A crude oil water content analysis device and analysis method

Abstract

The application discloses a crude oil water content analysis device, which comprises an analysis device body and a flow computer, a signal shielding heating device is arranged in the analysis device body, a waveguide radar transmitter is arranged on the top of the analysis device body, a waveguide radar sensor is arranged in the analysis device body and electrically connected with the waveguide radar transmitter and extends to the inside of the signal shielding heating device, crude oil inlet pipes, exhaust pipes and liquid discharge pipes are arranged on the side of the analysis device body and are in communication with the inside of the analysis device body, crude oil inlet electromagnetic valves, exhaust electromagnetic valves and liquid discharge electromagnetic valves are arranged on the crude oil inlet pipes, the exhaust pipes and the liquid discharge pipes respectively. The waveguide radar sensor can accurately measure the liquid levels of water and oil in the case of crude oil layering, and the water content is calculated, so that the error is small.

Description

TECHNICAL FIELD

[0001] The application belongs to the field of crude oil measurement, and particularly relates to a crude oil water content analysis device and analysis method. BACKGROUND

[0002] The water content of crude oil is a key data in oil exploitation, transportation and oil product transaction. Online measurement of the water content of oil wells is of great significance to digital oilfield construction, such as water and oil layer position of oil wells, estimation of crude oil production, prediction of the development life of oil wells, yield and quality control of oil wells, state detection of oil wells, water injection operation, etc. Most of the domestic oilfield wellhead crude oil water content measurement adopts the manual sampling measurement method. This method is seriously dependent on the representativeness of the sampling point and the reliability of the manual operation, and the measurement result is influenced by many factors, cannot be applied to the well conditions with frequent changes in water content, and has the disadvantages of time-consuming and laborious. The manual sampling measurement method cannot be used for real-time measurement of the online measurement system, and cannot meet the requirements of automatic management of oilfield production, and has great limitations in determining the water injection scheme, calculating the crude oil production, and predicting the development life of oil wells. In addition, the existing online measurement methods of water content include: 1. density method; 2. ray method; 3. capacitance method; 4. microwave method, etc. The above methods are all affected by gas, and cannot correctly analyze the water content under the condition that the density of the measured oil and water is similar, and the cost is high. If the ray is used, the environment and the operator are in great danger. Moreover, the errors of the above measurement methods are all between ± 5% and 10%. SUMMARY

[0003] The technical problem to be solved by the application is to provide a crude oil water content analysis device and analysis method to solve the above problems of the prior art. The liquid levels of water and oil can be accurately measured under the condition of crude oil stratification by the guided wave radar sensor, and the water content is calculated, so that the error is small.

[0004] The technical scheme adopted by the present application is: a crude oil water content analysis device, comprising an analysis device body and a flow computer, a signal shielding heating device is arranged in the analysis device body, a guided wave radar transmitter is arranged on the top of the analysis device body, a guided wave radar sensor is arranged in the analysis device body and electrically connected with the guided wave radar transmitter and extends to the inside of the signal shielding heating device, crude oil inlet pipes, exhaust pipes and liquid discharge pipes are arranged on the side of the analysis device body and communicate with the inside of the analysis device body, crude oil inlet electromagnetic valves, exhaust electromagnetic valves and liquid discharge electromagnetic valves are arranged on the crude oil inlet pipes, the exhaust pipes and the liquid discharge pipes respectively, a double-flange liquid level meter is arranged on the side of the analysis device body, a blowdown pipe is arranged at the bottom of the analysis device body and communicates with the inside of the analysis device body, a mass flow meter is arranged at the end of the blowdown pipe away from the analysis device body, a blowdown electromagnetic valve is arranged on the blowdown pipe, the liquid discharge pipe communicates with the blowdown pipe and the communication position is between the mass flow meter and the blowdown electromagnetic valve, and the signal shielding heating device, the guided wave radar transmitter, the crude oil inlet electromagnetic valves, the exhaust electromagnetic valves and the liquid discharge electromagnetic valves are electrically connected with the flow computer.

[0005] In one embodiment, the signal shielding heating device comprises a signal shielding device and an electric heat tracing wound outside the signal shielding device.

