GOST R 54389-2011

Group A22

NATIONAL STANDARD OF THE RUSSIAN FEDERATION

STABLE GAS CONDENSATE

Specifications

Stable gas condensate. Specifications

OKS 75.060
OKP 027132

Introduction date 2012-07-01

Foreword

Goals and principles of standardization in Russian Federation established by the Federal Law of December 27, 2002 N 184-FZ "On Technical Regulation", and the rules for the application of national standards of the Russian Federation - GOST R 1.0-2004 "Standardization in the Russian Federation. Basic provisions"

About the standard

1 DEVELOPED by the Society with limited liability"Research Institute of Natural Gases and Gas Technologies - Gazprom VNIIGAZ" (LLC "Gazprom VNIIGAZ")

2 INTRODUCED by the Technical Committee for Standardization TC 52 "Natural and liquefied gases"

3 APPROVED AND PUT INTO EFFECT by Order of the Federal Agency for Technical Regulation and Metrology dated August 30, 2011 N 247-st

4 INTRODUCED FOR THE FIRST TIME


Information about changes to this standard is published in the annually published information index "National Standards", and the text of changes and amendments- in monthly published information signs "National Standards". In case of revision (replacement) or cancellation of this standard, a corresponding notice will be published in the monthly published information index "National Standards". Relevant information, notification and texts are also placed in information system common use - on the official website of the national body of the Russian Federation for standardization on the Internet

1 area of ​​use

1 area of ​​use

This standard applies to stable gas condensate prepared at primary processing units for transportation and/or use as a raw material for further processing on the territory of the Russian Federation and for export.

2 Normative references

This standard uses Normative references to the following standards:

GOST R 8.580-2001 State system for ensuring the uniformity of measurements. Definition and application of indicators of precision of test methods for petroleum products

GOST R ISO 3675-2007 Crude oil and liquid oil products. Laboratory method for determining density using a hydrometer

GOST R ISO 14001-2007 Environmental management systems. Requirements and application guide

GOST R 50802-95 Oil. Method for determination of hydrogen sulfide, methyl and ethyl mercaptans

GOST R 51069-97 Oil and oil products. Method for Determining Density, Relative Density, and API Gravity with a Hydrometer

GOST R 51330.5-99 (IEC 60079-4-75) Explosion-proof electrical equipment. Part 4. Method for determining the auto-ignition temperature

GOST R 51330.11-99 (IEC 60079-12-78) Explosion-proof electrical equipment. Part 12: Classification of mixtures of gases and vapors with air according to safe experimental maximum clearances and minimum ignition currents

GOST R 51858-2002 Oil. General specifications

GOST R 51947-2002 Oil and oil products. Determination of sulfur by energy dispersive X-ray fluorescence spectrometry

GOST R 52247-2004 Oil. Methods for determination of organochlorine compounds

GOST R 52340-2005 Oil. Determination of vapor pressure by expansion method

GOST R 52659-2006 Oil and oil products. Manual selection methods

GOST R 53521-2009 Processing of natural gas. Terms and Definitions

GOST 12.0.004-90 Occupational safety standards system. Organization of labor safety training. General provisions

GOST 12.1.004-91 Occupational safety standards system. Fire safety. General requirements

GOST 12.1.005-88 System of labor safety standards. General sanitary and hygienic requirements for the air of the working area

GOST 12.1.007-76 Occupational safety standards system. Harmful substances. Classification and general safety requirements

GOST 12.1.019-79 * System of labor safety standards. Electrical safety. General requirements and nomenclature of types of protection
________________
* The document is not valid on the territory of the Russian Federation. Valid GOST R 12.1.019-2009, hereinafter in the text
 
GOST 12.1.044-89 (ISO 4589-84) Occupational safety standards system. Fire and explosion hazard of substances and materials. Nomenclature of indicators and methods for their determination

GOST 12.4.010-75 Occupational safety standards system. Facilities personal protection. Mittens are special. Specifications

GOST 12.4.011-89 System of labor safety standards. Means of protection for workers. General requirements and classification

GOST 12.4.020-82 Occupational safety standards system. Personal protective equipment for hands. Nomenclature of quality indicators

GOST 12.4.021-75 System of labor safety standards. Ventilation systems. General requirements

GOST 12.4.068-79 System of labor safety standards. Dermatological personal protective equipment. Classification and general requirements

GOST 12.4.103-83 Occupational safety standards system. Special protective clothing, personal protective equipment for legs and arms. Classification

GOST 2.4.111-82* System of labor safety standards. Man's suits for protection against oil and oil products. Specifications
________________
*Probably an original error. Should read: GOST 12.4.111-82. - Database manufacturer's note.

