A composite control device and method for tightening oil well tubing and couplings.

Abstract

This invention discloses a composite control device and method for the tightening process of oil well tubing and couplings, comprising: a torque measuring device mounted on a tightening chuck for measuring the output torque of the tightening chuck; a J-value measuring device mounted above the tightening position of the oil well tubing and coupling for measuring the J-value data of the coupling; a moving clamping controller connected to a moving clamping device; a tightening chuck controller connected to the tightening chuck; a position signal switch for detecting the position signal of the oil well tubing; a data interface unit for receiving the target J-value and target torque of the oil well tubing and coupling; and a tightening control unit for receiving data from the torque measuring device, the J-value measuring device, the position signal switch, and the data interface unit, and outputting control commands to the moving clamping controller and the tightening chuck controller. This invention continuously compares the real-time measurement of the J-value and torque with the target J-value and torque, reducing the J-value deviation while ensuring the torque.

Description

Technical Field

[0001] This invention relates to oil well pipe production process control technology, and more specifically, to a composite control device and method for the tightening process of oil well pipe and coupling. Background Technology

[0002] Oil well tubing is a primary type of oil pipeline, playing a crucial role in oil and gas exploration and development. Connected to each other via couplings, these couplings are the weakest link in the oil well pipeline system, and their quality directly impacts the safety, reliability, and lifespan of the pipeline. According to a survey by the American Petroleum Institute (API), most oil well tubing failures occur at the coupling joints. Therefore, tightening the couplings is a critical process for manufacturers, and the quality of the tightening largely determines the overall quality of the oil well tubing produced.

[0003] The coupling thread is a tapered pipe thread. The connection strength and sealing performance of the thread are achieved by the interference fit generated after tightening the coupling. The API standard specifies in detail the minimum and maximum tightening torques for various types of oil well pipes and couplings. It also specifies the J-value as an important coupling tightening parameter. The J-value refers to the distance from the end face of the oil well pipe to the center face of the coupling. It is the assembly dimension of the fit between the pipe thread and the coupling thread, reflecting the engagement length of the internal and external threads, the interference fit, etc. Because it is difficult to measure the J-value during the coupling tightening process, manufacturers only use torque to control the tightening of couplings. In the tightening unit, a target torque is set. When the coupling is tightened to the target torque, tightening is stopped. Theoretically, at this time, the threads of the coupling and the steel pipe should be in the optimal fit position. However, in actual production, due to various factors such as thread machining errors, coupling ovality errors, thread grease buildup, and even mis-threading, the torque cannot fully reflect the fit between the oil well pipe and coupling threads. This can easily lead to an overly dispersed distribution of the coupling tightening J-value, increasing the product defect rate. Meanwhile, because the J value is more convenient for users to measure and inspect, in recent years, the problems of scrap and quality disputes caused by non-compliant J values ​​have become increasingly prominent. Summary of the Invention

[0004] To address the shortcomings of existing technologies, the present invention aims to provide a composite control device and method for the tightening process of oil well pipes and couplings. By measuring the tightening J value and torque in real time and continuously comparing them with the target J value and target torque, the J value deviation is reduced while ensuring the torque, thus completing the coupling tightening operation.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] The first aspect of this invention provides a composite control device for the tightening process of oil well tubing and couplings, comprising:

[0007] A torque measuring device is mounted on the tightening chuck to measure the output torque of the tightening chuck.

[0008] The J-value measuring device is installed above the oil well pipe and coupling tightening station to measure the J-value data of the coupling.

[0009] A movable clamping controller, connected to the movable clamping device, is used to control the operation of the movable clamping device;

[0010] A chuck controller, connected to the chuck, is used to control the movement of the chuck;

[0011] A positioning signal switch is used to detect the positioning signal of the well pipe;

[0012] The data interface unit is used to receive the target J value and target torque data of the well pipe and the coupling;

[0013] The screwing control unit is used to receive data from the torque measuring device, the J-value measuring device, the position signal switch, and the data interface unit, and output control commands to the moving clamping controller and the tightening chuck controller.

