Speed regulating pig control algorithm verification device and experimental method

Abstract

The application discloses a kind of speed regulating pig control algorithm verification device and experimental method, which comprises: speed regulating pig is loaded into ball launching device;Open gas-liquid supply system, while adjusting gas-liquid flow, obtain pressure fluctuation and gas-liquid flow characteristics, so that serious slug flow appears in pipeline system;When the periodic serious slug flow appears in the pipeline system, after the pressure of the ball launching device reaches the predetermined pressure value, the pig is sent into the pipeline system;Collect the pressure data of the pipeline system, gas-liquid flow pattern, speed of speed regulating pig and liquid output;Close the gas-liquid supply system, and take out the speed regulating pig from the ball collecting device.The application can verify the speed regulating pig control algorithm under serious slug flow condition, so as to ensure the cleaning efficiency under serious slug flow condition and minimize the pressure fluctuation and liquid output.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of deepwater riser pigging, and particularly relates to a speed-adjusting pig control algorithm verification device and experimental method. BACKGROUND

[0002] With the increasing scarcity of onshore oil and gas resources and the increasing difficulty of exploitation, the development of offshore oil and gas resources has become a development trend. Like onshore pipelines, in order to ensure the quality of pipeline transportation, pigging and detection operations (pigging and detection are collectively referred to as pigging in the following) need to be carried out periodically to remove impurities such as wax, liquid, hydrate and the like formed by long-term transportation of the medium in the pipeline, or to detect pipeline damage in a timely manner, and to carry out corresponding maintenance and repair operations to avoid serious accidents.

[0003] However, unlike onshore pipelines, offshore pipeline transportation is mainly oil and gas water multi-phase mixed transportation, and the transportation medium is extremely prone to form serious slug flow under the induction of complex flow, terrain and other conditions. The liquid slug length formed by the serious slug flow is more than the length of the riser or even several times the length of the riser, and the pressure drop in the pipe and the gas-liquid flow fluctuation at the riser outlet caused thereby will be extremely serious. Serious slug flow will have a great impact on the production of offshore oil and gas fields, not only reducing the output of the oil and gas field, increasing the corrosion of the pipeline, and even destroying the downstream processing equipment, leading to a dead well accident.

[0004] Under the condition of serious slug flow, pigging operations are carried out on the offshore riser system, in addition to the interference of serious slug flow, the front end of the pig itself also produces a pigging slug flow, and after the superposition of the two slug flows, if the speed of the pig is not controlled by related theories and methods, the pigging operation efficiency will be low due to the unstable speed of the pig, and serious pigging accidents will occur due to the out-of-control speed of the pig, and the loss will be immeasurable.

[0005] In recent years, some scholars have found that by using a pig with a bypass, the speed of the pig can be reduced to a certain extent and the slug flow can be suppressed, and corresponding research results have been obtained. However, the flow of serious slug flow in the pipeline is complex and variable, and the fixed bypass hole cannot be adjusted according to the real-time flow pattern of the slug flow, resulting in unstable speed reduction and slug flow suppression effect of the pig at the present stage, and the instantaneous pressure and flow fluctuation occurs from time to time, and the impact on the riser and the platform is still unavoidable. In view of the existing problems, a pig with a real-time adjustable bypass flow is proposed for pigging of a deepwater riser to stabilize the pigging speed and suppress the influence of serious slug flow on the pigging process.

[0006] The bypass hole adjustable pig mainly has the principle that a hydraulic cylinder or a motor and the like active adjusting device is installed inside the pipeline, the bypass area inside the pig is changed by opening and closing of the adjusting device, the pressure difference before and after the pig is changed, and then the speed adjustment of the pig is completed. Meanwhile, the gas-liquid two-phase flow at the tail of the pig also changes the instantaneous flow characteristics due to the different bypass area sizes, has different influences on the slug flow at the front of the pig, and then plays a regulating role on the flow characteristics of the serious slug flow.

[0007] However, how to adjust the appropriate bypass size according to different instantaneous conditions of the slug flow is a technical problem faced after the engineering solution is proposed. That is, how to determine the appropriate pig bypass control strategy according to different geometric parameters of the riser, different flow rates, different pressures, different gas-liquid two-phase flow components and the like, so as to achieve a relatively stable slug flow suppression effect, so as to prevent the occurrence of pigging accidents is a technical problem to be solved urgently in the operation and maintenance of the marine riser.

