A method and system for identifying and evaluating damage of oil casing threaded joints

Abstract

This invention discloses a method and system for damage identification and assessment of oil casing threaded joints, relating to the field of threaded joint damage identification technology. It solves the technical problem of difficulty in conducting targeted monitoring of oil casing threaded joints used for different fluids, and the difficulty in quickly detecting faults in different types of oil casing threaded joints, thus affecting the accuracy of threaded joint damage identification. By designing corresponding detection schemes for different types of threaded joints, the accuracy and effectiveness of the assessment are improved. Different classifications and monitoring data facilitate the development of more scientific and reasonable maintenance plans. Analysis combining actual detection data and basic parameters helps to establish a more accurate fault identification system. A three-dimensional model is constructed by acquiring high-definition images to assess the deviation of the central axis of the pipes on both sides of the threaded joint. The quantitative assessment of the central axis deviation provides data support for subsequent damage identification.

Description

Technical Field

[0001] The invention belongs to the field of threaded joint damage identification, and in particular relates to a method and system for identifying and evaluating damage of oil casing threaded joints. Background Art

[0002] In the process of oil and gas extraction, oil casing is an important transportation and support structure, and the integrity of its threaded joints directly affects the safety and production efficiency of the wellbore. With the extension of oil and gas field development time, oil casing threaded joints are facing damage caused by various factors, such as corrosion, fatigue, wear, etc. These damages may not only cause equipment failures, but also cause environmental pollution and safety accidents. Therefore, establishing an effective damage identification and assessment system is crucial to ensure the safe and efficient operation of oil and gas operations. The development of modern technology provides support for this demand, including sensor technology, data analysis algorithms, and artificial intelligence, which can monitor and evaluate the health status of threaded joints in real time, thereby achieving preventive maintenance and risk management.

[0003] Most damage identification and assessment schemes for oil casing threaded joints only identify surface damage, which makes it difficult to conduct targeted monitoring of oil casing threaded joints used for different fluids, and difficult to quickly discover faults of different types of oil casing threaded joints. The impact of pipeline deviation on the performance of threaded joints is not fully considered, and the impact of various usage conditions of threaded joints on their performance is not considered, which affects the accuracy of threaded joint damage identification. Summary of the invention

[0004] The present invention aims to solve at least one of the technical problems existing in the prior art; to this end, the present invention proposes a method and system for identifying and evaluating damage of oil casing threaded joints, which is used to solve the technical problems that it is difficult to conduct targeted monitoring of oil casing threaded joints used for different fluids, it is difficult to quickly discover faults of different types of oil casing threaded joints, and this affects the accuracy of threaded joint damage identification.

[0005] To solve the above problems, the first aspect of the present invention provides a method for identifying and evaluating damage of a threaded joint of an oil casing, comprising the following steps:

[0006] According to the positions of the threaded joints of the oil casing in the management area, the threaded joints of the oil casing are allocated to different management blocks, and the basic parameters of the threaded joints in each threaded joint management block are collected;

[0007] The threaded joints in the threaded joint management area are classified into high-temperature threaded joint classification, high-pressure threaded joint classification and ordinary threaded joint classification. For the high-temperature threaded joint classification, the internal and external temperatures of the threaded joints and the temperature data of the threaded joints themselves are detected. For the high-pressure threaded joint classification, the internal and external pressure data of the threaded joints are detected. Based on the detected data and the basic parameters of the threaded joints, the operating stability coefficient of the threaded joints of the oil casing is evaluated;

[0008] Based on the high-definition images of the threaded joints of the oil casing and tubing, a three-dimensional model of the threaded joints of the oil casing and tubing is established, the central axis of the pipes on both sides of the threaded joint is detected, and the deviation of the central axis of the pipes on both sides of the threaded joint is evaluated;

[0009] Based on the evaluation results of the deviation of the central axis of the pipes on both sides of the threaded joint and the high-definition images of the threaded joint, a central axis deviation damage model of the threaded joint of the oil casing is established to evaluate the deviation damage coefficient of the threaded joint;

[0010] The damage degree of the threaded joints of the oil casing and tubing is evaluated by the number of times the threaded joints of the oil casing and tubing have been tightened and the service time, the initial tightening force at each tightening, the operating stability coefficient of the threaded joints of the oil casing and tubing and the deviation loss coefficient of the threaded joints.

