Device and method for evaluating under-pressure operation capability of slip based on friction coefficient

Abstract

The invention discloses a device and a method for evaluating the under-pressure operation capability of a slip based on a friction coefficient, and the device comprises a supporting platform, a slip assembly, a radial force testing assembly, an axial force testing assembly, a hydraulic assembly and an oil pipe, the oil pipe penetrates through the supporting platform, and the slip assembly clamps the upper end of the oil pipe; the radial force testing assembly is arranged in the slip assembly and used for testing the radial force borne by the slip, and the axial force testing assembly is arranged below the slip assembly and used for testing the axial force borne by the slip. The hydraulic assembly is installed at the bottom of the supporting platform and applies downward load to the oil pipe. And the processing module is used for carrying out data processing on the test component. The sudden change from the maximum friction force to the sliding friction force is measured, so that the friction coefficient is obtained, parameters such as the friction coefficient are analyzed more quickly and accurately, quantitative data about the working state of the slip can be obtained, the under-pressure working capacity of the slip can be evaluated, and the aims of improving the working safety and efficiency and achieving sustainable development are achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of pressure - operated operations in oil and gas wells, and more specifically, to a device and method for evaluating the pressure - operated operation ability of slips based on the friction coefficient. Background Art

[0002] The traveling slips are the equipment with the highest working frequency in pressure - operated operations. During the operation, it is necessary to use the slips to clamp, lift, and lower the pipe string, and the pipe string should be firmly clamped without slipping or damaging the tubing. There are slip jaws installed on the inner wall of the slips. There are many slip - jaw teeth on the inner side wall of the slip jaws. The slip - jaw teeth are the parts that directly contact the oil and gas pipe string. During the long - term operation of the slips, the slip - jaw teeth will inevitably be worn, resulting in a decrease in the pressure - operated operation ability of the slips. If the slips of the pressure - operated workover rig slip, accidents such as blowout and natural gas leakage are likely to occur, causing significant economic losses. The domestic research on the working ability of slips mainly focuses on the research of the wear of slip - jaw teeth, which mainly focuses on strengthening the slip - jaw teeth and changing the tooth shape structure, etc. In actual engineering, this can only delay the wear of the slip - jaw teeth, and cannot evaluate the pressure - operated operation ability of the slips and prevent the wear of the slip - jaw teeth, and cannot process the already - working slips to improve their operation ability. However, the pressure - operated operations in oil and gas wells are dangerous, and the operating conditions are harsh, with high requirements for the safety and reliability of the slips. There is an urgent need for a device to evaluate the pressure - operated working ability of the slips, that is, a device for evaluating the friction coefficient between the slips and the casing.

[0003] In the prior art, the patent with the publication number CN110553978A titled "Friction Coefficient Measuring Instrument and Friction Coefficient Measuring Method" discloses a test device and method for measuring the anti - skid performance of asphalt pavements, markings, or other material specimens, and evaluating the anti - skid performance of pavements or pavement material specimens in a wet state. The processor applies pressure to the slider through the control of the pressing device and the pressing rod according to the set pressure value, and reads the pressure N through the first force sensor. At the same time, a thrust is applied to the slider through the pushing device and the push rod to ensure that the pressing device and the slider slide uniformly on the surface to be measured, and the horizontal thrust F is read through the second force sensor to obtain μ = F / N. It is necessary to keep the measured slider sliding uniformly on the surface to be measured. In order to avoid measurement errors, the average value is obtained by measuring multiple times, which has systematic errors, requires a large site, is not convenient, and only measures the sliding friction force. For the relevant application fields of slips, the maximum static friction force is also very important. Therefore, this single - way of measuring the sliding friction force is not applicable to evaluating the operation ability of slips. Summary of the Invention

