SY/T 5542-2000 Analysis methods for physical properties of formation crude oil
Some standard content:
ICS 75.180.99
Registration No.: 8193—2001
Petroleum and Natural Gas Industry Standard of the People's Republic of ChinaSY/T5542—2000
Analytical method for reservoir crude oil physical properties2000-12-25Release
State Administration of Petroleum and Chemical Industry
2001—06-01Implementation
SY/T 55422000
Reference standards
Instruments
Instruments calibration and verification
6Sample inspection
Formation fluid preparation
8Sample transfer
9Analysis and calculation of physical properties of formation crude oil
10Test report items and requirements
Appendix A (suggested appendix)
Appendix (suggested appendix)
Formation crude oil separation experiment
Formation crude oil physical property test report format
SY/T 5542—2000
Reservoir fluid analysis data is an important basic data for reservoir reserve calculation, development plan, reservoir engineering and production technology research. SY/T5542-92 "Analysis Method of Physical Properties of Formation Crude Oil - Mercury-free Instrumental Analysis Method" is limited to the use of GF mercury-free PVT instrument. At the same time, it is found in practice that there are some clauses that need to be revised. With the continuous improvement of reservoir fluid analysis instruments and experimental analysis methods, the original standard is no longer suitable for the current production and scientific research needs. For this reason, SY/T 5542-92 has been revised. The name of the revised standard is changed to "Analysis Method of Physical Properties of Formation Source Oil". At present, there are many types of instruments used for formation crude oil analysis and detection in China, and they have basically achieved mercury-free. The operating methods of various instruments are different, but the experimental principles are consistent, and the main analysis methods are basically the same. The revised standard improves the physical property analysis and parameter calculation methods of formation crude oil, proposes unified analysis content and technical requirements, and standardizes and standardizes the analysis data to meet the needs of oil development and management. From the date of entry into force, this standard will replace SYT5542-92. Appendix A and Appendix B of this standard are both reminder appendices. This standard is proposed by China National Petroleum Corporation. This standard is under the jurisdiction of the Oil and Gas Field Development Professional Standardization Committee, and the drafting unit of this standard is the Institute of Petroleum Recovery, Petroleum Exploration and Development Research Institute. The drafters of this standard are Liu Ning, Zheng Xitan
This standard was first issued in February 1993, and this is the first revision. 1 Scope
Petroleum and Natural Gas Industry Standard of the People's Republic of China Analysis Method for Reservoir Crude Oil Physical Properties
Analytlcal method for reservoir crude oil physical propertiesSY/T 5542-—2000
Replaces SY/T5542—92
This standard specifies the calibration methods of instruments and meters used for the analysis of reservoir crude oil physical properties, the inspection of oil and gas samples, the preparation, transfer, analysis and testing of reservoir crude oil, and the calculation methods. This standard is applicable to general reservoir crude oil, and both plunger and piston PVT instruments can be used. Other types of PVT instruments can be implemented as a reference.
2 Reference standards
The clauses contained in the following standards constitute the clauses of this standard by being cited in this standard. When this standard is published, the versions shown are valid. All standards will be revised, and the parties using this standard should explore the possibility of using the latest versions of the following standards. SY/T0529-93 Analysis of CC12, N2, CO, components in oilfield gas Correlation gas chromatography SH/T0169-92 Determination of average molecular weight of mineral insulating oil Freezing point depression method SH/T 0604-94 Determination of liquid density and relative density Digital density meter method 3 Definitions
This standard adopts the following definitions (pressures in this standard are absolute pressures): 3.1 Standard conditions
Standard reference conditions specified for measuring oil and gas. The standard conditions for petroleum and natural gas measurement in my country are 20℃ and 0.101325MPa. 3.2 Oil in the tank
Liquid hydrocarbons in equilibrium with the tank gas under atmospheric conditions after hydrocarbon fluids in the oil and gas reservoir are separated by the oil and gas separator
3.3 Dead oil
Liquid hydrocarbons obtained by flashing hydrocarbon fluids in the oil and gas reservoir to atmospheric conditions. 3.4 Residual oil
Liquid hydrocarbons remaining under atmospheric pressure after multiple degassing or constant volume depletion experiments of hydrocarbon fluids at formation temperature. 3.5 Production gas-oil ratio
The ratio of the gas production of the first separator under standard conditions to the oil production of the tank (20°C), m/m. 3.6 Separator gas-oil ratio
The ratio of the gas production of the first separator under standard conditions to the oil production of the first separator (separator conditions), m2/m33.7 Compression coefficient
The rate of change of crude oil volume with pressure under isothermal conditions. 3.8 Thermal expansion coefficient
The rate of change of crude oil volume with temperature under isobaric conditions. 3.9 Volume coefficient
The ratio of the volume of crude oil under formation conditions to the volume of degassed oil on the ground (20°C) is called the formation crude oil volume coefficient. The size of the formation crude oil volume coefficient is related to the degassing method. When quoting, it is necessary to distinguish the ratio of the volume of gas under formation conditions to its volume under standard conditions, which is called the formation gas volume coefficient. When the formation pressure is lower than the saturation pressure, the ratio of the total volume of oil and gas under a certain pressure to the volume of residual oil (20°C) is called the oil and gas two-phase volume coefficient under that pressure.
3.10 Gas deviation coefficient
The multiplication factor introduced into the ideal gas state equation to correct the deviation between the actual gas and the ideal gas. Its physical meaning is: under specified temperature and pressure conditions, the ratio of the volume of any mass of gas to the volume of the gas calculated according to the ideal gas law under the same conditions. It is also called the gas compression factor.
3.11 Single degassing
The process in which a single-phase hydrocarbon fluid in a certain state expands to another state instantly through throttling. Generally speaking, in this process, the system changes from a single phase to a gas-liquid two-phase while the total composition remains constant. It is also called contact degassing or single flash evaporation. 3.12 Multiple degassing
The process of degassing and exhausting a hydrocarbon system by stepping down the pressure at a certain temperature. In this process, the total composition of the system changes continuously. It is also called differential degassing or differential separation. 4 Instruments and meters
4.1PVT instrument and sample preparation device: the rated working temperature is not less than 150℃, the temperature control accuracy is ±0.5℃, and the rated working pressure is not less than 50MPa.
4.2 High-pressure metering pump: capacity 100~500cm, minimum scale resolution 0.01cm2, rated working pressure not less than 50MPa. 4.3 Separator: rated working pressure not less than 3MPa, rated temperature not less than 35℃, temperature control accuracy ±0.5℃4.4 High-pressure viscometer: measurement error less than 3%, rated temperature not less than 150℃, temperature control accuracy 0.5℃, rated working pressure not less than 50MPao
4.5 Standard pressure gauge or pressure sensor: pressure gauge accuracy not less than 0.35 level, pressure sensor accuracy not less than 0.2%. 4.6 Densitometer: reading accuracy not less than 0.0001g/cm, temperature control accuracy ±0.05℃. 4.7 Gas chromatograph: natural gas component analysis to above heptane, mole fraction accurate to 0.0001, crude oil component analysis to above carbon 30, mass fraction accurate to 0.0001.
4.8 Relative molecular mass meter: measuring range 150700, measuring error not more than 5%. 4.9 Gas meter: capacity greater than 1000cm3, minimum scale resolution 1cm3. 4.10
Balance: measuring range not less than 160g, sensitivity 0.1mg. Atmospheric pressure gauge: accuracy 0.4 level.
