functional groups, called hydrocarbyls....
analysis data for refiners, oil traders and producers. Assay data help refineries determine if a crude oil feedstock is compatible for a particular petroleum refinery or if the crude oil could cause yield, quality, production, environmental and other problems.
The assay can be an inspection assay or comprehensive assay. Testing can include crude oil characterization of whole crude oils and the various boiling range fractions produced from physical or simulated distillation by various procedures. Information obtained from the petroleum assay is used for detailed refinery engineering and client marketing purposes. Feedstock assay data are an important tool in the refining process.
See also
- API gravityAPI gravityThe American Petroleum Institute gravity, or API gravity, is a measure of how heavy or light a petroleum liquid is compared to water. If its API gravity is greater than 10, it is lighter and floats on water; if less than 10, it is heavier and sinks...
- Cetane indexCetane indexCetane index is used as a substitute for the cetane number of diesel fuel. The cetane index is calculated based on the fuel's density and distillation range . There are two methods used, ASTM D976 and D4737. The older D976, or "two-variable equation" is outdated and should no longer be used for...
- Cloud pointCloud pointThe cloud point of a fluid is the temperature at which dissolved solids are no longer completely soluble, precipitating as a second phase giving the fluid a cloudy appearance...
- Cold filter plugging pointCold filter plugging pointCold filter plugging point is the lowest temperature, expressed in 1°C, at which a given volume of diesel type of fuel still passes through a standardized filtration device in a specified time when cooled under certain conditions. This test gives an estimate for the lowest temperature that a fuel...
- DensityDensityThe mass density or density of a material is defined as its mass per unit volume. The symbol most often used for density is ρ . In some cases , density is also defined as its weight per unit volume; although, this quantity is more properly called specific weight...
- Diesel fuel
- Flash pointFlash pointThe flash point of a volatile material is the lowest temperature at which it can vaporize to form an ignitable mixture in air. Measuring a flash point requires an ignition source...
- Freeze point
- GasolineGasolineGasoline , or petrol , is a toxic, translucent, petroleum-derived liquid that is primarily used as a fuel in internal combustion engines. It consists mostly of organic compounds obtained by the fractional distillation of petroleum, enhanced with a variety of additives. Some gasolines also contain...
- List of crude oil products
- Micro Carbon Residue
- Octane ratingOctane ratingOctane rating or octane number is a standard measure of the anti-knock properties of a motor or aviation fuel. The higher the octane number, the more compression the fuel can withstand before detonating...
- PetroleumPetroleumPetroleum 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...
- Petroleum cokePetroleum cokePetroleum coke is a carbonaceous solid derived from oil refinery coker units or other cracking processes. Other coke has traditionally been derived from coal....
- PONA numberPONA numberThe PONA number is an index for oil components. It is used to determine the paraffins , olefins , naphthenes and aromatics content of FCC and coker gasoline....
- Pour pointPour pointThe pour point of a liquid is the lowest temperature at which it will pour or flow under prescribed conditions. It is a rough indication of the lowest temperature at which oil is readily pumpable. In crude oil a high pour point is generally assosiated with a high paraffin content. And typically...
- PNA analysis
- Ramsbottom Carbon ResidueRamsbottom Carbon ResidueRamsbottom Carbon Residue, which abbreviation is RCR, is well known in the petroleum industry as a method to calculate the carbon residue of a fuel. The carbon residue value is considered by some to give an approximate indication of the combustibility and deposit forming tendencies of the...
- Reid Vapour Pressure
- SARASaturate, Aromatic, Resin and AsphalteneSaturate, Aromatic, Resin and Asphaltene is an analysis method that divides crude oil components according to their polarizability and polarity. The saturate fraction consists of nonpolar material including linear, branched, and cyclic saturated hydrocarbons . Aromatics, which contain one or...
- Smoke pointSmoke pointThe smoke point generally refers to the temperature at which a cooking fat or oil begins to break down to glycerol and free fatty acids, and produce bluish smoke. The glycerol is then further broken down to acrolein which is a component of the smoke. It is the presence of the acrolein that causes...
- TAN number
- True vapor pressureTrue vapor pressureTrue vapor pressure is a common measure of the volatility of petroleum distillate fuels. It is defined as theequilibrium partial pressure exerted by a volatile organic liquid as a function of temperature as determined by the test method ASTM D 2879....
- ViscosityViscosityViscosity is a measure of the resistance of a fluid which is being deformed by either shear or tensile stress. In everyday terms , viscosity is "thickness" or "internal friction". Thus, water is "thin", having a lower viscosity, while honey is "thick", having a higher viscosity...
External links
Many oil companies have links to crude oil assays on their web pages. The assays are often on the pages with the field information.
- Statoils page for links to crude oil assays
- Chevron page for links to crude oil assays
- BP page for links to crude oil assays
- Total page for links to crude oil assays
- ExxonMobil page for links to crude oil assays
- Santos page for links to crude oil assays
- Canadian page for links to crude oil assays
- Shell Capline for links to crude oil assays
- Environment Canada link to crude oil properties database
- Malaysian page for links to crude oil assays
- Kernel Energy crude oil assays