[0004] To address the deficiencies of the above-mentioned existing technologies, the present invention provides a device and method for evaluating the pressure-bearing operation ability of slips based on the friction coefficient, measuring the sudden change from the maximum frictional force to the sliding frictional force to obtain the friction coefficient, which is faster, more accurate, and more suitable for the relevant field of slips than the method of measuring speed. By analyzing parameters such as the friction coefficient, quantitative data on the working state of the slips can be obtained, thereby evaluating its pressure-bearing operation ability and achieving the goals of improving operation safety, efficiency, and sustainable development.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows: A device for evaluating the pressure-bearing operation ability of slips based on the friction coefficient includes a support platform, a slip assembly, a radial force test assembly, an axial force test assembly, a hydraulic assembly, and a tubing string. The tubing string is disposed through the support platform, the slip assembly is clamped at the upper end of the tubing string, the radial force test assembly is arranged inside the slip assembly to test the radial force on the slips, and the axial force test assembly is arranged below the slip assembly to test the axial force on the slips.

[0006] The hydraulic assembly is installed at the bottom of the support platform to apply a vertically downward load to the tubing string.

[0007] It further includes a processing module for processing data. The radial force test assembly is electrically connected to the data processing module, and the axial force test assembly is electrically connected to the data processing module.

[0008] Preferably, the slip assembly includes slips, a slip socket, and a slip seat. The slips are installed on the inner surface of the slip socket, the slip socket is used to fix the slips, and the slip seat is used to fix the slip socket. An inverted conical surface is used for the fit between the slip seat and the slip socket.

[0009] Preferably, the support platform includes a platform plate, and a through hole for the tubing string to pass through is provided in the middle of the platform plate.

[0010] Preferably, a tubing string step collar sleeve is provided in the middle of the tubing string.

[0011] Preferably, the radial force test assembly includes a radial pressure sensor, and the radial pressure sensor is installed between the contact surfaces of the slips and the slip socket.

[0012] Preferably, the radial force test assembly further includes a test base fixed on the platform plate of the support platform, and the slip assembly is installed on the test base.

[0013] Preferably, the axial force test assembly includes an annular force sensor, and the annular force sensor is installed below the tubing string step collar sleeve.

[0014] Preferably, the hydraulic component includes a telescopic hydraulic rod, a hydraulic pipeline, and a hydraulic control unit. One end of the telescopic hydraulic rod is connected to the lower surface of the tubing step pier sleeve, and the other end is connected to the hydraulic pipeline. The other end of the hydraulic pipeline is connected to the hydraulic control unit.

[0015] Preferably, the hydraulic component further includes a digital display hydraulic pressure gauge installed on the hydraulic pipeline.

[0016] A method for using a device for evaluating the pressure - holding operation ability of a slip based on the friction coefficient is as follows: S1. Install the radial force test component and the axial force test component on the support platform; S2. Connect the radial pressure sensor and the annular force - measuring sensor to the processing module through signal lines; S3. Continuously increase the load F pulling the tubing downward through the hydraulic control unit, and accurately measure the axial force in combination with the annular force - measuring sensor; S4. Observe the radial pressure sensor N between the slip and the slip seat through the processing module; S5. Monitor the axial force and the radial force in real time through the processing module, respectively obtain the axial - force - radial - force - load - time curve graph, and calculate and process through the formula to obtain the friction - coefficient - μ - time curve graph between the slip and the tubing, and obtain its maximum static friction coefficient and sliding friction coefficient; S6. Repeat steps S1 - S5, and average the maximum static friction coefficients of the load - time curve graphs measured in multiple experiments to obtain the actual range of the friction performance between the slip and the tubing; S7. Repeat steps S1 - S6 for the slips in different wear states to obtain the mapping relationship between the friction coefficient and the wear state; S8. Repeat steps S1 - S6 for the slip whose pressure - holding operation ability needs to be evaluated, measure the actual range of its performance with the tubing, evaluate the pressure - holding operation ability of the slip through calculation, and determine the slip operation ability according to the measured friction - coefficient value and the mapping relationship between the friction coefficient and the slip operation ability.

[0017] The beneficial effects brought by the present invention are as follows: 1. Compared with the prior art, it can evaluate the pressure - holding operation ability of the slip. The present invention aims to provide an accurate and reliable method to evaluate the performance and reliability of the slip during the pressure - holding operation. By measuring the mutation from the maximum friction coefficient to the sliding friction coefficient and analyzing the obtained frictional force, quantitative data on the working state of the slip can be obtained, thereby evaluating its pressure - holding operation ability.