GOST 12.4.112-82 Occupational safety standards system. Women's suits for protection against oil and oil products. Specifications

GOST 17.1.3.05-82 Nature protection. Hydrosphere. General requirements for the protection of surface and groundwater from pollution by oil and oil products

GOST 17.1.3.10-83 Nature protection. Hydrosphere. General requirements for the protection of surface and groundwater from pollution by oil and oil products during pipeline transportation

GOST 17.1.3.12-86 Nature protection. Hydrosphere. General rules protection of waters from pollution during drilling and oil and gas production on land

GOST 17.1.3.13-86 Nature protection. Hydrosphere. General requirements for the protection of surface waters from pollution

GOST 17.2.3.02-78 Nature protection. Atmosphere. Rules for establishing permissible emissions of harmful substances by industrial enterprises

GOST 17.4.2.01-81 Nature protection. Soils. Nomenclature of indicators of sanitary condition

GOST 17.4.3.04-85 Nature protection. Soils. General requirements for control and protection against pollution

GOST 1510-84 Oil and oil products. Marking, packaging, transportation and storage

GOST 1756-2000 (ISO 3007-99) Oil products. Determination of saturation vapor pressure

GOST 2177-99 (3405-88) Petroleum products. Methods for determining the fractional composition

GOST 2477-65 Oil and oil products. Method for determining the water content

GOST 2517-85 Oil and oil products. Sampling methods

GOST 3900-85 Oil and oil products. Methods for determining density

GOST 6370-83 Oil, oil products and additives. Method for determination of mechanical impurities

GOST 11851-85 Oil. Paraffin determination method

GOST 14192-96 Marking of goods

GOST 19121-73 Petroleum products. Method for determining the sulfur content by burning in a lamp

GOST 19433-88 Dangerous goods. Classification and labeling

GOST 21534-76 Oil. Methods for determining the content of chloride salts

GOST 31340-2007 Warning labeling of chemical products. General requirements

Note - When using this standard, it is advisable to check the validity of the reference standards according to the relevant indexes drawn up on January 1 of the current year, and according to information indexes published in the current year. If the reference document is replaced (modified), then when using this standard, you should be guided by the replacing (modified) standard. If the referenced document is canceled without replacement, then the provision in which the link to it is given applies to the extent that this link is not affected.

3 Terms and definitions

This standard uses the terms according to GOST R 53521, as well as the following terms with the corresponding definitions:

3.1 stable gas condensate; KGS: Gas condensate obtained by cleaning unstable gas condensate from impurities and separating C-C hydrocarbons from it, which meets the requirements of this standard.

Note - Stable gas condensate is obtained by primary processing of unstable gas condensate.

4 Technical requirements

4.1 KGS must comply with the requirements of Table 1.


Table 1 - Requirements for KGS

4.3 In the symbol of the KGS, its group is indicated depending on the values ​​​​of the concentration of chloride salts, mass fraction hydrogen sulfide and methyl and ethyl mercaptans.

Example symbol KGS - Stable gas condensate, group 1, GOST R.

5 Safety requirements

5.1 According to the degree of impact on the human body, KGS belongs to the 4th hazard class according to GOST 12.1.007.

Contact with CHC has a harmful effect on the central nervous system, causes irritation of the skin, mucous membranes of the eyes and upper respiratory tract.

When working with KGS, the maximum permissible concentrations (MPC) of harmful substances of KGS in the air of the working area, established by GOST 12.1.005 and hygienic standards, are taken into account. MPC of harmful substances in the air of the working area, contained in the KGS, for aliphatic carbons limit C-C in terms of carbon - 900/300 mg/m (where 900 mg/m is the maximum single MPC, and 300 mg/m is the average shift MPC).