[0008] Therefore, there is still a lack of reliable control strategy to guide the pigging operation under the condition of serious slug flow, and the control algorithm needs to be verified through experiments, so the research on the speed-regulating pig control algorithm verification device under the condition of serious slug flow is extremely important. SUMMARY

[0009] In order to overcome the above-mentioned defects of the prior art, the technical problem to be solved by the embodiment of the present application is to provide a speed-regulating pig control algorithm verification device and experimental method, which can test the pressure, flow characteristics, liquid output, speed-regulating pig speed and the like related characteristic parameters of the serious slug flow under different conditions, and is used for verifying the speed-regulating pig control algorithm under the condition of serious slug flow in the downward inclined pipe-vertical riser system, so as to ensure the pigging efficiency under the condition of serious slug flow while minimizing the pressure fluctuation and liquid output, so as to guide the pigging operation of the marine riser system and prevent the occurrence of marine pipeline pigging accidents.

[0010] The specific technical scheme in the embodiment of the present application is:

[0011] A speed-regulating pig control algorithm verification device, the speed-regulating pig control algorithm verification device comprises a gas-liquid supply system, a ball launching device, a pipeline system, a ball collecting device, a data acquisition system and a speed-regulating pig;

[0012] The gas-liquid supply system comprises a water tank for storing liquid, a pump for pressurizing the fluid, and an air compressor;

[0013] One end of the ball launching device is connected with the pipeline system, and the other end is connected with the pump;

[0014] The pipeline system comprises several downward pipes, a bottom elbow of the riser, the riser and a top elbow of the riser connected in sequence; the pipeline system is further provided with a pressure sensor connecting port at a predetermined position;

[0015] The ball collecting device is arranged at the outlet of the pipeline system and used for recovering the pig;

[0016] The data acquisition system comprises a processor and an image acquisition device, a liquid level meter and a pressure sensor electrically connected to the processor, the liquid level meter is arranged on the ball collecting device and used for acquiring instantaneous liquid discharge, the pressure sensor is arranged at the pressure sensor connecting port, and the image acquisition device is used for acquiring the gas-liquid flow pattern of the pipeline system.

[0017] The speed-adjustable pig comprises a hollow core pipe, an adjusting valve arranged on the core pipe and used for adjusting bypass flow, a driving mechanism arranged in the core pipe and used for driving the adjusting valve, and a speed detection mechanism used for measuring the speed of the speed-adjustable pig.

[0018] In a preferred embodiment, the ball launching device comprises a hollow ball launching cylinder, one end of the ball launching cylinder is provided with a quick-opening blind plate, the other end is provided with a valve, and a first liquid inlet is further arranged on the ball launching cylinder and used for being communicated with the pump.

[0019] In a preferred embodiment, the ball launching cylinder comprises a first part close to the quick-opening blind plate and a second part close to the valve, the inner diameter of the first part is greater than that of the second part, and the first part and the second part are connected through a variable cross-section horn.

[0020] In a preferred embodiment, the speed-adjustable pig control algorithm verification device further comprises a pipeline support and support system, and the pipeline system is installed in the pipeline support and support system.

[0021] In a preferred embodiment, the speed-adjustable pig control algorithm verification device further comprises a ball collecting support used for fixing the ball collecting device, and the ball collecting support is arranged on the support system.

[0022] In a preferred embodiment, the ball collecting device is connected with the water tank through a water pipe, and the position of the ball collecting device is higher than that of the water tank.

[0023] In a preferred embodiment, the pressure sensor connection port comprises: a first pressure sensor connection port, a second pressure sensor connection port, a third pressure sensor connection port and a fourth pressure sensor connection port, in the fluid flow direction, the first pressure sensor connection port is located on the most downstream downcomer; the second pressure sensor connection port is located in the standpipe bottom elbow; the third pressure sensor connection port is located in the standpipe; and the fourth pressure sensor connection port is located in the standpipe near the standpipe top elbow.

[0024] In a preferred embodiment, the driving mechanism comprises: a motor, a lead screw driven by the motor, the regulating valve comprises a valve body and a valve core, the valve body is provided with a bypass hole, the motor drives the valve core to move during the axial movement of the lead screw, and the flow section of the bypass hole is changed. In a preferred embodiment, the speed detection mechanism comprises: a permanent magnet arranged on the speed-regulating pig, and a coil wound around the pipe surface of the pipe system.

[0025] A standpipe pigging simulation experiment method for verifying the control algorithm of the above-mentioned speed-regulating pig, the speed-regulating pig stores the control algorithm, and the standpipe pigging simulation experiment method comprises:

[0026] Loading the speed-regulating pig into the ball launching device;

[0027] Opening the gas-liquid supply system, adjusting the gas-liquid flow at the same time, obtaining the pressure fluctuation and the gas-liquid flow characteristics, and making the pipe system appear severe slug flow;

[0028] After the periodic severe slug flow appears in the pipe system, the pig is sent into the pipe system when the pressure of the ball launching device reaches a predetermined pressure value;

[0029] Collecting the pressure data of the pipe system, the gas-liquid flow pattern, the speed of the speed-regulating pig and the liquid discharge amount;

[0030] Closing the gas-liquid supply system, and taking out the speed-regulating pig from the ball collecting device. In a preferred embodiment, the experiment method further comprises: adjusting the bypass rate of the speed-regulating pig based on the control algorithm and the obtained pressure data, gas-liquid flow pattern, speed of the speed-regulating pig and liquid discharge amount, and repeating the above steps, so as to ensure the pigging efficiency under the severe slug flow condition and minimize the pressure fluctuation and the liquid discharge amount.