[0014] Preferably, the J-value measuring device measures the J-value data in a non-contact manner.

[0015] Preferably, the screwing control unit is an industrial computer.

[0016] A second aspect of this invention provides a composite control method for the tightening process of oil well tubing and couplings:

[0017] During the process of screwing the coupling into the well pipe, the torque increases and the J value decreases. The combined control device for the tightening process of the well pipe and the coupling measures the torque and the J value in real time and continuously compares them with the target torque and the target J value. While ensuring the torque, the J value deviation is reduced, and the coupling screwing operation is completed.

[0018] Preferably, the real-time measurement of torque and J value and the comparison with target torque and target J value specifically include the following steps:

[0019] S1. The positioning signal switch detects that the oil well pipe has reached the coupling tightening position. The data interface unit collects the maximum and minimum values ​​of the target J value required to be controlled by the oil well pipe and the coupling, as well as the maximum, minimum, and optimal values ​​of the target torque.

[0020] S2. The screwing control unit sends a command to the moving clamping controller to control the moving clamping device to clamp the oil well pipe and send the pre-tightened coupling on the oil well pipe into the screwing chuck.

[0021] S3. The screwing control unit sends a command to the tightening chuck controller to control the tightening chuck to clamp the coupling and rotate it to screw the coupling into the oil well pipe;

[0022] S4. The torque measuring device measures the torque, and the J value measuring device measures the J value;

[0023] S5. The screwing control unit determines whether the torque has reached the minimum value of the target torque. If yes, proceed to step S6; otherwise, return to step S4.

[0024] S6. The screwing control unit determines whether the J value is less than the minimum value of the target J value. If yes, proceed to step S12; otherwise, proceed to step S7.

[0025] S7. The torque measuring device continues to measure the torque, and the J value measuring device continues to measure the J value;

[0026] S8. The screwing control unit determines whether the torque has reached the optimal torque. If yes, proceed to step S9; otherwise, return to step S6.

[0027] S9. The screwing control unit determines whether the J value is less than the maximum value of the target J value. If yes, proceed to step S12; otherwise, proceed to step S10.

[0028] S10. The torque measuring device continues to measure the torque, and the J value measuring device continues to measure the J value;

[0029] S11. The screwing control unit determines whether the torque has reached the maximum value of the target torque. If yes, proceed to step S12; otherwise, return to step S9.

[0030] S12. The screwing control unit sends a command to the tightening chuck controller to control the tightening chuck to stop rotating and loosen the coupling;

[0031] S13. The screwing control unit sends a command to the moving clamping controller to control the moving clamping device to move the oil well pipe and the coupling together back to the initial position and release the oil well pipe to complete the screwing operation of the oil well pipe and the coupling.

[0032] The present invention provides a composite control device and method for the tightening process of oil well tubing and couplings. By measuring the J value and torque in real time during the process of tightening the coupling into the oil well tubing, and continuously comparing it with the target torque and J value requirement range, the J value deviation is reduced while ensuring the torque, and the coupling tightening operation is completed. This has a good effect on ensuring the quality of coupling tightening. Attached Figure Description

[0033] Figure 1 This is a schematic diagram of the structure of the composite control device of the present invention;

[0034] Figure 2 This is a schematic diagram of the J-value between the oil well casing and the coupling;

[0035] Figure 3 This is a flowchart illustrating the composite control method of the present invention. Detailed Implementation

[0036] To better understand the above-mentioned technical solutions of the present invention, the technical solutions of the present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0037] Combination Figure 1 As shown, the present invention provides a composite control device for the tightening process of oil well tubing and couplings, comprising:

[0038] The torque measuring device 1 is installed on the tightening chuck 2 to measure the output torque of the tightening chuck 2 in real time and transmit the measurement result to the tightening control unit 11 in real time.