[0018] 2. The present invention can also save space. Since the prior art measures the speed and calculates the average value through multiple measurements to obtain the sliding friction force in the uniform motion state, a certain range of site needs to be arranged. However, in this application, the processing module measures the situation of the sudden change from the maximum friction force to the sliding friction force, and the data can be obtained quickly, accurately and without occupying space.

[0019] 3. The present invention can also discover potential problems and hidden dangers in advance. By evaluating the pressure-bearing operation ability of the slips, potential problems and hidden dangers such as poor friction and excessive wear can be discovered early. This helps to take corresponding measures to repair or replace the slips and avoid accidents and production interruptions caused by slip failures.

[0020] 4. The present invention can also improve the operation safety. By accurately evaluating the pressure-bearing operation ability of the slips, the operation safety can be improved. Timely discovering the problems of the slips, corresponding preventive and maintenance measures can be taken to reduce the accident risk and protect the safety of the operating personnel and equipment.

[0021] 5. The present invention can also improve the operation efficiency. The invention aims to provide a method for quickly evaluating the pressure-bearing operation ability of the slips. Through rapid detection and evaluation, operation interruptions and downtime can be reduced, operation efficiency can be improved, maintenance costs can be reduced, and production benefits can be increased.

[0022] 6. The present invention can also promote sustainable development. By improving the safety and efficiency of the pressure-bearing operation of the slips, the invention helps to promote the sustainable development of oil and gas resources. Reducing the occurrence of accidents and failures, reducing resource waste and environmental damage, and realizing the effective utilization and protection of resources. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 is a flowchart of the present invention.

[0024] Figure 2 is a schematic structural diagram of the present invention.

[0025] Figure 3 is a cross-sectional view of the radial force test assembly of the present invention.

[0026] Figure 4 is a schematic structural diagram of the axial force test assembly of the present invention.

[0027] Figure 5 is an axial force load time curve graph of the present invention.

[0028] Figure 6 is a schematic structural diagram of the support platform of the present invention.

[0029] Reference numerals: 1 - Support platform, 11 - Platform board, 12 - Support column, 13 - Base, 2 - Radial force test component, 21 - Slip, 22 - Radial pressure sensor, 23 - Slip socket, 24 - Slip seat, 25 - Radial force test base, 3 - Axial force test component, 31 - Tubing step pier sleeve, 32 - Annular force sensor, 41 - Telescopic hydraulic rod, 42 - Hydraulic pipeline, 43 - Hydraulic control unit, 44 - Digital display hydraulic gauge, 5 - Tubing, 6 - Processing module. Specific implementation mode

[0030] The following will clearly and completely describe the concept, specific structure and technical effects of the present invention in combination with embodiments and drawings to fully understand the purpose, features and effects of the present invention.

[0031] Embodiment 1 Specific implementation mode: As Figures 1 to 4 shown, a device for evaluating the pressure - holding operation ability of a slip based on the friction coefficient includes a support platform 1, a slip assembly, a radial force test component 2, an axial force test component 3, a hydraulic component 4 and a tubing 5. The tubing 5 is disposed through the support platform 1, the slip assembly is clamped at the upper end of the tubing 5, the radial force test component 2 is disposed inside the slip assembly to test the radial force received by the slip 21, and the axial force test component 3 is disposed below the slip assembly to test the axial force received by the slip 21.

[0032] Figure 6 The above - mentioned support platform 1 shown includes a base 13, a support column 12 and a platform board 11. The radial force test component 2 is disposed on the platform board 11. The support column 12 is used to provide support for the platform board 11, and the base 13 is used to place the hydraulic component 4 and also provide support for the entire device.

[0033] This device measures the radial force and axial force between the slip 21 and the tubing 5 and analyzes to obtain parameters such as the friction coefficient μ, obtaining quantitative data on the working state of the slip 21, so as to evaluate its pressure - holding operation ability.

[0034] The hydraulic component 4 is installed at the bottom of the support platform 1 to apply a vertically downward load to the tubing 5.