[0006] The present application also discloses an analysis method of a crude oil water content analysis device, which is realized by the crude oil water content analysis device and comprises the following steps:

[0007] Step 10: crude oil enters the analysis device body through the crude oil inlet pipe;

[0008] Step 20: the flow computer sets the heating temperature and the heating time according to the actual working condition, controls the signal shielding heating device to start, heats the crude oil in the analysis device body, and the oil and water in the crude oil are separated and the gas is volatilized;

[0009] Step 30: when the heating time is reached, the flow computer opens the exhaust electromagnetic valve, and the gas is discharged from the exhaust pipe;

[0010] Step 40: the guided wave radar sensor collects the liquid levels of the separated oil and water respectively, outputs the collected oil liquid level and water liquid level to the guided wave radar transmitter, and the guided wave radar transmitter outputs the collected oil liquid level and water liquid level data to the flow computer;

[0011] Step 50: the flow computer receives the oil liquid level and water liquid level data and performs water content analysis, when the analysis result is high water content, the flow computer starts the liquid discharge electromagnetic valve to continuously discharge the water in the analysis device body, and when the oil in the analysis device body reaches the liquid level height of the accurate measurement range of the guided wave radar sensor, the liquid discharge electromagnetic valve is closed;

[0012] Step 60, the dual-flange liquid level meter measures the total height of the effluent water and the height of the crude oil and outputs the measured data to the flow computer, the guided wave radar sensor measures the water level height and the crude oil height and outputs the measured data to the flow computer, and the mass flow meter measures the density of the water and the density of the crude oil and outputs the measured data to the flow computer;

[0013] Step 70, the flow computer calculates the volumetric water cut and the mass water cut.

[0014] In one embodiment, in step 70, the calculation of the volumetric water cut is as follows:

[0015]

[0016] wherein W ct is the volumetric water cut, h w is the water level height, h l is the total height of the effluent water, and h0 is the height of the crude oil.

[0017] In one embodiment, in step 70, the calculation of the mass water cut is as follows:

[0018]

[0019] wherein W mt is the mass water cut, p w is the density of the water, h w is the water level height, h l is the total height of the effluent water, p o is the density of the crude oil, h o is the height of the crude oil.

[0020] In one embodiment, the crude oil water analysis method further comprises a guided wave radar sensor data accuracy correction step, and the accuracy correction comprises effluent water mass correction, total liquid level height correction, effluent water level height correction, and indirect water cut correction.

[0021] In one embodiment, the effluent water mass correction is as follows:

[0022] The mass flow meter measures the mass of the effluent water;

[0023] The mass of the effluent water is calculated, and the calculation formula is as follows: m w = p w · v w = p w · h l · A, wherein m w is the mass of the effluent water, p w is the density of the water, v wh is the height of the water level of the effluent water, A is the cross-sectional area of the internal cavity of the analyzer body, and l h is the height of the water level of the effluent water, A is the cross-sectional area of the internal cavity of the analyzer body, and

[0024] The mass of the effluent water measured by the mass flow meter is compared with and corrected by the calculated mass of the effluent water.

[0025] In one embodiment, the total liquid level height correction is as follows:

[0026] The total liquid level heights measured by the guided wave radar transmitter and the double-flange liquid level meter are compared and corrected.

[0027] In one embodiment, the effluent water level height correction is as follows:

[0028] The flow rate of the effluent water measured by the mass flow meter is used to calculate the water level height of the effluent water, and the calculation formula is as follows:

[0029]

[0030] wherein m w is the mass of the effluent water, p w is the density of water, and A is the cross-sectional area of the internal cavity of the analyzer body

[0031] The calculated water level height of the effluent water is compared with and corrected by the water level heights of the effluent water measured by the double-flange liquid level meter and the guided wave radar transmitter.

[0032] In one embodiment, the indirect correction of the water content is as follows:

[0033] After the water content analysis is completed, the water and oil in the internal cavity of the analyzer body are discharged, and the mass flow meter measures the average density p' of the crude oil.

[0034] The total mass of the sampling fluid and the total volume of the sampling fluid are calculated by the volume water content and the mass water content calculated in step 70, and the calculation formulas are as follows:

[0035]

[0036] wherein M is the total mass of the sampling fluid, M w is the mass of the effluent water, W mt is the mass water content, V is the total volume of the sampling fluid, h w is the water level height, h l is the total height of the effluent water, A is the cross-sectional area of the internal cavity of the analyzer body, and W ct is the volume water content

[0037] The average density is calculated by the total mass of the sampling fluid and the total volume of the sampling fluid, and the calculation formula is as follows:

[0038]

[0039] Wherein, the average density of the crude oil calculated is ρ'', the total mass of the sampling fluid is M, and the total volume of the sampling fluid is V;

[0040] The difference between the average density ρ' of the crude oil measured by the mass flow meter and the average density ρ'' of the crude oil calculated is set, and the mass water content and the volume water content are output by comparing ρ' and ρ''.