[0039] The J-value measuring device 3 is installed above the oil well pipe 4 and the coupling tightening station. It uses a non-contact method to measure the J-value data of the coupling 5 in real time when tightening, and transmits the measurement results to the tightening control unit 11 in real time.

[0040] The movable clamping controller 6 is connected to the movable clamping device 7 and is used to control the clamping and loosening of the oil well pipe 4 by the movable clamping device 7. It can also drive the oil well pipe 4 to move in the horizontal direction and receive control commands output by the screwing control unit 11.

[0041] The chuck controller 8 is connected to the chuck 2 and is used to control the clamping and loosening of the coupling 5 by the chuck 2. It can also drive the coupling 5 to rotate and receive control commands output by the tightening control unit 11.

[0042] The position signal switch 9 is a limit switch that detects whether the oil well pipe 9 has reached the coupling tightening position. When the oil well pipe 9 is in position, it outputs a signal to the tightening control unit 11.

[0043] The data interface unit 10 is a data signal communication device used to receive the minimum and maximum values ​​of the target J value of the current oil well pipe 4 and coupling 5, as well as the minimum, maximum, and optimal values ​​of the target torque, and transmit these data to the screwing control unit 11.

[0044] The screwing control unit 11 is used to receive torque data, J value data, position signal, oil well pipe and coupling specifications, target torque and J value, etc. transmitted by the torque measuring device 1, J value measuring device 3, position signal switch 9, and data interface unit 10, and output control commands to the moving clamping controller 6 and tightening chuck controller 8 to drive the moving clamping device 7 and tightening chuck 2 to perform screwing operations.

[0045] The screwing control unit 11 is an industrial computer, which mainly performs tasks such as signal and data acquisition and screwing control output execution.

[0046] The tightening chuck 2 is a device for tightening couplings, used to tighten couplings 5 ​​onto the well pipe 4. It can clamp and drive couplings 5 ​​to rotate, and the horizontal position remains unchanged during rotation.

[0047] The movable clamping device 7 is a device for tightening couplings, used to clamp the oil well pipe 4, fixing it in the direction of rotation, but allowing it to move in the horizontal direction.

[0048] Combination Figure 2 As shown, the J value is defined as the distance between the end face of the oil well pipe 4 and the center plane of the coupling 5. It is the assembly dimension of the oil well pipe 4 and the coupling 5, reflecting the degree of fit between the threads of the coupling 5 and the oil well pipe 4. It is also an important process and quality control parameter in the production of oil well pipes, and there are clear requirements in various domestic and foreign standards.

[0049] The oil well pipe and coupling tightening operation consists of two steps: pre-tightening and machine tightening. Pre-tightening can be done manually, but in steel pipe manufacturing companies, machines are usually used instead. A small torque is set for pre-tightening to tighten the coupling onto the oil well pipe for fixation. Then, the machine tightening is performed at the next coupling tightening station. The torque continuously increases as the coupling is tightened into the oil well pipe. When the torque reaches the set value, the tightening operation of that coupling is completed. This invention also provides a composite control method for the oil well pipe and coupling tightening process:

[0050] During the process of screwing the coupling into the well pipe, the torque increases and the J value decreases. The combined control device for the tightening process of the well pipe and the coupling measures the torque and J value in real time and continuously compares them with the target torque and the target J value. While ensuring the torque, the J value deviation is reduced, and the coupling screwing operation is completed.

[0051] Example 1

[0052] Combination Figure 3 As shown, the real-time measurement of torque and J value in the composite control method of the present invention, and the comparison with the target torque and target J value, specifically includes the following steps:

[0053] S1. When the positioning signal switch 9 detects that the oil well pipe 4 has reached the coupling tightening position, the data interface unit 10 collects the maximum value of the target J value required to be controlled by the current oil well pipe 4 and coupling 5, which is 15.5mm and the minimum value is 9.5mm, as well as the maximum value of the target torque, which is 2800N, the minimum value is 2200N, and the optimal value is 2500N.

