Any condensate is obtained after the transition of a gaseous substance into a liquid due to a decrease in pressure or temperature. In the bowels of the earth there are not only gas, but also gas condensate deposits. When pressure and temperature are reduced as a result of drilling a well, gas condensate is formed - a mixture of liquid hydrocarbons that have separated from the gas.
Under condensation understand the content of liquid hydrocarbons in gas under reservoir conditions (cm 3 /m 3).
Gas condensate factor is the reciprocal of condensation.
Distinguish raw And stable condensates. By raw we mean hydrocarbons that, under standard conditions, are in a liquid state with gaseous components dissolved in them (methane, ethane, propane, butanes). Condensate consisting only of liquid hydrocarbons (from pentanes and above) under standard conditions is usually called stable.
According to physical properties condensates are characterized by great diversity. Density condensates varies from 0.677 to 0.827 g/cm 3 ; refractive index from 1.39 to 1.46; molecular mass - from 92 to 158.
Compound. Numerous studies have established the genetic connection of the underlying (formed) oils. Condensates, like oil, consist of three types of hydrocarbons - methane, naphthenic and aromatic.
However, the distribution of these hydrocarbon groups in condensates have the following peculiarities unlike oils:
1) the absolute content (on average) of aromatic hydrocarbons in gasoline fractions of condensates is higher than in oils;
2) there are gasoline fractions that simultaneously contain a large amount of naphthenic and aromatic hydrocarbons;
4) concentrations of branched methane hydrocarbons are lower than the concentration of normal structures;
5) the share of ethylbenzene among aromatic hydrocarbons of composition C 8 H 10 is on average. significantly lower % than in oils.
Thus, condensates consist of simpler compounds than oil. Cyclopentane hydrocarbons predominate in oils, and cyclohexane hydrocarbons predominate in condensates. Aromatic hydrocarbons in oils are usually concentrated in high-boiling fractions; in condensates, on the contrary, in low-boiling ones. The sulfur content in condensates ranges from 0-1.2%. In individual deposits or wells, condensates may be found, the hydrocarbon composition of which may deviate from general patterns; this is due to the geological features of a particular area.
The condensates are noticeably different and by fractional composition. On average, they boil 60-80% to 200C, but there are condensates (or oil-condensate mixtures) whose end boiling point is 350-500C, containing asphaltenes.
During the development of gas condensate deposits, the composition of condensates changes. As the pressure decreases, partial condensation of hydrocarbons in the formation occurs, and this part is basically no longer extracted to the surface. As a result, there is a change in the quantitative and qualitative characteristics of the reservoir gas-condensate mixture - a change in the group hydrocarbon composition. As the pressure decreases, high-boiling condensate fractions fall into the formation, and its density decreases. Sometimes the density of condensates, on the contrary, increases, which is mainly characteristic of developed gas caps.
Gas condensate is a colorless or slightly colored liquid. Under natural conditions (in deposits), as a rule, it is in a gaseous state. Condenses from natural (reservoir) gases with increasing pressure (above dew point pressure) and/or a decrease in temperature ( hydrocarbon dew point). It consists of gasoline (boiling range from 30-80 to 200°C), kerosene (200-300°C) and, to a lesser extent, higher boiling components. For most gas condensates, the yield of gasoline fractions is 70-85%.
Depending on the presence/absence of gases in the product, they distinguish unstable gas condensate (raw gas condensate), which contains dissolved gases, and stable gas condensate , obtained by degassing the unstable (mainly by rectification).
In its turn stable condensate depending on the place of production it is divided into field condensate (lease condensate- English), obtained directly in the field, next to the well, and factory condensate (plant condensate- English), produced at gas processing plants.
When the pressure decreases, as gas is consumed, gas condensate is released in the geological formation and disappears for the consumer. Therefore, when exploiting fields with a high content of gas condensate, hydrocarbons C 3 and higher are released from the gas produced to the surface of the earth, and the C 1 -C 2 fraction is pumped back in to maintain pressure in the formation.
