Well cementation rubber plug descending process abrasion testing device and method

Abstract

The invention discloses a device and a method for testing abrasion of a well cementation rubber plug in a descending process. The device comprises a pressure supply pipeline, a reversing pipeline, an experimental pipeline, a pressure relief pipeline, a liquid storage tank and a control part, the pressure supply pipeline is respectively communicated with the reversing pipeline and the liquid storage tank, and a turning mechanism is arranged between the experimental pipeline and the reversing pipeline; the reversing pipeline, the pressure supply pipeline and the experiment pipeline are connected through an electric four-way reversing valve, and the reversing pipeline is divided into a first side pipeline and a second side pipeline by the electric four-way reversing valve; one end, far away from the electric four-way reversing valve, of the pressure relief pipeline is connected with the liquid storage tank; under the action of the control part, the pressure supply pipeline can alternately supply fluid media to the experiment pipeline in different directions along the first side pipeline and the second side pipeline, and the well cementation rubber plug placed in the experiment pipeline is synchronously and alternately reversed by the turning mechanism. According to the scheme, the problem of deformation errors caused by manual reversing of the well cementation rubber plug in an experiment in the prior art is solved.

Description

Technical Field

[0001] The invention relates to the technical field of oil and natural gas drilling and production, and in particular to a device and method for testing the wear resistance of cementing rubber plugs. Background Art

[0002] With the development of oil and gas drilling and production technology, cementing plugs are key tools to ensure the quality of oil and gas well sealing. The wear resistance of cementing plugs directly affects the sealing effect after long-distance displacement. Poor sealing of the plugs can easily cause cement slurry pollution, affecting the quality of cementing and the judgment of the on-site construction personnel on the impact pressure of the plugs, resulting in plugging and emptying of the plugs. Studies have shown that the wear resistance of materials will be different under different abrasive wear conditions, such as the difference in wear resistance of high chromium cast iron under different impact angles and impact energies, and the interphase corrosion problem in acid mortar containing corrosive media. These research results provide a scientific basis for the selection and improvement of cementing plug materials.

[0003] In terms of the development of cementing plug technology, cementing technology has been continuously improving, especially in the fields of shale gas long horizontal section horizontal well cementing technology, ultra-long sealing section large temperature difference cementing technology, etc. The development of these technologies has put forward higher requirements on the performance of cementing plugs, such as the development of elastic materials, toughening agents, and the research of intelligent cementing materials. These materials can respond in specific environments, solve the problem of air channeling in the annular space, and improve the quality of cementing. At the same time, the development of automated and intelligent cementing equipment has become a trend, which requires cementing plug testing equipment to have higher precision and intelligence to meet the development needs of cementing technology. At the same time, in the existing testing methods, there are also problems such as the inability to simulate the wear conditions under actual working conditions or insufficient test accuracy.

[0004] Traditional experiments to test the wear performance of rubber plugs usually use a manual reversing method. After the rubber plug is pumped into the side end of the experimental casing, the rubber plug must be manually removed and put back into the starting side for pumping, and the rubber plug displacement distance is continuously added. Each time the rubber plug is removed from the casing and reinserted into the starting side of the casing, the rubber plug must undergo a process of compression-recovery-recompression. Repeating this process many times will change the elasticity of the rubber plug, especially the rubber plug lip. However, the rubber plug is always compressed during the actual working process underground (without the step of recovery deformation). Therefore, there is a certain gap between previous experiments and the actual underground rubber plug displacement process. This experimental device just solves this problem and realizes the continuous simulation of the rubber plug displacement process. Summary of the invention

[0005] The present invention aims to provide a high-precision, automated cementing plug wear test device and method capable of simulating actual working conditions, so as to solve the shortcomings of existing test methods and avoid the problem of deformation error introduced by manual reversal of cementing plugs in experiments in the prior art.

[0006] The present invention is achieved through the following scheme:

[0007] A wear test device for a cementing plug during its downward movement comprises a pressure supply pipeline, a reversing pipeline, a test pipeline, a pressure relief pipeline, a liquid reservoir and a control unit; the pressure supply pipeline is respectively connected to the reversing pipeline and the liquid reservoir, and a reversing mechanism is provided between the test pipeline and the reversing pipeline; the reversing pipeline, the pressure supply pipeline and the test pipeline are connected via an electric four-way reversing valve, wherein the reversing pipeline is divided into a first side pipeline and a second side pipeline by the electric four-way reversing valve; the pressure relief pipeline is connected to the liquid reservoir at one end away from the electric four-way reversing valve; under the action of the control unit, the pressure supply pipeline can alternately supply fluid medium to the test pipeline in different directions along the first side pipeline and the second side pipeline, and the cementing plug placed in the test pipeline is synchronously and alternately reversed by the reversing mechanism.

[0008] In this scheme, a fluid medium is provided for the entire experiment through a liquid storage tank, and the fluid medium is pressurized through a pressure supply pipeline to provide a high-pressure fluid medium for the experimental pipeline. The pressurized fluid medium enters the experimental pipeline along the direction of the first side pipeline or the second side pipeline. The first side pipeline, the second side pipeline, the experimental pipeline and the pressure relief pipeline form a circulation pipeline, and the cementing plugs in the experimental pipeline are subjected to dynamic cementing plug wear tests in an alternating cycle. The cementing plugs will reverse as a whole under the action of the turning mechanism and perform reciprocating motion along the experimental pipeline.

[0009] Based on the structure of the above-mentioned cementing plug downward wear test device, the pressure supply pipeline includes a horizontal slurry pump, an electric three-way reversing valve and a flow meter. The horizontal slurry pump is connected to the liquid storage tank through a pump water inlet pipe, and a filter is also provided at the connection between the liquid storage tank and the pump water inlet pipe; the horizontal slurry pump is driven by a horizontal slurry pump motor, and the flow meter is arranged at the connection between the pressure supply pipeline and the electric four-way reversing valve; a one-way valve is arranged at the output port of the horizontal slurry pump, and the electric three-way reversing valve is arranged between the one-way valve and the flow meter; an overflow pipe and a safety valve are also provided between the electric three-way reversing valve and the liquid storage tank.

[0010] This scheme can filter the particle size by setting a filter, which is selected according to the maximum particle size of the mixed liquid required for the experiment. Its purpose is to prevent larger rocks or metal blocks from entering the pipeline, causing blockage or affecting the cementing plug wear test results. The flow meter is set to count the flow volume within the specified time, which is convenient for the calculation of subsequent wear tests. Driven by the slurry pump motor, the horizontal slurry pump is activated, and the fluid medium in the liquid storage tank is pressurized and transported to the electric three-way reversing valve, and finally pressurized and transported in a predetermined direction through the electric four-way reversing valve.

[0011] Based on the structure of the above-mentioned wear testing device for the cementing plug descending process, the first side pipeline and the second side pipeline are respectively connected to different interfaces of the electric four-way reversing valve, and a turning mechanism is provided at the connection between the first side pipeline, the second side pipeline and the experimental pipeline, and a first pressure sensor is provided at the connection between the first side pipeline, the second side pipeline and the turning mechanism.

