GB/T 28910-2026Measurement methods for the rheological properties of crude oil (English PDF)

5.1 Rotational Viscometer

5.1.1 Measurement system. Usually only coaxial cylinder or single cylinder type; the types of commonly used rotational viscometer measurement systems are shown in GB/T 10247.

5.1.2 Temperature control and acquisition unit. Temperature control accuracy ±0.5°C.

5.1.3 Pressure control unit. pressure gauge accuracy class 0.25, pressure sensor accuracy ±0.5%FS.

5.2 Rotational Rheometer

5.2.1 Measurement System. Commonly used types include coaxial cylinder, cone-plate, parallel plate, etc., with continuous variable shear mode or stepped variable shear mode. It has the ability to measure parameters such as yield stress in shear mode and at extremely low shear rates or stresses.

5.2.2 Temperature control and acquisition unit. It has continuous temperature change or stepped temperature change mode, and the temperature control accuracy is ±0.5°C.

5.2.3 Pressure control unit. pressure gauge accuracy class 0.25, pressure sensor accuracy ±0.5%FS.

5.3 Gravity capillary viscometer

5.3.1 Glass capillary viscometer. The specifications shall be selected in accordance with the provisions of GB/T 10247.

5.3.2 Temperature control unit. Temperature control accuracy ±0.1°C.

5.3.3 Density meter. The scale division value shall not be less than

0.001 g/cm3.

5.3.4 Timer. A stopwatch or other timing device with a resolution of no more than 0.01s.

5.4 High-Pressure Capillary Rheological Measurement Apparatus

5.4.1 A schematic diagram of the high-pressure capillary rheology measuring device is shown in Figure 1.

5.4.2 High-pressure thin tube. The ratio of tube length to tube diameter is greater than 250.

5.4.3 Flow regulation unit. Flow accuracy ±1.0%.

5.4.4 Temperature control unit. Temperature control accuracy ±1°C.

5.4.5 Back pressure control unit. pressure gauge accuracy class 0.25, pressure sensor accuracy ±0.5%FS.

5.4.6 Pressure and Differential Pressure Measurement Unit. Pressure gauge accuracy 0.25%, pressure sensor accuracy ±0.5%FS, differential pressure sensor accuracy... ±0.5%FS.

5.4.7 Gas source and pressure regulation unit. to meet the experimental pressure requirements.

5.5 Falling Ball Viscometer

5.5.1 A schematic diagram of a falling ball viscometer is shown in Figure 2.

5.5.2 Small balls. Drop type with a diameter of 1mm~4mm, and rolling type with a diameter of 11mm~15.8mm; material. stainless steel, alloy steel, or... Glass.

5.5.3 Sample Tube. The timing mark interval of the sample tube shall not be less than 50 mm. The diameter of the drop-type sample tube shall be 5 to 10 times the diameter of the measuring ball. The diameter of the rolling sample tube is

1.5 times the diameter of the measuring ball.

5.5.4 Thermostatic bath. Temperature control accuracy ±1°C.

5.5.5 Timer. A stopwatch or other timing device with a resolution of no more than 0.01s.

5.6 Apparatus for Measuring the Rheological Properties of Porous Media

5.6.1 A schematic diagram of the apparatus for measuring the rheological properties of porous media is shown in Figure 3.

5.6.2 Flow rate control unit. scale division value is

0.001 mL/min.

5.6.3 Temperature control unit. Temperature control accuracy ±1°C.

5.6.4 Back pressure control unit. pressure gauge accuracy class 0.25, pressure sensor accuracy ±0.5%FS.

5.6.5 Pressure and Differential Pressure Measurement Unit. Pressure gauge accuracy 0.25%, pressure sensor accuracy ±0.5%FS, differential pressure sensor accuracy... ±0.5%FS.

5.6.6 Sample container. meets the requirements of experimental pressure and sample volume.

5.6.7 Gas source and pressure regulation unit. to meet the experimental pressure requirements.

5.6.8 Porous media. representative rock cores or porous materials.

5.6.9 Clamps. Meet the experimental temperature and pressure requirements.

5.7 Closed-loop filtration device

5.7.1 A schematic diagram of the closed filtration device is shown in Figure 4.

5.7.2 Pressure gauge or pressure sensor. Pressure gauge accuracy class 0.25, pressure sensor accuracy ±0.5%FS.

5.7.3 Sample container. meets the requirements of experimental pressure and sample volume.

5.7.4 Molded core or sand tube. permeability 800mD~1200mD.

5.7.5 Pump. Meets the requirements for experimental injection.

5.7.6 Temperature control unit. Temperature control accuracy ±1°C.

5.7.7 Clamp. Meets the temperature and pressure requirements for closed filtration.

6.2 Preparation of degassed crude oil

6.2.1 Crude oil dehydration The water content of crude oil samples should be determined according to the method of GB/T 8929.When the water content is greater than 0.5%, the sample should be dehydrated.