[0054] S2. The screwing control unit 11 sends a command to the moving clamping controller 6 to control the moving clamping device 7 to clamp the oil well pipe 4 and send the pre-tightened coupling 5 on the oil well pipe 4 into the screwing chuck 2.

[0055] S3. The screwing control unit 11 sends a command to the tightening chuck controller 8 to control the tightening chuck 2 to clamp the coupling 5 and rotate it to screw the coupling 5 into the oil well pipe 4;

[0056] S4. Torque measuring device 1 measures torque, and J value measuring device 3 measures J value;

[0057] S5. The screwing control unit 11 determines whether the torque has reached the minimum target torque of 2200N. If yes, proceed to step S6; otherwise, return to step S4.

[0058] S6. The screwing control unit 11 determines whether the J value is less than the minimum target J value of 9.5mm. If yes, proceed to step S12; otherwise, proceed to step S7.

[0059] S7. Torque measuring device 1 continues to measure torque, and J value measuring device 3 continues to measure J value;

[0060] S8. The screwing control unit 11 determines whether the torque has reached the optimal value of the target torque of 2500N. If yes, proceed to step S9; otherwise, return to step S6.

[0061] S9. The screwing control unit 11 determines whether the J value is less than the maximum value of the target J value of 15.5mm. If yes, proceed to step S12; otherwise, proceed to step S10.

[0062] S10, Torque measuring device 1 continues to measure torque, and J value measuring device 3 continues to measure J value;

[0063] S11. The screwing control unit 11 determines whether the torque has reached the maximum value of the target torque of 2800N. If yes, proceed to step S12; otherwise, return to step S9.

[0064] S12, The screwing control unit 11 sends a command to the tightening chuck controller 8 to control the tightening chuck 2 to stop rotating and loosen the coupling 5;

[0065] S13, the screwing control unit 11 sends a command to the moving clamping controller 6 to control the moving clamping device 7 to move the oil well pipe 4 and the coupling 5 back to the initial position together, and release the oil well pipe 4 to complete the screwing operation of the current oil well pipe 4 and coupling 5.

[0066] Example 2

[0067] Combination Figure 3 As shown, the real-time measurement of torque and J value in the composite control method of the present invention, and the comparison with the target torque and target J value, specifically includes the following steps:

[0068] S1. When the positioning signal switch 9 detects that the oil well pipe 4 has reached the coupling tightening position, the data interface unit 10 collects the maximum value of the target J value required to be controlled by the current oil well pipe 4 and coupling 5, which is 19.05mm and the minimum value is 6.35mm, as well as the maximum value of the target torque, which is 3000N, the minimum value is 2300N, and the optimal value is 2700N.

[0069] S2. The screwing control unit 11 sends a command to the moving clamping controller 6 to control the moving clamping device 7 to clamp the oil well pipe 4 and send the pre-tightened coupling 5 on the oil well pipe 4 into the screwing chuck 2.

[0070] S3. The screwing control unit 11 sends a command to the tightening chuck controller 8 to control the tightening chuck 2 to clamp the coupling 5 and rotate it to screw the coupling 5 into the oil well pipe 4;

[0071] S4. Torque measuring device 1 measures torque, and J value measuring device 3 measures J value;

[0072] S5. The screwing control unit 11 determines whether the torque has reached the minimum target torque of 2300N. If yes, proceed to step S6; otherwise, return to step S4.

[0073] S6. The screwing control unit 11 determines whether the J value is less than the minimum target J value of 6.35mm. If yes, proceed to step S12; otherwise, proceed to step S7.

[0074] S7. Torque measuring device 1 continues to measure torque, and J value measuring device 3 continues to measure J value;

[0075] S8. The screwing control unit 11 determines whether the torque has reached the optimal value of the target torque of 2700N. If yes, proceed to step S9; otherwise, return to step S6.

[0076] S9. The screwing control unit 11 determines whether the J value is less than the maximum value of the target J value of 19.05mm. If yes, proceed to step S12; otherwise, proceed to step S10.