[0012] In this scheme, the first pressure sensor is used to monitor the left and right turning mechanisms and the pressure inside the casing, to assist in judging the sealing effect after the cementing plug is replaced over a long distance, and to monitor whether the pressure inside the casing exceeds the designed working pressure of the equipment; the first side pipeline and the second side pipeline can be high-pressure steel wire hoses; the main function of the reversing pipeline in this scheme is to control the flow direction switching of the high-pressure liquid in the wear test pipeline.

[0013] Based on the structure of the above-mentioned wear testing device for the cementing plug descending process, the turning mechanism includes a supporting shell, a valve core and a power assembly; a matching cylinder cooperating with the power assembly is provided on the supporting shell, and a limiting hole cooperating with the power assembly is provided on the valve core; the power assembly can drive the valve core to rotate at a predetermined angle in the supporting shell; through holes cooperating with the first side pipeline or the second side pipeline, and the experimental casing are respectively provided on both sides of the supporting shell.

[0014] In this scheme, the fluid medium flows into the support shell from the first side pipeline or the second side pipeline and fills the entire experimental casing. The valve core loaded with the cementing plug is rotated to prevent the fluid medium from pushing the plug into the casing during the process of filling the pipeline, causing the plug to enter the casing in advance and making it impossible for the fluid medium to fill the pipeline. When the entire pipeline is filled with the fluid medium, the valve core is reset by the power component to make the valve core and the experimental casing colinear. At this time, the pressure supply pipeline is started, and the high-pressure fluid medium pushes the cementing plug in a first direction. When it reaches the turning mechanism on the other side, the power component on the other side rotates an integer multiple of ° according to the internal control valve logic to reverse the cementing plug therein. At this time, the high-pressure fluid medium reverses synchronously to push the reversed cementing plug to move, and the experiment is carried out reciprocatingly.

[0015] Based on the structure of the above-mentioned cementing plug downward wear test device, the power assembly includes a stepper motor, a driving shaft and a driven shaft; a first gear is provided at the output end of the stepper motor, and a second gear matching the first gear is provided on the driving shaft; the first gear and the second gear are meshed, and a rotating seal is provided between the driving shaft and the driven shaft and the support shell; the valve core is driven to rotate by the driving shaft.

[0016] In this solution, liquid is arranged in the supporting shell, so a rotating seal is required to realize sealing; the action of the stepper motor can drive the driving shaft to rotate, thereby rotating the valve core, and the driven shaft is used to cooperate with the valve core to rotate stably.

[0017] Based on the structure of the above-mentioned wear test device for the cementing plug downward process, the end cover on the driven shaft side can be a flange end cover, and a limiting cylinder is arranged on the flange end cover, and the limiting cylinder is provided with a cross groove; the driven shaft is also provided with a cross groove, and a linear rack speed regulating motor is arranged on the outside of the driven shaft, and a cross limiting frame is arranged at the end of the limiting push rod of the linear rack speed regulating motor close to the cross groove; under the action of the linear rack speed regulating motor, the cross limiting frame can be pushed into or pulled out of the limiting cylinder and the cross groove of the driven shaft; a valve core frame fixedly connected to the valve core is arranged on the outside of the valve core, and the rectangular structure end of the driven shaft or the driving shaft is connected to the valve core frame, and the supporting shell includes a main shell and a sub-shell, and a sealing gasket is arranged at the connection between the main shell and the sub-shell, and the main shell and the sub-shell are connected as a whole by bolts; a sieve plate and a position sensor are arranged inside the end plate of the sub-shell; the position sensor is arranged at the center position of the sieve plate.

[0018] The present invention also provides a method for testing the wear of cementing plugs during their downward movement, comprising the following steps:

[0019] Step 1, preparing a mixed solution;

[0020] Step 2: Equipment debugging;

[0021] Step 3: Experimental parameter setting;

[0022] Step 4: cementing plug wear test;

[0023] Step 5: Generate an experimental report.

[0024] Step 2, specifically: install the pressure supply, reversing, pressure relief pipelines and the turning mechanism, put the cementing plug into the valve core of the turning mechanism, install the experimental pipe bundle, and adjust the working pressure of the safety valve and the pressure reducing valve;

[0025] Initially, the electric three-way reversing valve connects the pressure supply pipeline and the reversing pipeline, and the electric four-way reversing valve connects the pressure supply pipeline. During equipment debugging, the stepper motor of the reversing mechanism drives the active shaft to rotate 90° clockwise, the valve core pipeline is perpendicular to the experimental casing, and the gap between the valve core and the valve core frame wall forms a flow channel. The fluid enters the experimental tube bundle through the pressure supply pipeline and the flow channel on the wall of the valve core of the left reversing mechanism, and flows back to the liquid storage tank through the wall of the valve core of the reversing mechanism and the pressure relief pipeline. When the pipeline is filled with fluid, the electric three-way reversing valve rotates to switch the pressure supply pipeline to connect the pressure relief pipeline. There is no pressure supply in the left and right reversing pipelines. The stepper motor drives the active shaft to rotate 90° counterclockwise, and the valve core pipeline is in line with the casing. At this time, the hemispherical surface of the valve core forms a seal with the sieve plate and the hemispherical surface of the casing joint. The fluid can only flow from the valve core casing, and the equipment debugging is completed;

[0026] Step 4, specifically: Specific implementation method of cementing plug wear experiment: After the experimental debugging and parameter setting are completed, turn on the horizontal slurry pump. At this time, the left flow channel line of the cementing plug is the pressure supply pipeline, and the high-pressure fluid route is the horizontal slurry pump-pressure supply pipeline-first side pipeline-left turning mechanism-cementing plug; the right flow channel line of the cementing plug is the pressure-maintaining flow channel line, and the pressure-maintaining fluid route is the cementing plug-experimental casing-right turning mechanism-second side pipeline-pressure relief pipeline; the high-pressure mixed liquid pushes the cementing plug from the left turning mechanism to the right, and when the cementing plug moves to the right valve core pipeline, the position sensor is triggered, and the central console processor receives the cementing plug reaching the valve core casing position signal through the signal collector, and records the number of times the cementing plug passes through the single-pass experimental tube bundle; then the turning mechanism drives the cementing plug to reverse, and the high-pressure mixed liquid performs the reversing operation synchronously; when the plug running distance reaches the set plug wear test total distance, the experiment stops and ends.

[0027] In step five, specifically, after the experiment is completed, the central console generates the total wear distance of the cementing plug according to the recorded number of times the cementing plug passes through the experimental tube bundle, the monitored flow signal, pressure fluctuation signal and other information, marks the starting position of the leakage, and marks the corresponding wear distance every time the single displacement increases by 1 / 10 flow volume; the central console marks the leakage position according to the wear stroke of the cementing plug, generates a coordinate diagram of the wear stroke and the leakage generating point, and generates a leakage curve diagram corresponding to the wear stroke of the cementing plug according to the change in the volume of the pumped mixed liquid monitored by the flowmeter; and generates pressure curves of the pressure supply pipeline and the pressure relief pipeline that change with the wear stroke according to the pressure signals monitored by the left and right pressure sensors.