[0031] The technical scheme of the present application has the following remarkable beneficial effects:

[0032] The application provides a kind of severe plug flow condition under the control algorithm verification device and experimental method of speed regulating pig, can test the pressure, flow characteristics, liquid output, pig speed and other related characteristic parameters of severe plug flow under different working conditions, for verifying the control algorithm of speed regulating pig under severe plug flow condition in downpipe-vertical riser system, so as to ensure the pigging efficiency under severe plug flow condition, and make the pressure fluctuation and liquid output to a minimum, to guide the pigging operation of marine riser system, prevent the occurrence of marine pipeline pigging accident.

[0033] Specific embodiments of the application are disclosed herein, and illustrated in the accompanying drawings, which are meant to be exemplary and not limiting. It is to be understood that the embodiments of the application are not limited in scope to the specific embodiments disclosed. Many modifications, equivalents, and alternatives shown and described in connection with one embodiment are applicable to other embodiments. Features described and / or illustrated in connection with one embodiment can be used in combination with or in place of features of another embodiment. BRIEF DESCRIPTION OF DRAWINGS

[0034] The accompanying drawings, which are included to provide a further understanding of the application and are incorporated in and constitute a part of this application, illustrate embodiments of the application and together with the description serve to explain the principles of the application. In the drawings:

[0035] Figure 1 A schematic diagram of the overall structure of a speed regulating pig control algorithm verification device provided by an embodiment of the application.

[0036] Figure 2 A schematic diagram of a ball launching device of a speed regulating pig control algorithm verification device provided by an embodiment of the application.

[0037] Figure 3 A schematic diagram of a pipeline system of a speed regulating pig control algorithm verification device provided by an embodiment of the application.

[0038] Figure 4 A schematic diagram of a support system of a speed regulating pig control algorithm verification device provided by an embodiment of the application.

[0039] Figure 5 A schematic diagram of the structure of a speed regulating pig of a speed regulating pig control algorithm verification device provided by an embodiment of the application.

[0040] Figure 6A schematic diagram of a speed measurement scheme of a speed-adjustable pig provided in an embodiment of the present application.

[0041] Figure 7 A flow chart of steps of a riser pigging simulation experiment method provided in an embodiment of the present application.

[0042] Reference numerals of the above drawings:

[0043] 1, ball launching device; 11, quick-opening blind plate; 12, first liquid inlet; 13, ball launching cylinder; 14, valve;

[0044] 15, speed-adjustable pig; 151, core pipe; 152, lead screw; 153, motor; 154, built-in permanent magnet;

[0045] 2, pipeline system; 21, first downwardly inclined pipe; 211, second liquid inlet; 212, gas inlet; 22, second downwardly inclined pipe; 23, third downwardly inclined pipe; 24, fourth downwardly inclined pipe; 25, fifth downwardly inclined pipe; 251, first pressure sensor connection port; 26, riser bottom elbow; 261, second pressure sensor connection port; 27, first riser; 271, third pressure sensor connection port; 28, second riser; 281, fourth pressure sensor connection port; 29, riser top elbow;

[0046] 3, ball collecting device;

[0047] 4, support system; 41, bearing table; 42, first bearing beam; 43, ladder; 44, second bearing beam; 45, cross beam;

[0048] 5, ball collecting support;

[0049] 6, pipeline support;

[0050] 7, data acquisition system; 71, high-speed camera; 72, pressure sensing mechanism; 73, processor;

[0051] 8, gas-liquid supply system; 81, water tank; 82, pump; 83, air compressor;

[0052] 9, speed measurement coil. DETAILED DESCRIPTION

[0053] The technical solutions of the present application will be described in detail below in combination with the drawings and specific embodiments, and it should be understood that these embodiments are only used to illustrate the present application and not to limit the scope of the present application, and after reading the present application, various equivalent modifications of the present application by those skilled in the art fall within the scope defined by the appended claims.

[0054] It is to be noted that when an element such as a layer, film, region, or substrate is referred to as being "on" another element, it can be directly on the other element or intervening elements can also be present. In addition, it is to be understood that when a layer is referred to as being "connected", "coupled", or "adjacent" to another element, it can be directly connected, coupled, or adjacent to the other element, or intervening elements can also be present. As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items.

[0055] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in the description of the application herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items.