KGS containing hydrogen sulfide (dihydrosulfide) with a mass fraction of more than 20 million is considered hydrogen sulfide-containing in accordance with GOST R 51858 and is assigned to the 2nd hazard class. For hydrogen sulfide (dihydrosulfide), the maximum one-time MPC in the air of the working area is 10 mg/m, the maximum one-time MPC for hydrogen sulfide (dihydrosulfide) mixed with aliphatic saturated hydrocarbons С-С in the air of the working zone is 3.0 mg/m, hazard class 2.

Control of the content of harmful substances in the air of the working area is carried out in accordance with GOST 12.1.005.

5.2 KGS refers to flammable liquids of the 3rd class according to GOST 19433.

5.3 KGS vapors form explosive mixtures with air with temperatures: flash - below 0 °C, self-ignition - above 250 °C. For KGS of a specific composition, the concentration ignition limits are determined according to GOST 12.1.044.

Explosion category and group of explosive mixtures of KGS vapors with air - IIA and T3 according to GOST R 51330.11 and GOST R 51330.5, respectively.

5.4 Safety requirements when working with KGS must not be lower than the requirements of GOST 12.1.004, safety rules - and electrical safety rules in accordance with GOST 12.1.019.

5.5 Those working with CGS must comply with the requirements of safety rules and be trained in labor safety rules in accordance with GOST 12.0.004 and measures fire safety in accordance with the fire safety standards of the Federal Law and the Order of the Ministry of Emergency Situations.

5.6 When working with KGS, you should use individual funds protection in accordance with GOST 12.4.010, GOST 12.4.011, GOST 12.4.020, GOST 12.4.068, GOST 12.4.103, GOST 12.4.111, GOST 12.4.112 and standard industry standards approved in the prescribed manner.

5.7 Sanitary and hygienic requirements for microclimate indicators and the permissible content of harmful substances in the air of the working area must comply with GOST 12.1.005.

5.8 All buildings, premises, laboratories in which operations with CGS are carried out must be provided with ventilation that meets the requirements of GOST 12.4.021 and sanitary rules, must comply with fire safety requirements and have fire extinguishing equipment in accordance with the Federal Law. Also, they should provide for a set of fire prevention measures in accordance with safety rules, building codes and regulations, fire safety standards and fire safety codes.

Artificial lighting and electrical equipment of buildings, premises and structures must meet the explosion safety requirements in accordance with the Decree of the Government of the Russian Federation.

6 Environmental requirements

6.1 When carrying out work with CGS, the requirements established by law Russian Federation in the field of protection environment, and the environmental management system must comply with GOST R ISO 14001. At the same time, it must be ensured that the standards for permissible environmental impact are not exceeded.

6.2 The rules for establishing permissible emissions of CHC into the atmosphere are carried out in accordance with GOST 17.2.3.02

Standards for emissions of CGS into the atmospheric air, harmful physical effects on the atmospheric air and temporarily agreed emissions are established, developed and approved in accordance with federal law on the protection of atmospheric air in the manner determined by the Decree of the Government of the Russian Federation.

Hygienic requirements for ensuring the quality of atmospheric air in populated areas are regulated by sanitary rules and the current legislation of the Russian Federation.

6.3 General requirements for the protection of surface and groundwater are established by the Federal Law, GOST 17.1.3.05, GOST 17.1.3.10, GOST 17.1.3.12, GOST 17.1.3.13.

MPC KGS in the water of objects of cultural and domestic use and household and drinking purposes - no more than 0.1 mg / dm3 according to sanitary norms and rules. MPC KGS in the water of water bodies of fishery significance is not more than 0.05 mg / dm3 in accordance with the Order of the Federal Agency for Fishery.

6.4 Soil protection from CGS pollution is carried out in accordance with GOST 17.4.2.01, GOST 17.4.3.04 and the current legislation of the Russian Federation.

Sanitary and epidemiological requirements for soil quality are regulated by sanitary rules.

6.5 Waste management activities are carried out in accordance with sanitary rules and are regulated by the Federal Law.

The procedure for the development and approval of waste generation standards and limits for their disposal is determined by the Order of the Ministry of Natural Resources of the Russian Federation.