2 Vacuum pump: displacement not less than 4L/s, vacuum degree 1.33Pa4.12
4.13 Several piston-type high-pressure vessels: volume not less than 500cm, rated working pressure not less than 50MPa, rated temperature not less than 150℃. Gas booster pump: rated pressure not less than 50MPa. 4.14
5 Calibration and verification of instruments and meters
5.1. Calibration of PVT container
There are many types of PVT instruments used for formation crude oil physical property analysis in China, mainly plunger or piston PVT instruments with or without windows, which basically realize mercury-free operation. The calibration work includes the calibration of container dead volume, container volume, temperature variation coefficient, and pressure variation coefficient to obtain the volume equation of the PVT container. Different instruments have different specific calibration methods, and corresponding calibration methods need to be formulated according to the type of each instrument.
5.2 Calibration of high-pressure metering pump
5.2.1 Calibration method:
The high-pressure metering pump scale calibration adopts the segmented drainage weighing method. 2
5.2.2 Calibration steps
SY/T5542—2000
5.2.2.1 The reading pressure of the metering pump calibration is 10MPac5.2.2.2 Clean the pump cavity, evacuate to 200Pa, continue to pump for 30min, and fill it with double distilled water. 5.2.2.3 The full range of the metering pump is divided into four sections for calibration. Each section is drained and weighed three times, each time about 20cm2, accurate to 0.001g. Each time the pump is drained, the initial and final readings of the pump must be read at the calibration pressure and in the pump state, and the readings are accurate to 0.01cm3.5.2.2.4 Record the room temperature.
5.2.3 Data collation:
5.2.3.1 Calculate the pump reading difference as shown in formula (1). AN=N2i-Na
Where: AN—difference in readings of the i-th pump, cm;
N2i—final reading of the i-th pump, cm;
Niii—initial reading of the i-th pump, cm.
5.2.3.2 Calculate the volume of discharged water as shown in formula (2). Vwi=Wwilew
Where: Vw——actual volume of water discharged by the i-th pump, cmWwii-th mass of water discharged, g,
Pwdensity of distilled water at the calibrated pressure and room temperature, g/cm2. 5.2.3.3 Calculate the pump correction factor as shown in formula (3). Where: F—pump correction factor;
N——total number of drainages.
5.2.4 The calibration period of the pump is 12 months.
5.2.5 In the subsequent analysis work (except for gas meter calibration), the pump readings must be read at the calibration pressure (10MPa) and in the pump-in state.
5.2.6 When the room temperature differs from the temperature during calibration by more than 5°C, the pump correction factor needs to be recalibrated at the corresponding temperature. 5.3 Calibration of high-pressure falling ball viscometer
The formation fluid viscosity can be measured by capillary viscometer, falling ball viscometer or electromagnetic viscometer. The test of fluid viscosity in conventional PVT experiments generally refers to the measurement of liquid phase oil viscosity at different pressures. The high-pressure falling ball viscometer is currently used more. The following is its calibration method. Those who use other types of viscometers must develop calibration methods for the corresponding instruments. 5.3.1 Calibration method
Fill the viscometer test cavity with different known viscosity and density viscosity standard fluids, measure the falling time of steel balls of different diameters at different angles, and obtain the relationship curve or relationship between viscosity and falling ball time. 5.3.2 Calibration steps:
5.3.2.1 Prepare a series of viscosity standard fluids with known viscosity and density. 5.3.2.2 Clean and blow dry the viscometer.
5.3.2.3 Fill the viscometer test cavity with viscosity standard fluid. 5.3.2.4 Select a suitable steel ball and install it in the test cavity. 5.3.2.5
Keep the viscometer at the required temperature of the standard fluid for more than 4 hours. Select a test angle and measure more than five times in parallel according to the viscometer test procedure. The relative error of the ball falling time is required to be less than 1%. Change the measurement angle and repeat the measurement in 5.3.2.6. Select another viscosity standard fluid and repeat the measurement in 5.3.2.25.3.2.7. 3
SY/T 5542—2000
5.3.2.9 Each viscosity calibration curve requires at least 6~7 standard fluids with different viscosity values. 5.3.2.10 The ball falling time should be controlled within 10~80s. 5.3.3 Data collation:
5.3.3.1 According to the measurement results, calculate the product of the ball falling time and the density difference between the steel ball and the standard liquid at different measurement angles for each steel ball, and plot it with the known viscosity value on the arithmetic coordinate system to obtain the calibration curve of a steel ball at different measurement angles as shown in Figure 1. 80
Measurement angle 1
Measurement angle 2
t(0f0.).5-g/cm*
Figure 1 Calibration curve of falling ball viscometer
5.3.3,2 According to the measurement results, the corresponding viscosity calculation formula can also be regressed. μ=k: (pb-pa)
Where: -
Viscosity of the measured liquid, mPa's;
t—Viscometer constant of a steel ball at a certain measuring angle, obtained from calibration; Density of the steel ball at the measuring temperature, &/cm; Ph
Pe Density of the standard liquid at the measuring temperature, g/cm2; Ball drop time, 50
5.3.4 The calibration period is 18 months.
5.4 Calibration of gas, volume meter
5.4.1 Calibration method:
Gas meter scale calibration adopts segmented inflation metering method at atmospheric pressure and room temperature. 5.4.2 Calibration steps:
5.4.2.1 Prepare a calibrated metering pump equipped with a precision atmospheric pressure gauge, clean it and blow it. 5.4.2.2
Open the pump drain valve and fill the pump with air. 5.4.2.3
After the pressure in the gas meter cylinder stabilizes at atmospheric pressure, record the initial reading of the gas meter. 5.4.2.4
Close the drain valve. Connect the pump to the gas meter cylinder. After the air pressure in the pump stabilizes at atmospheric pressure, record the initial reading of the pump.
Slowly add a certain volume of air into the gas meter. When the pressure gauge stabilizes at atmospheric pressure, record the final readings of the pump and gas meter in 5.4.2.5
. Repeat the measurement three or more times.
5.4.2.6 The full range of the gas meter is divided into four sections, which are calibrated in sections according to 5.4.2.2--5.4.2.5. 5.4.3 Data collation:
5.4,3.1 Calculate the pump reading difference
Use formula (1) to calculate
5.4.3.2 Calculate the gas meter reading difference as shown in formula (5). Where: Vt—the difference between the 2 gas meter readings, cm2; Vazi—the final reading of the i gas meter, cm;
Vglii—the initial reading of the i gas meter, ctm3
5.4.3.3 Calculate the gas meter correction factor as shown in formula (6). Where: F. —Gas meter correction factor
N Total number of calibrations.
5,4.4 The calibration cycle is 24 months.
5.5 Calibration of crude oil density and relative density measuring instrumentsSY/T 55422000
Vet= Ve2, - Vgh?
If a digital density meter is used for determination, the calibration shall be carried out in accordance with SH/InG)4. Other measuring instruments shall be carried out in accordance with relevant standards. 5.6 Calibration of crude oil average relative molecular mass measuring instrument The crude oil average relative molecular mass is determined by freezing point depression method, and the calibration shall be carried out in accordance with SII/T0169. 5.7 Calibration of gas chromatograph
In addition to being calibrated by legal measurement units on a regular basis, the gas chromatograph should also be calibrated with standard gas during each test for gas analysis to ensure that the test data is accurate and reliable. The analysis and calibration of natural gas components shall be carried out according to SY/T0529. Sample inspection
6.1 Purpose
Judge the quality of sampling and whether there is leakage during the storage and transportation of samples: 6.2 Initial inspection
When receiving the sample, check the number of samples, whether the well number and label are consistent with the sample delivery form, whether the sampling record data is complete, whether there is oil leakage on the appearance, etc.