[0056] The speed-adjusting pig control algorithm verification device provided in the embodiments of the application mainly comprises a pig, a ball launching device, a pipeline system, a data acquisition system, a gas-liquid supply system and a speed-adjusting pig. In addition, the speed-adjusting pig control algorithm verification device can further comprise a ball collecting device, a support system, a ball collecting support, a pipeline support and the like.

[0057] In order to have a clearer understanding of the technical features, objectives and effects of the application, the specific embodiments, structures, features and effects of the speed-adjusting pig control algorithm verification device provided by the application are described in detail below in combination with the drawings and preferred embodiments. In addition, through the description of the specific embodiments, the technical means and effects adopted by the application to achieve the predetermined objectives can be more deeply and specifically understood. However, the drawings are provided only for reference and illustration, and are not used to limit the application.

[0058] In the embodiments of the application, Figure 1 A schematic diagram of the overall structure of the speed-adjusting pig control algorithm verification device provided in the embodiments of the application; Figure 2 A schematic diagram of the ball launching device of the speed-adjusting pig control algorithm verification device provided in the embodiments of the application; Figure 3 A schematic diagram of the pipeline system of the speed-adjusting pig control algorithm verification device provided in the embodiments of the application; Figure 4 A schematic diagram of the support system of the speed-adjusting pig control algorithm verification device provided in the embodiments of the application; Figure 5 A schematic diagram of the structure of the speed-adjusting pig of the speed-adjusting pig control algorithm verification device provided in the embodiments of the application; Figure 6 A schematic diagram of the speed-adjusting pig control algorithm verification device provided in the embodiments of the application; Figure 6 A schematic diagram of the speed-adjusting pig speed measurement scheme provided in the embodiments of the application.

[0059] Please refer to Figure 1 The speed-adjusting pig control algorithm verification device can include a gas-liquid supply system 8, a ball launching device 1, a pipeline system 2, a ball collecting device 3, a data acquisition system 7 and a speed-adjusting pig 15. The gas-liquid supply system 8 includes a water tank 81 for storing liquid, a pump 82 for pressurizing the liquid, and an air compressor 83. One end of the ball launching device 1 is connected to the pipeline system 2, and the other end is connected to the pump 82. The pipeline system 2 includes a plurality of downward pipes, a bottom elbow pipe 26 of a riser, a riser and a top elbow pipe 29 of the riser connected in sequence. The pipeline system 2 is also provided with a pressure sensor connection port at a predetermined position. The ball collecting device 3 is arranged at the outlet of the pipeline system 2 and is used to recover the speed-adjusting pig 15. The data acquisition system 7 includes a processor 73 and an image acquisition device, a liquid level meter and a pressure sensor electrically connected to the processor 73. The liquid level meter is arranged on the ball collecting device and is used to obtain the instantaneous liquid output. The pressure sensor is used to be installed at the pressure sensor connection port. The image acquisition device is used to obtain the gas-liquid flow pattern of the pipeline system 2. The speed-adjusting pig 15 includes a hollow core pipe 151, wherein an adjusting valve for adjusting the bypass flow is arranged on the core pipe 151. A driving mechanism for driving the adjusting valve is arranged in the core pipe 151. The speed-adjusting pig 15 further includes a speed detection mechanism for measuring the speed of the speed-adjusting pig.

[0060] In the embodiments of the present application, the gas-liquid supply system 8 mainly includes a water tank 81, a pump 82 and an air compressor 83. The water tank 81 can be a hollow box structure, which can be used to contain the liquid required for the riser pigging simulation test. The pump 82 is connected to the water tank 81 through a pipeline and is used to output the water in the water tank 81 after pressurization. Specifically, one end of the pump 82 can be connected to the water outlet of the water tank 81 through a connecting pipeline, and the other end can be connected to the ball launching device 1 through a connecting pipeline. The air compressor 83 is used to provide pressurized air. Specifically, the air compressor 83 can be connected to the ball launching device 1 through a connecting pipeline.

[0061] Please refer to Figure 2 In the embodiments of the present application, the ball launching device 1 can be fixed on the pipeline support 6, one end of which is connected to the pipeline system 2, and the other end of which is connected to the pump 82. Under the action of the pump 82, the liquid enters the ball launching device 1 from the water tank 81, and the speed-adjusting pig 15 can be sent into the pipeline system 2.

[0062] The ball-launching device 1 may include a hollow ball-launching tube 13, with a quick-opening blind flange 11 at one end and a valve 14 at the other end. A first liquid inlet 12 is also provided on the ball-launching tube 13, which is used to connect to a pump 82. Opening the quick-opening blind flange 11 allows a speed-regulating pig 15 to be installed inside the ball-launching tube 13; subsequently, opening the valve 14 allows the speed-regulating pig 15 to be sent into the pipeline system 2.