6.6 When transporting and using CGS, measures must be taken to prevent it from getting into domestic and storm sewer systems, as well as into open water bodies and soil. Places of possible spills of KGS should have a dike and a special drainage system. Prevention and liquidation of emergencies associated with the spill of KGS shall be carried out in accordance with the plan for liquidation of emergency spills of KGS.

7 Acceptance rules

7.1 KGS is accepted in batches. A batch is considered to be the amount of KGS sent to one address and accompanied by quality documents in accordance with GOST 1510 (quality passport).

7.1.1 The following is accepted as a batch of KGS:

- at the metering station with continuous pumping through the condensate pipeline, the amount of gas pumped over a certain period of time, measured by metering devices and agreed upon by the supplier (consignor) and consumer (consignee);

- at the metering station when shipped to vehicles- the number of CGS, determined by agreement between the supplier and the consumer.

7.2 To check the compliance of the CGS with the requirements of this standard, acceptance tests are carried out according to the indicators given in table 1.

7.3 The selection of KGS is carried out in accordance with GOST 2517 and GOST R 52659.

7.4 The quality document (passport) issued by the manufacturer or seller (at enterprises that store products ready for sale) must contain:

- name of the manufacturer (seller);

- name and group of KGS;

- normative values ​​of the characteristics established by this standard for this group of CGS;

- the actual values ​​of these characteristics determined from the test results;

- number of the tank (batch number) from which this sample of CGS was taken;

- date of selection;

- the date of the analysis of the CGS.

The quality document (passport) is signed by the head of the enterprise or a person authorized by him and certified with a seal.

7.6 If any of the indicators does not comply with the requirements of this standard or there is disagreement on this indicator, the same sample is retested if it is taken from a sampler installed on the stream, or a re-taken sample if it is taken from a tank or other container.

The results of repeated tests are extended to the entire batch.

7.7 In case of disagreement in the assessment of the quality of the SSC between the supplier and the consumer, tests of the stored arbitration sample are carried out. Tests are carried out in a laboratory determined by agreement of the parties. The test results of the arbitration sample are considered final and are included in the quality document for this batch of CGS.

8 Test methods

8.1 Saturated vapor pressure, fraction yield, mass fraction of hydrogen sulfide and light mercaptans are determined in point samples taken according to GOST 2517 or GOST R 52659.

The rest of the KGS quality indicators are determined in a combined sample taken according to GOST 2517 or GOST R 52659.

8.2 Saturated vapor pressure of KGS is determined according to GOST 1756, GOST R 52340 or.

It is allowed to apply the method in accordance with reduction to saturated vapor pressure in accordance with GOST 1756.

8.3 The mass fraction of water is determined according to GOST 2477.

You can use the or method.

In case of disagreement in assessing the quality of CGS, the mass fraction of water is determined according to GOST 2477 using anhydrous xylene or toluene.

8.4 Mass concentration chloride salts in KGS are determined according to GOST 21534. During the analysis, 1 cm 6 mol / dm of sulfuric acid is added to the aqueous extract and boiled for at least 30 minutes. It is allowed to apply the method according to.

8.5 The mass fraction of sulfur is determined according to GOST R 51947, GOST 19121 or,.

8.6 The density of the KGS at a temperature of 20 ° C is determined according to GOST 3900, at a temperature of 15 ° C - according to GOST R 51069, GOST R ISO 3675 or -.

The density of the CGS on the flow in the pipeline is determined by densitometers.

8.7 Determination of the mass fraction of organic chlorides in KGS is performed according to GOST R 52247 or according to.

To obtain a fraction that boils up to a temperature of 204 °C, it is allowed to use equipment in accordance with GOST 2177 (method B).

8.8 In case of disagreement in assessing the quality of an indicator determined according to this standard by several methods, the method indicated first in Table 1 is considered to be arbitration.

8.9 Disagreements arising in the assessment of the quality of the CGS for any of the indicators are resolved using GOST R 8.580.

9 Marking, packaging, transport and storage

9.1 KGS marking - according to GOST 14192, GOST 19433 and GOST 31340.

9.2 Transportation of KGS - in accordance with GOST 1510 and in accordance with the rules for the carriage of goods established for each mode of transport.

9.3 The main volume of CGS is classified as dangerous goods of the 3rd class according to GOST 19433. The hazard subclass of the supplied KGS and the UN number are set by the consignor.