[0041] The present application has the following advantages:

[0042] 1. The waveguide radar sensor is arranged, the liquid levels of water and oil can be accurately measured in the case of crude oil layering, the water content is calculated, the water content analysis can be completed under the condition that the oil and water densities are similar, and the error is less than ±1%, which is much better than the traditional water content analyzer.

[0043] 2. The waveguide radar sensor, the double-flange liquid level meter and the mass flow meter are used in cooperation, the data measured by the double-flange liquid level meter and the mass flow meter are used to correct the data measured by the waveguide radar sensor, and the authenticity and stability of the measurement are ensured.

[0044] 3. The signal shielding and heating device is arranged in the analysis device body, the interference signals of the waveguide radar are shielded, the false measurement is not easy to occur, the oil and water can be quickly layered, and the gas can be quickly discharged from the upper part. BRIEF DESCRIPTION OF DRAWINGS

[0045] Figure 1 The present application is a structural schematic view.

[0046] In the figure: 1, waveguide radar transmitter; 2, waveguide radar sensor; 3, crude oil inlet electromagnetic valve; 4, double-flange liquid level meter; 5, signal shielding and heating device; 6, liquid discharge electromagnetic valve; 7, sewage discharge electromagnetic valve; 8, mass flow meter; 9, exhaust port electromagnetic valve; 10, analysis device body; 11, flow computer; 12, crude oil inlet pipe; 13, exhaust pipe; 14, liquid discharge pipe; 15, sewage discharge pipe. DETAILED DESCRIPTION

[0047] The present application will be further described in detail below by combining the drawings and specific embodiments.

[0048] For example, Figure 1As shown, a crude oil water content analysis device comprises an analysis device body 10 and a flow computer 11, the analysis device body 10 is internally provided with a signal shielding heating device 5, the top of the analysis device body 10 is provided with a guided wave radar transmitter 1, the inside of the analysis device body 10 is provided with a guided wave radar sensor 2 which is electrically connected with the guided wave radar transmitter 1 and extends to the inside of the signal shielding heating device 5, the side of the analysis device body 10 is respectively provided with a crude oil inlet pipe 12, an exhaust pipe 13 and a liquid discharge pipe 14 which are in communication with the inside of the analysis device body 10, the crude oil inlet pipe 12, the exhaust pipe 13 and the liquid discharge pipe 14 are respectively provided with a crude oil inlet electromagnetic valve 3, an exhaust electromagnetic valve 9 and a liquid discharge electromagnetic valve 6, the side of the analysis device body 10 is further provided with a double-flange liquid level meter 4, the bottom of the analysis device body 10 is provided with a blowdown pipe 15 which is in communication with the inside of the analysis device body 10, the end of the blowdown pipe 15 away from the analysis device body 10 is provided with a mass flow meter 8, the blowdown pipe 15 is provided with a blowdown electromagnetic valve 7, the liquid discharge pipe 14 is in communication with the blowdown pipe 15 and the communication position is between the mass flow meter 8 and the blowdown electromagnetic valve 7, the signal shielding heating device 5, the guided wave radar transmitter 1, the crude oil inlet electromagnetic valve 3, the exhaust electromagnetic valve 9 and the liquid discharge electromagnetic valve 6 are electrically connected with the flow computer 11.

[0049] In the embodiment, the signal shielding heating device 5 comprises a signal shielding device and an electric heat tracing which is wound outside the signal shielding device.

[0050] The analysis device is used for crude oil sampling and water content analysis.

[0051] The application further comprises an analysis method of the crude oil water content analysis device, the analysis method is realized by the above-mentioned crude oil water content analysis device and comprises the following steps.