6.3 Inspection of downhole fluid samples
Downhole fluid samples refer to samples obtained from the downhole sampler in the downhole cylinder: 6.3.1 Determination of opening pressure:
6.3.1.1 The metering pump is filled with working medium, and the connection process is as shown in Figure 2. The pipeline is vented and pressure tested, and the pump reading is read. Ho
1-High pressure metering record: 2-Lower sampler; 3-Thermostatic sleeve; 4.5, 6-Sample adapter: Valve Figure 2 Underground fluid sample inspection process
SY/T5542-2000
6.3.1.2 The metering pump is pressurized to a pressure higher than the sampling point, and valves 6 and 4 are opened to connect the sample. 6.3.1.3 The sampler is heated to a constant temperature to the sampling point temperature. The sample should be shaken continuously during the heating process to prevent excessive pressure. 6.3.1.4 The temperature is kept constant for more than 4 hours, and after sufficient shaking, the pressure value after the pressure stabilizes is the opening pressure of the sample. 6.3.2 Water content check:
At the sampling point temperature, place the sampler upright for 4 hours, close valve 6, slightly open valve 5, and release all water and dirt. Measure the released water and dirt. The sampler is qualified if it does not contain water and dirt, or its content is not more than 5%. 6.3.3 Determination of saturation pressure:
6.3.3.1 At the sampling point temperature, pressurize the sample to above the formation pressure, shake it fully, and make the sample into a single phase. After stabilization, record the pressure value and pump reading.
6.3.3.2 Reduce the pressure to the next predetermined pressure (pressure interval is 1MPa~2MPa), shake it fully until the pressure is stable, and then record the pressure and pump reading. In this way, the pump readings at each pressure are measured respectively. 6.3.3.3 With pressure as the ordinate and the cumulative pump reading difference as the abscissa, plot the test results on the arithmetic coordinate system to obtain the saturation pressure test curve shown in Figure 3. The inflection point of the curve is the saturation pressure. 400
Cumulative pump reading difference, cm3
Figure 3 Saturation pressure test curve
6.3.3.4 Replace another fluid sample and repeat the measurements in 6.3.3.1 to 6.3.3.3. 6.3.3.5 Representative samples have the following conditions: (1) The relative error of the saturation pressure of at least two samples is less than 3%; (2) The saturation pressure is equal to or less than the sampling point pressure, and the relative error is not greater than 3%. 6.3.3.6 If several samples are qualified after inspection, the sample with the higher saturation pressure is generally taken as the analysis sample. 6.4 Inspection of surface fluid samples
Surface fluid samples generally refer to oil and gas samples obtained from the first-stage separator. 6.4.1 Inspection of separator gas sample:
6.4.1.1 Heat the separator gas sample bottle upright and keep the temperature constant to the separator temperature for more than 4 hours. Connect the pressure gauge as shown in Figure 4. 6.4.1.2 Open the valve on the gas bottle to connect the pressure gauge. The pressure gauge reading is the gas sample pressure. 6.4.1.3 The relative error between the gas sample pressure and the separator pressure is less than 5%, which is qualified. 6.4.1.4 Take gas samples to analyze their components. The test method is in accordance with SY/T0529. 6.4.2 Inspection of separator oil sample:
6.4.2.1 Refer to 6.3.1~6.3.3 for oil sample inspection. 6.4.2.2 The relative error between the saturated pressure of the separator oil and the separator pressure is less than 5%, which is qualified. 6.4.2.3 While measuring the saturated pressure, refer to 9.5 to measure the compressibility coefficient (Co) of the separator oil. 6
6.4.3 Single degassing test of separator oil
SY/T5542—2000
1-Separator gas sample bottle: 2-Pressure gauge;
3-Thermostatic jacket: 4-Valve
Figure 4 Separator gas sample inspection process
6.4.3.1 Select a separator oil bottle that has passed the inspection, refer to the methods and steps of 9.2.2.2~9.2.2.8, and test it at the separator temperature.
6.4.3.2 Data collation:
a) Calculate the oil volume of the oil tank as shown in formula (7).
Vot=Wa/pot
Where: Va—oil volume of the oil tank, cm;
Wo oil mass of the oil tank, g,
pa——oil density of the oil tank (20℃), g/cm. b) Calculate the volume coefficient of the separator oil as shown in formula (8): Bee = Vos/Vot
Where: B
is the volume coefficient of the separator oil;
Vu is the volume of the separator oil (calculated by correcting the difference in pump readings), cms. c) Calculate the gas-oil ratio of the separator oil as shown in formula (9). GOR.=
ToprVi
Where: GOR—gas-oil ratio of separator, cm/cm2 or m/m; To—standard temperature, 293.15K;
Atmospheric pressure during test, MPa;
/Vot-1
V1—volume of released gas at room temperature and atmospheric pressure (volume measured by gas meter), cm; Po
—standard pressure, 0.101325MPa;
Ti——room temperature, K,
d) Calculate the molar composition of tank oil as shown in formula (10). Xu
（8）
：(9)
（10）
........
Where: Xt——molar fraction of component i of tank oil; Xwi——mass fraction of component i of tank oil; M, relative mass of component i.
e) Calculate the composition of separator oil as shown in formula (11). SY/T 5542-2000
X:+4.157×10-1
1+ 4.157× 10 5GOR.
Wherein: X.“--the mole fraction of separator oil; Yt.--the mole fraction of the main component of the tank gas; Mat--the average relative mass of the oil in the tank. 6.4.4 Inspection of oil and gas separation equilibrium state and sampling quality: 6.4.4,1 Inspection purpose:
After the ground separator oil and gas samples are inspected and qualified, it is necessary to check whether the pressure and temperature control of the on-site separator are stable based on the component composition data of the oil and gas samples, and further judge the representativeness of the samples. 6.4.4.2 Inspection method:
According to the thermodynamic relationship, the composition of the separator oil and gas samples in equilibrium, from methane to hexane, lgK should be linearly related to b1
[see formula (12)--formula (14)] TbiTaep
IgKppoct
K;= YsiXst
lgpei -lg (0.101)
where K:
—equilibrium constant of component i;
first-stage separator pressure, MPa;
b—characteristic constant of component i, calculated by formula (14):Th—boiling point of component i, K;
Tp—stage separator temperature, K;
Ysi—molar fraction of component i in separator gas;Pei—critical pressure of component i, MPa;Tci—i Critical temperature of the component, K. 7 Formation fluid preparation
7.1 Preparation
7.1.1 Recompression of separator gas:
Use gas booster pump method or freezing recompression method to transfer the separator gas at the separator temperature into a piston high-pressure container and pressurize it to the sample preparation pressure.