[0011] As a further solution of the present invention: according to the positions of the threaded joints of the oil casing in the management area, the threaded joints of the oil casing are allocated to different management blocks, and the basic parameters of the threaded joints in each threaded joint management block are collected, including the following steps:

[0012] Obtain the layout of the oil casing and tubing in the management area, as well as the locations of the threaded joints of the oil casing and tubing;

[0013] Code the oil casing and tubing in the management area, and code the threaded joints on the oil casing and tubing according to the codes of the oil casing and tubing;

[0014] Divide the management blocks from the initial fluid inlet on the layout diagram of the oil casing to the fluid outlet, so that each management block includes a certain number of threaded joints;

[0015] A data processing node is set in each threaded joint management block, and the number of times the threaded joint is tightened and the service time, as well as the initial tightening force at each tightening, are recorded through the data processing node, so as to collect the basic parameters of the threaded joint in the threaded joint management block;

[0016] The data processing node cleans and denoises the basic parameters of the threaded joint, adds the code of the threaded joint as a label to the basic parameters, and adds the basic parameters after the label is added.

[0017] As a further solution of the present invention, collecting basic parameters of the threaded joint in the threaded joint management block includes the following steps:

[0018] A plurality of stress detection sheets are arranged at the threads of the threaded joint, and the stress detection sheets are arranged in a ring array along the central axis of the threaded joint;

[0019] Collect stress data at the thread of the threaded joint, and collect thickness data at the thread of the threaded joint through ultrasonic testing technology;

[0020] The collected stress data at the threads of the threaded joint and the thickness data at the threads of the threaded joint are used as the basic parameters of the threaded joint.

[0021] As a further solution of the present invention: classifying the threaded joints in the threaded joint management block into high-temperature threaded joints, high-pressure threaded joints and ordinary threaded joints, including the following steps:

[0022] The temperature and pressure of the fluid medium inside the threaded joints of the oil casing in the collection management area;

[0023] If the temperature of the fluid medium inside the threaded joint of the oil casing is greater than 200°C, the threaded joint of the oil casing is classified as a high-temperature threaded joint;

[0024] If the pressure of the fluid medium inside the threaded joint of the oil casing is greater than 10MPa, the threaded joint of the oil casing is classified as a high-pressure threaded joint.

[0025] As a further solution of the present invention: evaluating the operation stability coefficient of the threaded joint of the oil casing according to the detected data combined with the basic parameters of the threaded joint, including the following steps:

[0026] For high-temperature threaded joints, the preset detection time interval is obtained. The temperature inside and outside the high-temperature threaded joint is detected, as well as the temperature data of the threaded joint itself. The temperature data of the threaded joint itself within the detection time interval is normalized so that the temperature data of the threaded joint itself is within the interval [0,1]. Combined with the basic parameters of the threaded joint, the operation stability coefficient of the threaded joint of the oil casing is evaluated by the following formula:

[0027]

[0028] Among them, α1 is the operation stability coefficient of the threaded joint of the high-temperature threaded joint type, St is the variance of the temperature change of the threaded joint itself within the detection time interval, Sn is the variance of the temperature change inside the threaded joint within the detection time interval, Sw is the variance of the temperature change inside the threaded joint within the detection time interval, Sh is the variance of the thickness change at the thread of the threaded joint within the detection time interval, Sf is the variance of all stress detection values ​​at the thread of the threaded joint within the detection time interval, μ1 is the average value of the temperature change of the threaded joint itself within the detection time interval, μ2 is the average value of the temperature change inside the threaded joint within the detection time interval, μ3 is the average value of the thickness change at the thread of the threaded joint within the detection time interval, and μ4 is the average value of all stress detection values ​​at the thread of the threaded joint within the detection time interval;

