An online detection and sampling system for crude oil pipelines

Abstract

The invention discloses an online detection sampling system for a crude oil pipeline, and belongs to the technical field of crude oil sampling detection. The invention is a detection sampling system for crude oil bypass sampling detection arranged on the oil pipeline, and a gas-liquid separation mechanism is added in the sampling module. When the crude oil is introduced into the sampling tube, the crude oil moves in a serpentine shape from top to bottom along a plurality of flow-guiding cavitation components, which not only extends the flow path, but also changes the flow direction of the crude oil, cooperates with a plurality of vibration bars on a vibration net to intensify the impact force on the crude oil, so that the crude oil is fully dispersed to precipitate gas, and under the action of ultrasonic waves, the vibration sleeve, the vibration net and the vibration bars play a vibration cavitation role on the crude oil flowing through each separation space, which makes it easier for the gas in the crude oil to precipitate. In the process of performing multiple cycles of gas-liquid separation, it not only plays a good gas-liquid separation role, but also plays a good stirring and dispersing role on the crude oil, and improves the degree of oil-water mixing, so as to improve the accuracy of subsequent detection results.

Description

Technical Field

[0001] The present invention relates to the technical field of crude oil sampling and detection, and more specifically to an online detection sampling system for a crude oil pipeline. Background Art

[0002] The water content of crude oil is a basic production data in the field of oil exploration. It plays an important role in oil production engineering, storage and transportation engineering, and petrochemical industry. In the crude oil water content detection system, the sampling detection structure is generally installed on the oil pipeline, and the probe is used to emit electromagnetic waves in all directions. After passing through the medium, it is reflected back by the reflection wall. Due to the different absorption capacity of oil and water for electromagnetic waves, the specific oil-water ratio can be calculated by the attenuation amplitude and phase change of the reflected signal. In the case of pure liquid, the accuracy is higher. When the gas content of the oil well increases, part of the gas is filled in the pipeline, making it impossible for the measuring probe to be completely submerged in the liquid, and the measurement accuracy is reduced.

[0003] After searching, the Chinese patent number is: CN117849317A, which discloses "An automatic sampling and detection device for the water content of crude oil". This patent uses a double flow channel on the basis of the original device to achieve gas-liquid separation by setting a settling pipe and an electric valve on the pipeline. However, in the actual sampling and detection process, there are still certain defects, as follows: when the double flow channel is used for crude oil to pass, the crude oil will be deposited in the settling pipe under the action of gravity, and the upper and lower ends of the settling pipe and the oil pipeline are always in a flow state. The crude oil in the oil pipeline will continue to flow through the settling pipe. When the crude oil continues to flow, the gas will also enter the settling pipe, making it difficult to achieve a good gas-liquid separation, thus affecting the subsequent detection accuracy to a certain extent.

[0004] Therefore, we propose an online detection and sampling system for crude oil pipelines to address the above problems. Summary of the invention

[0005] The purpose of the present invention is to solve the existing practical problems. Compared with the existing technology, an online detection sampling system for a crude oil pipeline is provided. The detection sampling system is set on the oil pipeline as a crude oil bypass sampling detection, and a gas-liquid separation mechanism is added in the sampling module. When the crude oil is introduced into the sampling tube, the crude oil moves in a serpentine shape from top to bottom along multiple flow-guiding cavitation components, which not only extends the flow path, but also changes the flow direction of the crude oil. The impact force on the crude oil is intensified by cooperating with multiple vibration bars on the vibration net, so that the crude oil is fully dispersed to precipitate gas, and under the action of ultrasonic waves, the vibration sleeve, the vibration net and the vibration bar play a vibration cavitation role on the crude oil flowing through each separation space, which makes it easier for the gas in the crude oil to precipitate. In the process of multiple cycles of gas-liquid separation, it not only plays a good gas-liquid separation role, but also plays a good stirring and dispersion role on the crude oil, improves the degree of oil-water mixing, so as to improve the accuracy of subsequent detection results.

