SY/T 0520-1993 Determination of crude oil viscosity - Rotational viscometer balance method

SY/T 0520-1993 Determination of crude oil viscosity by rotational viscometer equilibrium methodSY/T0520-1993 Standard download decompression password: www.bzxz.net

Petroleum and Natural Gas Industry Standard of the People's Republic of China SY/T0520—93bZxz.net
Determination of Crude Oil Viscosity
Rotational Viscometer Balance Method
1993-03-27 Issued
Ministry of Energy of the People's Republic of China
1993-09-01 Implementation
1 Subject Content and Scope of Application
Petroleum and Natural Gas Industry Standard of the People's Republic of China Rotational Viscometer Balance Method
Determination of Crude Oil Viscosity
This standard specifies the method for determining the viscosity of crude oil using a coaxial cylinder rotational viscometer. This standard is applicable to the determination of the viscosity and apparent viscosity of crude oil containing no more than 0.5% water. 2 Measurement principle
SY/T 0520—93
The rotating circular cylinder makes the surrounding fluid rotate stably in layers, and the viscous torque of the fluid will act on the cylinder. The relationship between the viscosity and torque of the fluid can be expressed by formula (1):
Wherein: n—-viscosity of the fluid, Pa'st
—viscous torque of the fluid acting on the circular cylinder, N·m; rotation speed of the circular cylinder, rad/si
K—flow field constant, m-8.
According to the relationship between M and T, α and 7, the shear stress t of the cylindrical flow layer 1.1 is expressed by formula (2), and the viscosity or apparent viscosity is calculated by formula (3) (for non-Newtonian fluids, n should be the apparent viscosity m) (2)
Shear stress, Pa
Wu Zhong: r——
Z-instrument measurement system constant, Pa
α-instrument indication,
-shear rate, sl.
3 Equipment and materials
3.1 Viscometer
Use a coaxial circular cylinder rotation viscometer, and the instrument test accuracy should not exceed 4%. 3.2 Constant temperature circulator
The temperature fluctuation does not exceed 0.1℃.
3.3 Thermometer
A mercury thermometer with a graduation value of not more than 0.1℃ or other temperature measuring equipment. 3.4 Others
Thermostatic bath, electric oven or airflow dryer, sampler. Approved by the Ministry of Energy of the People's Republic of China on March 27, 1993 and implemented on September 1, 1993
4 Test steps
4. Test specimens and pretreatment
SY/T 0520--93
4.1.1 Pretreatment of the whole batch of samples: Pack the samples into 50-100mL ground-mouth bottles, and then heat them to 80℃ in a thermostatic bath. After 1h of constant temperature, take them out and cool them to room temperature. Store them in a dark place for 481 seconds before use. 4.1.2 A sample can only be used once at a heating temperature. The sample should be replaced when the heating temperature is changed. 4.2 Sample loading
4.2.1 Take out the sample from the bottle, replace the bottle cap with a rubber stopper with a thermometer and tighten it, then place it in a constant temperature bath and heat it to the heating temperature required by the user, keep the temperature constant for 10 minutes, and then reduce it to the oil filling temperature at a rate of (0.51.0℃)/min. The oil filling temperature is generally 5-10℃ higher than the test temperature of the sample. The oil filling temperature of the same batch of samples should be the same. 4.2.2 While heating the sample, start the constant temperature circulation system of the rotary viscometer and preheat it to the oil filling temperature. 4.2.3 When the user requires direct on-site testing, the sample does not need to be reheated. 4.2.4 Use a preheated sampler (the preheating temperature should not be higher than the sample oil filling temperature) to take out a sample slightly more than the specified capacity and put it into the test tube.
4.3 Cooling and constant temperature
Control the constant temperature circulation system to drop to the test temperature at a speed of (0.5~~1.0℃)/min, and keep the temperature constant for 10~60min according to the characteristics of the viscometer. 4.4 Measurement
4.4.1 The selection of shear rate should be determined according to user requirements. When it is impossible to determine whether it is a Newtonian body or a non-Newtonian body in advance, multiple shear rate measurements should be applied, and the test must be carried out from low shear rate to high shear rate in sequence. 4.4.2 Viscosity measurement
At the selected shear rate, start the viscometer, and when the instrument indication is basically stable, the first α value can be recorded, and then recorded every 5min. If four α values ​​are recorded continuously, the arithmetic mean of the three subsequent α values ​​does not deviate from the previous value by more than 5%, it is considered that the equilibrium value has been reached, and the core value test under the shear rate has been completed, and the last α value is taken as the test result. 4.4.3 When the sample is a non-Newtonian body, the sample must be replaced when the test temperature is changed. 5 Calculation of results
Calculate the viscosity value or apparent viscosity value according to formula (2) and (3). 6 Precision
Judge the reliability of the measurement results (95% confidence level) according to the following provisions. 6.1 Non-Newtonian fluids
6.1.1 Reproducibility
The difference between two results of repeated measurements of the same sample by the same operator in the same laboratory using the same instrument and following the steps specified in the method in a continuous period of time shall not exceed 15% of the average value. 6.1.2 Reproducibility
The difference between two results of repeated measurements of the same sample by different operators in different laboratories using different instruments of the same type and following the steps specified in the method in a continuous period of time shall not exceed 20% of the average value. 6.2 Newtonian fluids
6.2.1 Repeatability
The difference between two results of repeated measurements by the same operator in the same laboratory using the same instrument and following the steps specified in the method in a continuous period of time shall not exceed 6% of the average value. 2
Report
SY/T 0520--93
The arithmetic mean of two repeated test results is the viscosity value (apparent viscosity value). The test report must include the following contents: a. Heating temperature:
b. Test temperature,
c Shear rate,
d. Viscosity or apparent viscosity value, the arithmetic mean of two repeated test results is taken. Additional remarks:
This standard was proposed by China National Petroleum Corporation Furan Gas Company. This standard is under the jurisdiction of the Planning and Design Institute of China National Petroleum Corporation. The Daqing Oilfield Construction Design Institute is responsible for drafting this standard. The drafters of this standard are Zhao Guozhong and Jiang Guanmao. 3
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