[0035] It further includes a processing module 6 for processing data. The radial force test component is electrically connected to the processing module 6, and the axial force test component is electrically connected to the processing module 6. Using the processing module 6 to process data is more efficient, and it can also conveniently directly see the change relationship of the friction coefficient with time from the terminal, and more intuitively draw conclusions.

[0036] The slips assembly includes slips 21, a slips socket 23, and a slips seat 24. The slips 21 are installed on the inner surface of the slips socket 23. The slips socket 23 is used to fix the slips, and the slips seat 24 is used to fix the slips socket 23. An inverted conical surface is used for the fit between the slips seat 24 and the slips socket 23.

[0037] Further, the support platform 1 includes a platform plate 13. A through hole for the oil supply pipe 5 to pass through is provided in the middle of the platform plate 13. The oil pipe passes through the through hole and is vertically arranged on the support platform.

[0038] An oil pipe step pier sleeve 31 is provided in the middle of the oil pipe 5 for installing the annular force sensor 32.

[0039] Furthermore, the radial force test assembly 2 includes a radial pressure sensor 22. The radial pressure sensor 22 is installed between the contact surfaces of the slips 21 and the slips socket 23, and the radial pressure sensor 22 is used to measure the normal pressure N between the slips 21 and the slips socket 23.

[0040] The radial force test assembly 2 further includes a test base 25 fixed on the platform plate 13 of the support platform 1. The slips assembly is installed on the test base 25. When a downward load is applied to the oil pipe 5, due to the interaction of forces, the entire slips assembly will also be subjected to a downward force. The setting of the test base 25 is to ensure the stability inside the slips assembly.

[0041] The axial force test assembly 3 includes an annular force sensor 32. The annular force sensor 32 is installed below the oil pipe step pier sleeve 31 to measure the actual axial force F received by the slips 21.

[0042] Further, the setting of the hydraulic assembly can realize the slow increase of the applied load F, accurately obtain the axial force, and has a small error. The hydraulic assembly 4 includes a telescopic hydraulic rod 41, a hydraulic pipeline 42, and a hydraulic control unit 43. One end of the telescopic hydraulic rod 41 is connected to the lower surface of the oil pipe step pier sleeve 31, and the other end is connected to the hydraulic pipeline 42. The other end of the hydraulic pipeline 42 is connected to the hydraulic control unit 43.

[0043] Furthermore, the hydraulic assembly 4 further includes a digital display hydraulic pressure gauge 44 installed on the hydraulic pipeline 42 for displaying the internal pressure of the hydraulic pipeline 42 to facilitate the hydraulic control unit 43 to control the telescopic hydraulic rod 41.

[0044] Embodiment 2 The above-mentioned slip assembly only lists the basic connection method. Other improved models on the market can also use the device provided by this application for measurement and analysis. This device is configured to set the slip assembly at the end of the tubing 5, and then apply a downward load F to the tubing 5. By measuring the normal pressure and axial force and combining with the processing module 6, the friction coefficient between the slip and the tubing 5 can be measured and calculated. Effective measurement and analysis can be carried out using this device.

[0045] Embodiment 3 As Figure 5 shown, the measured axial force F increases from zero, first reaches the maximum static friction force and then suddenly changes to the sliding friction force. Therefore, not only the maximum static friction force but also two specific data of the sliding friction force can be obtained from the graph.

[0046] When the slip assembly clamps the tubing, the normal pressure of the slip on the tubing is fixed, that is, the radial force is fixed. By the processing module 6, the axial force F and the radial force N are monitored in real time. The actual sliding friction force is equal to the sum of the measured axial force F and the self-weight of the tubing. Since the self-weight of the tubing is much smaller than the axial force F at this time, it is ignored here. By calculation, the friction coefficient μ load-time curve graph between the slip 21 and the tubing 5 is obtained.

[0047] From the maximum static friction coefficient and the sliding friction coefficient calculated from the above two data, not only the ultimate clamping force of the slip but also the clamping force within the safe range can be determined in the actual use environment, thereby improving the operation safety.