[0029] For high-pressure threaded joints, obtain the pressure data inside and outside the high-pressure threaded joints, combine the basic parameters of the threaded joints, and use the following formula to evaluate the operating stability coefficient of the threaded joints of the oil casing:

[0030]

[0031] Among them, α1 is the operation stability coefficient of the threaded joint of the high-temperature threaded joint type, St is the variance of the temperature change of the threaded joint itself within the detection time interval, Spn is the variance of the pressure change inside the threaded joint within the detection time interval, and Spw is the variance of the pressure change outside the threaded joint within the detection time interval;

[0032] For common threaded joints, the running stability coefficient of the threaded joints of oil casing is evaluated according to the basic parameters of the threaded joints:

[0033]

[0034] Among them, α3 is the operating stability coefficient of the threaded joint of the ordinary threaded joint type.

[0035] As a further solution of the present invention: according to the high-definition image of the threaded joint of the oil casing, a three-dimensional model of the threaded joint of the oil casing is established, the central axis of the pipes on both sides of the threaded joint is detected, and the deviation of the central axis of the pipes on both sides of the threaded joint is evaluated, including the following steps:

[0036] The high-definition images of the threaded joints of the oil casing were de-noised and contrast enhanced using GIMP image processing software;

[0037] The edge detection algorithm is used to extract the edge and contour information of the threaded joint and the pipes on both sides of the threaded joint from the high-definition image of the threaded joint of the oil casing;

[0038] Perform three-dimensional reconstruction through three-dimensional modeling software to generate a three-dimensional model;

[0039] Extract the central axis of the pipes on both sides of the threaded joint in the 3D model. The central axis refers to the center line inside the pipe.

[0040] Detect the deviation angle between the central axis of the pipes on both sides of the threaded joint, and the distance between the two closest end points of the central axis of the pipes on both sides of the threaded joint;

[0041] The deviation of the center axis of the pipes on both sides of the threaded joint is evaluated based on the deviation angle between the center axis of the pipes on both sides of the threaded joint and the distance between the two closest end points of the center axis of the pipes on both sides of the threaded joint.

[0042] As a further solution of the present invention: according to the deviation angle between the central axes of the pipes on both sides of the threaded joint and the distance between the two closest end points of the central axes of the pipes on both sides of the threaded joint, the deviation of the central axes of the pipes on both sides of the threaded joint is evaluated, comprising the following steps:

[0043] Obtaining the distance between the pipes on both sides of the threaded joint in the generated three-dimensional model of the threaded joint of the oil casing and the pipes on both sides;

[0044] According to the distance between the pipes on both sides of the threaded joint, the deviation angle between the central axes of the pipes on both sides of the threaded joint, and the distance between the two closest endpoints of the central axes of the pipes on both sides of the threaded joint, the deviation of the central axes of the pipes on both sides of the threaded joint is evaluated by the following formula:

[0045]

[0046] Among them, K is the deviation of the central axis of the pipes on both sides of the threaded joint, θ is the deviation angle between the central axes of the pipes on both sides of the threaded joint, L1 is the distance between the pipes on both sides of the threaded joint, L2 is the distance between the two nearest endpoints of the central axis of the pipes on both sides of the threaded joint, and e is a natural constant.

[0047] As a further solution of the present invention: based on the evaluation results of the deviation of the central axis of the pipes on both sides of the threaded joint and the high-definition image at the threaded joint, a central axis deviation damage model of the threaded joint of the oil casing is established to evaluate the deviation damage coefficient of the threaded joint, including the following steps:

[0048] Acquire historical data of high-definition images of threaded joints with surface defects, and mark defective parts in the high-definition images of the threaded joints;

[0049] The Mask R-CNN image segmentation model is trained through annotated images to mark the defects in high-definition images.

