GB/T 2538-1988 Crude oil test method GB/T2538-1988 standard download decompression password: www.bzxz.net

National Standard of the People's Republic of China
Crude oils-Test methods
1 Subject content and scope of application
UDC 665.51
GB/T 2538 --- 88
Replaces GB2538--81
This standard specifies the test methods for crude oil sampling, dehydration, density, kinematic viscosity, fluidity, carbon residue, moisture, sulfur content, distillation range, ash content, salt content, water and sediment, and acid value. This standard applies to crude oil.
2 Reference standards
GB/T255 Determination of distillation range of petroleum products
GB/T260 Determination of moisture content of petroleum products
GB/T265 Determination of kinematic viscosity and calculation of dynamic viscosity of petroleum productsGB/T268 Determination of carbon residue in petroleum products (Conrad method)GB/T 387
Determination of sulfur content in dark petroleum products (tube furnace method)Determination of sulfur content in petroleum products (oxygen bomb method)GB/T 388
GB/T508
GB/T510
GB/T 514
Determination of ash content in petroleum products
Determination of freezing point of petroleum products
Technical conditions for liquid thermometers for testing petroleum productsGB/T 1884
GB/T 1885
GB/T3535
GB/T 4756
GB/T6531
GB/T6532
GB/T 6533
GB/T 7304
GB/T11137
SH/T 0121
Determination of density of petroleum and liquid petroleum products (densitometer method)Conversion table for petroleum measurement
Determination of pour point of petroleum
Sampling method for petroleum and liquid petroleum products (manual method)Determination of sediment in petroleum and fuel oil (extraction method)Determination of salt content of crude oil and its products
Determination of water and sediment in crude oil (centrifugation method)Determination of neutralization value of petroleum products and lubricants (potentiometric titration method)Determination of viscosity of dark petroleum products (countercurrent method) and calculation method of dynamic viscosityTechnical conditions for distillation range determination equipment of petroleum productsSH/T 0170
Determination of carbon residue in petroleum products (electric furnace method)3 Sampling of crude oil
Sampling of crude oil shall be carried out in accordance with GB/T4756. For sampling of single wells in mining areas, in addition to the requirements of GB/T4756, the well number, stratum, sampling date, sampler and sample delivery unit, etc. shall be indicated on the label of the sample container. Approved by China Petrochemical Corporation on July 27, 1988, and implemented on June 1, 1989
4 Crude oil dehydration
GB/T 2538--88
Crude oil dehydration allows the use of autoclaves, heated sedimentation, thermochemistry, high voltage direct current and other dehydration methods. This standard is for crude oil distillation dehydration. 4.1 Instruments
4.1.1 Distillation flask: 500mL.
4.1.2 Beaker: 1000mL.
4.1.3 Separating funnel: 250mL.
4.1.4 Petroleum product distillation range measuring instrument: in accordance with the technical requirements of SH/T0121. 4.1.5 Distillation thermometer: in accordance with the technical requirements of GB/T514. 4.1.6 Concave electric furnace or electric heating jacket.
4.1.7 Infrared lamp: 500W.
4.2 Preparation
4.2.1 Heat the sample to 40~50℃ and stir gently. 4.2.2 Weigh about 250g of the sample and inject it into a clean and dry distillation flask (500mL), put some porcelain pieces in it, and then plug the bottle mouth with a cork with a thermometer inserted, so that the upper edge of the mercury ball is exactly at the lower edge of the branch tube of the distillation flask. 4.2.3 Place the distillation flask containing the sample on a concave electric furnace, and connect the branch tube of the distillation flask to the condenser of the distillation range measuring device tightly. Wipe the inner wall of the condenser with a soft cloth wrapped on a metal wire to remove the liquid left over from the last distillation. 4.2.4 Place the separatory funnel at the end of the condenser, so that the condenser extends into the funnel about 25mm, and place the separatory funnel in a beaker filled with ice-water mixture.
Note: A cold trap should be added for light crude oil.
4.2.5 Pour ice-water mixture into the condenser water tank and keep the temperature at 05℃. 4.3 Test steps
4.3.1 After installing the instrument, start heating slowly and adjust the heating intensity so that the liquid in the distillation flask does not boil suddenly. If there is a sudden boil or a violent sound, the heating intensity should be reduced in time.
4.3.2 Control the distillation rate of the oil-water condensate to 1~2mL per minute. 4.3.3 In order to make the water droplets condensed on the bottleneck of the distillation flask evaporate quickly, it is necessary to heat the bottleneck with an infrared lamp. 4.3.4 When the foam of the liquid in the distillation flask gradually decreases, the heating intensity can be appropriately increased until the temperature reaches 200℃, and the dehydration is considered to be complete.