[0063] Specifically, the ball-serving device 1's ball-serving tube 13 may include two parts: a first part near the quick-opening blind plate 11 and a second part near the valve 14. The inner diameter of the first part is larger than that of the second part. The first part and the second part can be connected by a variable cross-section bell mouth. This facilitates the insertion of the speed-regulating pig 15 into the ball-serving tube 13 and also helps to create a pressure difference across the two ends of the speed-regulating pig 15.

[0064] Before the test begins, the quick-opening blind flange 11 is opened, and then the speed-regulating pig 15 is placed into the launching tube 13. The first liquid inlet 12 is connected to the pump 82. After opening the valve 14, the speed-regulating pig 15 can enter the pipeline system 2 under the action of the pressure difference across the two ends of the speed-regulating pig 15.

[0065] like Figure 3 As shown in the embodiments described in this application, the piping system 2 can be installed on the pipe support 6 and the support system 4. Specifically, the piping system 2 may include a plurality of downward-sloping pipes, bottom bends 26 of the riser, risers, and top bends 29 of the riser, which are sequentially connected to form the piping system 2. The number of downward-sloping pipes, bottom bends 26 of the riser, risers, and top bends 29, especially the number of downward-sloping pipes and risers, may vary depending on the actual application scenario and the size of the downward-sloping pipes and risers themselves, and this application does not impose a specific limitation here. Generally, the number of bottom bends 26 and top bends 29 of the riser is one.

[0066] The pipeline system 2 can be equipped with a pressure sensor connection port to connect a pressure sensor and collect fluid pressure data during the test.

[0067] The pipeline connecting the subsea oil well and the offshore platform is laid along the seabed towards the platform after leaving the wellhead, sloping downwards as it approaches the offshore platform, and then extending vertically upwards from below the platform to the sea surface. The pipeline system 2 provided by this invention is a scaled-down version of an actual subsea pipeline system 2, constructed indoors.

[0068] In one specific embodiment, the pipe system 2 can include 5 downcomers (first downcomer 21, second downcomer 22, third downcomer 23, fourth downcomer 24, and fifth downcomer 25), 1 downcomer bottom elbow 26, 2 risers (first riser 27 and second riser 28), and 1 riser top elbow 29, which are connected in sequence by flanges to form the pipe system 2.

[0069] In one specific embodiment, the pipe system 2 can include 5 downcomers (first downcomer 21, second downcomer 22, third downcomer 23, fourth downcomer 24, and fifth downcomer 25), 1 downcomer bottom elbow 26, 2 risers (first riser 27 and second riser 28), and 1 riser top elbow 29, which are connected in sequence by flanges to form the pipe system 2.

[0070] The pipe system 2 is provided with a second liquid inlet 211 and a gas inlet 212, which are connected to the pump 82 and the air compressor 83, respectively, for delivering fluid medium to the pipe system 2. The pipe system 2 is provided with four pressure sensor connection ports (first pressure sensor connection port 251, second pressure sensor connection port 261, third pressure sensor connection port 271, and fourth pressure sensor connection port 281), which are used to connect pressure sensors to collect fluid pressure data during the test.

[0071] In one specific embodiment, the first pressure sensor connection port 251 can be located on the most downstream downcomer (e.g., the fifth downcomer 25) along the fluid flow direction; the second pressure sensor connection port 261 can be located in the downcomer bottom elbow 26; the third pressure sensor connection port can be located in the riser; and the fourth pressure sensor connection port 281 can be located in the riser near the riser top elbow 29. The outlet of the pipe system 2 is connected to the ball collecting device 3.

[0072] In one specific embodiment, the ball collecting device 3 can be used to recover the speed-regulating pig 15. In addition, the ball collecting device 3 can also be used to separate gas and liquid. Specifically, the ball collecting device 3 can be connected to the water tank 81 through a water pipe. The ball collecting device 3 is located on the ball collecting support 5, which is located on the support system 4. The ball collecting device 3 is located higher than the water tank 81. Under the action of gravity, the water in the ball collecting device 3 returns to the water tank 81, and the liquid is circulated in the test device.

[0073] In one specific embodiment, the ball collecting support 5 is mainly used to fix the ball collecting device 3. The support system 4 is mainly used to fix the riser and support the ball collecting support 5.

[0074] As Figure 4As shown, the support system 4 mainly includes: a support platform 41, a first support beam 42, a ladder 43, a second support beam 44, and a crossbeam 45. There can be multiple first support beams 42, distributed below the support platform 41. Specifically, the number of first support beams 42 can vary depending on the specific shape and size of the support platform 41, and this application does not impose a specific limitation here. There can be two second support beams 44. The height of the second support beam 44 is greater than the height of the first support beam 42. For example, the height of the first support beam 42 can be 3m, the height of the second support beam 44 can be 4.5m, and the length of the crossbeam 45 can be 1m.

[0075] The crossbeam 45 can be located between two adjacent second load-bearing beams 44. There can be multiple crossbeams 45, which can be distributed at intervals along the height direction. Specifically, the number of crossbeams 45 can vary depending on the height of the second load-bearing beam 44, and this application does not impose a specific limitation on it.