[0050] Obtain the collected high-definition images of the threaded joints, and annotate the defective parts in the high-definition images of the threaded joints using the trained Mask R-CNN image segmentation model;

[0051] Calculate the percentage of the defective part in the high-definition image of the threaded joint to the surface area of ​​the threaded joint;

[0052] Based on the evaluation results of the deviation of the central axis of the pipes on both sides of the threaded joint and the percentage of the defective part in the high-definition image of the threaded joint to the surface area of ​​the threaded joint, the central axis deviation damage model of the threaded joint of the oil casing is established by the following formula:

[0053]

[0054] Among them, β is the deviation loss coefficient of the central axis of the threaded joint of the oil casing, and f is the percentage of the defective part in the high-definition image of the threaded joint to the surface area of ​​the threaded joint.

[0055] As a further solution of the present invention, the damage degree of the threaded joint of the oil casing is evaluated by the number of times the threaded joint of the oil casing is tightened and the service time, the initial tightening force at each tightening, the operation stability coefficient of the threaded joint of the oil casing and the deviation loss coefficient of the threaded joint, including the following steps:

[0056] Obtain the number of times the threaded joint is tightened and the service time recorded by the data processing node, as well as the initial tightening force during each tightening;

[0057] Detect the number of times n that the threaded joint is tightened. If the number of times n that the threaded joint is tightened is an even number, divide the initial tightening force values ​​of the threaded joint at each tightening into two parts according to the order in which the initial tightening force values ​​of the threaded joint are recorded each time, and calculate the difference U between the sum of the initial tightening force values ​​of the first part and the sum of the initial tightening force values ​​of the second part;

[0058] If the number of times n of tightening the threaded joint is an odd number, remove the initial tightening force data at the (n+1) / 2nd tightening, divide the initial tightening force values ​​of the threaded joint at each tightening into two parts according to the order of recording the initial tightening force values ​​of the threaded joint at each tightening, and calculate the difference U between the sum of the initial tightening force values ​​of the first part and the sum of the initial tightening force values ​​of the second part;

[0059] According to the acquired data, the running stability coefficient of the threaded joint of the oil casing and the deviation loss coefficient of the threaded joint, the damage degree of the threaded joint of the oil casing and the casing is evaluated:

[0060]

[0061] Among them, E is the damage evaluation value of the oil casing threaded joint, ft is the percentage of the service life of the oil casing threaded joint in the total service life, Fz is the sum of the initial tightening force of the threaded joint each time it is tightened, and S0 is the variance of the initial tightening force of the threaded joint each time it is tightened;

[0062] If the damage degree evaluation value of the oil casing threaded joint exceeds the preset threshold, the corresponding threaded joint is damaged and the corresponding threaded joint is replaced.

[0063] As another aspect of the present invention: a system for identifying and evaluating damage of oil casing threaded joints, the system adopts the above-mentioned method for identifying and evaluating damage of oil casing threaded joints to realize damage identification and evaluation of oil casing threaded joints.

[0064] Compared with the prior art, the present invention has the following beneficial effects:

[0065] The present invention classifies the threaded joints in the threaded joint management block into high-temperature threaded joint classification, high-pressure threaded joint classification and ordinary threaded joint classification, and designs corresponding detection schemes for different types of threaded joints, thereby improving the accuracy and effectiveness of the evaluation; for the high-temperature threaded joint classification, the temperature inside and outside the threaded joint, as well as the temperature data of the threaded joint itself, are detected, and the temperature state under high temperature conditions is monitored in real time, so as to facilitate timely discovery of potential risks and reduce the probability of accidents; for the high-pressure threaded joint classification, the pressure data inside and outside the threaded joint are detected, and through different classifications and monitoring data, it is convenient to formulate a more scientific and reasonable maintenance plan and enhance the accuracy of fault identification; through the changes in temperature and pressure data, the operating stability coefficient of the threaded joint of the oil casing is evaluated, and analysis is carried out in combination with actual detection data and basic parameters, which is conducive to establishing a more accurate fault identification system.

