Gas condensate

Liquid mixtures of hydrocarbons (all of them differ in different molecular structure and boil at high temperature), which are released as a by-product in gas condensate, gas and oil fields, are united by a common name - gas condensates. The composition and number of them depend on the location and conditions of production, and therefore vary widely. However, they can be divided into two types:

• Stable gas condensate in the form of gasoline-kerosene fractions (and sometimes even higher-molecular liquid components of oil),
• Unstable product, which, in addition to hydrocarbons C5 and above, includes gaseous hydrocarbons in the form of a methane-butane fraction.

Condensate can come from three types of wells, where it is extracted:

1. Crude oil (it comes in the form of associated gas, which can fall under the ground separately from crude oil (strata) or be dissolved in it).
2. Dry natural gas (it has a low content of hydrocarbons dissolved in it, the condensate yield is low).
3. Wet natural gas (produced in 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 m3 per 1 m3 of gas. For example, the output of stable gas condensate in various fields:

• Vuktylskoye (Komi Republic) - 352.7 g / m³;
• Urengoy (Western Siberia) - 264 g / m³;
• Gazlinskoye (Central Asia) - 17 g / m³;
• Shebelin (Ukraine) - 12 g / m³.

Natural gas condensate is a multicomponent mixture of various liquid hydrocarbons with low density, in which gaseous components are present. It condenses from the raw gas during the temperature drop when drilling wells (below the dew point of the produced hydrocarbons). It is often called simply "condensate" or "gasoline gas."

The schemes of separation of condensate from natural gas or oil are diverse and depend on the deposit and the purpose of the products. As a rule, at the technological unit built next to the gas or gas condensate field, the produced gas is prepared for transportation: water is separated, purified to a certain limit from sulfur compounds, the hydrocarbons C1 and C2 are transported to the consumer, a small fraction (from the extracted) is pumped into reservoirs Maintenance of pressure. The separated fraction (after removal of components C3, but with a small content of them) is the gas condensate that is sent as a feed stream to oil refineries or to petrochemical synthesis plants. Transportation is carried out by pipeline or by bulk transport.

Gas condensate in oil refineries is used as a raw material for the production of gasoline with a low octane number, for the increase of which antiknock additives are used. In addition, the product is characterized by a high temperature of turbidity and congealing, so it is used to produce summer fuel. As a diesel fuel, gas condensate is used less often, since additional dewaxing is required. This direction uses less than a third of the condensates produced.

The most interesting technological solution is the use of such a product as a wide fraction of light hydrocarbons for petrochemical synthesis. From its reception, the processing of gas condensate begins. Deeper processes continue at pyrolysis facilities, where NGL is used as a raw material for the production of important monomers such as ethylene, propylene and many other related products. Ethylene is then sent to polymerization plants, polyethylene of various grades is obtained from it. As a result of the polymerization of propylene, polypropylene is obtained. Butylene-butadiene fraction is used for the manufacture of rubber. Hydrocarbons C6 and above are raw materials for the production of petrochemical synthesis (benzene is produced), and only fraction C5, which is the raw material for obtaining the most valuable products, is used so far inefficiently.