7.1.2 Determination of gas deviation coefficient under sample preparation conditions: 7.1.2.1 Experimental steps:
SY/T5542—2000
) Connect the process according to Figure 5. Constant temperature bath keeps the temperature at the sample preparation temperature for more than 4h6
1-High pressure metering pump: 2-High pressure container; 3-Constant temperature bath; 4-Gas indicator bottle; 5-Gas meter; 6-Valve Figure 5 Gas deviation coefficient determination process|| tt||b) Use a metering pump to pressurize the separator gas sample in the high-pressure container to the sample pressure and keep it stable: c) Record the initial readings of the metering pump and gas meter.
d) Open the top valve of the high-pressure container, maintain the pressure and slowly discharge about 20cm3 of high-pressure gas, and close the top valve; e) Read the final readings of the pump and gas meter, and record the room temperature and atmospheric pressure. f) Repeat the test three or more times according to c) to e). 7.1.2,2 Calculate the gas deviation coefficient under sample conditions as shown in formula (15). Z,=-V,z
TppiVi
Where: Z. ——Gas deviation coefficient under sample conditions: p.-\-sample pressure, MPa:
V—Volume of high-pressure gas (calculated by the difference in pump readings after correction), cn; T. ——Sample temperature (generally set to the separator temperature), K; Z,——Gas deviation coefficient under room temperature and atmospheric pressure (generally approximately equal to 1). 7.2 Sample calculation
7.2.1 Correction of on-site gas-oil ratio is shown in formula (16). GOR, = GOR
Where: GOR—corrected gas-oil ratio, m2/m2; GOR
On-site gas-oil ratio, m/;
d—relative density of natural gas used for on-site gas volume calculation: Z—deviation coefficient of natural gas used for on-site gas volume calculation; L----relative density of natural gas measured in the laboratory; dz
—deviation coefficient of natural gas under separator conditions measured in the laboratory 7.2.2 Calculation of first-stage separator gas-oil ratio:
If the separator gas-oil ratio is provided on the sample delivery form, it can be corrected according to 7.2.1. If the production gas-oil ratio is provided, it must be converted into the separator gas-oil ratio [see formula (17)]. GOR, = GOR,/B.
Where: (GO)R,
First-stage separator gas-oil ratio, m2/m2.2 Reduce the pressure to the next predetermined pressure (pressure interval is 1MPa~2MPa), shake thoroughly until the pressure stabilizes, and then record the pressure and pump readings. Measure the pump readings at each pressure accordingly. 6.3.3.3 With pressure as the ordinate and the accumulated pump reading difference as the abscissa, plot the test results on the arithmetic coordinate system to obtain the saturation pressure test curve shown in Figure 3. The inflection point of the curve is the saturation pressure. 400
Accumulated pump reading difference, cm3
Figure 3 Saturation pressure test curve
6.3.3.4 Replace another pump and add the fluid sample, and repeat the determination in 6.3.3.1 to 6.3.3.3. 6.3.3.5 Representative samples have the following conditions: (1) The relative error of the saturation pressure of at least two samples is less than 3%; (2) The saturation pressure is equal to or less than the pressure at the sampling point, and the relative error is not greater than 3%. 6.3.3.6 If several samples are qualified after inspection, the sample with the higher saturation pressure is generally taken as the analysis sample. 6.4 Inspection of surface fluid samples
Surface fluid samples generally refer to oil and gas samples obtained from the first-stage separator. 6.4.1 Inspection of separator gas samples:
6.4.1.1 Heat the separator gas sample bottle upright and keep the temperature constant at the separator temperature for more than 4 hours. Connect the pressure gauge as shown in Figure 4. 6.4.1.2 Open the valve on the gas bottle to connect the pressure gauge. The pressure gauge reading is the gas sample pressure. 6.4.1.3 The relative error between the gas sample pressure and the separator pressure is less than 5% to be qualified. 6.4.1.4 Take gas samples to analyze their components. The test method shall be in accordance with SY/T0529. 6.4.2 Inspection of separator oil samples:
6.4.2.1 Oil sample inspection shall be carried out in accordance with 6.3.1~6.3.3. 6.4.2.2 The separator oil saturation pressure and the separator pressure relative error is less than 5% to be qualified. 6.4.2.3 While measuring the saturation pressure, measure the compressibility coefficient (Co) of the separator oil in accordance with 9.5. 6
6.4.3 Single degassing test of separator oil
SY/T5542—2000
1-Separator gas sample bottle: 2-Pressure gauge;
3-Thermostatic jacket: 4-Valve
Figure 4 Separator gas sample inspection process
6.4.3.1 Select a separator oil bottle that has passed the inspection, refer to the methods and steps of 9.2.2.2~9.2.2.8, and test it at the separator temperature.
6.4.3.2 Data collation:
a) Calculate the oil volume of the oil tank as shown in formula (7).
Vot=Wa/pot
Where: Va—oil volume of the oil tank, cm;
Wo oil mass of the oil tank, g,
pa——oil density of the oil tank (20℃), g/cm. b) Calculate the volume coefficient of the separator oil as shown in formula (8): Bee = Vos/Vot
Where: B
is the volume coefficient of the separator oil;
Vu is the volume of the separator oil (calculated by correcting the difference in pump readings), cms. c) Calculate the gas-oil ratio of the separator oil as shown in formula (9). GOR.=
ToprVi
Where: GOR—gas-oil ratio of separator, cm/cm2 or m/m; To—standard temperature, 293.15K;
Atmospheric pressure during test, MPa;
/Vot-1
V1—volume of released gas at room temperature and atmospheric pressure (volume measured by gas meter), cm; Po
—standard pressure, 0.101325MPa;
Ti——room temperature, K,
d) Calculate the molar composition of tank oil as shown in formula (10). Xu
（8）
：(9)
（10）
........
Where: Xt——molar fraction of component i of tank oil; Xwi——mass fraction of component i of tank oil; M, relative mass of component i.
e) Calculate the composition of separator oil as shown in formula (11). SY/T 5542-2000
X:+4.157×10-1
1+ 4.157× 10 5GOR.
Wherein: X.“--the mole fraction of separator oil; Yt.--the mole fraction of the main component of the tank gas; Mat--the average relative mass of the oil in the tank. 6.4.4 Inspection of oil and gas separation equilibrium state and sampling quality: 6.4.4,1 Inspection purpose:
After the ground separator oil and gas samples are inspected and qualified, it is necessary to check whether the pressure and temperature control of the on-site separator are stable based on the component composition data of the oil and gas samples, and further judge the representativeness of the samples. 6.4.4.2 Inspection method:
According to the thermodynamic relationship, the composition of the separator oil and gas samples in equilibrium, from methane to hexane, lgK should be linearly related to b1
[see formula (12)--formula (14)] TbiTaep
IgKppoct
K;= YsiXst
lgpei -lg (0.101)
where K:
—equilibrium constant of component i;
first-stage separator pressure, MPa;
b—characteristic constant of component i, calculated by formula (14):Th—boiling point of component i, K;
Tp—stage separator temperature, K;
Ysi—molar fraction of component i in separator gas;Pei—critical pressure of component i, MPa;Tci—i Critical temperature of the component, K. 7 Formation fluid preparation
7.1 Preparation
7.1.1 Recompression of separator gas:
Use gas booster pump method or freezing recompression method to transfer the separator gas at the separator temperature into a piston high-pressure container and pressurize it to the sample preparation pressure.