[0048] A method for using a device for evaluating the pressure-bearing operation ability of a slip based on the friction coefficient is as follows: S1. Install the radial force test assembly 2 and the axial force test assembly 3 on the support platform 1; S2. Connect the radial pressure sensor 22 and the annular force sensor 32 to the processing module 6 through signal lines; S3. Continuously increase the downward pulling load F on the tubing 5 through the hydraulic control unit 43, and accurately measure the axial force in combination with the annular force sensor 32; S4. Observe the normal pressure N received by the radial pressure sensor 22 of the slip 21 and the slip seat 23 through the processing module 6; S5. Monitor the axial force and the radial force in real time through the processing module 6, respectively obtain the load-time curve graphs of the axial force and the radial force, and through the formula calculate and process to obtain the friction coefficient μ time curve graph between the slip 21 and the tubing 5, and obtain its maximum static friction coefficient and sliding friction coefficient; S6. Repeat steps S1 to S5, and the load-time curves measured in multiple experiments Figure for obtaining the average value of the maximum static friction coefficient to measure the actual range of the friction performance between the slips 21 and the tubing 5; S7. Repeat steps S1 to S6 for the slips in different wear states to obtain the mapping relationship between their friction coefficients and wear states; S8. Repeat steps S1 to S6 for the slips whose pressure - operated work ability needs to be evaluated, measure the actual range of the performance between the slips 21 and the tubing 5, evaluate the pressure - operated work ability of the slips 21 through calculation, and determine the work ability of the slips according to the mapping relationship between the measured friction coefficient value and the work ability of the slips.

[0049] Since the prior art measures the speed, takes multiple measurements and calculates their average value to obtain the sliding friction force in the uniform motion state, a certain range of site needs to be arranged. However, in this application, the processing module 6 measures the sudden change from the maximum friction force to the sliding friction force. The data can be obtained quickly, accurately and without occupying much space, which can save the site.

[0050] When all the structures of the device are successfully connected, the hydraulic control unit 43 continuously increases the downward pulling load F on the tubing 5, and accurately measures the axial force in combination with the annular force - measuring sensor 32; observe the test data N of the radial pressure sensor 22 between the slips 21 and the slip seat 23 through the processing module 6; according to the formula The processing module 6 monitors the axial force and the radial force in real - time, and calculates and obtains the friction coefficient μ - load time curve graph between the slips 21 and the tubing 5.

[0051] Embodiment 4 If in order to obtain relatively accurate data of a certain slip 21, it is necessary to repeatedly conduct experiments on the same slip 21 for many times, take the average value of the measured load time curve graph, so as to measure the actual range close to the friction performance between the slip 21 and the tubing 5; if in order to obtain data of the slips 21 in different wear states, the above steps need to be repeated to obtain multiple groups of mapping relationships between the friction coefficient μ and the wear states; at the same time, repeat the above steps for the slips 21 whose pressure - operated work ability needs to be evaluated, measure the actual range of their performance with the tubing 5, and determine the work ability of the slips according to the mapping relationship between the measured friction coefficient value and the work ability of the slips.

[0052] The above has specifically described the implementation manners of the present invention. However, the present invention is not limited to the described embodiments. Those skilled in the art can make various equivalent modifications or substitutions without departing from the spirit of the present invention, and these equivalents or substitutions are all included within the scope defined by the claims of the present invention.

Claims

1. A device for evaluating the pressure - holding operation ability of slips based on the friction coefficient, characterized in that: It includes a support platform (1), a slip assembly, a radial - force testing assembly (2), an axial - force testing assembly (3), a hydraulic assembly (4) and a tubing (5). The tubing (5) is disposed through the support platform (1). The slip assembly clamps the upper end of the tubing (5). The radial - force testing assembly (2) is arranged inside the slip assembly to test the radial force received by the slips (21), and the axial - force testing assembly (3) is arranged below the slip assembly to test the axial force received by the slips (21); The hydraulic assembly (4) is installed at the bottom of the support platform (1) to apply a vertically downward load to the tubing (5); It further includes a processing module (6) for processing data. The radial - force testing assembly (2) is electrically connected to the processing module (6), and the axial - force testing assembly (3) is electrically connected to the processing module (6).