[0076] In summary of the embodiments described in this application, the data acquisition system 7 mainly includes an image acquisition device (e.g., a high-speed camera 71), multiple pressure sensors, and a processor 73. The high-speed camera 71 and the pressure sensors are both electrically connected to the processor 73, thereby transmitting the acquired image information and pressure signals to the processor 73.

[0077] Specifically, the multiple pressure sensors form a pressure sensing mechanism 72. The number of pressure sensors corresponds to the number of pressure sensor connection ports. When there are four pressure sensor connection ports, there are also four pressure sensors.

[0078] like Figure 5 As shown, the speed-regulating pig 15 mainly includes: a hollow core tube 151, a regulating valve for adjusting the bypass flow, a drive mechanism for driving the regulating valve, and a speed detection mechanism for measuring the speed of the speed-regulating pig 15. The drive mechanism may include: a motor 153, a lead screw 152 driven by the motor 153, and the regulating valve including a valve body and a valve core. The valve body has a bypass hole. During the axial movement of the lead screw 152 driven by the motor 153, the valve core moves, changing the flow cross-section of the bypass hole, thus changing the bypass rate. This allows for efficient and accurate adjustment of the speed of the speed-regulating pig 15, and further research on using the speed-regulating pig 15 to suppress severe slugging flow.

[0079] In addition, it should be noted that the specific form of the adjusting valve and the specific form of the driving mechanism, as well as the matching relationship between the two, are not limited to the above examples. In addition to driving the valve core of the adjusting valve to rotate relative to the valve body, the driving mechanism can also drive the valve core to rotate relative to the valve body, so as to adjust the flow area between the valve body and the valve core, change the bypass rate, and thus be able to adjust the speed of the speed-adjusting pig 15, and further study the use of the speed-adjusting pig 15 to suppress severe plug flow.

[0080] Please refer to Figure 6 The speed detection mechanism comprises a permanent magnet arranged on the speed-adjusting pig and a coil wound on the pipe surface of the pipe system.

[0081] Specifically, the speed measuring coil 9 is wound on the pipe surface of the pipe system 2, and the built-in permanent magnet 154 is installed on the speed-adjusting pig 15. The speed measuring coil 9 is arranged at a distance along the extension direction of the pipeline, and when the speed-adjusting pig 15 moves in the pipeline, the speed-adjusting pig 15 will generate two pulses when passing through the nearest two speed measuring coils 9. The speed of the speed-adjusting pig 15 can be accurately and reliably measured by testing the interval time of the two pulses.

[0082] The speed-adjusting pig control algorithm verification device provided by the present application can first control the gas-liquid inlet speed to form severe plug flow when testing. Then, the speed-adjusting pig 15 is used for pigging, and pressure data, gas-liquid flow pattern, speed of the speed-adjusting pig 15 and liquid output are tested. Then, the bypass rate of the speed-adjusting pig 15 (i.e. the flow passage section of the adjusting valve) is changed, so as to change the speed of the speed-adjusting pig 15.

[0083] Please refer to Figure 7 Based on the speed-adjusting pig control algorithm verification device provided in the above embodiments of the present application, the present application further provides an experimental method of the speed-adjusting pig control algorithm verification device, wherein the speed-adjusting pig 15 stores a control algorithm, and the experimental method comprises the following steps:

[0084] Step S1: loading the speed-adjusting pig 15 into the ball launching device 1;

[0085] Step S2: opening the gas-liquid supply system 8, adjusting the gas-liquid flow, obtaining pressure fluctuation and gas-liquid flow characteristics, and making the pipe system 2 appear severe plug flow;

[0086] Step S3: after the periodic severe plug flow appears in the pipe system 2, the speed-adjusting pig 15 is sent into the pipe system 2 when the pressure of the ball launching device 1 reaches a predetermined pressure value;

[0087] Step S4: collecting pressure data, gas-liquid flow pattern, speed of the speed-adjustable pig and liquid discharge volume of the pipeline system 2;

[0088] Step S5: closing the gas-liquid supply system 8 and taking out the speed-adjustable pig 15 from the ball collecting device 3.

[0089] In addition, the experimental method further comprises: adjusting the bypass rate of the speed-adjustable pig 15 based on the control algorithm and the acquired pressure data, gas-liquid flow pattern, speed of the speed-adjustable pig 15 and liquid discharge volume, and repeating steps 1 to 5 to ensure the pigging efficiency under the condition of severe slug flow and minimize the pressure fluctuation and liquid discharge volume.