[0028] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are:

[0029] 1. This scheme pumps high-pressure mixed liquid into the experimental tube bundle to push the cementing plug to move in the casing. The turning mechanism installed at both ends of the experimental tube bundle completes the straight-line turning of the cementing plug in the casing and switches the flow direction of the pressure supply pipeline to simulate the cementing plug going into the well. The experimental platform controls the operation of each electric mechanism through the central console to realize the automated cementing plug wear experiment.

[0030] 2. This scheme provides fluid medium for the entire experiment through a liquid storage tank, and pressurizes the fluid medium through a pressure supply pipeline. The pressurized fluid medium enters the experimental pipeline along the direction of the first side pipeline or the second side pipeline. The first side pipeline, the second side pipeline, the experimental pipeline and the pressure relief pipeline form a circulation pipeline, and the cementing plugs in the experimental pipeline are subjected to dynamic cementing plug wear tests in an alternating cycle. The cementing plugs will reverse as a whole under the action of the turning mechanism and reciprocate along the experimental pipeline.

[0031] 3. The present invention can significantly improve the accuracy and efficiency of cementing plug wear testing through automated control and high-precision monitoring, reduce manual intervention, and reduce experimental errors. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 This is a schematic diagram of the wear test platform structure of the present invention;

[0033] Figure 2 It is a structural diagram of the pressure supply pipeline in the present invention;

[0034] Figure 3 It is a structural diagram of the liquid storage tank in the present invention;

[0035] Figure 4 This is an appearance diagram of the turning mechanism in the present invention;

[0036] Figure 5 It is a cross-sectional view of the power transmission of the U-turn mechanism in the present invention;

[0037] Figure 6 It is a cross-sectional view of the flow channel of the U-turn mechanism in the present invention;

[0038] Figure 7 It is a circuit connection diagram in the present invention;

[0039] Markings in the figure: 1. Pressure supply pipeline; 2. Reversing pipeline; 3. Experimental pipeline; 4. Pressure relief pipeline; 5. Liquid storage tank; 6. Control unit; 7. Turning mechanism; 8. Electric four-way reversing valve; 11. Horizontal slurry pump; 12. Electric three-way reversing valve; 13. Flow meter; 14. Pump inlet pipe; 15. Filter; 16. Horizontal slurry pump motor; 17. Check valve; 18. Overflow pipe; 19. Safety valve; 21. First side pipeline; 22. Second side pipeline; 23. First pressure sensor; 31. Support frame; 32. Experimental casing; 33. Coupling; 41. Pressure reducing valve; 51. Agitator; 52. Agitator motor; 71 , support shell; 72, valve core; 73, power assembly; 74, rotating seal; 711, main shell; 712, auxiliary shell; 713, sealing gasket; 714, sieve plate; 715, position sensor; 721, valve core frame; 731, stepper motor; 732, driving shaft; 733, driven shaft; 734, first gear; 735, second gear; 736, rectangular structure; 741, support cylinder; 742, end cover; 743, first bearing; 744, second bearing; 745, sealing ring; 746, limit cylinder; 747, cross groove; 748, linear rack speed control motor; 749, cross limit frame. DETAILED DESCRIPTION

[0040] All features disclosed in this specification, or steps in all methods or processes disclosed, except mutually exclusive features and / or steps, can be combined in any manner.

[0041] Any feature disclosed in this specification (including any additional claims and abstract), unless otherwise stated, may be replaced by other equivalent or alternative features having similar purposes. That is, unless otherwise stated, each feature is only an example of a series of equivalent or similar features.

[0042] In the description of the present invention, it is necessary to understand that the directions or positional relationships indicated by the terms "up", "down", "left", "right", etc. are based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a predetermined direction, be constructed and operated in a predetermined direction, and therefore cannot be understood as a limitation on the present invention.

[0043] In addition, the terms "first", "second", etc. are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first", "second", etc. may explicitly or implicitly include one or more of the features.

[0044] Example 1

[0045] like Figure 1 to Figure 7 As shown, the present invention provides a technical solution:

[0046] A wear test device for a cementing plug during its downward movement, comprising at least but not limited to a pressure supply pipeline 1, a reversing pipeline 2, a test pipeline 3, a pressure relief pipeline 4, a fluid reservoir 5 and a control unit 6; the pressure supply pipeline 1 is respectively connected to the reversing pipeline 2 and the fluid reservoir 5, and a reversing mechanism 7 is provided between the test pipeline 3 and the reversing pipeline 2; the reversing pipeline 2, the pressure supply pipeline 1 and the test pipeline 3 are connected via an electric four-way reversing valve 8, wherein the reversing pipeline 2 is divided into a first side pipeline 21 and a second side pipeline 22 by the electric four-way reversing valve 8; the pressure relief pipeline 4 is connected to the fluid reservoir 5 at one end away from the electric four-way reversing valve 8; under the action of the control unit 6, the pressure supply pipeline 1 can alternately supply fluid medium to the test pipeline 3 in different directions along the first side pipeline 21 and the second side pipeline 22, and the cementing plug placed in the test pipeline 3 is synchronously alternately reversed by the reversing mechanism 7.

[0047] Based on the above structure, the fluid medium is provided for the entire experiment through the liquid storage tank 5, and the fluid medium is pressurized through the pressure supply pipeline 1. The pressurized fluid medium enters the experimental pipeline 3 along the direction of the first side pipeline 21 or the second side pipeline 22. The first side pipeline 21, the second side pipeline 22, the experimental pipeline 3 and the pressure relief pipeline 4 form a circulation pipeline, and the cementing plugs in the experimental pipeline 3 are subjected to dynamic cementing plug wear tests in an alternating cycle. The cementing plugs will reverse as a whole under the action of the turning mechanism 7 and reciprocate along the experimental pipeline 3.

[0048] As an example, the pressure supply pipeline 1 may include a horizontal slurry pump 11, an electric three-way reversing valve 12 and a flow meter 13. The horizontal slurry pump 11 is connected to the liquid storage tank 5 through a pump water inlet pipe 14, and a filter 15 may also be provided at the connection between the liquid storage tank 5 and the pump water inlet pipe 14; the horizontal slurry pump 11 is driven by a horizontal slurry pump motor 16, and the flow meter 13 is arranged at the connection between the pressure supply pipeline 1 and the electric four-way reversing valve 8; a one-way valve 17 is provided at the output port of the horizontal slurry pump 11, and the electric three-way reversing valve 12 is arranged between the one-way valve 17 and the flow meter 13; an overflow pipe 18 and a safety valve 19 may also be provided between the electric three-way reversing valve 12 and the liquid storage tank 5.

[0049] Based on the above structure, the particle size can be filtered by setting a filter 15, which is selected according to the maximum particle size of the mixed liquid required for the experiment. The purpose is to prevent larger rocks or metal blocks from entering the pipeline, causing blockage or affecting the cementing plug wear test results. The flow meter 13 is set to count the flow volume within a specified time, which is convenient for the calculation of subsequent wear tests. Driven by the slurry pump motor, the horizontal slurry pump 11 is activated, and the fluid medium in the liquid storage tank 5 is pressurized and transported to the electric three-way reversing valve 12, and finally pressurized and transported along the predetermined direction through the electric four-way reversing valve 8.