7.1.2 Determination of gas deviation coefficient under sample preparation conditions: 7.1.2.1 Experimental steps:
SY/T5542—2000
) Connect the process according to Figure 5. Constant temperature bath keeps the temperature at the sample preparation temperature for more than 4h6
1-High pressure metering pump: 2-High pressure container; 3-Constant temperature bath; 4-Gas indicator bottle; 5-Gas meter; 6-Valve Figure 5 Gas deviation coefficient determination process|| tt||b) Use a metering pump to pressurize the separator gas sample in the high-pressure container to the sample pressure and keep it stable: c) Record the initial readings of the metering pump and gas meter.
d) Open the top valve of the high-pressure container, maintain the pressure and slowly discharge about 20cm3 of high-pressure gas, and close the top valve; e) Read the final readings of the pump and gas meter, and record the room temperature and atmospheric pressure. f) Repeat the test three or more times according to c) to e). 7.1.2,2 Calculate the gas deviation coefficient under sample conditions as shown in formula (15). Z,=-V,z
TppiVi
Where: Z. ——Gas deviation coefficient under sample conditions: p.-\-sample pressure, MPa:
V—Volume of high-pressure gas (calculated by the difference in pump readings after correction), cn; T. ——Sample temperature (generally set to the separator temperature), K; Z,——Gas deviation coefficient under room temperature and atmospheric pressure (generally approximately equal to 1). 7.2 Sample calculation
7.2.1 Correction of on-site gas-oil ratio is shown in formula (16). GOR, = GOR
Where: GOR—corrected gas-oil ratio, m2/m2; GOR
On-site gas-oil ratio, m/;
d—relative density of natural gas used for on-site gas volume calculation: Z—deviation coefficient of natural gas used for on-site gas volume calculation; L----relative density of natural gas measured in the laboratory; dz
—deviation coefficient of natural gas under separator conditions measured in the laboratory 7.2.2 Calculation of first-stage separator gas-oil ratio:
If the separator gas-oil ratio is provided on the sample delivery form, it can be corrected according to 7.2.1. If the production gas-oil ratio is provided, it must be converted into the separator gas-oil ratio [see formula (17)]. GOR, = GOR,/B.
Where: (GO)R,
First-stage separator gas-oil ratio, m2/m2.2 Reduce the pressure to the next predetermined pressure (pressure interval is 1MPa~2MPa), shake thoroughly until the pressure stabilizes, and then record the pressure and pump readings. Measure the pump readings at each pressure accordingly. 6.3.3.3 With pressure as the ordinate and the accumulated pump reading difference as the abscissa, plot the test results on the arithmetic coordinate system to obtain the saturation pressure test curve shown in Figure 3. The inflection point of the curve is the saturation pressure. 400
Accumulated pump reading difference, cm3
Figure 3 Saturation pressure test curve
6.3.3.4 Replace another pump and add the fluid sample, and repeat the determination in 6.3.3.1 to 6.3.3.3. 6.3.3.5 Representative samples have the following conditions: (1) The relative error of the saturation pressure of at least two samples is less than 3%; (2) The saturation pressure is equal to or less than the pressure at the sampling point, and the relative error is not greater than 3%. 6.3.3.6 If several samples are qualified after inspection, the sample with the higher saturation pressure is generally taken as the analysis sample. 6.4 Inspection of surface fluid samples
Surface fluid samples generally refer to oil and gas samples obtained from the first-stage separator. 6.4.1 Inspection of separator gas samples:
6.4.1.1 Heat the separator gas sample bottle upright and keep the temperature constant at the separator temperature for more than 4 hours. Connect the pressure gauge as shown in Figure 4. 6.4.1.2 Open the valve on the gas bottle to connect the pressure gauge. The pressure gauge reading is the gas sample pressure. 6.4.1.3 The relative error between the gas sample pressure and the separator pressure is less than 5% to be qualified. 6.4.1.4 Take gas samples to analyze their components. The test method shall be in accordance with SY/T0529. 6.4.2 Inspection of separator oil samples:
6.4.2.1 Oil sample inspection shall be carried out in accordance with 6.3.1~6.3.3. 6.4.2.2 The separator oil saturation pressure and the separator pressure relative error is less than 5% to be qualified. 6.4.2.3 While measuring the saturation pressure, measure the compressibility coefficient (Co) of the separator oil in accordance with 9.5. 6
6.4.3 Single degassing test of separator oil
SY/T5542—2000
1-Separator gas sample bottle: 2-Pressure gauge;
3-Thermostatic jacket: 4-Valve
Figure 4 Separator gas sample inspection process
6.4.3.1 Select a separator oil bottle that has passed the inspection, refer to the methods and steps of 9.2.2.2~9.2.2.8, and test it at the separator temperature.
6.4.3.2 Data collation:
a) Calculate the oil volume of the oil tank as shown in formula (7).
Vot=Wa/pot
Where: Va—oil volume of the oil tank, cm;
Wo oil mass of the oil tank, g,
pa——oil density of the oil tank (20℃), g/cm. b) Calculate the volume coefficient of the separator oil as shown in formula (8): Bee = Vos/Vot
Where: B
is the volume coefficient of the separator oil;
Vu is the volume of the separator oil (calculated by correcting the difference in pump readings), cms. c) Calculate the gas-oil ratio of the separator oil as shown in formula (9). GOR.=
ToprVi
Where: GOR—gas-oil ratio of separator, cm/cm2 or m/m; To—standard temperature, 293.15K;
Atmospheric pressure during test, MPa;
/Vot-1
V1—volume of released gas at room temperature and atmospheric pressure (volume measured by gas meter), cm; Po
—standard pressure, 0.101325MPa;
Ti——room temperature, K,
d) Calculate the molar composition of tank oil as shown in formula (10). Xu
（8）
：(9)
（10）
........
Where: Xt——molar fraction of component i of tank oil; Xwi——mass fraction of component i of tank oil; M, relative mass of component i.
e) Calculate the composition of separator oil as shown in formula (11). SY/T 5542-2000
X:+4.157×10-1
1+ 4.157× 10 5GOR.
Wherein: X.“--the mole fraction of separator oil; Yt.--the mole fraction of the main component of the tank gas; Mat--the average relative mass of the oil in the tank. 6.4.4 Inspection of oil and gas separation equilibrium state and sampling quality: 6.4.4,1 Inspection purpose:
After the ground separator oil and gas samples are inspected and qualified, it is necessary to check whether the pressure and temperature control of the on-site separator are stable based on the component composition data of the oil and gas samples, and further judge the representativeness of the samples. 6.4.4.2 Inspection method:
According to the thermodynamic relationship, the composition of the separator oil and gas samples in equilibrium, from methane to hexane, lgK should be linearly related to b1
[see formula (12)--formula (14)] TbiTaep
IgKppoct
K;= YsiXst
lgpei -lg (0.101)
where K:
—equilibrium constant of component i;
first-stage separator pressure, MPa;
b—characteristic constant of component i, calculated by formula (14):Th—boiling point of component i, K;
Tp—stage separator temperature, K;
Ysi—molar fraction of component i in separator gas;Pei—critical pressure of component i, MPa;Tci—i Critical temperature of the component, K. 7 Formation fluid preparation
7.1 Preparation
7.1.1 Recompression of separator gas:
Use gas booster pump method or freezing recompression method to transfer the separator gas at the separator temperature into a piston high-pressure container and pressurize it to the sample preparation pressure.