[0090] When the experimental method is performed by using the speed-adjustable pig control algorithm verification device, the initial bypass rate of the speed-adjustable pig 15 can be determined first, and the speed-adjustable pig 15 is assembled; the speed-adjustable pig 15 is placed into the ball launching device 1; the gas-liquid supply system 8 is opened, and the gas-liquid flow is adjusted at the same time, and the pressure fluctuation in the pipeline and the gas-liquid flow characteristics are observed, so that the severe slug flow phenomenon occurs in the pipeline; after the periodic severe slug flow occurs, the fluid inlet valve 14 of the ball launching device 1 is opened, and the pressure reading of the ball launching device 1 is observed; when the pressure reaches a certain value, the valve 14 between the ball launching device 1 and the pipeline is opened, and the speed-adjustable pig 15 is sent into the pipeline system 2 under the action of the liquid. The valve 14 of the ball launching device 1 is closed. The pressure data in the pipeline is collected. The high-speed camera 71 is used to collect the gas-liquid flow pattern during the pigging process; the speed detection mechanism is used to collect the speed of the speed-adjustable pig 15, and the liquid level meter is used to acquire the liquid discharge volume. The gas-liquid supply system 8 is closed. The speed-adjustable pig 15 is taken out from the ball collecting device 3. The bypass rate of the speed-adjustable pig 15 is changed subsequently, and the above experimental steps are repeated to analyze the characteristics of the bypass pigging process under the condition of severe slug flow and verify the speed-adjustable pig control algorithm under the condition of severe slug flow.

[0091] The control algorithm is stored in the speed-adjustable pig 15, and the control algorithm specifically refers to the corresponding relationship among the pressure data, gas-liquid flow pattern, speed of the speed-adjustable pig 15 and liquid discharge volume. Specifically, the corresponding relationship can be different according to different models and the like, which is not limited herein.

[0092] After the pressure data, gas-liquid flow pattern, speed of the speed-adjustable pig 15 and liquid discharge volume data are acquired through the experiment, the acquired data can be substituted into the control algorithm, on the one hand, the characteristics of the bypass pigging process under the condition of severe slug flow can be analyzed, and the speed-adjustable pig control algorithm under the condition of severe slug flow is verified, on the other hand, the speed of the speed-adjustable pig 15 can be adjusted by optimizing the control algorithm, so that the pigging efficiency is ensured under the condition of severe slug flow and the pressure fluctuation and liquid discharge volume are minimized, thereby guiding the pigging operation of the marine riser system and preventing the occurrence of marine pipeline pigging accidents.

[0093] It should be noted that in the description of the present application, the terms "first", "second" and the like are used only for the purpose of description and distinguishing similar objects, and there is no precedence or significance between them. In addition, in the description of the present application, unless otherwise specified, the meaning of "a plurality of" is two or more.

[0094] The above various embodiments in the specification are described in a progressive manner, and the same or similar parts between the various embodiments can be referred to each other, and each embodiment focuses on the difference from other embodiments.

[0095] The purpose of the detailed explanation of the above embodiments is only to explain the present application, so as to better understand the present application, but these descriptions cannot be explained as the limitation of the present application for any reason, especially, the features described in different embodiments can be combined with each other arbitrarily, so as to form other embodiments, except for the explicit opposite description, these features should be understood as being able to be applied to any one embodiment, and not limited to the described embodiment.

[0096] The above is only a few embodiments of the present application, although the embodiments disclosed by the present application are as above, but the content is only for the convenience of understanding the present application and the adopted embodiment, and is not used to limit the present application. Any person skilled in the art of the present application can make any modification and change in the form and details of the embodiments without departing from the spirit and scope of the present application disclosed, but the patent protection scope of the present application shall be subject to the scope defined by the appended claims.