[0050] In this scheme, the horizontal slurry pump 11 can pump clean water, mud, and a mixture of small-sized rocks, metals and other particles. The designed working pressure is determined according to the maximum pump head of the horizontal slurry. The safety pressure of the safety valve 19 is designed according to the pressure required by the experiment. When the pressure of the pressure supply pipeline exceeds the overflow pressure of the safety valve 19, the safety valve 19 opens to release pressure to prevent the excessive pressure in the pressure supply pipeline from damaging the pump or pipeline. The electric three-way reversing valve 12 is an L-shaped valve core 72. The valve core 72 rotates to control the switching of the pressure supply pipeline, the reversing pipeline and the pressure relief pipeline. When the pressure supply pipeline is connected to the reversing pipeline, the high-pressure liquid pushes the cementing plug to move. When the cementing plug moves to the valve core 72 casing and triggers the position sensor 715, the electric three-way reversing valve 12 rotates to connect the pressure supply pipeline 1 with the pressure relief pipeline 4. There is no pressure source in the reversing pipeline and the experimental pipe bundle, which is convenient for the turning mechanism 7 and the reversing work of the electric four-way reversing valve 8.

[0051] As an example, an agitator 51 and a stirring motor 52 may be provided in the liquid storage tank 5 , wherein the agitator 51 is provided in the liquid storage tank, and the stirring motor 52 is connected to the agitator 51 and provided outside the liquid storage tank 5 .

[0052] Based on the above structure, the liquid storage tank 5 serves as a container for storing the mixed liquid, and has a built-in agitator 51 to continuously stir the mixed liquid in the liquid storage tank 5 to ensure that the proportion of the pumped mixed liquid is stable; if it is necessary to pump in a high-temperature fluid for experiments, a heating device must be installed outside the liquid storage tank 5 to meet the experimental requirements under high-temperature conditions. The heating device sets an initial heating temperature, and after heating, the temperature is fed back by the temperature sensor inside the storage tank to control the on and off of the heater, thereby keeping the temperature of the mixed liquid within the designed temperature range.

[0053] As an example, the first side pipeline 21 and the second side pipeline 22 are respectively connected to different interfaces of the electric four-way reversing valve 8, and a turning mechanism 7 is provided at the connection between the first side pipeline 21 and the second side pipeline 22 and the experimental pipeline 3, and a first pressure sensor 23 is provided at the connection between the first side pipeline 21 and the second side pipeline 22 and the turning mechanism 7.

[0054] Based on the above structure, the first pressure sensor 23 is used to monitor the left and right turning mechanisms 7 and the pressure inside the casing, to assist in judging the sealing effect after the cementing plug is replaced over a long distance, and to monitor whether the pressure inside the casing exceeds the designed working pressure of the equipment; the first side pipeline 21 and the second side pipeline 22 can be high-pressure steel wire hoses; the main function of the reversing pipeline 2 in this scheme is to control the flow direction switching of the high-pressure liquid in the wear test pipeline 3.

[0055] As an example, the experimental pipeline 3 is arranged between the two turning mechanisms 7, and a plurality of support frames 31 are arranged at the bottom of the experimental pipeline 3; the experimental pipeline 3 may include an experimental casing 32 and a coupling 33; and the experimental casing 32 is connected as a whole by the coupling 33.

[0056] Based on the above structure, the pressure supply pipeline 1 and the reversing pipeline 2 reciprocate and alternately provide high-pressure fluid medium to the experimental pipeline 3 in different directions, so that the cementing plug can continue to reciprocate in the experimental pipeline 3, thereby realizing the automated cementing plug wear test. The support frame 31 is used to support the experimental pipeline 3 to prevent the pipeline from deforming and affecting the progress of the experiment. The main function of the experimental pipeline 3 is to simulate the cementing plug being pushed by high-pressure fluid in the casing, and to simulate the long-distance displacement process of the cementing plug underground.

[0057] As an example, the pressure relief pipeline 4 is connected to the electric four-way reversing valve 8, and a pressure reducing valve 41 may be provided on the pressure relief pipeline 4. After passing through the electric four-way reversing valve 8, the high-pressure fluid medium flows to the pressure reducing valve 41, and flows back to the liquid storage tank 5 after being decompressed; the main function of the pressure relief pipeline 4 is to maintain the pressure of the pressure relief pipeline 4 during operation, and to safely release the pressure of the pressure relief pipeline 4 after the work is completed; the main function of the pressure reducing valve 41 is to set the pipeline pressure required for the experiment, to maintain the pressure in the pipeline in a stable range during operation, to release the pressure when the pressure is too high, to maintain the pressure when the pressure is too low, and to safely release the pressure in the pipeline after the work stops.

[0058] As an example, the turning mechanism 7 may include a supporting shell 71, a valve core 72 and a power assembly 73; the supporting shell 71 is provided with a matching cylinder that cooperates with the power assembly 73, and the valve core 72 is provided with a limiting hole that cooperates with the power assembly 73; the power assembly 73 can drive the valve core 72 to rotate at a predetermined angle in the supporting shell 71; through holes that cooperate with the first side pipeline 21 or the second side pipeline 22, and the experimental sleeve 32 are respectively provided on both sides of the supporting shell 71.

[0059] Based on the above structure, the fluid medium flows from the first side pipeline 21 or the second side pipeline 22 into the support shell 71 and fills the entire experimental casing 32. By rotating the valve core 72 loaded with the cementing plug, it is prevented from pushing the plug into the casing during the process of filling the pipeline with the fluid medium, causing the plug to enter the casing in advance and making it impossible for the fluid medium to fill the pipeline. When the entire pipeline is filled with the fluid medium, the valve core 72 is reset by the power component 73 to make the valve core 72 and the experimental casing 32 colinear. At this time, the pressure supply pipeline 1 is started, and the high-pressure fluid medium pushes the cementing plug in a first direction. When it reaches the turning mechanism 7 on the other side, the power component 73 on the other side rotates 180° integer multiples according to the internal control valve logic to reverse the cementing plug therein. At this time, the high-pressure fluid medium synchronously reverses and pushes the reversed cementing plug to move, and the experiment is carried out reciprocatingly.

[0060] As an example, the power assembly 73 may include a stepper motor 731, a driving shaft 732 and a driven shaft 733; a first gear 734 is provided at the output end of the stepper motor 731, and a second gear 735 cooperating with the first gear 734 is provided on the driving shaft 732; the first gear 734 and the second gear 735 are meshed, and a rotating seal 74 is provided between the driving shaft 732 and the driven shaft 733 and the support shell 71; the valve core 72 is driven to rotate by the driving shaft 732.

[0061] Based on the above structure, since liquid is set in the supporting shell 71, a rotating seal 74 is required to achieve sealing; the operation of the stepper motor 731 can drive the active shaft 732 to rotate, thereby causing the valve core 72 to rotate, and the driven shaft 733 is used to cooperate with the valve core 72 for stable rotation.