9.4 Packing and storage of KGS in accordance with GOST 1510.

10 Manufacturer's warranties

10.1 The manufacturer guarantees that the quality of the KGS meets the requirements of this standard, subject to the conditions of transportation and storage, for 6 months from the date of manufacture indicated in the quality document (quality certificate).

10.2 After the expiration of the warranty period of storage, the KGS is tested for compliance with the requirements of this standard to make a decision on the possibility of its use or further storage in the prescribed manner.

Appendix A (recommended). Form of document on quality (quality certificate) of stable gas condensate

Test results of stable gas condensate

Electronic text of the document
prepared by CJSC "Kodeks" and checked against:
official publication
M.: Standartinform, 2012

Any condensate is obtained after the transition of a gaseous substance to 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 decrease as a result of drilling a well, gas condensate is formed - a mixture of liquid hydrocarbons separated from the gas.

Under condensate understand the content of liquid hydrocarbons in gas in reservoir conditions (cm 3 /m 3).

The gas condensate factor is the reciprocal of condensate.

Distinguish raw And stable condensates. By raw hydrocarbons are meant, under standard conditions, being in a liquid state with gaseous components dissolved in them (methane, ethane, propane, butanes). A condensate consisting only of liquid hydrocarbons (from pentanes and above) is usually called stable under standard conditions.

By 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.

Composition. Numerous studies have established the genetic relationship of the underlying (formed) oils. Condensates, like oils, consist of three types of hydrocarbons - methane, naphthenic and aromatic.

However, the distribution of these HC groups in condensates have the following peculiarities unlike oils:

1) the absolute content (in cf.) of aromatic hydrocarbons in gasoline fractions of condensates is higher than in oils;

2) there are gasoline fractions that contain both a large number of naphthenic and aromatic hydrocarbons;

4) the concentration of branched methane hydrocarbons is lower than the concentration of normal structures;

5) the share of ethylbenzene among aromatic hydrocarbons of the composition C 8 H 10 falls in cf. much smaller % than in oils.

Thus, condensates are composed of simpler compounds than oils. In oils, cyclopentane hydrocarbons predominate, in condensates - cyclohexane hydrocarbons. Aromatic hydrocarbons in oils are usually concentrated in high-boiling fractions, in condensates, on the contrary, in low-boiling fractions. The sulfur content in condensates ranges from 0-1.2%. In individual deposits or wells, condensates can be found, the hydrocarbon composition of which may deviate from the 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 off by 60-80% up to 200C, but there are condensates (or oil-condensate mixtures), the boiling point of which is 350-500C, containing asphaltenes in their composition.

During the development of gas condensate deposits, the composition of condensates changes. As the pressure decreases, partial condensation of hydrocarbons in the reservoir 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. With a decrease in pressure, high-boiling condensate fractions fall into the reservoir, 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 mixture of liquid hydrocarbons condensing from natural gases. Gas condensate is a colorless or slightly colored liquid. Outwardly, as a rule, gas condensate is a transparent liquid. The color of this liquid can vary from straw yellow to yellow-brown. What determines the color of a substance?

It turns out that the color intensity of the liquid depends on the amount of oil impurities contained in it. You may have heard the name "white oil". So - this is the common name for gas condensate.

How is gas condensate separated? Deep in the bowels of our earth lie various fossils. Including gas and gas condensate. Having discovered these deposits, the mining company drills a well into the earth, trying to get to the gas-bearing formations. During drilling, the pressure in the formations decreases and, in parallel, the temperature decreases. As you know, any condensate appears when either the ambient temperature or pressure drops significantly. This is exactly the process that occurs in the case of gas production. The pressure and temperature drop, and at the same time, liquid hydrocarbons of mixed composition (C5 and above) begin to separate from the gas. This is our "white oil".

At the same time, the higher the barothermal parameters before the start of condensation, the greater the amount of hydrocarbons that can be dissolved in the produced gas. Also, the amount of hydrocarbons is 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 be concentrated in the reservoir within different limits - from 5 g/m? up to 1000 g/m?. If gas deposits are located at a great depth, then in order to obtain condensate, it is necessary not only to lower the temperature of the gas, but also to absorb and rectify it additionally.