Claims

1. A speed-regulated pig control algorithm verification device, characterized in that, The speed-adjusting pig control algorithm verification device comprises a gas-liquid supply system, a ball launching device, a pipeline system, a ball collecting device, a data acquisition system and a speed-adjusting pig; The gas-liquid supply system comprises a water tank for storing liquid, a pump for pressurizing fluid, and an air compressor; One end of the ball launching device is connected with the pipeline system, and the other end is connected with the pump; The pipeline system comprises a plurality of downward pipes, a bottom elbow pipe of a vertical pipe, the vertical pipe and a top elbow pipe of the vertical pipe connected in sequence; the pipeline system is further provided with a pressure sensor connection port at a predetermined position; The ball collecting device is arranged at the outlet of the pipeline system and is used for recovering the pig; The data acquisition system comprises a processor and an image acquisition device, a liquid level meter and a pressure sensor electrically connected with the processor; the liquid level meter is arranged on the ball collecting device and is used for acquiring instantaneous liquid discharge amount; the pressure sensor is arranged at the pressure sensor connection port; and the image acquisition device is used for acquiring the gas-liquid flow pattern of the pipeline system. The speed-adjusting pig comprises a hollow core pipe, an adjusting valve arranged on the core pipe for adjusting bypass flow, and a driving mechanism arranged in the core pipe for driving the adjusting valve; the speed-adjusting pig further comprises a speed detection mechanism for measuring the speed of the speed-adjusting pig. The speed detection mechanism comprises a permanent magnet arranged on the speed-adjusting pig and a coil wound around the surface of the pipeline of the pipeline system; the coil is a speed measuring coil; one speed measuring coil is arranged at a distance along the extension direction of the pipeline; when the speed-adjusting pig moves in the pipeline, the speed-adjusting pig passes through the nearest two speed measuring coils to generate two pulses; the speed of the speed-adjusting pig is calculated by testing the interval time of the two pulses. The driving mechanism comprises a motor and a lead screw driven by the motor; the adjusting valve comprises a valve body and a valve core; the valve body is provided with a bypass hole; the motor drives the lead screw to move along the axial direction, drives the valve core to move, changes the flow cross section of the bypass hole, and changes the bypass rate. The speed-adjusting pig stores a control algorithm; the control algorithm is a corresponding relationship among pressure data, gas-liquid flow pattern, speed of the speed-adjusting pig and liquid discharge amount; after obtaining the pressure data, gas-liquid flow pattern, speed of the speed-adjusting pig and liquid discharge amount data through experiments, the obtained data are substituted into the control algorithm to analyze the bypass pigging process characteristic law under the condition of severe slug flow, verify the speed-adjusting pig control algorithm under the condition of severe slug flow, optimize the control algorithm, adjust the speed of the speed-adjusting pig, and ensure the pigging efficiency under the condition of severe slug flow while minimizing the pressure fluctuation and liquid discharge amount.

2. The pig control algorithm verification apparatus of claim 1, wherein, The ball launching device comprises a hollow ball launching cylinder; one end of the ball launching cylinder is provided with a quick-opening blind plate, and the other end is provided with a valve; a first liquid inlet is further arranged on the ball launching cylinder and is used for being connected with the pump.

3. The pig control algorithm verification apparatus of claim 2, wherein, The serving cylinder comprises a first part close to the quick-opening blind plate and a second part close to the valve, the inner diameter of the first part is larger than that of the second part, and the first part and the second part are connected through a variable cross-section horn.

4. The pig control algorithm verification apparatus of claim 1, wherein, The speed-adjusting pig control algorithm verification device further comprises a pipeline support and support system, and the pipeline system is installed in the pipeline support and support system.

5. The pig control algorithm verification apparatus of claim 4, wherein, The speed-adjusting pig control algorithm verification device further comprises a ball collecting support for fixing the ball collecting device, and the ball collecting support is located on the support system.

6. The pig control algorithm verification apparatus of claim 5, wherein, The ball collecting device is connected with the water tank through a water pipe, and the position of the ball collecting device is higher than that of the water tank.

7. The pig control algorithm verification apparatus of claim 1 wherein, The pressure sensor connection port comprises a first pressure sensor connection port, a second pressure sensor connection port, a third pressure sensor connection port and a fourth pressure sensor connection port, In the fluid flow direction, the first pressure sensor connection port is located on the most downstream downward inclined pipe, the second pressure sensor connection port is located in the bottom elbow of the riser pipe, the third pressure sensor connection port is located in the riser pipe, and the fourth pressure sensor connection port is located in the riser pipe close to the top elbow of the riser pipe.

8. The pig control algorithm verification apparatus of claim 1 wherein, The driving mechanism comprises a motor, a lead screw driven by the motor, and the adjusting valve comprises a valve body and a valve core, and a bypass hole is arranged on the valve body, and the motor drives the lead screw to move in the axial direction, drives the valve core to move, and changes the flow cross section of the bypass hole.

9. An experimental method for applying the speed control pig control algorithm verification device of claim 1, characterized in that, The speed-adjusting pig stores a control algorithm, and the experimental method comprises: loading the speed-adjusting pig into the ball serving device; opening the gas-liquid supply system, adjusting the gas-liquid flow, obtaining the pressure fluctuation and gas-liquid flow characteristics, and causing severe plug flow in the pipeline system; after the pipeline system appears periodic severe plug flow, the pressure of the ball serving device reaches a predetermined pressure value, and the pig is sent into the pipeline system; collecting the pressure data, gas-liquid flow pattern, speed of the speed-adjusting pig and liquid output of the pipeline system; closing the gas-liquid supply system and taking out the speed-adjusting pig from the ball collecting device.

10. The experimental method of claim 9, wherein, The experimental method further comprises: based on the control algorithm and the obtained pressure data, gas-liquid flow pattern, speed of the speed-adjusting pig and liquid output, adjusting the bypass rate of the speed-adjusting pig, repeating the steps of claim 9, ensuring the cleaning efficiency under severe plug flow conditions while minimizing the pressure fluctuation and liquid output.

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