[0062] As an example, the ends of the driving shaft 732 and the driven shaft 733 close to the valve core 72 are set as rectangular structures 736, and rectangular grooves matched with the rectangular structures 736 are set on both sides of the valve core 72;

[0063] Based on the above structure, the valve core 72 can be rotated more stably through the rectangular groove, so that the valve core 72 can rotate more accurately.

[0064] As an example, the rotating seal 74 may include a support cylinder 741, an end cover 742, a first bearing 743 and a second bearing 744; a support through hole is provided on the support shell 71 for the driving shaft 732 or the driven shaft 733 to pass through, the support cylinder 741 is arranged along the circumferential position of the support through hole, the end cover 742 is arranged at the end of the support cylinder 741 away from the support shell 71, and a connecting through hole is provided on the end cover 742 to cooperate with the driving shaft 732 or the driven shaft 733, the driving shaft 732 or the driven shaft 733 is arranged through the support through hole and the connecting through hole, and a sealing ring 745 is provided on the contact part between the driving shaft 732 and the driven shaft 733 and the connecting through hole.

[0065] Based on the above structure, under the action of the power assembly 73, the driving shaft 732 can be driven to move smoothly in the support tube 741. The accuracy of rotation can be guaranteed by two parallel bearings, and the sealing ring 745 can prevent the liquid in the support shell 71 from escaping.

[0066] As an example, the end cover 742 on the side where the driven shaft 733 is provided may be a flange end cover 742, on which a limiting cylinder 746 is provided, and the limiting cylinder 746 is provided with a cross groove 747; the driven shaft 733 is also provided with a cross groove 747, and a linear rack speed regulating motor 748 is provided on the outer side of the driven shaft 733, and a cross limiting frame 749 is provided at the end of the limiting push rod of the linear rack speed regulating motor 748 near the cross groove 747; under the action of the linear rack speed regulating motor 748, the cross limiting frame 749 can be pushed into or pulled out of the limiting cylinder 746 and the cross groove 747 of the driven shaft 733.

[0067] Based on the above structure, since it is necessary to ensure that the valve core 72 is accurately aligned with the experimental sleeve 32 during rotation, otherwise the high-pressure fluid medium will find the stamping on the edge of the support shell 71 when passing through the valve core 72, and it will also cause abnormal experimental pressure and deviation in the experiment. Therefore, a special cross limit frame 749 is provided to cooperate with the cross groove 747 on the limit cylinder 746 to achieve precise positioning; the driven shaft 733 flange end cover 742 is connected by bolts, the purpose of which is to position the cross groove 747 to ensure that the valve core 72 and the experimental sleeve 32 remain in the same line after the cross limit frame 749 is inserted into the cross limit frame 749.

[0068] As an example, a valve core frame 721 to which the valve core 72 is fixed is provided on the outside of the valve core 72, and the end of the rectangular structure 736 of the driven shaft 733 or the driving shaft 732 is connected to the valve core frame 721. The support shell 71 may include a main shell 711 and a sub-shell 712. A sealing gasket 713 is provided at the connection between the main shell 711 and the sub-shell 712, and the main shell 711 and the sub-shell 712 are connected as a whole by bolts.

[0069] The first side pipeline 21 and the second side pipeline 22 are connected to the water inlet interface at the end of the auxiliary shell 712. There are multiple water inlet interfaces. A sieve plate 714 and a position sensor 715 can be arranged on the end plate of the auxiliary shell 712; the position sensor 715 is arranged at the center position of the sieve plate 714.

[0070] Based on the above structure, the sieve plate 714 is mainly used to connect the experimental tube bundle and the pressure supply tube bundle, while limiting the cementing plug from moving to the pressure supply tube bundle outside the experimental tube bundle. There are multiple water inlet interfaces, which is convenient for alleviating the problem of excessive flow velocity in the pressure supply pipeline 1 when replacing a larger size casing and increasing the casing flow; a position sensor 715 is also provided to detect when the cementing plug reaches the limit position. When the cementing plug reaches the limit position, the high-pressure medium fluid starts to reverse, and the turning mechanism 7 drives the fixed cementing plug to reverse synchronously; the auxiliary shell 712 is bolted to the main shell 711, so that when the experiment is completed or the equipment is repaired, the auxiliary shell 712 can be disassembled to take out the valve core 72 and other components.

[0071] The position sensor 715 is triggered by the push rod installed on the screen plate 714. The reset spring on the push rod pushes the push rod to reset after the push rod cancels the trigger force. The position sensor 715 is not triggered. When the cementing plug reaches the end of the valve core 72, the push rod position is pushed, triggering the position sensor 715. The external cementing plug arrival indicator light turns on, indicating that the cementing plug has arrived in the casing of the valve core 72. The position sensor 715 transmits the cementing plug arrival signal to the central control console, and the central control console sends a limit rod pull-out signal. After the stepper motor 731 completes the rotation, it sends a limit signal, and the cross limit frame 749 is pushed into the cross slot 747 for limiting.

[0072] Specifically, when the cementing plug triggers the position sensor 715, the linear rack speed regulating motor 748 controls the limit rod to move outward, so that the limit rod is pulled out from the limit groove of the driven shaft 733 and the end cover 742, and the rotation restriction of the driven shaft 733 is cancelled. When the stepper motor 731 completes the rotation, the linear rack speed regulating motor 748 controls the limit rod to move inward, so that the limit rod is stuck in the limit groove, and the rotation restriction of the driven shaft 733 and the valve core 72 is completed.

[0073] In this scheme, the joint of the experimental casing 32 is connected to the main shell 711 through an oil-retaining joint, and a rubber sealing gasket is provided at the connection. The pipe interface of the experimental casing 32 is a tapered thread, which is consistent with the tapered thread of the coupling 33, which is convenient for casing connection, and the other end is a hemispherical surface corresponding to the valve core 72; when the experiment is completed or when it is necessary to replace the casing of a different size for cementing plug wear test, the experimental casing 32 joint is disassembled and assembled, and the valve core 72 is replaced from the experimental casing 32 joint, so it is more convenient to use an oil-retaining joint.

[0074] In this solution, the main function of the turning mechanism 7 is to monitor whether the cementing plug reaches the valve core 72 and realize the linear turning of the cementing plug. The experimental casing 32 and the coupling 33 and the turning mechanism 7 constitute a complete path for the movement of the cementing plug. The more the experimental casing 32 and the coupling 33 are, the longer the one-way moving distance of the cementing plug is, and the fewer the turning times of the turning mechanism 7 are required to complete the experiment under the same experimental distance.

[0075] The turning mechanism 7 is composed of a main housing 711, a sub-housing 712, a valve core 72 holder, a valve core 72, a driving shaft 732, a driven shaft 733, a casing joint, a screen plate 714, a stepping motor 731, a linear rack speed regulating motor 748, a position sensor 715, etc. The main function is to monitor the cementing plug after entering the casing of the valve core 72 and complete the task of linear turning of the cementing plug.

[0076] The main housing 711 of the turning mechanism 7 is mainly used to install the driving shaft 732, the driven shaft 733, and the sleeve joint, and plays a supporting and fixing role.