7.1.2 Determination of gas deviation coefficient under sample preparation conditions: 7.1.2.1 Experimental steps:
SY/T5542—2000
) Connect the process according to Figure 5. Constant temperature bath keeps the temperature at the sample preparation temperature for more than 4h6
1-High pressure metering pump: 2-High pressure container; 3-Constant temperature bath; 4-Gas indicator bottle; 5-Gas meter; 6-Valve Figure 5 Gas deviation coefficient determination process|| tt||b) Use a metering pump to pressurize the separator gas sample in the high-pressure container to the sample pressure and keep it stable: c) Record the initial readings of the metering pump and gas meter.
d) Open the top valve of the high-pressure container, maintain the pressure and slowly discharge about 20cm3 of high-pressure gas, and close the top valve; e) Read the final readings of the pump and gas meter, and record the room temperature and atmospheric pressure. f) Repeat the test three or more times according to c) to e). 7.1.2,2 Calculate the gas deviation coefficient under sample conditions as shown in formula (15). Z,=-V,z
TppiVi
Where: Z. ——Gas deviation coefficient under sample conditions: p.-\-sample pressure, MPa:
V—Volume of high-pressure gas (calculated by the difference in pump readings after correction), cn; T. ——Sample temperature (generally set to the separator temperature), K; Z,——Gas deviation coefficient under room temperature and atmospheric pressure (generally approximately equal to 1). 7.2 Sample calculation
7.2.1 Correction of on-site gas-oil ratio is shown in formula (16). GOR, = GOR
Where: GOR—corrected gas-oil ratio, m2/m2; GOR
On-site gas-oil ratio, m/;
d—relative density of natural gas used for on-site gas volume calculation: Z—deviation coefficient of natural gas used for on-site gas volume calculation; L----relative density of natural gas measured in the laboratory; dz
—deviation coefficient of natural gas under separator conditions measured in the laboratory 7.2.2 Calculation of first-stage separator gas-oil ratio:
If the separator gas-oil ratio is provided on the sample delivery form, it can be corrected according to 7.2.1. If the production gas-oil ratio is provided, it must be converted into the separator gas-oil ratio [see formula (17)]. GOR, = GOR,/B.
Where: (GO)R,
First-stage separator gas-oil ratio, m2/m2.5 Representative samples have the following conditions: (1) The relative error of the saturation pressure of at least two samples is less than 3%; (2) The saturation pressure is equal to or less than the pressure at the sampling point, and the relative error is not greater than 3%. 6.3.3.6 If several samples are qualified after inspection, the sample with the higher saturation pressure is generally taken as the analysis sample. 6.4 Inspection of surface fluid samples
Surface fluid samples generally refer to oil and gas samples obtained from the first-stage separator. 6.4.1 Inspection of separator gas samples:
6.4.1.1 Heat the separator gas sample bottle upright and keep the temperature constant at the separator temperature for more than 4 hours. Connect the pressure gauge as shown in Figure 4. 6.4.1.2 Open the valve on the gas bottle to connect the pressure gauge. The pressure gauge reading is the gas sample pressure. 6.4.1.3 The relative error between the gas sample pressure and the separator pressure is less than 5% to be qualified. 6.4.1.4 Take gas samples to analyze their components. The test method shall be in accordance with SY/T0529. 6.4.2 Inspection of separator oil samples:
6.4.2.1 Oil sample inspection shall be carried out in accordance with 6.3.1~6.3.3. 6.4.2.2 The separator oil saturation pressure and the separator pressure relative error is less than 5% to be qualified. 6.4.2.3 While measuring the saturation pressure, measure the compressibility coefficient (Co) of the separator oil in accordance with 9.5. 6
6.4.3 Single degassing test of separator oil
SY/T5542—2000
1-Separator gas sample bottle: 2-Pressure gauge;
3-Thermostatic jacket: 4-Valve
Figure 4 Separator gas sample inspection process
6.4.3.1 Select a separator oil bottle that has passed the inspection, refer to the methods and steps of 9.2.2.2~9.2.2.8, and test it at the separator temperature.
6.4.3.2 Data collation:
a) Calculate the oil volume of the oil tank as shown in formula (7).
Vot=Wa/pot
Where: Va—oil volume of the oil tank, cm;
Wo oil mass of the oil tank, g,
pa——oil density of the oil tank (20℃), g/cm. b) Calculate the volume coefficient of the separator oil as shown in formula (8): Bee = Vos/Vot
Where: B
is the volume coefficient of the separator oil;
Vu is the volume of the separator oil (calculated by correcting the difference in pump readings), cms. c) Calculate the gas-oil ratio of the separator oil as shown in formula (9). GOR.=
ToprVi
Where: GOR—gas-oil ratio of separator, cm/cm2 or m/m; To—standard temperature, 293.15K;
Atmospheric pressure during test, MPa;
/Vot-1
V1—volume of released gas at room temperature and atmospheric pressure (volume measured by gas meter), cm; Po
—standard pressure, 0.101325MPa;
Ti——room temperature, K,
d) Calculate the molar composition of tank oil as shown in formula (10). Xu
（8）
：(9)
（10）
........
Where: Xt——molar fraction of component i of tank oil; Xwi——mass fraction of component i of tank oil; M, relative mass of component i.
e) Calculate the composition of separator oil as shown in formula (11). SY/T 5542-2000
X:+4.157×10-1
1+ 4.157× 10 5GOR.
Wherein: X.“--the mole fraction of separator oil; Yt.--the mole fraction of the main component of the tank gas; Mat--the average relative mass of the oil in the tank. 6.4.4 Inspection of oil and gas separation equilibrium state and sampling quality: 6.4.4,1 Inspection purpose:
After the ground separator oil and gas samples are inspected and qualified, it is necessary to check whether the pressure and temperature control of the on-site separator are stable based on the component composition data of the oil and gas samples, and further judge the representativeness of the samples. 6.4.4.2 Inspection method:
According to the thermodynamic relationship, the composition of the separator oil and gas samples in equilibrium, from methane to hexane, lgK should be linearly related to b1
[see formula (12)--formula (14)] TbiTaep
IgKppoct
K;= YsiXst
lgpei -lg (0.101)
where K:
—equilibrium constant of component i;
first-stage separator pressure, MPa;
b—characteristic constant of component i, calculated by formula (14):Th—boiling point of component i, K;
Tp—stage separator temperature, K;
Ysi—molar fraction of component i in separator gas;Pei—critical pressure of component i, MPa;Tci—i Critical temperature of the component, K. 7 Formation fluid preparation
7.1 Preparation
7.1.1 Recompression of separator gas:
Use gas booster pump method or freezing recompression method to transfer the separator gas at the separator temperature into a piston high-pressure container and pressurize it to the sample preparation pressure.