[0006] The object of the present invention can be achieved through the following technical solutions: an online detection sampling system for a crude oil pipeline, comprising an assembly box installed at the lower end of the oil pipeline, wherein a sampling module, a detection module and a discharge module connected end to end are installed inside the assembly box, wherein the sampling module and the discharge module are respectively connected to the lower end walls on both sides of the oil pipeline, wherein the sampling module comprises a sampling tube fixedly installed at the lower end of the oil pipeline, wherein a gas-liquid separation mechanism and an exhaust mechanism are installed on the sampling tube, and a circulating pump connected to the top end thereof is installed at the bottom end of the sampling tube;

[0007] The gas-liquid separation mechanism includes an ultrasonic generator installed at the outer end wall of the sampling tube and a vibration sleeve that is sleeved in the sampling tube and acts on the ultrasonic generator. A plurality of flow-guiding cavitation components that are connected end to end are installed inside the vibration sleeve from top to bottom. The upper and lower plurality of flow-guiding cavitation components divide the interior of the vibration sleeve into a plurality of separation spaces. A flow port is provided on the lower end wall of each flow-guiding cavitation structure. A plurality of exhaust holes that are respectively connected to the top end of the separation space are provided on the end walls on both sides of the vibration sleeve that are in contact with the sampling tube.

[0008] Furthermore, the detection module includes a detection tube installed at the bottom end of the sampling tube and a conical sleeve installed on the detection tube, and the conical sleeve is provided with a detector extending into the interior of the detection tube and capable of moving up and down. The discharge module includes a discharge pipe fixed to the other end of the detection tube, and the discharge end of the discharge pipe is connected to the bottom end wall of the oil pipeline through a pump, and the exhaust end of the exhaust mechanism is fixed to the discharge end of the pump.

[0009] Furthermore, the sampling tube is in an L-shaped structure, and the flow-guiding cavitation structure is installed on the vertical section of the L-shaped tube, and the detection module is docked and installed on the horizontal section of the L-shaped tube.

[0010] Furthermore, the guide cavitation structure includes a guide plate obliquely fixed on the inner wall of the vibration sleeve, the upper end wall of the guide plate is fixedly connected with a vibration net matching its structure, and a plurality of vibration bars are embedded and installed on the upper end of the vibration net. The vibration net and the vibration bars are both provided with dense holes, and the upper and lower guide plates are inclined downward and staggered end to end, so as to make the crude oil introduced from the oil pipeline move in a serpentine manner from top to bottom to extend the flow path, and a vibration net connected to the vibration sleeve is added to the guide plate. Under the action of the ultrasonic generator, the vibration sleeve and the vibration net play a vibration cavitation role on the crude oil flowing through the sampling tube, making it easier for the gas in the crude oil to precipitate.

[0011] Furthermore, the exhaust mechanism includes an air collecting box installed on the outer end walls on both sides of the sampling tube, and the air collecting box is embedded with a plurality of one-way exhaust ports inserted in the exhaust holes. A pair of top ends of the air collecting boxes are connected by a connecting sleeve, and the connecting sleeve is connected to the outside of the exhaust pipe with a connecting pipe connected to the discharge end of the pump through the exhaust pipe.

[0012] Furthermore, a flow meter for detecting the gas flow is fixedly installed on the connecting pipe, and the gas flow passing through the connecting pipe is detected at preset time intervals. When the detected gas flow is less than the preset flow threshold, there is no need to perform gas-liquid separation operation. At this time, the circulation pump is turned off, and the second solenoid valve is opened. The crude oil separated for the last time in the sampling tube is passed into the detection tube for subsequent detection work.

[0013] Furthermore, a solenoid valve 1 is installed at the end where the sampling tube is connected to the oil pipeline, and a solenoid valve 2 and a solenoid valve 3 are installed respectively at the left and right ends where the detection tube is connected to the sampling tube and the discharge tube.

[0014] Furthermore, a support frame is fixedly installed inside the assembly box, the detector is slidably installed in the support frame through a moving block, and an electric push rod for driving the moving block to move up and down is fixedly installed at the bottom end of the support.