6.2.2 Crude oil impurity removal

6.2.2.1 Filter screen filtration method. For crude oil that is not easily volatile, a filter screen with a pore size of 0.043mm is selected for filtration.

6.2.2.2 Closed Filtration Method. Volatile crude oil should be filtered using a closed filtration device. The crude oil is placed in a sample container and filtered using a constant-rate method or... The constant pressure method displaces crude oil to achieve filtration through molded cores or sand pipes.

6.2.2.3 Crude oil containing iron filings should have the iron filings removed before further impurities are removed.

6.2.3 Recovering Cut History

6.2.3.1 Crude oil that is solid at room temperature should be heated to a flowable state, held at that temperature for 2 hours, and then allowed to cool naturally to room temperature. Leave for more than 2 hours.

6.2.3.2 Crude oil that is in a fluid state at room temperature does not require heating treatment and can be left at room temperature for more than 2 hours.

6.3 Formation crude oil preparation Formation crude oil preparation shall be carried out in accordance with the method of GB/T 26981.

7.1 Rotation Method

7.1.1 Select a rotational viscometer or rotational rheometer based on the estimated viscosity range of the sample to be tested, and match a suitable measurement system.

7.1.2 Place the degassed crude oil sample into the measuring cell of a rotational viscometer or rotational rheometer; the sample should be free of air bubbles. Formation crude oil samples should be processed according to... The sample was transferred according to the method of GB/T 26981.

7.1.3 Under the set temperature and pressure conditions, the equilibration time shall be more than 20 minutes, and the temperature and pressure values shall be recorded.

7.1.4 Set the shear rate and start the measurement. The sample to be measured should be in a laminar flow state. Record the dynamic viscosity value after the dynamic viscosity value stabilizes.

7.2.1 Gravity capillary method

7.2.1.1 The density of the degassed crude oil sample at the test temperature shall be determined according to the method of GB/T 1884, GB/T 13377, or SH/T 0604. Line measurement.

7.2.1.2 Load the degassed crude oil sample into the reservoir of the gravity capillary viscometer. The sample inside the reservoir should not contain air bubbles, and the liquid level should be higher than [the specified value]. Top scale line.

7.2.1.3 The glass capillary viscometer is vertically fixed in the temperature control unit.

7.2.1.4 Adjust the temperature control unit to the test temperature, and continue to maintain the temperature for no less than 10 minutes after reaching the test temperature.

7.2.1.5 Release the sample to be tested to begin the measurement, allowing it to flow freely through the capillary tube under gravity. Use a timer to record the liquid level as it drops from the upper graduation mark. The time to the lower scale mark. Without reloading the sample, repeat the measurement twice. The relative deviation between the two measurements should not exceed 0.5%. Record the two flow measurements. The average of the times is used as the final flow time.

7.2.1.6 Kinematic viscosity is calculated according to formula (1).

7.2.1.7 Dynamic viscosity is calculated according to formula (2).

7.2.2 High-Pressure Capillary Tube Method

7.2.2.1 Select a high-pressure capillary tube with appropriate inner diameter and length based on the estimated crude oil viscosity range and measurement pressure.

7.2.2.2 When connecting the high-pressure capillary rheology measuring device, all connections should be well sealed.

7.2.2.3 The degassed crude oil was placed into a sample container and kept at the test temperature for 2 hours. Formation crude oil samples were prepared according to the method in GB/T 26981. Transfer the sample and maintain constant temperature and pressure for 2 hours.

7.2.2.4 Set the system outlet back pressure so that the crude oil sample being tested passes through the high-pressure capillary tube at a certain flow rate until the pressure difference stabilizes.

7.2.2.5 The shear stress of the crude oil sample on the wall of the high-pressure capillary tube is calculated according to formula (3).

7.2.2.6 The non-Newtonian property index is calculated according to formula (4).

7.2.2.7 The shear rate of the crude oil sample on the wall of the high-pressure capillary tube is calculated according to formula (5).

7.2.2.8 The dynamic viscosity of the crude oil sample in the high-pressure capillary tube is calculated according to formula (6).

7.3 Drop ball method

7.3.1 Select an appropriate measuring ball based on the viscosity range of the sample being tested.

7.3.2 The density measurement of degassed crude oil at the test temperature shall be performed in accordance with the provisions of GB/T 1884, GB/T 13377 or SH/T 0604.