In order to keep the pressure in the reservoir at a high level for as long as possible, C1-C2 fraction hydrocarbons are pumped back into the well. As a result, the so-called "unstable" condensate is obtained directly from the well. It comes to consumers through special conductive systems. Unstable condensate is subjected to thorough purification from impurities, gas is removed from the composition. Now it becomes "stable". This type of gas condensate reaches the end user either through pipelines or bulk 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 affected by the conditions of the formation; the conditions under which the selection of the substance occurs. It is very important to take into account the period of time during which this deposit is exploited. Earlier, we mentioned the effect of “oil rims” present in the reservoir on the composition of the condensate. The conditions of gas condensate migration into the deposit during its formation, as well as the chemical composition of the reservoir gas, should also be taken into account. In general, the content of gas condensate is similar to that of 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 °С - +200 °С, kerosene - within +200 °С - +300 °С. Included in the condensate and a small amount of high-boiling components. The output of gasoline fractions is usually more than half. If the reservoir is located at a great depth, then kerosene components and gas oil predominate in its composition. Condensates containing methane and naphthenes are more common, less often - containing aromatic or naphthenic hydrocarbons.

What is gas condensate used for? Gas condensate serves as a basis for obtaining fuel or products of the petrochemical industry. So from gas condensate or high quality gasoline. To improve the quality, gasoline fractions obtained from condensate are subjected to additional processing. In order to increase the resistance of the fuel to detonation, antiknock agents are introduced into the composition. Without additional processing, these types of fuel can be used only in the warm season, as they quickly become cloudy and solidify. In order for these fuels to work in cold weather, paraffin is removed from their composition.

Aromatic hydrocarbons, olefins and other monomeric molecules obtained during the processing of gas condensate are used for the production of plastics, synthetic rubbers, various fibers and resins. Mining companies are interested in developing condensates available at large fields. They put into operation installations with a large unit capacity.

For example, Gazprom owns fields with gas condensate reserves of more than 1 billion tons. This company produces about 13 million tons of gas condensate per year.
Liquid mixtures of hydrocarbons (all of which have different molecular structures and boil at high temperatures), which are released as a by-product in gas condensate, gas and oil fields, are united by a common name - gas condensates. Their composition and quantity depend on the place and conditions of extraction, therefore they 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 C5 and higher hydrocarbons, 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 occur underground separately from crude oil (strata) or be dissolved in it). Dry natural gas (characterized by a low content of dissolved hydrocarbons in it, the 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? for 1 m? gas. For example, the yield of stable gas condensate at various fields: Vuktylskoye (Komi Republic) - 352.7 g/m?; Urengoy (Western Siberia) - 264 g/m?; Gazlinskoe (Central Asia) - 17 g/m?; Shebelinskoe (Ukraine) - 12 g/m?.

Natural gas condensate is a low-density multicomponent mixture of various liquid hydrocarbons containing 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 referred to simply as "condensate" or "gasoline". Schemes for separating condensate from natural gas or oil are varied and depend on the field and the purpose of the products. As a rule, at a process plant built near a gas or gas condensate field, the produced gas is prepared for transportation: water is separated, it is purified to a certain extent from sulfur compounds, C1 and C2 hydrocarbons are transported to the consumer, a small portion of them (of the produced gas) is pumped into the reservoirs for maintaining pressure. The isolated 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 refineries or petrochemical synthesis units. Transportation is carried out by pipeline or bulk transport.

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

Most interesting technological solution is the use of such a product as a wide fraction of light hydrocarbons for petrochemical synthesis. With its receipt, the processing of gas condensate begins. Deeper processes continue at pyrolysis plants, where NGLs are used as feedstock to produce important monomers such as ethylene, propylene, and many other related products. Then ethylene is sent to polymerization units, from which polyethylene of various grades is obtained. As a result of the polymerization of propylene, polypropylene is obtained. The butylene-butadiene fraction is used to make rubber. Hydrocarbons C6 and above are raw materials for the production of petrochemical synthesis (benzene is obtained), and only the C5 fraction, which is a raw material for obtaining the most valuable products, is still inefficiently used.

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 clear liquid with a specific odor. It is light, medium and heavy, differs in composition and scope.