7.1.2 Determination of gas deviation coefficient under sample preparation conditions: 7.1.2.1 Experimental steps:
SY/T5542—2000
) Connect the process according to Figure 5. Constant temperature bath keeps the temperature at the sample preparation temperature for more than 4h6
1-High pressure metering pump: 2-High pressure container; 3-Constant temperature bath; 4-Gas indicator bottle; 5-Gas meter; 6-Valve Figure 5 Gas deviation coefficient determination process|| tt||b) Use a metering pump to pressurize the separator gas sample in the high-pressure container to the sample pressure and keep it stable: c) Record the initial readings of the metering pump and gas meter.
d) Open the top valve of the high-pressure container, maintain the pressure and slowly discharge about 20cm3 of high-pressure gas, and close the top valve; e) Read the final readings of the pump and gas meter, and record the room temperature and atmospheric pressure. f) Repeat the test three or more times according to c) to e). 7.1.2,2 Calculate the gas deviation coefficient under sample conditions as shown in formula (15). Z,=-V,z
TppiVi
Where: Z. ——Gas deviation coefficient under sample conditions: p.-\-sample pressure, MPa:
V—Volume of high-pressure gas (calculated by the difference in pump readings after correction), cn; T. ——Sample temperature (generally set to the separator temperature), K; Z,——Gas deviation coefficient under room temperature and atmospheric pressure (generally approximately equal to 1). 7.2 Sample calculation
7.2.1 Correction of on-site gas-oil ratio is shown in formula (16). GOR, = GOR
Where: GOR—corrected gas-oil ratio, m2/m2; GOR
On-site gas-oil ratio, m/;
d—relative density of natural gas used for on-site gas volume calculation: Z—deviation coefficient of natural gas used for on-site gas volume calculation; L----relative density of natural gas measured in the laboratory; dz
—deviation coefficient of natural gas under separator conditions measured in the laboratory 7.2.2 Calculation of first-stage separator gas-oil ratio:
If the separator gas-oil ratio is provided on the sample delivery form, it can be corrected according to 7.2.1. If the production gas-oil ratio is provided, it must be converted into the separator gas-oil ratio [see formula (17)]. GOR, = GOR,/B.
Where: (GO)R,
First-stage separator gas-oil ratio, m2/m2.5 Representative samples have the following conditions: (1) The relative error of the saturation pressure of at least two samples is less than 3%; (2) The saturation pressure is equal to or less than the pressure at the sampling point, and the relative error is not greater than 3%. 6.3.3.6 If several samples are qualified after inspection, the sample with the higher saturation pressure is generally taken as the analysis sample. 6.4 Inspection of surface fluid samples
Surface fluid samples generally refer to oil and gas samples obtained from the first-stage separator. 6.4.1 Inspection of separator gas samples:
6.4.1.1 Heat the separator gas sample bottle upright and keep the temperature constant at the separator temperature for more than 4 hours. Connect the pressure gauge as shown in Figure 4. 6.4.1.2 Open the valve on the gas bottle to connect the pressure gauge. The pressure gauge reading is the gas sample pressure. 6.4.1.3 The relative error between the gas sample pressure and the separator pressure is less than 5% to be qualified. 6.4.1.4 Take gas samples to analyze their components. The test method shall be in accordance with SY/T0529. 6.4.2 Inspection of separator oil samples:
6.4.2.1 Oil sample inspection shall be carried out in accordance with 6.3.1~6.3.3. 6.4.2.2 The separator oil saturation pressure and the separator pressure relative error is less than 5% to be qualified. 6.4.2.3 While measuring the saturation pressure, measure the compressibility coefficient (Co) of the separator oil in accordance with 9.5. 6
6.4.3 Single degassing test of separator oil
SY/T5542—2000
1-Separator gas sample bottle: 2-Pressure gauge;
3-Thermostatic jacket: 4-Valve
Figure 4 Separator gas sample inspection process
6.4.3.1 Select a separator oil bottle that has passed the inspection, refer to the methods and steps of 9.2.2.2~9.2.2.8, and test it at the separator temperature.
6.4.3.2 Data collation:
a) Calculate the oil volume of the oil tank as shown in formula (7).
Vot=Wa/pot
Where: Va—oil volume of the oil tank, cm;
Wo oil mass of the oil tank, g,
pa——oil density of the oil tank (20℃), g/cm. b) Calculate the volume coefficient of the separator oil as shown in formula (8): Bee = Vos/Vot
Where: B
is the volume coefficient of the separator oil;
Vu is the volume of the separator oil (calculated by correcting the difference in pump readings), cms. c) Calculate the gas-oil ratio of the separator oil as shown in formula (9). GOR.=
ToprVi
Where: GOR—gas-oil ratio of separator, cm/cm2 or m/m; To—standard temperature, 293.15K;
Atmospheric pressure during test, MPa;
/Vot-1
V1—volume of released gas at room temperature and atmospheric pressure (volume measured by gas meter), cm; Po
—standard pressure, 0.101325MPa;
Ti——room temperature, K,
d) Calculate the molar composition of tank oil as shown in formula (10). Xu
（8）
：(9)
（10）
........
Where: Xt——molar fraction of component i of tank oil; Xwi——mass fraction of component i of tank oil; M, relative mass of component i.
e) Calculate the composition of separator oil as shown in formula (11). SY/T 5542-2000
X:+4.157×10-1
1+ 4.157× 10 5GOR.
Wherein: X.“--the mole fraction of separator oil; Yt.--the mole fraction of the main component of the tank gas; Mat--the average relative mass of the oil in the tank. 6.4.4 Inspection of oil and gas separation equilibrium state and sampling quality: 6.4.4,1 Inspection purpose:
After the ground separator oil and gas samples are inspected and qualified, it is necessary to check whether the pressure and temperature control of the on-site separator are stable based on the component composition data of the oil and gas samples, and further judge the representativeness of the samples. 6.4.4.2 Inspection method:
According to the thermodynamic relationship, the composition of the separator oil and gas samples in equilibrium, from methane to hexane, lgK should be linearly related to b1
[see formula (12)--formula (14)] TbiTaep
IgKppoct
K;= YsiXst
lgpei -lg (0.101)
where K:
—equilibrium constant of component i;bzxz.net
first-stage separator pressure, MPa;
b—characteristic constant of component i, calculated by formula (14):Th—boiling point of component i, K;
Tp—stage separator temperature, K;
Ysi—molar fraction of component i in separator gas;Pei—critical pressure of component i, MPa;Tci—i Critical temperature of the component, K. 7 Formation fluid preparation
7.1 Preparation
7.1.1 Recompression of separator gas:
Use gas booster pump method or freezing recompression method to transfer the separator gas at the separator temperature into a piston high-pressure container and pressurize it to the sample preparation pressure.
7.1.2 Determination of gas deviation coefficient under sample preparation conditions: 7.1.2.1 Experimental steps:
SY/T5542—2000
) Connect the process according to Figure 5. Constant temperature bath keeps the temperature at the sample preparation temperature for more than 4h6
1-High pressure metering pump: 2-High pressure container; 3-Constant temperature bath; 4-Gas indicator bottle; 5-Gas meter; 6-Valve Figure 5 Gas deviation coefficient determination process|| tt||b) Use a metering pump to pressurize the separator gas sample in the high-pressure container to the sample pressure and keep it stable: c) Record the initial readings of the metering pump and gas meter.
d) Open the top valve of the high-pressure container, maintain the pressure and slowly discharge about 20cm3 of high-pressure gas, and close the top valve; e) Read the final readings of the pump and gas meter, and record the room temperature and atmospheric pressure. f) Repeat the test three or more times according to c) to e). 7.1.2,2 Calculate the gas deviation coefficient under sample conditions as shown in formula (15). Z,=-V,z
TppiVi
Where: Z. ——Gas deviation coefficient under sample conditions: p.-\-sample pressure, MPa:
V—Volume of high-pressure gas (calculated by the difference in pump readings after correction), cn; T. ——Sample temperature (generally set to the separator temperature), K; Z,——Gas deviation coefficient under room temperature and atmospheric pressure (generally approximately equal to 1). 7.2 Sample calculation
7.2.1 Correction of on-site gas-oil ratio is shown in formula (16). GOR, = GOR
Where: GOR—corrected gas-oil ratio, m2/m2; GOR
On-site gas-oil ratio, m/;
d—relative density of natural gas used for on-site gas volume calculation: Z—deviation coefficient of natural gas used for on-site gas volume calculation; L----relative density of natural gas measured in the laboratory; dz
—deviation coefficient of natural gas under separator conditions measured in the laboratory 7.2.2 Calculation of first-stage separator gas-oil ratio:
If the separator gas-oil ratio is provided on the sample delivery form, it can be corrected according to 7.2.1. If the production gas-oil ratio is provided, it must be converted into the separator gas-oil ratio [see formula (17)]. GOR, = GOR,/B.