7.3.3 Slowly pour the degassed crude oil sample to be tested into the sample tube of the falling ball viscometer, adjust the constant temperature bath to the experimental temperature, and maintain the temperature for no less than [time missing]. 30 minutes.

7.3.4 At the experimental temperature, record the time required for the ball to fall through the upper and lower timing marks. Repeat the measurement twice. The relative deviation of the time is no more than 1%, and the average of the two measurement times is taken as the falling time of the ball.

7.3.5 Dynamic viscosity is calculated according to formula (7).

7.3.6 Formation crude oil viscosity measurement shall be performed in accordance with the method of GB/T 26981.

7.4 Porous Media Method

7.4.1 Vacuum the porous medium in the porous medium rheology measuring device, and slowly inject degassed crude oil until fully saturated; then... Porous media should be loaded into the holder, and all connections should be properly sealed. Formation crude oil transfer should be performed according to GB/T 26981.

7.4.2 Set the system outlet back pressure. After the porous medium reaches the experimental temperature, continue to maintain the temperature for more than 2 hours to allow the crude oil sample to flow at a certain rate. The flow rate is passed through a porous medium until the pressure difference stabilizes, and the flow rate, inlet pressure, outlet pressure, or pressure difference are recorded.

7.4.3 The average shear stress of the crude oil sample under test in the porous medium is calculated according to formula (8).

7.4.4 The average shear rate of the crude oil sample in the porous medium is calculated according to formula (9).

7.4.5 The dynamic viscosity of the crude oil sample in the porous medium is calculated according to formula (10).

8.1 Rotation Method

8.1.1 Select the measurement system, load the sample, and maintain constant experimental temperature and pressure according to the methods in

8.1.2 Continuous variable shear mode should be preferred; if no continuous variable shear mode is available, stepped variable shear mode or single-point shear mode may be used, at least... Nine different shear rates were set.

8.1.3 The shear rate should be set from low shear to high shear, or from high shear to low shear, or from low shear to high shear and then low shear. The specific parameters should be set according to different experimental objectives.

8.1.4 Begin measuring and recording the shear stress at the corresponding shear rate. For non-Newtonian crude oil samples, shear history recovery should be performed.

8.1.5 Plot the relationship curve between shear rate and shear stress. See Figure A.1 in Appendix A for a schematic diagram.

8.2 High-Pressure Thin Tube Method

8.2.1 Select the appropriate high-pressure capillary tube, connect the process, load the sample, and maintain constant experimental temperature and pressure according to the methods in 7.2.2.1~7.2.2.3.

8.2.2 Set the system outlet back pressure so that the crude oil sample being tested passes through the high-pressure capillary tube at a certain flow rate until the pressure difference stabilizes. Change the flow rate... (At least 5) measurements were taken.

8.2.3 Calculate the shear rate and shear stress under different flow conditions according to formulas (5) and (3).

8.2.4 Plot the relationship curve between shear rate and shear stress. See Figure A.1 for a schematic diagram.

8.3 Porous Media Method

8.3.1 Pack the sample according to the method in 7.4.1.

8.3.2 Set the system outlet back pressure, and after the porous medium reaches the experimental temperature, continue to maintain the temperature for more than 2 hours.

8.3.3 Pass the crude oil sample to be tested through the porous medium at a certain flow rate until the pressure difference stabilizes, and record the flow rate, inlet pressure, outlet pressure, or pressure. Poor. Measure at different flow rates (at least 5).

8.3.4 Calculate the shear rate and shear stress under different flow conditions according to formulas (9) and (8).

8.3.5 Plot the relationship curve between shear rate and shear stress. See Figure A.1 for a schematic diagram.

9.1 Rotation Method

9.1.1 Select the measurement system, load the sample, and maintain constant experimental temperature and pressure according to the methods in

9.1.2 Select the shearing mode and set the shearing rate according to the methods in 8.1.2~8.1.3.

9.1.3 Begin measuring and recording the dynamic viscosity at the corresponding shear rate.

9.1.4 Plot the curves showing the relationship between dynamic viscosity and shear rate. See Figure A.2 for a schematic diagram.

9.2 High-Pressure Capillary Tube Method

9.2.1 Select the high-pressure capillary tube, connect the process, load the sample, and maintain constant experimental temperature and pressure according to the methods in 7.2.2.1~7.2.2.3.

9.2.2 Set the system outlet back pressure so that the crude oil sample being tested passes through the high-pressure capillary tube at a certain flow rate until the pressure difference stabilizes. Change different flow rates... Measure at least 5 items.

9.2.3 Calculate the shear rate and dynamic viscosity under different flow conditions according to formulas (5) and (6).

9.2.4 Plot the curves showing the relationship between dynamic viscosity and shear rate. See Figure A.2 for a schematic diagram. 9...