[0052] Step 10, the crude oil enters the analysis device body 10 through the crude oil inlet pipe 12;

[0053] Step 20, the flow computer 11 sets the heating temperature and the heating time according to the actual working condition, controls the signal shielding heating device 5 to start, heats the crude oil in the analysis device body 10, and the oil and water in the crude oil are separated and the gas is volatilized;

[0054] Step 30, when the heating time is reached, the flow computer 11 opens the exhaust electromagnetic valve, and the gas is discharged from the exhaust pipe 13;

[0055] Step 40, the guided wave radar sensor 2 collects the liquid levels of the separated oil and water respectively, outputs the collected oil liquid level and water liquid level to the guided wave radar transmitter 1, and the guided wave radar transmitter 1 outputs the collected oil liquid level and water liquid level data to the flow computer 11;

[0056] Step 50, the flow computer 11 receives the oil level and water level data and carries out water content analysis, if the analysis result is high water content, the flow computer 11 starts the drain electromagnetic valve 6 to continuously drain the water in the analysis device body 10, when the oil in the analysis device body 10 reaches the liquid level height of the accurate measurement range of the guided wave radar sensor 2, the drain electromagnetic valve 6 is closed;

[0057] Step 60, the double-flange liquid level gauge 4 measures the total height of the drained water and the crude oil height and outputs the measured data to the flow computer 11, the guided wave radar sensor 2 measures the water level height and the crude oil height and outputs the measured data to the flow computer 11, and the mass flowmeter 8 measures the density of the water and the density of the crude oil and outputs the measured data to the flow computer 11;

[0058] Step 70, the flow computer 11 calculates the volume water content and the mass water content.

[0059] In this embodiment, in step 70, the calculation of the volume water content is as follows:

[0060]

[0061] Wherein, W ct is the volume water content, h w is the water level height, h l is the total height of the drained water, and h0 is the crude oil height.

[0062] In this embodiment, in step 70, the calculation of the mass water content is as follows:

[0063]

[0064] Wherein, W mt is the mass water content, ρ w is the density of the water, h w is the water level height, h l is the total height of the drained water, ρ o is the density of the crude oil, h o is the crude oil height.

[0065] In this embodiment, the crude oil water content analysis method further comprises a guided wave radar sensor 2 data accuracy correction step, and the accuracy correction comprises a drained water mass correction, a total liquid level height correction, a drained water level height correction, and an indirect water content correction.

[0066] In this embodiment, the drained water mass correction is as follows:

[0067] The mass flowmeter 8 measures the mass of the drained water;

[0068] The mass of the discharged water is calculated according to the following formula: m w = p w v w = p w h l A, wherein m w is the mass of the discharged water, p w is the density of water, v w is the volume of the discharged water, h l is the total height of the discharged water, and A is the cross-sectional area of the inner cavity of the analyzer body 10.

[0069] The mass of the discharged water measured by the mass flow meter 8 is compared with the calculated mass of the discharged water and corrected.

[0070] In this embodiment, the total liquid level height correction is as follows:

[0071] The total liquid level height is measured by the guided wave radar transmitter 1 and the double-flange liquid level meter 4, and the measured total liquid level height is compared and corrected.

[0072] In this embodiment, the water level height correction of the discharged water is as follows:

[0073] The flow rate of the discharged water is measured by the mass flow meter 8, and the water level height of the discharged water is calculated according to the following formula:

[0074]

[0075] wherein m w is the mass of the discharged water, p w is the density of water, and a is the cross-sectional area of the inner cavity of the analyzer body 10.

[0076] The calculated water level height of the discharged water is compared with the water level height of the discharged water measured by the double-flange liquid level meter 4 and the guided wave radar transmitter 1, and corrected.

[0077] In this embodiment, the indirect correction of the water content is as follows:

[0078] After the water content analysis is completed, the water and oil in the analyzer body 10 are discharged, and the average density p' of the crude oil is measured by the mass flow meter 8.

[0079] The total mass of the sampling fluid and the total volume of the sampling fluid are calculated according to the volume water content and the mass water content calculated in step 70, according to the following formulas:

[0080]

[0081] wherein M is the total mass of the sampling fluid, m w is the mass of the discharged water, and W is the total volume of the sampling fluid.mt is the mass water content, V is the total volume of the sampling fluid, h w is the water level height, h l is the total height of the discharged water, A is the cross-sectional area of the cavity in the analysis device body 10, W ct is the volume water content;

[0082] The average density is calculated by the total mass of the sampling fluid and the total volume of the sampling fluid, and the calculation formula is as follows:

[0083]

[0084] Wherein, ρ" is the calculated average density of the crude oil, M is the total mass of the sampling fluid, and V is the total volume of the sampling fluid;

[0085] The difference between the average density ρ' of the crude oil measured by the mass flowmeter 8 and the calculated average density ρ" of the crude oil is set, and ρ' and ρ" are compared, and if the difference is within the difference value, the mass water content and the volume water content are output.