[0015] Furthermore, the detection end of the detector extends into the detection tube, and the top fixed sleeve of the detection end of the detector is connected with a sealing plug that is sealingly and movably connected with the inner wall of the upper end of the conical sleeve. The detector can move up and down in the vertical direction. The detection end of the detector detects the crude oil in the detection tube and the conical sleeve at different heights. Since water and oil are separable, multiple detection data are obtained from top and bottom, which effectively avoids inaccurate detection caused by a single detection.

[0016] The present invention also provides a crude oil pipeline online detection sampling method, comprising the following steps:

[0017] Step 1: First, close the solenoid valve 2 and the solenoid valve 3, and open the solenoid valve 1. The sampling module is connected to the oil pipeline and is in working mode. The crude oil is quantitatively introduced into the sampling tube from the oil pipeline.

[0018] Step 2: The crude oil introduced into the sampling tube moves downward in a snake shape from top to bottom along multiple flow-guiding cavitation structures. During the flow, under the action of the ultrasonic generator, the vibration sleeve, the vibration net and the vibration strips vibrate and cavitate the crude oil, and the gas separated from the crude oil moves upward along the separation space and is introduced into the exhaust mechanism through the one-way exhaust port;

[0019] Step 3: After a fixed amount of crude oil is introduced into the sampling tube, close the solenoid valve 1, start the circulation pump, and use the circulation pump to circulate the crude oil at the bottom of the sampling tube into the top of the sampling tube again for the next round of gas-liquid separation. At the same time, the precipitated gas is discharged into the oil pipeline again through the exhaust pipe and the connecting pipe. During the gas-liquid separation process, the flow meter is used to detect the gas flow passing through the connecting pipe at preset time intervals until the detected gas flow is less than the preset flow threshold. At this time, the circulation pump is closed to end the gas-liquid separation operation of the first batch of crude oil;

[0020] Step 4: After the gas-liquid separation operation of the first batch of crude oil is completed, the second solenoid valve is opened, and the crude oil separated for the last time in the sampling tube is passed into the detection tube, and then the second solenoid valve is closed, and the crude oil is introduced into the detection tube and the conical sleeve, and the water content of the crude oil is detected by the detector. During the detection process, the detector is driven from top to bottom by the electric push rod, and the detection end of the detector detects the crude oil at different heights to obtain multiple detection data, and the detection data are averaged to obtain the final water content average. During the detection process, the first solenoid valve is opened again to perform the gas-liquid separation operation of the next batch of crude oil;

[0021] Step 5. After the first batch of testing is completed, open the solenoid valve 3 and use the pump to discharge the tested crude oil back into the oil pipeline. Repeat this cycle to obtain the average water content of the crude oil after multiple gas separations. After the sampling and testing work is completed, use the pump to drain the crude oil in the testing sampling system.

[0022] Compared with the prior art, the advantages of the present invention are:

[0023] The scheme is to set up a detection sampling system for crude oil bypass sampling detection on the oil pipeline, including a sampling module, a detection module and a discharge module connected end to end, wherein a gas-liquid separation mechanism is added in the sampling module. When the crude oil is introduced into the sampling tube, the crude oil moves in a serpentine shape from top to bottom along multiple flow-guiding cavitation components, which not only extends the flow path, but also changes the flow direction of the crude oil, cooperates with multiple vibration bars on the vibration net to intensify the impact force on the crude oil, so that the crude oil is fully dispersed to precipitate gas, and under the action of ultrasonic waves, the vibration sleeve, the vibration net and the vibration bar play a vibration cavitation role on the crude oil flowing through each separation space, which makes it easier for the gas in the crude oil to precipitate. In the process of multiple cycles of gas-liquid separation, it not only plays a good gas-liquid separation role, but also plays a good stirring and dispersion role on the crude oil, improves the degree of oil-water mixing, so as to improve the accuracy of subsequent detection results.