[0066] The present invention establishes a three-dimensional model of the threaded joint of the oil casing and casing based on the high-definition image of the threaded joint of the oil casing and casing, detects the central axis of the pipes on both sides of the threaded joint, and evaluates the deviation of the central axis of the pipes on both sides of the threaded joint; by collecting high-definition images to build a three-dimensional model, it can accurately reflect the actual structure and facilitate the evaluation of the deviation of the central axis of the pipes on both sides of the threaded joint; through the quantitative evaluation of the deviation of the central axis, clear data support is provided for subsequent maintenance and adjustment; at the same time, by monitoring the deviation of the central axis, it is convenient to timely discover potential problems, such as stress concentration or poor connection, increase the accuracy of fault identification, and thus reduce the risk of faults. BRIEF DESCRIPTION OF THE DRAWINGS

[0067] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0068] Figure 1 It is a schematic diagram of the process of the present invention;

[0069] Figure 2 It is a schematic flow chart of a method for collecting basic parameters of threaded joints in a threaded joint management block according to the present invention. DETAILED DESCRIPTION

[0070] The technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0071] See also Figure 1 The first embodiment of the present invention provides a method for identifying and evaluating damage of a threaded joint of an oil casing, comprising the following steps:

[0072] According to the positions of the threaded joints of the oil casing in the management area, the threaded joints of the oil casing are allocated to different management blocks, and the basic parameters of the threaded joints in each threaded joint management block are collected;

[0073] The threaded joints in the threaded joint management area are classified into high-temperature threaded joint classification, high-pressure threaded joint classification and ordinary threaded joint classification. For the high-temperature threaded joint classification, the internal and external temperatures of the threaded joints and the temperature data of the threaded joints themselves are detected. For the high-pressure threaded joint classification, the internal and external pressure data of the threaded joints are detected. Based on the detected data and the basic parameters of the threaded joints, the operating stability coefficient of the threaded joints of the oil casing is evaluated;

[0074] Based on the high-definition images of the threaded joints of the oil casing and tubing, a three-dimensional model of the threaded joints of the oil casing and tubing is established, the central axis of the pipes on both sides of the threaded joint is detected, and the deviation of the central axis of the pipes on both sides of the threaded joint is evaluated;

[0075] Based on the evaluation results of the deviation of the central axis of the pipes on both sides of the threaded joint and the high-definition images of the threaded joint, a central axis deviation damage model of the threaded joint of the oil casing is established to evaluate the deviation damage coefficient of the threaded joint;

[0076] The damage degree of the threaded joints of the oil casing and tubing is evaluated by the number of times the threaded joints of the oil casing and tubing have been tightened and the service time, the initial tightening force at each tightening, the operating stability coefficient of the threaded joints of the oil casing and tubing and the deviation loss coefficient of the threaded joints.

[0077] Specifically, in this embodiment, the threaded joints in the threaded joint management block are classified into high-temperature threaded joint classification, high-pressure threaded joint classification and ordinary threaded joint classification. By designing corresponding detection schemes for different types of threaded joints, the accuracy and effectiveness of the evaluation are improved; for the high-temperature threaded joint classification, the temperature inside and outside the threaded joint, as well as the temperature data of the threaded joint itself, are detected. By real-time monitoring of the temperature state under high temperature conditions, it is convenient to timely discover potential risks and reduce the probability of accidents; for the high-pressure threaded joint classification, the pressure data inside and outside the threaded joint is detected. Through different classifications and monitoring data, it is convenient to formulate a more scientific and reasonable maintenance plan and enhance the accuracy of fault identification; based on the detected data combined with the basic parameters of the threaded joint, the operating stability coefficient of the threaded joint of the oil casing is evaluated; through the changes in temperature and pressure data, combined with actual detection data and basic parameters for analysis, it is helpful to establish a more accurate fault identification system.