At the beginning of 2013, promising resources (C3) and proven recoverable reserves (A+B+C1) of gas condensate in Russia were estimated at 2 billion tons.
Gas condensate can accumulate in automotive gas equipment. The liquid is brownish-brown in color, has an unpleasant, corrosive odor of benzene resins (depending on the composition of the gas combustible mixture) and can have a range of odors from a sharp acetone to the smell of tobacco smoke (this depends on the composition of the additives that are added to make the gas smell). It is recommended to drain the gas reducer regularly. It is advisable not to touch it with your hands, because... it can be dangerous to your health.
Gas condensate is a mixture of liquid hydrocarbons condensed from natural gases. Gas condensate is a colorless or slightly colored liquid. Externally, as a rule, gas condensate is a transparent liquid. The color of this liquid can vary from straw yellow to yellow-brown. What does the color of a substance depend on?
It turns out that the intensity of the color of a liquid depends on the amount of oil impurities it contains. You may have heard the name “white oil”. So, this is the generally accepted name for gas condensate.
How is gas condensate separated? Deep in the depths of our earth lie various minerals. Including gas and gas condensate. Having discovered these deposits, the mining company drills a well into the thickness of the earth, trying to get to gas-containing layers. During drilling, the pressure in the formations decreases and at the same time the temperature decreases. As you know, any condensation appears when either the ambient temperature or pressure decreases significantly. This is exactly the process that occurs in gas production. The pressure and temperature drop, and at the same time liquid hydrocarbons of mixed composition (C5 and higher) begin to be released from the gas. This is our “white oil”.
Moreover, the higher the barothermal indicators before condensation begins, the greater the amount of hydrocarbons that can be dissolved in the produced gas. The amount of hydrocarbons is also affected by the composition of the gas in the reservoir and the presence of “oil rims”. An oil rim is a part of a reservoir containing oil, as well as gas and condensate. Gas condensate can concentrate in the formation within varying limits - from 5 g/m? up to 1000 g/m?. If gas deposits are located at great depths, then to obtain condensate it is necessary not only to lower the temperature of the gas, but also to additionally absorb and rectify it.
In order for the pressure in the formation to remain at a high level for as long as possible, hydrocarbons of the C1-C2 fraction are pumped back into the well. As a result, so-called “unstable” condensate is obtained directly from the well. It reaches consumers via special conductive systems. Unstable condensate is thoroughly cleaned from impurities and gas is removed from the composition. Now it becomes "stable". This type of gas condensate reaches the end consumer either through pipelines or liquid transport.
What is the composition of gas condensate? The composition of gas condensate is influenced by many factors. The hydrocarbon composition of the condensate and the number of fractions in it are influenced by the formation conditions; conditions under which the selection of a substance occurs. It is very important to take into account the period of time during which a given deposit is exploited. Earlier we mentioned the influence of the “oil rims” present in the reservoir on the composition of the condensate. The conditions for the migration of gas condensate into the deposits during its formation, as well as the chemical composition of the reservoir gas, should also be taken into account. In general, the contents of gas condensate are similar to oil. But, unlike oil, gas condensate does not contain resinous substances and asphaltenes. Basically, it includes gasoline and kerosene components.
Gasoline fractions boil at a temperature of +30 °C - +200 °C, kerosene fractions - within +200 °C - +300 °C. The condensate also contains a small amount of high-boiling components. The yield of gasoline fractions is usually more than half. If the formation is located at great depth, then its composition is dominated by kerosene components and gas oil. More often there are condensates containing methane and naphthenes, less often - containing aromatic or naphthenic hydrocarbons. 
What is gas condensate used for? Gas condensate serves as the basis for obtaining fuel or petrochemical products. So from gas condensate or high quality gasoline. To improve quality, gasoline fractions obtained from condensate are subjected to additional processing. In order to increase the fuel's resistance to detonation, anti-knock agents are added to the composition. Without additional processing, these types of fuel can only be used in the warm season, as they quickly become cloudy and solidify. In order for these types of fuel to work even in cold weather, paraffin is removed from their composition.