[0024] (2) This solution also adds a flow meter to the exhaust mechanism. During the gas-liquid separation process, the gas flow passing through the connection pipe is detected at preset time intervals until the detected gas flow is less than the preset flow threshold. The gas-liquid separation operation is terminated and the continuously separated gas flow is used as the judgment of the gas-liquid separation effect. This is beneficial to reduce the impact of gas on the detection results in the subsequent crude oil water content detection process. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0026] Figure 2 It is a structural schematic diagram of the oil pipeline, the sampling module, the detection module and the discharge module of the present invention;

[0027] Figure 3 It is a structural schematic diagram of the sampling module of the present invention;

[0028] Figure 4 The splitting diagram of the sampling module of the present invention is shown in FIG. Figure 1 ;

[0029] Figure 5 The splitting diagram of the sampling module of the present invention is shown in FIG. Figure 2 ;

[0030] Figure 6 It is a structural schematic diagram of the gas-liquid separation component of the present invention;

[0031] Figure 7 It is a partial cross-sectional view of the sampling module of the present invention;

[0032] Figure 8 It is a cross-sectional schematic diagram of the present invention during the gas-liquid separation operation during sampling;

[0033] Fig. 9 It is a cross-sectional schematic diagram of the present invention during the gas-liquid separation operation after sampling;

[0034] Fig.10 It is a cross-sectional schematic diagram of the present invention during detection.

[0035] Description of the numbers in the figure:

[0036] 1. Oil pipeline; 2. Assembly box; 3. Sampling tube; 4. Vibration sleeve; 5. Guide plate; 6. Vibration net; 601. Vibration strip; 7. Gas collecting box; 8. One-way exhaust port; 9. Ultrasonic generator; 10. Connecting sleeve; 101. Exhaust pipe; 11. Circulation pump; 12. Detection tube; 13. Conical sleeve; 14. Detector; 15. Electric push rod; 16. Drain pipe; 17. Pump; 18. Connecting pipe; 19. Flow meter; 20. Solenoid valve one; 21. Solenoid valve two; 22. Solenoid valve three. DETAILED DESCRIPTION

[0037] The following will combine the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all the embodiments. All other embodiments obtained by ordinary technicians in this field without creative work based on the embodiments of the present invention belong to the scope of protection of the present invention.

[0038] Example 1: The present invention discloses an online detection sampling system for crude oil pipelines. Figure 1, including an assembly box 2 fixedly installed at the lower end of the oil pipeline 1, a sampling module, a detection module and a discharge module connected end to end are installed inside the assembly box 2, and the sampling module and the discharge module are respectively connected to the lower end walls on both sides of the oil pipeline 1, a sampling tube 3 fixedly installed at the lower end of the oil pipeline 1, the sampling tube 3 is L-shaped and fixed on the lower end wall of the oil pipeline 1, and the guide cavitation structure is installed on the vertical section of the L-shaped tube, the detection module is docked and installed on the horizontal section of the L-shaped tube, and a solenoid valve 20 is installed at the end of the sampling tube 3 opposite to the oil pipeline 1.

[0039] See also Figure 2 The sampling tube 3 is provided with a gas-liquid separation mechanism and an exhaust mechanism. A circulation pump 11 connected to the top of the sampling tube 3 is provided at the bottom of the sampling tube 3. The liquid inlet and liquid outlet of the circulation pump 11 are respectively connected to the bottom and top of the sampling tube 3. The circulation pump 11 is used to reintroduce the crude oil introduced into the bottom of the sampling tube 3 into the top of the sampling tube 3, and performs multiple circulation separation operations through the gas-liquid separation mechanism.

[0040] Among them, see Figure 3-Figure 7 The gas-liquid separation mechanism includes an ultrasonic generator 9 fixedly mounted on the outer end wall of the sampling tube 3 and a vibration sleeve 4 sleeved in the sampling tube 3 and acting on the ultrasonic generator 9. A plurality of flow-guiding cavitation components connected end to end are installed inside the vibration sleeve 4 from top to bottom. The ultrasonic generator 9 converts the high-frequency electrical signal from the ultrasonic generator 9 into mechanical vibration by using an ultrasonic converter, that is, transmits the ultrasonic wave to the vibration sleeve 4 and the flow-guiding cavitation component.

[0041] The upper and lower multiple flow-guiding cavitation components divide the interior of the vibration sleeve 4 into multiple separation spaces. The lower end wall of each flow-guiding cavitation structure is provided with a flow opening, and the upper and lower multiple flow openings are staggered left and right. The end walls on both sides of the vibration sleeve 4 that are in contact with the sampling tube 3 are provided with multiple exhaust holes that are respectively connected to the top of the separation space.