[0078] Based on the high-definition images of the threaded joints of the oil casing and casing, a three-dimensional model of the threaded joints of the oil casing and casing is established, the central axis of the pipes on both sides of the threaded joint is detected, and the deviation of the central axis of the pipes on both sides of the threaded joint is evaluated; by collecting high-definition images to build a three-dimensional model, the actual structure can be accurately reflected, which is convenient for evaluating the deviation of the central axis of the pipes on both sides of the threaded joint; the quantitative evaluation of the deviation of the central axis provides clear data support for subsequent maintenance and adjustments; at the same time, by monitoring the deviation of the central axis, it is convenient to timely discover potential problems, such as stress concentration or poor connection, increase the accuracy of fault identification, and thus reduce the risk of faults.

[0079] Based on the evaluation results of the deviation of the central axis of the pipes on both sides of the threaded joint and the high-definition images of the threaded joint, a deviation damage model of the central axis of the threaded joint of the oil casing is established to evaluate the deviation damage coefficient of the threaded joint; by establishing the deviation damage model, it is easy to convert abstract concepts into specific values, thereby realizing quantitative analysis of the degree of deviation; the deviation damage coefficient can help identify potential structural risks, provide a scientific basis for subsequent maintenance and repair, and help reduce the accident rate. At the same time, by understanding the impact of different deviation conditions on the performance of the threaded joint, based on quantitative data support, it is easy to accurately evaluate the impact of pipeline deviation on the damage of the threaded joint.

[0080] The damage degree of the threaded joints of the oil casing and tubing is evaluated by the number of times the threaded joints of the oil casing and tubing have been tightened and the service time, the initial tightening force at each tightening, the operation stability coefficient of the threaded joints of the oil casing and tubing and the deviation loss coefficient of the threaded joints;

[0081] By combining multiple key parameters for evaluation, it is easy to fully understand the actual status of the threaded joint and avoid the misleading effect of a single indicator. At the same time, by quantifying various indicators, clear data support can be provided for the degree of damage, which helps to improve the accuracy of fault identification. Identifying potential problems in advance reduces the risk of failure and safety accidents of threaded joints, thereby improving overall operational safety. Regular monitoring of these indicators can ensure that the threaded joints are in good condition, thereby improving the reliability and durability of the entire oil casing system.

[0082] In one embodiment of the present invention, see Figure 2 According to the positions of the threaded joints of the oil casing in the management area, the threaded joints of the oil casing are allocated to different management blocks, and the basic parameters of the threaded joints in each threaded joint management block are collected, including the following steps:

[0083] Obtain the layout of the oil casing and tubing in the management area, as well as the locations of the threaded joints of the oil casing and tubing;

[0084] Code the oil casing and tubing in the management area, and code the threaded joints on the oil casing and tubing according to the codes of the oil casing and tubing;

[0085] Divide the management blocks from the initial fluid inlet on the layout diagram of the oil casing to the fluid outlet, so that each management block includes a certain number of threaded joints;

[0086] A data processing node is set in each threaded joint management block, and the number of times the threaded joint is tightened and the service time, as well as the initial tightening force at each tightening, are recorded through the data processing node, so as to collect the basic parameters of the threaded joint in the threaded joint management block;

[0087] The data processing node cleans and denoises the basic parameters of the threaded joint, adds the code of the threaded joint as a label to the basic parameters, and adds the basic parameters after the label is added.

[0088] Specifically, in this embodiment, the oil casing and tubing in the management area are coded {A1, A2, ..., An}, and the threaded joints are coded according to the coding of the oil casing and tubing. For example, the third threaded joint set on the oil casing and tubing numbered Ai is numbered Ai-003. At the same time, the management blocks are divided from the initial fluid inlet to the outlet on the layout diagram to ensure that each block contains a certain number of threaded joints, and data processing nodes are set. Coding and block division make the management of oil casing and tubing and their threaded joints more systematic, which helps to improve the overall management efficiency. Through clear coding, it is easy to quickly locate specific oil casing and threaded joints, thereby simplifying the maintenance and inspection process and improving the response speed. Setting up data processing nodes to achieve centralized monitoring and data analysis makes it easier to quickly process block data.