[0077] The driving shaft 732 and the driven shaft 733 support the valve core 72 and the valve core frame 721. A roller bearing is installed between the driving shaft 732 and the housing. One end of the driving shaft 732 is connected to the valve core frame 721 through a square hole to transmit torque, and the other end is connected to the gear of the stepper motor 731. An end cover 742 is connected to the housing for axial positioning and sealing.

[0078] When the motor controller receives the rotation signal, it controls the passage of the stepper motor 731, and the motor rotates and drives the driving shaft 732 to rotate 180°. Each time the stepper motor 731 rotates, the transmission ratio between the stepper motor 731 and the driving shaft 732 is calculated, and the stepper motor 731 controller is set through the computer.

[0079] As an example, the control unit 6 may include an electric three-way valve motor controller, an electric four-way valve motor controller, a stepper motor 731 controller, a linear rack speed control motor 748 controller, a central console processor and a display; the main functions are to input the corresponding experimental parameters before work and debug the control parameters of each motor controller; to display and monitor the pressure, flow and cementing plug stroke information in real time during the work; and to generate an experimental test report after the experiment is completed. The experimental process is visualized and the abnormal experimental data information is monitored in real time.

[0080] This solution monitors the received pressure signals in real time to display the pressure changes at the left and right ends of the experimental pipe. If the initial left-right pressure changes are consistent with the left-right pressure changes at the end of the experiment, it means that the cementing plug still maintains a high sealing effect after long-distance wear. If the pressure at the pressure supply end decreases during the experiment, the cementing plug may have a sealing leakage. After the central console detects the pressure drop signal, the computer displays a prompt light to remind the experimenter.

[0081] The oil-to-penetrating joints are all provided with sealing gaskets 713, which ensure the sealing effect of the experimental pipeline 3 while meeting the requirements of quick disassembly and assembly of parts.

[0082] Example 2

[0083] Based on the structure of the above embodiment 1, this solution provides a technical solution;

[0084] A method for testing wear of cementing plugs during their downward movement, comprising at least the following steps:

[0085] Step 1, preparing a mixed solution;

[0086] Step 2: Equipment debugging;

[0087] Step 3: Experimental parameter setting;

[0088] Step 4: cementing plug wear test;

[0089] Step 5: Generate an experimental report;

[0090] Step 1, specifically, comprises: preparing a mixed liquid to be pumped into the experimental tube bundle, wherein the particle size and proportion thereof are configured according to the specific experimental environment required, and the maximum particle size is smaller than the maximum pumping particle size of the horizontal slurry pump 11; pouring the particles weighed in proportion and water or other liquid into a storage tank, turning on the agitator 51 in the storage tank, and stirring the mixed liquid until it is uniform for use;

[0091] Step 2, specifically, is as follows: installing the pressure supply, reversing, and pressure relief pipelines 4 and the turning mechanism 7, and inserting the cementing plug into the valve core 72 of the turning mechanism 7, installing the experimental pipe bundle, and adjusting the working pressure of the safety valve 19 and the pressure reducing valve 41;

[0092] Initially, the electric three-way reversing valve 12 connects the pressure supply pipeline 1 and the reversing pipeline 2, and the electric four-way reversing valve 8 connects the pressure supply pipeline 1. When the equipment is debugged, the stepper motor rotates to the origin position (the valve core pipeline and the experimental pipeline are in line). The stepper motor 731 of the reversing mechanism 7 drives the active shaft 732 to rotate 90° clockwise. The valve core 72 pipeline is perpendicular to the experimental sleeve 32. The valve core 72 and the valve core frame 721 wall gap form a flow channel. The fluid enters through the pressure supply pipeline 1 and the wall flow channel of the valve core 72 of the left reversing mechanism 7. The experimental tube bundle flows back to the liquid storage tank 5 through the wall of the valve core 72 of the turning mechanism 7 and the pressure relief pipeline. When the pipeline is filled with fluid, the electric three-way reversing valve 12 rotates to switch the pressure supply pipeline 1 to connect the pressure relief pipeline 4. There is no pressure supply in the left and right reversing pipelines 2. The stepper motor 731 drives the driving shaft 732 to rotate 90° counterclockwise. The valve core 72 pipeline and the casing are in line. At this time, the hemispherical surface of the valve core 72 forms a seal with the sieve plate 714 and the hemispherical surface of the casing joint. The fluid can only flow from the valve core 72 casing, and the equipment debugging is completed;

[0093] Step three, specifically, before conducting the experiment, input the inner diameter of the assembled experimental casing 32, the one-way distance of the experimental tube bundle, and the experimental pressure information into the processing software in the computer, so that the processing software can calculate the cementing plug wear distance and evaluate the sealing performance of the cementing plug in combination with the experimental process data; when setting the experimental parameters, it is necessary to set the total distance of the plug wear experiment, and the total distance is divided by the one-way distance of the experimental tube bundle minus one to obtain the number of reversals required by the turning mechanism; the total distance of the experiment is preferably set to an integer multiple of the one-way distance of the experimental tube bundle.

[0094] Step 4, specifically: Specific implementation method of cementing plug wear experiment: After the experimental debugging and parameter setting are completed, turn on the horizontal slurry pump 11. At this time, the left flow channel line of the cementing plug is the pressure supply pipeline, and the high-pressure fluid route is the horizontal slurry pump 11-pressure supply pipeline-first side pipeline 21-left turning mechanism 7-cementing plug; the right flow channel line of the cementing plug is the pressure-maintaining flow channel line, and the pressure-maintaining fluid route is the cementing plug-experimental casing 32-right turning mechanism 7-second side pipeline 22-pressure relief pipeline; the high-pressure mixed liquid pushes the cementing plug from the left turning mechanism 7 to the right, and when the cementing plug moves to the right valve core 72 pipeline, the position sensor 715 is triggered, and the central console processor receives the cementing plug reaching the valve core 72 casing position signal through the signal collector, and records the number of times the cementing plug passes through the single-pass experimental pipe bundle;

[0095] When the cementing plug triggers the position sensor 715, the processing software in the computer sends a pre-programmed control instruction to the motor controller. The specific control process is as follows:

[0096] The computer processor receives the cementing plug to the casing signal of the valve core 72 sent by the signal collector, and controls the electric three-way reversing valve 12 to rotate according to the preset instructions. The pressure supply pipeline 1 is connected to the pressure relief pipeline 4, and the reversing pipeline 2 is closed. The high-pressure mixed liquid flows back to the storage tank through the pressure relief pipeline 4. At this time, there is no pressure supply from the reversing pipeline to the experimental tube bundle; the linear rack speed regulating motor 748 rotates counterclockwise, driving the limit push rod to pull out, and the driven shaft 733 and the valve core 72 release the rotation restriction; after the limit rod releases the limit, the stepper The motor 731 rotates, driving the active shaft 732 to rotate 180° or an odd multiple of 180°, so that the valve core 72 and the cementing plug can make a straight-line U-turn; after the stepper motor 731 completes the rotation, the linear rack speed regulating motor 748 rotates clockwise, driving the limit push rod to engage in the cross slot 747, and the rotation of the driven shaft 733 and the valve core 72 is limited; the above process enables the U-turn mechanism 7 to complete the purpose of linear U-turn of the cementing plug, and the cementing plug head changes from pointing to the right U-turn mechanism 7 to pointing to the left U-turn mechanism 7.