[0077] S10, Torque measuring device 1 continues to measure torque, and J value measuring device 3 continues to measure J value;

[0078] S11. The screwing control unit 11 determines whether the torque has reached the maximum value of the target torque of 3000N. If yes, proceed to step S12; otherwise, return to step S9.

[0079] S12, The screwing control unit 11 sends a command to the tightening chuck controller 8 to control the tightening chuck 2 to stop rotating and loosen the coupling 5;

[0080] S13, the screwing control unit 11 sends a command to the moving clamping controller 6 to control the moving clamping device 7 to move the oil well pipe 4 and the coupling 5 back to the initial position together, and release the oil well pipe 4 to complete the screwing operation of the current oil well pipe 4 and coupling 5.

[0081] Those skilled in the art should recognize that the above embodiments are merely illustrative of the present invention and are not intended to limit the present invention. Any variations or modifications to the above embodiments that are within the spirit and essence of the present invention will fall within the scope of the claims of the present invention.

Claims

1. A composite control method for the tightening process of oil well tubing and couplings, characterized in that: A torque measuring device is mounted on the tightening chuck to measure the output torque of the tightening chuck. The J-value measuring device is installed above the oil well pipe and coupling tightening station to measure the J-value data of the coupling. A movable clamping controller, connected to the movable clamping device, is used to control the operation of the movable clamping device; A chuck controller, connected to the chuck, is used to control the movement of the chuck; A positioning signal switch is used to detect the positioning signal of the well pipe; The data interface unit is used to receive the target J value and target torque data of the well pipe and the coupling; The screwing control unit is used to receive data from the torque measuring device, the J-value measuring device, the position signal switch, and the data interface unit, and output control commands to the moving clamping controller and the tightening chuck controller. During the process of screwing the coupling into the well pipe, the torque increases and the J value decreases. The torque and J value are measured in real time by a composite control device for the tightening process of the well pipe and the coupling, and are continuously compared with the target torque and the target J value. The J value deviation is reduced while ensuring the torque, and the coupling screwing operation is completed. The real-time measurement of torque and J value, and the comparison with target torque and target J value, specifically includes the following steps: S1. The positioning signal switch detects that the oil well pipe has reached the coupling tightening position. The data interface unit collects the maximum and minimum values ​​of the target J value required to be controlled by the oil well pipe and the coupling, as well as the maximum and minimum values ​​of the target torque. S2. The screwing control unit sends a command to the moving clamping controller to control the moving clamping device to clamp the oil well pipe and send the pre-tightened coupling on the oil well pipe into the screwing chuck. S3. The screwing control unit sends a command to the tightening chuck controller to control the tightening chuck to clamp the coupling and rotate it to screw the coupling into the oil well pipe; S4. The torque measuring device measures the torque, and the J value measuring device measures the J value; S5. The screwing control unit determines whether the torque has reached the minimum value of the target torque. If yes, proceed to step S6; otherwise, return to step S4. S6. The screwing control unit determines whether the J value is less than the minimum value of the target J value. If yes, proceed to step S12; otherwise, proceed to step S7. S7. The torque measuring device continues to measure the torque, and the J value measuring device continues to measure the J value; S8. The screwing control unit determines whether the torque has reached the target torque. If yes, proceed to step S8; otherwise, return to step S6. S9. The screwing control unit determines whether the J value is less than the maximum value of the target J value. If yes, proceed to step S12; otherwise, proceed to step S10. S10. The torque measuring device continues to measure the torque, and the J value measuring device continues to measure the J value; S11. The screwing control unit determines whether the torque has reached the maximum value of the target torque. If yes, proceed to step S12; otherwise, return to step S9. S12. The screwing control unit sends a command to the tightening chuck controller to control the tightening chuck to stop rotating and loosen the coupling; S13. The screwing control unit sends a command to the moving clamping controller to control the moving clamping device to move the oil well pipe and the coupling together back to the initial position and release the oil well pipe to complete the screwing operation of the oil well pipe and the coupling.

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