[0042] Specifically, the guide cavitation structure includes a guide plate 5 obliquely fixed on the inner wall of the vibration sleeve 4, and the upper end wall of the guide plate 5 is fixedly connected to a vibration net 6 matching its structure, and a plurality of vibration bars 601 are embedded and installed on the upper end of the vibration net 6. The vibration net 6 and the vibration bars 601 are both distributed with dense holes, see Figure 7 , Figure 8 The upper and lower guide plates 5 are tilted downward and staggered end to end, and are used to move the crude oil introduced from the oil pipeline 1 in a serpentine motion from top to bottom, which not only extends the flow path, but also changes the flow direction of the crude oil, cooperates with the multiple vibration bars 601 on the vibration net 6 to intensify the impact force on the crude oil, so that the crude oil is fully dispersed to precipitate gas;

[0043] Under the action of the ultrasonic generator 9, the vibration sleeve 4, the vibration net 6 and the vibration bar 601 play a vibration cavitation role on the crude oil flowing through the sampling tube 3, which makes it easier for the gas in the crude oil to precipitate. Under normal flow, the crude oil will not move to the upper end of the separation space, while the precipitated gas moves upward along the separation space until it is discharged from the one-way exhaust port 8. On the one hand, it has a good gas-liquid separation effect. On the other hand, in the process of multiple cycles of gas-liquid separation, it has a good stirring and dispersing effect on the crude oil, improves the degree of oil-water mixing, and is beneficial to subsequent detection work.

[0044] See also Figure 3 , Figure 5 as well as Figure 8 The exhaust mechanism includes an air collecting box 7 installed on the outer end walls of both sides of the sampling tube 3, and a plurality of one-way exhaust ports 8 inserted in the exhaust holes are embedded and installed on the air collecting box 7. The top ends of a pair of air collecting boxes 7 are connected by a connecting sleeve 10, and the connecting sleeve 10 is externally connected to a connecting pipe 18 connected to the discharge module through an exhaust pipe 101. The gas separated in the plurality of separation spaces is introduced into the air collecting box 7 through the one-way exhaust ports 8 at the top of each separation space, and the connecting sleeve 10 discharges the gas gathered in the two air collecting boxes 7 through the exhaust pipe 101 and the connecting pipe 18 back into the oil pipeline 1;

[0045] A flow meter 19 for detecting the gas flow is fixedly installed on the connecting pipe 18. The gas flow passing through the connecting pipe 18 is detected at preset time intervals. When the detected gas flow is less than the preset flow threshold, there is no need to perform gas-liquid separation operation. At this time, the circulation pump 11 is turned off, and the solenoid valve 21 is opened. The crude oil separated for the last time in the sampling tube 3 is passed into the detection tube 12 for subsequent detection work.

[0046] Embodiment 2: Based on Embodiment 1, this embodiment describes the detection module and the emission module in detail, as follows:

[0047] See also Figure 1 , Figure 2 The detection module includes a detection tube 12 fixedly mounted on the bottom end of the sampling tube 3 and a conical sleeve 13 mounted on the detection tube 12. The detection tube 12 is also positioned in the assembly box 2. A detector 14 extending into the interior of the detection tube 12 and capable of moving up and down is mounted on the conical sleeve 13. Solenoid valve 21 and solenoid valve 3 22 are mounted on the left and right ends of the detection tube 12 in sequence.

[0048] A support frame is fixedly installed inside the assembly box 2, and the detector 14 is slidably installed in the support frame through a moving block. An electric push rod 15 is fixedly installed at the bottom of the support frame to drive the moving block up and down. The detection end of the detector 14 extends into the detection tube 12. The top of the detection end of the detector 14 is fixedly sleeved with a sealing plug that is sealed and movably connected with the inner wall of the upper end of the conical sleeve 13. The detector 14 can move up and down appropriately in the vertical direction;

[0049] After the gas-liquid separation operation of the first batch of crude oil is completed, please refer to Fig.10 , open the electromagnetic valve 21, the crude oil separated for the last time in the sampling tube 3 is passed into the detection tube 12, and then the electromagnetic valve 21 is closed, and the crude oil is introduced into the detection tube 12 and the conical sleeve 13 for detection. In this process, the electric push rod 15 is used to drive the detector 14 from top to bottom. The detection end of the detector 14 detects the crude oil at different heights to obtain multiple detection data, and the detection data is averaged to obtain the final water content average. Due to the separation of water and oil, multiple detection data are obtained by up and down, which effectively avoids inaccurate detection caused by a single detection.