For the production of plastics, synthetic rubbers, various types of fibers and resins, aromatic hydrocarbons, olefins and other monomer molecules obtained by processing gas condensate are used. Mining companies are interested in developing condensates available in large fields. They commission installations with a large unit capacity.
For example, the Gazprom company owns fields with gas condensate reserves amounting to more than 1 billion tons. This company produces about 13 million tons of gas condensate per year.
Liquid mixtures of hydrocarbons (all of them differ in different molecular structures and boil at high temperatures), which are released as a by-product in gas condensate, gas and oil fields, are collectively called gas condensates. Their composition and quantity depend on the location and conditions of extraction, and therefore vary widely. However, they can be divided into two types: stable gas condensate in the form of gasoline-kerosene fractions (and sometimes higher molecular weight liquid components of oil), an unstable product, which, in addition to hydrocarbons C5 and higher, includes gaseous hydrocarbons in the form of methane-butane fraction .
Condensate can come from three types of wells where it is produced: Crude oil (it comes in the form of associated gas, which can lie underground separately from crude oil (in layers) or be dissolved in it). Dry natural gas (features a low content of hydrocarbons dissolved in it, condensate yield is low). Wet natural gas (produced from gas condensate fields and has a high content of gasoline condensate). The amount of liquid components in natural gases varies from 0.000010 to 0.000700 m? by 1 m? gas For example, the yield of stable gas condensate at various fields: Vuktylskoye (Komi Republic) - 352.7 g/m?; Urengoyskoe (Western Siberia) - 264 g/m?; Gazlinskoe (Central Asia) - 17 g/m?; Shebelinskoye (Ukraine) - 12 g/m?.
Natural gas condensate is a multicomponent mixture of various low-density liquid hydrocarbons, which contains gaseous components. It condenses from the raw gas during the temperature drop during well drilling (below the dew point of the produced hydrocarbons). It is often called simply "condensate" or "gas gasoline". Schemes for separating condensate from natural gas or oil are varied and depend on the field and purpose of the products. As a rule, at a technological installation built next to a gas or gas condensate field, the extracted gas is prepared for transportation: water is separated, purified to a certain extent from sulfur compounds, hydrocarbons C1 and C2 are transported to the consumer, a small fraction of them (of the extracted) is pumped into the formations for maintaining pressure. The separated fraction (after removing C3 components from it, but with a small content of them) is the gas condensate that is sent as a feed stream to oil refineries or petrochemical synthesis plants. Transportation is carried out by pipeline or liquid transport.
Gas condensate at oil refineries is used as a raw material for the production of gasoline with a low octane number, to increase which anti-knock additives are used. In addition, the product is characterized by a high cloud point and pour point, which is why it is used to produce summer fuel. Gas condensate is used less frequently as diesel fuel, since additional dewaxing is required. This direction uses less than a third of the produced condensates.
The most interesting technological solution is the use of a product such as a wide fraction of light hydrocarbons for petrochemical synthesis. With its receipt, the processing of gas condensate begins. Deeper processes continue in pyrolysis plants, where NGLs are used as feedstock to produce important monomers such as ethylene, propylene and many other related products. Then the ethylene is sent to polymerization units, from which various grades of polyethylene are produced. As a result of the polymerization of propylene, polypropylene is obtained. The butylene-butadiene fraction is used to make rubber. Hydrocarbons C6 and higher are the raw material for the production of petrochemical synthesis (benzene is obtained), and only the C5 fraction, which is the raw material for obtaining valuable products, is not yet used effectively.
Gas condensate distillate is an analogue of diesel fuel, close to it in density and other characteristics. It contains gasoline and kerosene fractions, but asphaltenes and resinous substances are absent. Gas condensate distillate is a transparent liquid with a specific odor. It can be light, medium and heavy, differing in composition and scope of application.