Where: (GO)R,
First-stage separator gas-oil ratio, m2/m2.3 Single degassing test of separator oil
SY/T5542—2000
1-Separator gas sample bottle: 2-Pressure gauge;
3-Thermostatic jacket: 4-Valve
Figure 4 Separator gas sample inspection process
6.4.3.1 Select a separator oil bottle that has passed the inspection, refer to the methods and steps of 9.2.2.2~9.2.2.8, and test it at the separator temperature.
6.4.3.2 Data collation:
a) Calculate the oil volume of the oil tank as shown in formula (7).
Vot=Wa/pot
Where: Va—oil volume of the oil tank, cm;
Wo oil mass of the oil tank, g,
pa——oil density of the oil tank (20℃), g/cm. b) Calculate the volume coefficient of the separator oil as shown in formula (8): Bee = Vos/Vot
Where: B
is the volume coefficient of the separator oil;
Vu is the volume of the separator oil (calculated by correcting the difference in pump readings), cms. c) Calculate the gas-oil ratio of the separator oil as shown in formula (9). GOR.=
ToprVi
Where: GOR—gas-oil ratio of separator, cm/cm2 or m/m; To—standard temperature, 293.15K;
Atmospheric pressure during test, MPa;
/Vot-1
V1—volume of released gas at room temperature and atmospheric pressure (volume measured by gas meter), cm; Po
—standard pressure, 0.101325MPa;
Ti——room temperature, K,
d) Calculate the molar composition of tank oil as shown in formula (10). Xu
（8）
：(9)
（10）
........
Where: Xt——molar fraction of component i of tank oil; Xwi——mass fraction of component i of tank oil; M, relative mass of component i.
e) Calculate the composition of separator oil as shown in formula (11). SY/T 5542-2000
X:+4.157×10-1
1+ 4.157× 10 5GOR.
Wherein: X.“--the mole fraction of separator oil; Yt.--the mole fraction of the main component of the tank gas; Mat--the average relative mass of the oil in the tank. 6.4.4 Inspection of oil and gas separation equilibrium state and sampling quality: 6.4.4,1 Inspection purpose:
After the ground separator oil and gas samples are inspected and qualified, it is necessary to check whether the pressure and temperature control of the on-site separator are stable based on the component composition data of the oil and gas samples, and further judge the representativeness of the samples. 6.4.4.2 Inspection method:
According to the thermodynamic relationship, the composition of the separator oil and gas samples in equilibrium, from methane to hexane, lgK should be linearly related to b1
[see formula (12)--formula (14)] TbiTaep
IgKppoct
K;= YsiXst
lgpei -lg (0.101)
where K:
—equilibrium constant of component i;
first-stage separator pressure, MPa;
b—characteristic constant of component i, calculated by formula (14):Th—boiling point of component i, K;
Tp—stage separator temperature, K;
Ysi—molar fraction of component i in separator gas;Pei—critical pressure of component i, MPa;Tci—i Critical temperature of the component, K. 7 Formation fluid preparation
7.1 Preparation
7.1.1 Recompression of separator gas:
Use gas booster pump method or freezing recompression method to transfer the separator gas at the separator temperature into a piston high-pressure container and pressurize it to the sample preparation pressure.
7.1.2 Determination of gas deviation coefficient under sample preparation conditions: 7.1.2.1 Experimental steps:
SY/T5542—2000
) Connect the process according to Figure 5. Constant temperature bath keeps the temperature at the sample preparation temperature for more than 4h6
1-High pressure metering pump: 2-High pressure container; 3-Constant temperature bath; 4-Gas indicator bottle; 5-Gas meter; 6-Valve Figure 5 Gas deviation coefficient determination process|| tt||b) Use a metering pump to pressurize the separator gas sample in the high-pressure container to the sample pressure and keep it stable: c) Record the initial readings of the metering pump and gas meter.
d) Open the top valve of the high-pressure container, maintain the pressure and slowly discharge about 20cm3 of high-pressure gas, and close the top valve; e) Read the final readings of the pump and gas meter, and record the room temperature and atmospheric pressure. f) Repeat the test three or more times according to c) to e). 7.1.2,2 Calculate the gas deviation coefficient under sample conditions as shown in formula (15). Z,=-V,z
TppiVi
Where: Z. ——Gas deviation coefficient under sample conditions: p.-\-sample pressure, MPa:
V—Volume of high-pressure gas (calculated by the difference in pump readings after correction), cn; T. ——Sample temperature (generally set to the separator temperature), K; Z,——Gas deviation coefficient under room temperature and atmospheric pressure (generally approximately equal to 1). 7.2 Sample calculation
7.2.1 Correction of on-site gas-oil ratio is shown in formula (16). GOR, = GOR
Where: GOR—corrected gas-oil ratio, m2/m2; GOR
On-site gas-oil ratio, m/;
d—relative density of natural gas used for on-site gas volume calculation: Z—deviation coefficient of natural gas used for on-site gas volume calculation; L----relative density of natural gas measured in the laboratory; dz
—deviation coefficient of natural gas under separator conditions measured in the laboratory 7.2.2 Calculation of first-stage separator gas-oil ratio:
If the separator gas-oil ratio is provided on the sample delivery form, it can be corrected according to 7.2.1. If the production gas-oil ratio is provided, it must be converted into the separator gas-oil ratio [see formula (17)]. GOR, = GOR,/B.
Where: (GO)R,
First-stage separator gas-oil ratio, m2/m2.3 Single degassing test of separator oil
SY/T5542—2000
1-Separator gas sample bottle: 2-Pressure gauge;
3-Thermostatic jacket: 4-Valve
Figure 4 Separator gas sample inspection process
6.4.3.1 Select a separator oil bottle that has passed the inspection, refer to the methods and steps of 9.2.2.2~9.2.2.8, and test it at the separator temperature.
6.4.3.2 Data collation:
a) Calculate the oil volume of the oil tank as shown in formula (7).
Vot=Wa/pot
Where: Va—oil volume of the oil tank, cm;
Wo oil mass of the oil tank, g,
pa——oil density of the oil tank (20℃), g/cm. b) Calculate the volume coefficient of the separator oil as shown in formula (8): Bee = Vos/Vot
Where: B
is the volume coefficient of the separator oil;
Vu is the volume of the separator oil (calculated by correcting the difference in pump readings), cms. c) Calculate the gas-oil ratio of the separator oil as shown in formula (9). GOR.=
ToprVi
Where: GOR—gas-oil ratio of separator, cm/cm2 or m/m; To—standard temperature, 293.15K;
Atmospheric pressure during test, MPa;
/Vot-1
V1—volume of released gas at room temperature and atmospheric pressure (volume measured by gas meter), cm; Po
—standard pressure, 0.101325MPa
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