[0050] The discharge module includes a discharge pipe 16 fixed to the other end of the detection tube 12. The discharge end of the discharge pipe 16 is connected to the bottom end wall of the oil pipeline 1 through a pump 17. The pump 17 is fixedly installed in the assembly box 2, and the connecting pipe 18 of the exhaust mechanism is fixed to the discharge end of the pump 17. When the first batch of detection processes is completed, the solenoid valve 22 is opened, and the detected crude oil is re-discharged into the oil pipeline 1 through the pump 17. After the sampling and detection work is completed as a whole, the pump 17 is used to drain the crude oil in the detection sampling system.

[0051] According to the combination of Example 1 and Example 2, the present invention also proposes an online detection sampling method for a crude oil pipeline, comprising the following steps:

[0052] Step 1: Please refer to Figure 8 First, close the solenoid valve 21 and the solenoid valve 3 22, open the solenoid valve 1 20, the sampling module is connected to the oil pipeline 1 and is in working mode, and the crude oil is quantitatively introduced from the oil pipeline 1 into the sampling tube 3;

[0053] Step 2: The crude oil introduced into the sampling tube 3 moves downward in a snake shape from top to bottom along the multiple flow-guiding cavitation structures. During the flow, under the action of the ultrasonic generator 9, the vibration sleeve 4, the vibration net 6, and the vibration bar 601 vibrate and cavitate the crude oil, and the gas precipitated from the crude oil moves upward along the separation space and is introduced into the exhaust mechanism through the one-way exhaust port 8;

[0054] Step 3: Please refer to Fig. 9After a fixed amount of crude oil is introduced into the sampling tube 3, the solenoid valve 20 is closed, and the circulation pump 11 is started. The crude oil at the bottom of the sampling tube 3 is circulated and introduced into the top of the sampling tube 3 by the circulation pump 11 again, and the next round of gas-liquid separation is performed. At the same time, the precipitated gas is discharged into the oil pipeline 1 again through the exhaust pipe 101 and the connecting pipe 18. During the gas-liquid separation process, the gas flow passing through the connecting pipe 18 is detected at a preset time interval by the flow meter 19 until the detected gas flow is less than the preset flow threshold. At this time, the circulation pump 11 is closed to end the gas-liquid separation operation of the first batch of crude oil;

[0055] Step 4: After the gas-liquid separation operation of the first batch of crude oil is completed, please refer to Fig.10 , open the electromagnetic valve 21, the crude oil separated for the last time in the sampling tube 3 is passed into the detection tube 12, and then close the electromagnetic valve 21, the crude oil is introduced into the detection tube 12 and the conical sleeve 13, and the water content of the crude oil is detected by the detector 14. During the detection process, the electric push rod 15 is used to drive the detector 14 from top to bottom. The detection end of the detector 14 detects the crude oil at different heights to obtain multiple detection data, and the detection data is averaged to obtain the final water content average. During the detection process, the electromagnetic valve 20 is opened again to perform the gas-liquid separation operation of the next batch of crude oil;

[0056] Step 5, when the first batch of detection processes are completed, open the solenoid valve 3 22, and discharge the detected crude oil back into the oil pipeline 1 through the pump 17. Repeat this cycle to obtain the average water content of the crude oil after multiple gas separations. After the sampling and detection work is completed, use the pump 17 to drain the crude oil in the detection sampling system.