2. The device for evaluating the pressure - holding operation ability of slips based on the friction coefficient according to claim 1, characterized in that, The slip assembly includes slips (21), a slip holder (23) and a slip seat (24). The slips (21) are installed on the inner surface of the slip holder (23), and the slip seat (24) is used to fix the slip holder (23). An inverted conical surface is used for the fit between the slip seat (24) and the slip holder (23).

3. The device for evaluating the pressure - holding operation ability of slips based on the friction coefficient according to claim 1, characterized in that, The support platform (1) includes a platform plate (11), and a through - hole for the tubing (5) to pass through is provided in the middle of the platform plate (11).

4. The device for evaluating the pressure - holding operation ability of slips based on the friction coefficient according to claim 1, characterized in that, A tubing step collar sleeve (31) is provided in the middle of the tubing (5).

5. The device for evaluating the pressure - holding operation ability of slips based on the friction coefficient according to claim 1, characterized in that, The radial - force testing assembly (2) includes a radial pressure sensor (22), and the radial pressure sensor is installed between the contact surfaces of the slips (21) and the slip holder (23).

6. The device for evaluating the pressure - holding operation ability of slips based on the friction coefficient according to claim 1, characterized in that, The radial - force testing assembly (2) further includes a test base (25) fixed on the platform plate (11) of the support platform (1), and the slip assembly is installed on the test base (25).

7. The device for evaluating the pressure - holding operation ability of slips based on the friction coefficient according to claim 1, characterized in that, The axial - force testing assembly (3) includes an annular force - measuring sensor (32), and the annular force - measuring sensor (32) is installed below the tubing step collar sleeve (31).

8. The device for evaluating the pressure - holding operation ability of slips based on the friction coefficient according to claim 1, characterized in that, The hydraulic component (4) includes a telescopic hydraulic rod (41), a hydraulic pipeline (42), and a hydraulic control unit (43). One end of the telescopic hydraulic rod (41) is connected to the lower surface of the tubing step pier sleeve (31), and the other end is connected to the hydraulic pipeline (42). The other end of the hydraulic pipeline (42) is connected to the hydraulic control unit (43).

9. The device for evaluating the pressure-bearing operation ability of a slip based on the friction coefficient according to claim 1, characterized in that, the hydraulic component (4) further includes a digital display hydraulic pressure gauge (44) installed on the hydraulic pipeline (42).

10. The usage method of the device for evaluating the pressure-bearing operation ability of a slip based on the friction coefficient according to any one of claims 1-9 is as follows: S1. Install the radial force test component (2) and the axial force test component (3) on the support platform (1); S2. Connect the radial pressure sensor (22) and the annular force measuring sensor (32) to the processing module (6) through signal lines; S3. Continuously increase the downward pulling load F on the tubing (5) through the hydraulic control unit (43), and accurately measure the axial force in combination with the annular force measuring sensor (32); S4. Observe the radial pressure sensor N of the slip (21) and the slip seat (23) through the processing module (6); S5. The axial force and the radial force are monitored in real time by the processing module (6), and the load-time curve graphs of the axial force and the radial force are obtained respectively. Through the formula The friction coefficient between the slips (21) and the tubing (5) is calculated and processed from the time curve graph, and the maximum static friction coefficient and the sliding friction coefficient are obtained; S6. Repeat steps S1-S5, and obtain the average value of the maximum static friction coefficient by finding the load-time curve graph measured in multiple experiments, so as to measure the actual range of the friction performance between the slip (21) and the tubing (5); S7. Repeat steps S1-S6 for the slips (21) in different wear states to obtain the mapping relationship between their friction coefficients and wear states; S8. Repeat steps S1 - S6 for the slips whose pressure - operated work capacity needs to be evaluated, measure the actual range of its performance with the tubing (5), evaluate the pressure - operated work capacity of the slips (21) through calculation, and determine the work capacity of the slips (21) according to the measured friction coefficient value and the mapping relationship between the friction coefficient and the work capacity of the slips (21).

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