[0086] In the method, in step 50, the accurate measurement range of the guided wave radar sensor 2 is determined by the design parameters of the guided wave radar sensor 2. At the same time, in step 50, the flow computer 11 receives the oil level and water level data to perform water content analysis, and the analysis method is: setting the high water content proportional relationship of the oil level and the water level, if the water level is higher than the oil level and exceeds the set proportional relationship, it is determined that the crude oil is in a high water content state.

[0087] In the method, during the measurement process, the flow computer 11 performs water content analysis, and if it is determined that the crude oil is in a high water content state, the water in the analysis device body 10 will be discharged. During this process, the double-flange liquid level meter 4 can feed back the liquid level signal to the flow computer 11 in real time, and the flow computer 11 can control the opening and closing of the crude oil inlet electromagnetic valve 3 to realize automatic adjustment of the liquid level height.

[0088] In the method, the guided wave radar transmitter 1 and the double-flange liquid level meter 4 respectively measure the total liquid level height, and the measured total liquid level height is compared and corrected. The total liquid level height is the height of the crude oil remaining in the analysis device body 10 + the height of the continuously discharged water. In the method, the difference between the average density ρ' of the crude oil measured by the mass flowmeter 8 and the calculated average density ρ" of the crude oil is generally set to 5%.

[0089] The above-described embodiments only express the specific implementation of the present application, and the description is more specific and detailed, but it cannot be understood as a limitation on the scope of the patent of the present application. It should be noted that for ordinary skilled persons in the art, without departing from the concept of the present application, a number of modifications and improvements can be made, which are within the scope of protection of the present application.

Claims

1. A crude oil water cut analysis device, characterized by: The analysis device comprises an analysis device body (10) and a flow computer (11), the inside of the analysis device body (10) is provided with a signal shielding heating device (5), the top of the analysis device body (10) is provided with a guided wave radar transmitter (1), the inside of the analysis device body (10) is provided with a guided wave radar sensor (2) which is electrically connected with the guided wave radar transmitter (1) and extends to the inside of the signal shielding heating device (5), the side of the analysis device body (10) is respectively provided with a crude oil inlet pipe (12), an exhaust pipe (13) and a liquid discharge pipe (14) which are in communication with the inside of the analysis device body (10), the crude oil inlet pipe (12), the exhaust pipe (13) and the liquid discharge pipe (14) are respectively provided with a crude oil inlet electromagnetic valve (3), an exhaust electromagnetic valve (9) and a liquid discharge electromagnetic valve (6), the side of the analysis device body (10) is further provided with a double-flange liquid level meter (4), the bottom of the analysis device body (10) is provided with a blowdown pipe (15) which is in communication with the inside of the analysis device body (10), the end of the blowdown pipe (15) away from the analysis device body (10) is provided with a mass flow meter (8), the blowdown pipe (15) is provided with a blowdown electromagnetic valve (7), the liquid discharge pipe (14) is in communication with the blowdown pipe (15) and the communication position is between the mass flow meter (8) and the blowdown electromagnetic valve (7), the signal shielding heating device (5), the guided wave radar transmitter (1), the crude oil inlet electromagnetic valve (3), the exhaust electromagnetic valve (9) and the liquid discharge electromagnetic valve (6) are electrically connected with the flow computer (11).

2. The water-in-crude oil analyzer of claim 1, wherein: The signal shielding heating device (5) comprises a signal shielding device and an electric heat tracing which is wound outside the signal shielding device.