[0057] In summary, the present invention is to set up a detection sampling system for crude oil bypass sampling detection on the oil pipeline 1, including a sampling module, a detection module and a discharge module connected end to end, wherein a gas-liquid separation mechanism and an exhaust mechanism are added to the sampling module, and the gas-liquid separation mechanism includes an ultrasonic generator 9, a vibration sleeve 4 and a plurality of flow-guiding cavitation components connected end to end. When the crude oil is introduced into the sampling tube 3, the crude oil moves in a serpentine shape from top to bottom along the plurality of flow-guiding cavitation components, which not only extends the flow path, but also changes the flow direction of the crude oil, cooperates with the plurality of vibration bars 601 on the vibration net 6 to intensify the impact force on the crude oil, so that the crude oil is fully dispersed to precipitate gas;

[0058] At the same time, under the action of the ultrasonic generator 9, the vibration sleeve 4 and the vibration net 6, 603 play a vibrating cavitation role on the crude oil flowing through, making it easier for the gas in the crude oil to precipitate. The precipitated gas moves upward along the separation space and is introduced into the exhaust mechanism through the one-way exhaust port 8. In the process of multiple cycles of gas-liquid separation, it not only plays a good gas-liquid separation role, but also plays a good stirring and dispersing role on the crude oil, thereby improving the degree of oil-water mixing, so as to improve the subsequent detection results;

[0059] During the gas-liquid separation process, the gas flow passing through the connecting pipe 18 is detected at preset time intervals until the detected gas flow is less than the preset flow threshold, and the gas-liquid separation operation is terminated. The continuously separated gas flow is used as the judgment of the gas-liquid separation effect, which is beneficial to reduce the impact of gas on the detection results in the subsequent crude oil water content detection process.

[0060] The above are only preferred specific implementation modes of the present invention; however, the protection scope of the present invention is not limited thereto; any technician familiar with the technical field within the technical scope disclosed by the present invention; any equivalent replacement or change based on the technical solution and improved concept of the present invention shall be covered within the protection scope of the present invention.

Claims

1. An online detection sampling system for a crude oil pipeline, comprising an assembly box (2) installed at the lower end of the oil pipeline (1), wherein a sampling module, a detection module and a discharge module connected end to end are installed inside the assembly box (2), characterized in that: The sampling module and the discharge module are respectively connected to the lower end walls of the oil pipeline (1) on both sides. The sampling module comprises a sampling tube (3) fixedly mounted on the lower end of the oil pipeline (1). A gas-liquid separation mechanism and an exhaust mechanism are mounted on the sampling tube (3). A circulation pump (11) connected to the top end of the sampling tube (3) is mounted at the bottom end. The gas-liquid separation mechanism comprises an ultrasonic generator (9) mounted on the outer end wall of the sampling tube (3) and a vibration sleeve (4) sleeved in the sampling tube (3) and interacting with the ultrasonic generator (9); a plurality of flow-guiding cavitation components butted end to end are mounted inside the vibration sleeve (4) from top to bottom; the plurality of flow-guiding cavitation components above and below divide the interior of the vibration sleeve (4) into a plurality of separation spaces; a flow opening is provided on the lower end wall of each flow-guiding cavitation structure; a plurality of exhaust holes respectively connected to the top end of the separation space are provided on the end walls on both sides of the vibration sleeve (4) that are in contact with the sampling tube (3); the detection module comprises a detection tube (12) mounted on the bottom end of the sampling tube (3) and a conical sleeve (13) mounted on the detection tube (12); a detector (14) extending into the interior of the detection tube (12) and capable of moving up and down is mounted on the conical sleeve (13); The discharge module comprises a discharge pipe (16) fixed to the other end of the detection tube (12); the discharge end of the discharge pipe (16) is connected to the bottom end wall of the oil pipeline (1) through a pump (17); and the exhaust end of the exhaust mechanism is fixed to the discharge end of the pump (17); the exhaust mechanism comprises an air collecting box (7) installed on the outer end walls of both sides of the sampling tube (3); the air collecting box (7) is embedded with a plurality of one-way exhaust ports (8) inserted in the exhaust holes; a pair of top ends of the air collecting boxes (7) are connected through a connecting sleeve (10); and the connecting sleeve (10) is externally connected to a connecting pipe (18) connected to the discharge end of the pump (17) through an exhaust pipe (101); and a flow meter (19) for detecting gas flow is fixedly installed on the connecting pipe (18); The flow-guiding cavitation structure comprises a flow-guiding plate (5) fixed obliquely on the inner wall of a vibration sleeve (4); a vibration net (6) matching its structure is fixedly connected to the upper end wall of the flow-guiding plate (5); a plurality of vibration bars (601) are embedded and installed at the upper end of the vibration net (6); and dense holes are distributed on both the vibration net (6) and the vibration bars (601); The end of the sampling tube (3) that is connected to the oil pipeline (1) is equipped with a first solenoid valve (20); the left and right ends of the detection tube (12) that are connected to the sampling tube (3) and the discharge tube (16) are equipped with a second solenoid valve (21) and a third solenoid valve (22) in sequence; A support frame is fixedly installed inside the assembly box (2), the detector (14) is slidably installed in the support frame via a moving block, and an electric push rod (15) is fixedly installed at the bottom end of the support frame for driving the moving block to move up and down.