We can say that gas condensate distillate, the price of which is relatively low, can be an excellent alternative to diesel fuel. And also, thanks to its decent quality, this product has gained immense popularity in the petrochemical and paint industries. 01/31/18
) and temperature, some gasoline and kerosene fractions and, less commonly, higher molecular weight liquid components of oil are in a vapor state. When developing fields, the pressure drops several times - to 4-8 MPa, and a raw, unstable condensate is released from the gas, which, in contrast to the stable one, contains not only hydrocarbons C 5 and higher, but also dissolved gases of the methane-butane fraction.
When the pressure decreases, as gas is consumed, gas condensate is released in the geological formation and disappears for the consumer. Therefore, when exploiting fields with a high content of gas condensate, hydrocarbons C 3 and higher are released from the gas produced to the surface of the earth, and the C 1 -C 2 fraction is pumped back in to maintain pressure in the formation.
At the beginning of 2013, promising resources (C3) and proven recoverable reserves (A+B+C1) of gas condensate in Russia were estimated at 2 billion tons.
Gas condensate can accumulate in automotive gas equipment. The liquid is brownish-brown in color, has an unpleasant, corrosive odor of benzene resins (depending on the composition of the gas combustible mixture) and can have a range of odors from a sharp acetone to the smell of tobacco smoke (this depends on the composition of the additives that are added to make the gas smell). It is recommended to drain the gas reducer regularly. It is advisable not to touch it with your hands, because... it can be dangerous to your health.
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Gas condensate is a mixture of liquid hydrocarbons,
released from natural gases during the exploitation of gas condensate deposits as a result of a decrease in reservoir pressure and temperature.
Another name for condensate is “white oil”, since condensate is usually transparent or slightly yellow in color due to oil impurities.
Gas condensate serves as the basis for obtaining fuel or petrochemical products. Thus, various types of jet, diesel or boiler fuel or high-quality gasoline are obtained from gas condensate. To improve quality, gasoline fractions obtained from condensate are subjected to additional processing.
Various minerals lie in the depths of our earth. Including gas and gas condensate. Having discovered these deposits, the mining company drills a well into the thickness of the earth, trying to get to gas-containing layers. During drilling, the pressure in the formations decreases and at the same time the temperature decreases. As you know, any condensation appears when either the ambient temperature or pressure decreases significantly. This is exactly the process that occurs in gas production. The pressure and temperature drop, and at the same time liquid hydrocarbons of mixed composition begin to be released from the gas. This is “white oil”.
4. Properties of natural gases Natural gas is a mineral in a gaseous state. It is used widely as a fuel. But natural gas itself is not used as fuel; its components are separated from it for separate use. Up to 98% of natural gas is methane; it also includes methane homologues - ethane, propane and butane. Sometimes carbon dioxide, hydrogen sulfide and helium may be present. Natural gas is colorless and odorless (if it does not contain hydrogen sulfide), it is lighter than air. Properties of individual components of natural gas Methane is a colorless, odorless gas, lighter than air. Ethane is a colorless, odorless, and colorless gas, slightly heavier than air. Not used as fuel. Propane is a colorless, odorless gas that is poisonous. Butane is similar in properties to propane, but has a higher density. Twice as heavy as air. Carbon dioxide is a colorless, odorless gas with an acidic taste. Unlike other components of natural gas (except helium), carbon dioxide does not burn. Helium is colorless, very light in color and odor. Does not burn. It is not toxic, but at elevated pressure it can cause narcosis, like other inert gases. Hydrogen sulfide is a colorless heavy gas with the smell of rotten eggs. Very poisonous, even at very low concentrations it causes paralysis of the olfactory nerve. Natural gas has several dangerous properties: Toxicity. This is the most dangerous property. It depends on the composition of the gas. For example, methane and ethane in their pure form are not poisonous, but with a lack of oxygen in the air they lead to suffocation. Gases that contain too much carbon monoxide and hydrogen sulfide are also hazardous to health. Explosiveness. All natural gases that contain oxygen form a substance that can easily explode in the presence of a fire source. Each gas has a certain ignition temperature, which depends on its molar mass. Natural gases do not always explode, but only if they contain too much oxygen.