[0097] After the reversing mechanism 7 completes the reversing task, the electric four-way reversing valve 8 rotates and reverses, so that the pressure supply pipeline 1 is connected to the second side pipeline 22, and the first side pipeline 21 is connected to the pressure relief pipeline 4; at this time, the right flow channel line of the cementing plug is the pressure supply line, and the high-pressure fluid route is slurry pump-pressure supply pipeline-second side pipeline 22-right reversing mechanism 7-cementing plug; the left flow channel line of the cementing plug is the pressure-maintaining flow channel line, and the pressure-maintaining fluid route is cementing plug-experimental casing 32-left reversing mechanism 7-first side pipeline 21-pressure relief pipeline; The high-pressure mixed liquid pushes the cementing plug from the right turning mechanism 7 to the left. When the cementing plug moves to the left valve core 72 casing, the position sensor 715 is triggered, and the central control console receives the signal that the cementing plug reaches the valve core 72 casing position, and accumulates the number of times the cementing plug passes through the one-way experimental pipe bundle; the central control console controls the left turning mechanism 7 to repeat the above control process of the right turning mechanism 7, completes the left turning task and the four-way valve reversing task, and realizes the reciprocating one-way movement of the cementing plug in the experimental pipe bundle, simulating the downward process of the cementing plug. When the running distance of the plug reaches the total distance set for the plug wear test, the experiment stops and ends.

[0098] During the 180° rotation of the valve core 72, the front and rear hemispherical surfaces of the valve core 72 will inevitably trigger the position sensor 715. To avoid the front and rear hemispherical surfaces of the valve core 72 triggering the position sensor 715 during the rotation, the trigger position sensor 715 can be replaced with a photoelectric sensor, or a certain gap can be set between the front and rear hemispherical surfaces of the valve core 72 and the plug plate and sleeve joints, so that a certain gap can be maintained between the trigger rod and the end face of the valve core 72 when the valve core 72 rotates.

[0099] The preset operation instructions of the above-mentioned central console realize the simulation of the cementing plug descending process. The central console records the number of times the cementing plug completes turning, which is consistent with the number of times the cementing plug completes the one-way experimental bundle movement. The processor calculates the cementing plug friction test distance through the one-way experimental bundle distance input when setting the experimental parameters, and updates it in real time on the central console display screen.

[0100] The flow meter 13 is used to monitor the flow supplied to the experimental tube bundle in real time. The central control console receives the flow signal as a valid signal when the pressure supply pipeline 1 is connected to the reversing pipeline 2 according to the reversing signal of the electric three-way reversing valve 12, and uses it to calculate the flow volume pumped into the experimental tube bundle. The flow signal is judged as an invalid signal in other time periods, and the central control console does not perform flow volume calculation. The flow volume pumped into the experimental pipeline is calculated by integrating the flow signal monitored by the flow meter 13 and the flow volume change of the cementing plug through the one-way experimental tube bundle is compared. If the flow volume of the cementing plug through the one-way experimental tube bundle is significantly increased, it means that the high-pressure mixed liquid of the cementing plug has leaked into the pressure relief pipeline 4, the sealing performance of the cementing plug has decreased, and the cementing plug may be worn or scratched.

[0101] The above-mentioned high-pressure liquid leakage is the increase or decrease in the one-way flow volume monitored by the flow meter 13; when the leakage is positive, it means that the mixed liquid in the high-pressure pipeline leaks to the pressure relief pipeline; when the leakage is negative, it means that the mixed liquid in the pressure relief pipeline flows back to the high-pressure pipeline.

[0102] The oil-repellent pressure sensors installed on the left and right reversing pipes are used to monitor the pressure signals of the left and right reversing pipes and the experimental pipes. The central console receives the pressure signal when the pressure supply pipe 1 is connected to the reversing pipe 2 according to the reversing signal of the electric three-way valve and determines it as a valid signal. It is used as the pressure signal basis for judging the sealing performance of the cementing plug. The received pressure signal is judged as an invalid signal in other time periods and is not used as the basis for judging the sealing performance of the cementing plug by the central console. The left and right pressure sensors display the pressure conditions in the left and right pipes separated by the cementing plugs during the experiment in real time on the central console display. When the flow information shows that the flow volume in the one-way experimental pipe bundle has increased significantly, the left and right pressure change information is observed to assist in verifying the decrease in the sealing performance of the cementing plug. Secondly, the pressure sensor can also monitor the pressure conditions in the pipeline and issue an early warning when the pressure exceeds the working pressure of the equipment.

[0103] In step five, specifically, after the experiment is completed, the central control console generates the total wear distance of the cementing plug based on the recorded number of times the cementing plug passes through the experimental tube bundle, the monitored flow signal, pressure fluctuation signal and other information, marks the starting position of the leakage, and marks the corresponding wear distance every time the single displacement increases by 1 / 10 flow volume.

[0104] The central console marks the leakage position according to the wear stroke of the cementing plug, generates a coordinate diagram of the wear stroke and the leakage point, and generates a leakage curve corresponding to the wear stroke of the cementing plug according to the volume change of the pumped mixed liquid monitored by the flow meter 13. According to the pressure signals monitored by the left and right pressure sensors, the pressure curves of the pressure supply pipeline and the pressure relief pipeline that change with the wear stroke are generated.

[0105] The above operation flow is the specific operation flow of cementing plug wear test. According to the experimental requirements, different sizes and materials of casings, different mixed media and mixed liquids, and different pressure environments can be replaced. If a high-temperature environment cementing plug wear test is required, the high-pressure steel wire hose needs to be replaced with a high-temperature resistant high-pressure steel wire hose. When it is necessary to simulate the high-temperature fluid medium experimental environment, turn on the heater to heat the mixed liquid in the liquid storage tank 5, and keep the mixed liquid in a reasonable temperature range through the temperature control device.

[0106] The temperature control system transmits the real-time temperature information of the mixed liquid to the central console by monitoring the electronic temperature sensor installed in the liquid storage tank 5. When the temperature of the mixed liquid is lower than the set temperature range, the central console issues a heater turn-on command to start the heater. When the temperature of the mixed liquid is higher than the set temperature range, the central console issues a heater turn-off command to stop the heater.

[0107] The outside of the heater and the outside of the pipeline are wrapped with high temperature resistant heat-insulating materials, which play a role in heat preservation for the mixed liquid in the liquid storage tank 5 and the pipeline.

[0108] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A wear test device for cementing plug during descending process, characterized in that: It includes a pressure supply pipeline, a reversing pipeline, an experimental pipeline, a pressure relief pipeline, a liquid storage tank and a control unit; the pressure supply pipeline is connected with the reversing pipeline and the liquid storage tank respectively, and a reversing mechanism is arranged between the experimental pipeline and the reversing pipeline; the reversing pipeline, the pressure supply pipeline and the experimental pipeline are connected through an electric four-way reversing valve, wherein the reversing pipeline is divided into a first side pipeline and a second side pipeline by the electric four-way reversing valve; the end of the pressure relief pipeline away from the electric four-way reversing valve is connected to the liquid storage tank; under the action of the control unit, the pressure supply pipeline can alternately supply fluid medium to the experimental pipeline in different directions along the first side pipeline and the second side pipeline, and the cementing plug placed in the experimental pipeline is synchronously alternately reversed by the reversing mechanism.