We can say that gas condensate distillate, the price of which is relatively low, can be an excellent alternative to diesel fuel. And also, due to its decent quality, this product has gained immense popularity in the petrochemical and paint industries. 31/01/18

Stable gas condensate

Hydrocarbon liquid, consisting of heavy hydrocarbons C 5+ , in which no more than 2-3% of the mass is dissolved. propane-butane fraction. Two groups (I and II) of stable condensate have been established depending on the content of impurities - water, mechanical impurities, chloride salts.

In accordance with the OST 51.65 - 80 standard, stable condensate is defined as a mixture of methane, naphthenic and aromatic hydrocarbons that meets the requirements for a number of physical and chemical parameters. The main indicator - saturated vapor pressure - at plus 38º C should be 66650 Pa (500 mm Hg). Thus, the vapor pressure of a stable condensate must be such that at normal atmospheric pressure it can be stored in a liquid state up to a temperature of the order of plus 60 ° C.

Properties of the transported fluid

The properties of oil that characterize the possibility of transportation by pipeline or transportation in tankers depend on its composition. The properties of oil determines the quantitative ratio between paraffinic, naphthenic, aromatic hydrocarbons and other components. These properties must be taken into account at all stages of handling oil (and oil products):

in commodity accounting operations;

when pumping or during transportation;

during processing and use as fuel.

Density. Density usually varies from 650 to 920 kg/m 3 . The concept of relative density is also used, which is determined by the ratio of the density of liquid hydrocarbons to the density of water at 20º C. Precise definition density of liquid hydrocarbons is of great commercial importance, since the volumes of the tanks used are well known, and this allows you to more accurately determine the commercial weight of the pumped product.

General property densities of liquid hydrocarbons - they decrease with increasing temperature (1 oil barrel \u003d 42 gallons \u003d 0.158988 m 3 \u003d 159 l).

It follows from the following graph (see Fig. 2.) that for the considered oils with an increase in temperature by 100 gr. Celsius, their density decreases by 120-150 kg / m 3, i.e. by 15-18%.

Rice. 2.

The volumetric compression ratio is a value that characterizes the change in the relative volume of a liquid with a change in pressure per unit. The characteristic values ​​of this coefficient for oil and condensate are in the range (5-15).10 - 4 1/MPa, i.e. these products have low compressibility.

So big values volumetric compression coefficients of oil and liquid hydrocarbons are responsible for strong hydraulic shocks in pipelines that occur when unsteadiness occurs during the movement of the transported product.

The general pattern is that the volumetric compression ratio decreases as the density of the liquid increases.

The coefficient of volumetric expansion is a value that characterizes the relative change in the volume of a liquid with a change in temperature by 1º C.

Liquefied hydrocarbon gases have a particularly high volume expansion coefficient among liquid hydrocarbons. With the same increase in temperature, propane (butane) expands 16.1 (11.2) times more than water, and 3.2 (2.2) times more than such an oil product as kerosene.

When the temperature rises, the LPG, expanding, creates dangerous stresses in the metal, which can lead to the destruction of the tanks. This should be taken into account when filling out the latter, keeping the required for safe operation vapor phase volume, i.e. a steam cushion must be provided. For tanks where the design temperature rise of the stored product does not exceed 40 ° C, the degree of filling is taken equal to 0.85, with a larger design temperature difference, the degree of filling is taken even less.

The vast majority of pumped into main pipelines liquid hydrocarbons under transportation conditions belong to the so-called. Newtonian fluids, the main property of which is the ability to move even when a minimum shear stress is applied to them.

Providing pumping of a liquid hydrocarbon mixture in a single-phase state and maintaining its "Newtonian" properties, not only minimal energy losses for its transportation are ensured, but also stable conditions for its pumping.

To do this, during the transportation of liquid hydrocarbon mixtures, the necessary thermobaric parameters are maintained, and the liquid mixtures themselves, if necessary, are appropriately processed in order to achieve the properties necessary for pipeline transportation.

Viscosity. The choice of pumping technology, energy consumption for the transportation of liquid hydrocarbons, etc., depend on the viscosity of the transported product. A feature of viscosity as a physical property of a liquid is a very wide range of its values ​​for various hydrocarbon liquid systems, as well as its strong dependence on the transportation temperature. A common property of the viscosity of liquid hydrocarbons is that it decreases with increasing temperature.