4.3.5 Stop heating for 10~~15min, remove the distillation flask, place it in a cool place, and cool it to 40~50℃. 4.3.6 Remove the separatory funnel and let it stand for a while. After the oil and water layers are clearly separated, carefully release the water layer, then pour the evaporated light oil completely back into the crude oil at 40-50°C (be careful not to lose it), and mix it carefully for testing. 5 Determination of crude oil densitybZxz.net
The determination of crude oil density shall be carried out in accordance with GB/T1884 and GB/T1885. 6 Determination of crude oil kinematic viscosity
The determination of crude oil kinematic viscosity shall be carried out in accordance with GB/T265 or GB/T11137. The measurement temperature is 20, 50 or 80°C, and the kinematic viscosity at several temperatures can also be measured as required. When GB/T11137 is used for determination, the difference between the two results of repeated determination shall not be greater than 2% of their arithmetic mean.
7 Determination of crude oil fluidity
7.1 The determination of crude oil pour point shall be carried out in accordance with GB/T510, and the following items shall be supplemented: 7.1.1 After the crude oil is heated and dehydrated, it needs to be placed for no less than 48 hours before the pour point can be determined. 30
GB/T 2538-88
7.1.2 When determining the pour point of crude oil, the bath temperature should be controlled to be 10℃ lower than the expected pour point. 7.1.3 When the pour point of crude oil is higher than 40℃, the preheating temperature can be 10℃ higher than the expected pour point. Note: For crude oil whose preheating has a greater effect on the pour point, the pour point can be determined without preheating, but the test report should indicate this. 7.1.4 The difference between the two results of repeated measurements should not be greater than 4℃. 7.2 The determination of crude oil pour point shall be carried out in accordance with GB/T3535. For crude oil that has been heated and dehydrated, it needs to be placed for no less than 48 hours before the pour point can be determined.
8 Determination of crude oil carbon residue
The determination of crude oil carbon residue shall be carried out in accordance with GB/T268 or SH/T0170. When GB/T268 is used to determine crude oil carbon residue, the sample shall be weighed according to the following table:
Determination of crude oil moisture
Carbon, %
The determination of crude oil moisture shall be carried out in accordance with GB/T260. 10 Determination of crude oil sulfur content
The determination of crude oil sulfur content shall be carried out in accordance with GB/T387 or GB/T388. 11 Determination of crude oil distillation range
11.1 Instrument
Petroleum product distillation range determination instrument: in accordance with the technical requirements of SH/T0121. The asbestos pad (C) in this standard is used for distillation, and a special concave electric furnace is allowed for heating.
11.2 Preparation
11.2.1 Before determination, the water content of crude oil shall be determined in accordance with GB/T260. If the water content of crude oil is greater than 0.5%, it is necessary to dehydrate it according to the method of crude oil dehydration in Chapter 4. If the crude oil does not contain water or the water content does not exceed 0.5%, the following preparations can be carried out directly. 11.2.2 Place the distillation flask on the balance and weigh 80mL of crude oil at 20℃ by weight method, accurate to 0.2g. 11.2.3 Install the instrument according to GB/T255.
11.2.4 The water temperature in the condenser is controlled at 20±5℃. 11.3 Test steps
11.3.1 After the preparation is completed, start heating the distillation flask, and the time from heating to the initial distillation point is controlled at 15~~20min. 11.3.2 The distillation rate after the initial distillation should be controlled uniformly. When the distillation temperature is lower than 250℃, the rate is 2~4mL per minute; when the distillation temperature is higher than 250℃, the rate is 4~5mL per minute.
11.3.3 When the distillation temperature exceeds 200℃, the temperature of the condensed water in the condensation tank should be gradually increased. When the distillation temperature reaches 250℃, adjust the water temperature of the condensation tank to 50~～~65℃. 11.3.4 When the distillation temperature reaches 100℃, record the distillate volume (mL) in the measuring cylinder. Record it every 20℃ thereafter. When the temperature reaches 300℃, stop heating, condense the sample vapor in the condenser, and continue to flow into the same measuring cylinder for 5 minutes. Record the total distillate volume (mL) in the measuring cylinder.
11.4 Precision
Repeatability: The difference between the distillate volume of two repeated measurements at the same temperature should not be greater than 1mL. 11.5 Report
GB/T2538-88
Take the arithmetic mean of the two repeated measurements as the measurement result. 12
Determination of crude oil ash
The determination of crude oil ash shall be carried out in accordance with GB/T508. 13 Determination of crude oil salt content
The determination of crude oil salt content shall be carried out in accordance with GB/T6532. 14 Determination of crude oil sediment
The determination of crude oil sediment shall be carried out in accordance with GB/T6531. Determination of water and sediment in crude oil
Determination of water and sediment in crude oil shall be carried out in accordance with GB/T6533. Determination of acid value of crude oil
Determination of acid value of crude oil shall be carried out in accordance with GB/T7304. Additional remarks:
This standard is under the technical jurisdiction of the Petrochemical Research Institute. This standard was drafted by the Petrochemical Research Institute. 32
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