3. A method for water-in-crude oil analysis, characterized by: The analysis method is realized by the crude oil water content analysis device in any one of claims 1-2, and comprises the following steps: Step 10, crude oil enters the analysis device body (10) through the crude oil inlet pipe (12); Step 20, the flow computer (11) sets the heating temperature and the heating time according to the actual working condition, controls the signal shielding heating device (5) to start, and heats the crude oil in the analysis device body (10), so that the oil and water in the crude oil are separated and the gas is volatilized; Step 30, when the heating time is reached, the flow computer (11) opens the exhaust electromagnetic valve, and the gas is discharged through the exhaust pipe (13); Step 40, the guided wave radar sensor (2) collects the liquid levels of the separated oil and water respectively, and outputs the collected oil liquid level and water liquid level to the guided wave radar transmitter (1), and the guided wave radar transmitter (1) outputs the collected oil liquid level and water liquid level data to the flow computer (11); Step 50, the flow computer (11) receives the oil liquid level and water liquid level data and performs water content analysis, if the analysis result is high water content, the flow computer (11) starts the liquid discharge electromagnetic valve (6) to continuously discharge the water in the analysis device body (10), and when the oil in the analysis device body (10) reaches the liquid level height of the accurate measurement range of the guided wave radar sensor (2), the liquid discharge electromagnetic valve (6) is closed. Step 60, the double-flange liquid level meter (4) measures the total height of the discharged water and the crude oil height and outputs the measured data to the flow computer (11), the guided wave radar sensor (2) measures the water level height and the crude oil height and outputs the measured data to the flow computer (11), and the mass flowmeter (8) measures the density of the water and the density of the crude oil and outputs the measured data to the flow computer (11); Step 70, the flow computer (11) calculates the volume water cut and the mass water cut.

4. A method of water-in-crude oil analysis according to claim 3, characterized in that: In step 70, the volume water cut is calculated in the following manner: where W ct is the volumetric water content, h w is the water level height, h l is the total height of the drained water, and ho is the height of the crude oil.

5. The method of claim 3, wherein: In step 70, the mass water cut is calculated in the following manner: where W mt is the mass water content, p w is the density of water, h w is the water level height, h l is the total height of the water drained, p o is the density of the crude oil, h o is the height of the crude oil.

6. A method of water-in-crude oil analysis according to claim 5, characterized in that: The crude oil water analysis method further comprises a guided wave radar sensor (2) data accuracy correction step, and the accuracy correction comprises a discharged water mass correction, a total liquid level height correction, a discharged water water level height correction, and an indirect water cut correction.

7. A method of water-in-crude oil analysis according to claim 6, characterized in that: The discharged water mass correction is as follows: The mass flowmeter (8) measures the mass of the discharged water; The mass of the discharged water is calculated according to the following formula: m w = p w · v w = p w · h l · A, wherein m w is the mass of the discharged water, p w is the density of the water, v w is the volume of the discharged water, h l is the total height of the discharged water, and A is the cross-sectional area of the inner cavity of the analysis device body (10). The mass of the discharged water measured by the mass flowmeter (8) is compared with the calculated mass of the discharged water and corrected.

8. The method of claim 6, wherein: The total liquid level height correction is as follows: The guided wave radar transmitter (1) and the double-flange liquid level meter (4) respectively measure the total liquid level height, and the measured total liquid level heights are compared and corrected.

9. The method of claim 6, wherein: The discharged water water level height correction is as follows: The mass flowmeter (8) measures the flow of the discharged water, and the water level height of the discharged water is calculated according to the following formula: wherein m w is the mass of water expelled, p w is the density of water, A is the cross-sectional area of the internal cavity of the analytical device body (10). The calculated water level height of the discharged water is compared with the water level height of the discharged water measured by the double-flange liquid level meter (4) and the guided wave radar transmitter (1) and corrected.

10. The method of claim 6, wherein: The indirect water cut correction is as follows: After the water cut analysis is completed, the water and oil in the discharge analysis device body (10) are measured by the mass flowmeter (8) to obtain the average density of the crude oil ρ′; The total mass of the sampling fluid and the total volume of the sampling fluid are calculated according to the volume water cut and the mass water cut calculated in step 70, and the calculation formulas are as follows: where M is the total mass of the sampled fluid, M w is the mass of the drained water, W mt is the mass water content, V is the total volume of the sampled fluid, h w is the water level height, h l is the total height of the drained water, A is the cross-sectional area of the inner chamber of the body of the analysis device (10), W ct is the volumetric water content; The average density is calculated according to the calculated total mass of the sampling fluid and the total volume of the sampling fluid, and the calculation formula is as follows: Wherein, ρ″ is the calculated average density of the crude oil, M is the total mass of the sampling fluid, and V is the total volume of the sampling fluid; The difference between the average density of the crude oil ρ′ measured by the mass flowmeter (8) and the calculated average density of the crude oil ρ″ is set, and ρ′ and ρ″ are compared, and if the difference is within the difference value, the mass water cut and the volume water cut are output.

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