2. According to claim 1, a wear test device for cementing plug during descending process, characterized in that: The pressure supply pipeline includes a horizontal slurry pump, an electric three-way reversing valve and a flow meter. The horizontal slurry pump is connected to the liquid storage tank through a pump water inlet pipe, and a filter is also provided at the connection between the liquid storage tank and the pump water inlet pipe; the horizontal slurry pump is driven by the horizontal slurry pump motor, and the flow meter is provided at the connection between the pressure supply pipeline and the electric four-way reversing valve; a one-way valve is provided at the output port of the horizontal slurry pump, and the electric three-way reversing valve is provided between the one-way valve and the flow meter; an overflow pipe and a safety valve are also provided between the electric three-way reversing valve and the liquid storage tank.

3. A cementing plug wear test device during descending process according to claim 1 or 2, characterized in that: The first side pipeline and the second side pipeline are respectively connected to different interfaces of the electric four-way reversing valve, and a turning mechanism is provided at the connection between the first side pipeline, the second side pipeline and the experimental pipeline, and a first pressure sensor is provided at the connection between the first side pipeline, the second side pipeline and the turning mechanism.

4. According to claim 3, a wear test device for cementing plug during descending process, characterized in that: The turning mechanism includes a supporting shell, a valve core and a power assembly; a matching cylinder matching with the power assembly is arranged on the supporting shell, and a limiting hole matching with the power assembly is arranged on the valve core; the power assembly can drive the valve core to rotate at a predetermined angle in the supporting shell; through holes matching with the first side pipeline or the second side pipeline, and the experimental sleeve are respectively arranged on both sides of the supporting shell.

5. A cementing plug wear test device during descending process according to claim 1 or 2, characterized in that: The power assembly includes a stepper motor, a driving shaft and a driven shaft; a first gear is arranged at the output end of the stepper motor, and a second gear matching the first gear is arranged on the driving shaft; the first gear and the second gear are meshed, and a rotating seal is arranged between the driving shaft and the driven shaft and the supporting shell; the valve core is driven to rotate by the driving shaft.

6. A cementing plug wear test device during descending process according to claim 1 or 2, characterized in that: The end cover on the driven shaft side can be a flange end cover, and a limiting cylinder is provided on the flange end cover, and the limiting cylinder is provided with a cross groove; the driven shaft is also provided with a cross groove, and a linear rack speed regulating motor is provided on the outer side of the driven shaft, and a cross limiting frame is provided at the end of the limiting push rod of the linear rack speed regulating motor close to the cross groove; under the action of the linear rack speed regulating motor, the cross limiting frame can be pushed into or pulled out of the limiting cylinder and the cross groove of the driven shaft; a valve core frame fixedly connected to the valve core is provided on the outer side of the valve core, and the rectangular structure end of the driven shaft or the driving shaft is connected to the valve core frame, and the supporting shell includes a main shell and a sub-shell, and a sealing gasket is provided at the connection between the main shell and the sub-shell, and the main shell and the sub-shell are connected as a whole by bolts; a sieve plate and a position sensor are provided inside the end plate of the sub-shell; the position sensor is arranged at the center position of the sieve plate.

7. A testing method based on the wear testing device for cementing plug descending process according to any one of claims 1 to 6, characterized in that: The following steps are involved: Step 1, preparing a mixed solution; Step 2: Equipment debugging; Step 3: Experimental parameter setting; Step 4: cementing plug wear test; Step 5: Generate an experimental report.

8. A method for testing wear of cementing plugs during their downward movement according to claim 7, characterized in that: Step 2, specifically: install the pressure supply, reversing, pressure relief pipelines and the turning mechanism, put the cementing plug into the valve core of the turning mechanism, install the experimental pipe bundle, and adjust the working pressure of the safety valve and the pressure reducing valve; Initially, the electric three-way reversing valve connects the pressure supply pipeline and the reversing pipeline, and the electric four-way reversing valve connects the pressure supply pipeline. During equipment debugging, the stepper motor of the reversing mechanism drives the active shaft to rotate 90° clockwise, the valve core pipeline is perpendicular to the experimental casing, and a flow channel is formed between the valve core and the wall of the valve core frame. The fluid enters the experimental tube bundle through the pressure supply pipeline and the flow channel on the wall of the valve core of the left reversing mechanism, and flows back to the liquid storage tank through the wall of the valve core of the reversing mechanism and the pressure relief pipeline. When the pipeline is filled with fluid, the electric three-way reversing valve rotates to switch the pressure supply pipeline to connect the pressure relief pipeline. There is no pressure supply in the left and right reversing pipelines. The stepper motor drives the active shaft to rotate 90° counterclockwise, and the valve core pipeline is in line with the casing. At this time, the hemispherical surface of the valve core forms a seal with the sieve plate and the hemispherical surface of the casing joint. The fluid can only flow from the valve core casing, and the equipment debugging is completed.

9. A method for testing wear of cementing plugs during descending according to claim 7 or 8, characterized in that: Step 4, specifically: Specific implementation method of cementing plug wear experiment: After the experimental debugging and parameter setting are completed, turn on the horizontal slurry pump. At this time, the left flow channel line of the cementing plug is the pressure supply pipeline, and the high-pressure fluid route is the horizontal slurry pump-pressure supply pipeline-first side pipeline-left turning mechanism-cementing plug; the right flow channel line of the cementing plug is the pressure-maintaining flow channel line, and the pressure-maintaining fluid route is the cementing plug-experimental casing-right turning mechanism-second side pipeline-pressure relief pipeline; the high-pressure mixed liquid pushes the cementing plug from the left turning mechanism to the right, and when the cementing plug moves to the right valve core pipeline, the position sensor is triggered, and the central console processor receives the cementing plug reaching the valve core casing position signal through the signal collector, and records the number of times the cementing plug passes through the single-pass experimental tube bundle; then the turning mechanism drives the cementing plug to reverse, and the high-pressure mixed liquid performs the reversing operation synchronously; when the plug running distance reaches the set plug wear test total distance, the experiment stops and ends.

10. A method for testing wear of cementing plugs during their downward movement according to claim 7 or 8, characterized in that: In step five, specifically, after the experiment is completed, the central console generates the total wear distance of the cementing plug according to the recorded number of times the cementing plug passes through the experimental tube bundle, the monitored flow signal, and the pressure fluctuation signal information, and marks the starting position of the leakage. Every time the single displacement increases by 1 / 10 of the flow volume, the corresponding wear distance is marked; the central console marks the leakage position according to the wear stroke of the cementing plug, generates a coordinate diagram of the wear stroke and the leakage generating point, and generates a leakage curve diagram corresponding to the wear stroke of the cementing plug according to the change in the volume of the pumped mixed liquid monitored by the flowmeter; based on the pressure signals monitored by the left and right pressure sensors, the pressure curves of the pressure supply pipeline and the pressure relief pipeline that change with the wear stroke are generated.

Images