2. The crude oil pipeline online detection sampling system according to claim 1 is characterized by: The sampling tube (3) is in an L-shaped structure, and the flow-guiding cavitation structure is installed on the vertical section of the L-shaped tube, and the detection module is docked and installed on the horizontal section of the L-shaped tube.

3. The crude oil pipeline online detection sampling system according to claim 1 is characterized by: The detection end of the detector (14) extends into the detection tube (12), and the top of the detection end of the detector (14) is fixedly sleeved with a sealing plug that is sealingly and movably connected to the inner wall of the upper end of the conical sleeve (13).

4. A crude oil pipeline online detection sampling method, using a crude oil pipeline online detection sampling system as claimed in any one of claims 1 to 3, characterized in that: The following steps are involved: Step 1: First, the electromagnetic valve 2 (21) and the electromagnetic valve 3 (22) are closed, and the electromagnetic valve 1 (20) is opened. The sampling module is connected to the oil pipeline (1) and is in working mode. Crude oil is quantitatively introduced from the oil pipeline (1) into the sampling tube (3); Step 2: The crude oil introduced into the sampling tube (3) moves downward in a snake shape from top to bottom along the multiple flow-guiding cavitation structures. During the flow, under the action of the ultrasonic generator (9), the vibration sleeve (4), the vibration net (6), and the vibration bar (601) vibrate and cavitate the crude oil, and the gas separated from the crude oil moves upward along the separation space and is introduced into the exhaust mechanism through the one-way exhaust port (8); Step 3: After a fixed amount of crude oil is introduced into the sampling tube (3), the electromagnetic valve 1 (20) is closed, and the circulation pump (11) is started. The crude oil at the bottom end of the sampling tube (3) is circulated again into the top end of the sampling tube (3) by the circulation pump (11) to perform the next round of gas-liquid separation. At the same time, the precipitated gas is discharged into the oil pipeline (1) again by the exhaust mechanism. During the gas-liquid separation process, the gas flow rate flowing through the connecting tube (18) is detected at preset time intervals by the flow meter (19). When the detected gas flow rate is less than a preset flow rate threshold, the circulation pump (11) is closed to terminate the gas-liquid separation operation of the first batch of crude oil. Step 4: After the gas-liquid separation operation of the first batch of crude oil is completed, the second solenoid valve (21) is opened, and the crude oil separated for the last time in the sampling tube (3) is passed into the detection tube (12), and then the second solenoid valve (21) is closed, and the crude oil is introduced into the detection tube (12) and the conical sleeve (13), and the water content of the crude oil is detected by the detector (14). During the detection process, the detector (14) is driven from top to bottom by the electric push rod (15), and the detection end of the detector (14) detects the crude oil at different heights to obtain multiple detection data, and the detection data are averaged to obtain the final water content average value. During the detection process, the first solenoid valve (20) is opened again to perform the gas-liquid separation operation of the next batch of crude oil; Step 5, when the first batch of testing processes are completed, the electromagnetic valve 3 (22) is opened, and the tested crude oil is discharged back into the oil pipeline (1) through the pump (17). This cycle is repeated to obtain the average water content of the crude oil after multiple gas separations. After the sampling and testing work is completed, the crude oil in the testing sampling system is completely discharged using the pump (17).

Images