Presumably, in the impression of most laymen, the oil called "black gold" has always been a dark, viscous liquid with a special smell.
Recently, Sinopec Shengli Oilfield produced the first colorless, clear and transparent condensate in the shallow sea area in the north of Dongying City, Shandong Province, which is known as "white oil" in the industry.
Transparent condensate can be used directly as fuel
The condensate oil produced this time came from Well X394, Shengbei offshore Chengbei, located in the offshore Chengdao area of Shengli Oilfield. It is an oil-rich strip and belongs to conventional oil reservoirs. Its proven oil and gas reserves exceed 10 million tons. . The well was formally put into development on June 17, with a daily output of 42 tons of oil and 35,000 cubic meters of natural gas. When testing the well, the condensate reservoir was discovered. At present, the south and north directions of the well zone are accelerating the research on the deployment of production capacity construction plans, in an effort to achieve greater exploration and development of new discoveries.
The condensate oil produced this time is colorless, clear and transparent, and the water content of the tested oil sample is 0. This type of oil refers to the liquid phase component condensed from the condensate gas field or the associated natural gas in the oil field. It is also called "natural gasoline". It exists in the gas phase underground, but it is liquid after being extracted to the surface. It is directly used as fuel and added to tractors, and is also a high-quality raw material for the refining and chemical industry.This is not the first time that "colorless crude oil" has appeared. Prior to this, the United States California, the former Soviet Union Baku, Romania and Indonesia Sumatra have produced this crude oil.
How is colorless crude oil formed? What is the biggest difference from ordinary crude oil?
How colorless crude oil is formed
Colorless crude oil contains no or little gum and asphaltenes, and is generally condensate. When condensate is stored underground, due to high formation pressure and high temperature, they often change to gaseous state or dissolve in gas in the form of small droplets, that is, exist in the form of natural gas, which is called condensate gas. In the process of being mined out of the ground, the pressure and temperature are continuously decreasing, and condensate gas condenses into liquid crude oil and is mined out of the ground.
There are currently three situations where colorless crude oil may form: colorless crude oil is formed underground, and the internal fluid in the reservoir forms a distribution of gas caps, oil columns, and bottom water from top to bottom according to the density difference. The flowing light parts converge into condensate gas; it may also be that in the relatively closed environment underground, if the generated crude oil is not discharged in time, it will crack under high temperature and high pressure conditions, resulting in an increase in light components and the formation of natural gas and other components. Condensate gas will also appear at the same time; In addition, there is a case that because natural gas has the characteristics of small molecules and strong mobility, natural gas from different sources is easy to charge into the same space to form a reservoir, and condensate oil will also appear after mining .
The color can reflect the quality of crude oil
Crude oil generally has four ethnic components, namely saturated hydrocarbons, aromatic hydrocarbons, gums and asphaltenes. Among them, saturated hydrocarbons have no color, aromatic hydrocarbons are yellow, colloids and asphaltenes are brown and black. The different colors of crude oil are mainly related to the different proportions of aromatic hydrocarbons, colloids and asphaltenes contained in crude oil.
The darker the color, the higher the content of colloid and asphaltene. From the perspective of crude oil as a fuel, these two components are impurities, so for a long time in the past, people will think from experience that the darker the color of crude oil , The worse the quality.
At present, the quality of crude oil is distinguished by the proportion of API (a measure of the density of petroleum and petroleum products).
In general, the color of crude oil is related to the number of carbon atoms in the crude oil molecules. The more carbon atoms, the darker the color of crude oil and the greater the density, the less likely it is to be refined into gasoline. And such colorless and transparent crude oil can be said to be the best in oil.
Different quality crude oils have different refining processes
There are many basic methods for crude oil refining, such as distillation, which uses the principles of gasification and condensation to divide the oil into components with different boiling points. The lighter the component, the lower the boiling point, and the fraction is distilled first. The best quality; in addition, the common cracking method is to change the molecular structure of heavy oil under certain conditions, which can increase the proportion of light components.
No matter what kind of refining method is obtained, only the fraction of the refined oil is obtained. Afterwards, through the refining and blending procedures, additives are added to improve its performance. After reaching the product requirements, it is considered to be the refined oil.
It is understood that crude oils of different colors have slightly different specific operations in the refining process because of the different contents of colloid and asphaltene. Generally speaking, this difference is mainly reflected in the processing technology and equipment. For example, it is difficult for refineries processing light oil to process heavy oil because of the lack of heavy oil refining equipment such as delayed coking.