IN international system SI units dynamic (molecular, shear) viscosity is measured in poise (centipoise, centipoise) or in MPa. c: the viscosity of liquid hydrocarbons varies over a wide range - from 0.5 to 250 MPa. from.

pour point- this is the temperature at which the oil (petroleum product) in the test tube does not change the level when the test tube is tilted by 45º for 1 min. The transition of oil from a liquid to a solid state occurs gradually, in a certain temperature range. From the standpoint of physicochemical mechanics of petroleum disperse systems, the pour point of oil is defined as the transition from a free-dispersed sol to a bound-dispersed state (gel).

The temperature of the oil (liquid hydrocarbon product) pumped through an underwater pipeline depends (except for the temperature at the inlet to the pipeline) depends on the temperature of the bottom layer of sea water in the case when the pipeline is laid on the seabed without burial, or on the temperature of the soil in the case when the pipeline located in an underwater trench.

The temperature of the pumped liquid determines the viscosity and its other rheological characteristics and thus affects the pumping mode; it determines the possibility of solidification of oil (liquid hydrocarbon product) if its temperature reaches the value of the pour point.

Since the temperature of the transported product usually decreases as it moves through the pipeline, this can lead to a noticeable increase in its viscosity and hydraulic resistance coefficient and, as a result, to an increase in hydraulic friction losses, as long as the temperature of the product drops. Sometimes, this can lead to a complete shutdown of the pipeline.

If the oil being transported is waxy or highly waxy (non-Newtonian for transportation conditions) media, such loading fluctuations complicate the operation of pipelines, especially in the case of offshore fields and underwater pipelines. The transport of products with low productivity leads to the formation of stagnant zones and the accumulation of wax deposits (sometimes, even with the use of wax inhibitors) with a gradual increase in pressure drop in the pipeline.

The main reason for the formation of paraffin deposits is the temperature factor - its decrease during transportation, and the distribution of paraffin deposits in the pipeline is determined by the characteristics of its thermal regime.

On non-extended offshore pipelines, most often field pipelines, sometimes a technology is used based on the use of associated heating of the product, which occurs due to heating of the pipe walls.

Along with oil and gas fields, the development of gas condensates is of great importance for the energy sector in Russia, the Middle East and the Asia-Pacific region.This product in the form prepared for transportation is a mixture of high-boiling complex hydrocarbons of the C5 + type, that is, in which the number of carbon atoms in the molecules is more than five.

The types of gas condensate are determined by the type of fields where it is extracted as a main or accompanying mineral. Most of all it is produced in gas condensate fields, less in gas and oil.

Production of gas and gas condensate

It is carried out from great depths - from 2 to 5 km. In gas-bearing formations at enormous pressure (up to 60 MPa) and high temperature, condensate is not physically present - it is formed (condenses into liquid) only when the mixture comes to the surface, when the temperature and pressure of the medium are significantly reduced.

The gas-liquid substance extracted from deposits is unstable, since it contains, in addition to gas:

1. light hydrocarbons: methane, butane, propane, ethane;
2. water-methanol liquid;
3. stable condensate to be separated from the rest of the components.

Through complex and multi-stage technological operations purification of the product from gases, mechanical impurities, sulfur, chloride salts and water, liquid (at normal pressure) condensate is obtained, which is transported for processing to petrochemical and fuel enterprises. The density of gas condensate is from 660 to 840 kg/m³.

Gas condensate processing

The purified mixture consists of hydrocarbon molecules with the number of carbon atoms from 5 to 30. The boiling point of the condensate is from 150 to 320 ºС.

It is a light straw or yellow liquid. It has a high yield of light oil products (75-98 percent). This means that much more gasoline and diesel fuel are obtained from gas condensate than from oil, in which the yield of light products does not exceed 40 percent.

Oil gas condensate, which is associated with oil fields, may have a darker color (brown) due to the presence of oil.

The properties of gas condensate are determined by its fractional composition, which, in turn, depends on the type of field, depth of occurrence, service life, and other factors.

The main components of the condensate are the gasoline fraction with a boiling point of 30 to 200 ºС, kerosene (200-300 ºС) and high-boiling, from which other products are obtained.