[0089] In one embodiment of the present invention, collecting basic parameters of the threaded joint in the threaded joint management block includes the following steps:

[0090] A plurality of stress detection sheets are arranged at the threads of the threaded joint, and the stress detection sheets are arranged in a ring array along the central axis of the threaded joint;

[0091] Collect stress data at the thread of the threaded joint, and collect thickness data at the thread of the threaded joint through ultrasonic testing technology;

[0092] The collected stress data at the threads of the threaded joint and the thickness data at the threads of the threaded joint are used as the basic parameters of the threaded joint.

[0093] In one embodiment of the present invention, the threaded joints in the threaded joint management block are classified into high temperature threaded joints, high pressure threaded joints and ordinary threaded joints, including the following steps:

[0094] The temperature and pressure of the fluid medium inside the threaded joints of the oil casing in the collection management area;

[0095] If the temperature of the fluid medium inside the threaded joint of the oil casing is greater than 200°C, the threaded joint of the oil casing is classified as a high-temperature threaded joint;

[0096] If the pressure of the fluid medium inside the threaded joint of the oil casing is greater than 10MPa, the threaded joint of the oil casing is classified as a high-pressure threaded joint.

[0097] In one embodiment of the present invention, the operation stability coefficient of the threaded joint of the oil casing is evaluated according to the detected data combined with the basic parameters of the threaded joint, including the following steps:

[0098] For high-temperature threaded joints, the preset detection time interval is obtained. The temperature inside and outside the high-temperature threaded joint is detected, as well as the temperature data of the threaded joint itself. The temperature data of the threaded joint itself within the detection time interval is normalized so that the temperature data of the threaded joint itself is within the interval [0,1]. Combined with the basic parameters of the threaded joint, the operation stability coefficient of the threaded joint of the oil casing is evaluated by the following formula:

[0099]

[0100] Among them, α1 is the operation stability coefficient of the threaded joint of the high-temperature threaded joint type, St is the variance of the temperature change of the threaded joint itself within the detection time interval, Sn is the variance of the temperature change inside the threaded joint within the detection time interval, Sw is the variance of the temperature change inside the threaded joint within the detection time interval, Sh is the variance of the thickness change at the thread of the threaded joint within the detection time interval, Sf is the variance of all stress detection values ​​at the thread of the threaded joint within the detection time interval, μ1 is the average value of the temperature change of the threaded joint itself within the detection time interval, μ2 is the average value of the temperature change inside the threaded joint within the detection time interval, μ3 is the average value of the thickness change at the thread of the threaded joint within the detection time interval, and μ4 is the average value of all stress detection values ​​at the thread of the threaded joint within the detection time interval;

[0101] For high-pressure threaded joints, obtain the pressure data inside and outside the high-pressure threaded joints, combine the basic parameters of the threaded joints, and use the following formula to evaluate the operating stability coefficient of the threaded joints of the oil casing:

[0102]

[0103] Among them, α1 is the operation stability coefficient of the threaded joint of the high-temperature threaded joint type, St is the variance of the temperature change of the threaded joint itself within the detection time interval, Spn is the variance of the pressure change inside the threaded joint within the detection time interval, and Spw is the variance of the pressure change outside the threaded joint within the detection time interval;

[0104] For common threaded joints, the running stability coefficient of the threaded joints of oil casing is evaluated according to the basic parameters of the threaded joints:

[0105]

[0106] Among them, α3 is the operating stability coefficient of the threaded joint of the ordinary threaded joint type.

[0107] In one embodiment of the present invention, a three-dimensional model of the threaded joint of the oil casing is established based on a high-definition image of the threaded joint of the oil casing, the central axis of the pipes on both sides of the threaded joint is detected, and the deviation of the central axis of the pipes on both sides of the threaded joint is evaluated, including the following steps:

[0108] The high-definition images of the threaded joints of the oil casing were de-noised and contrast enhanced using GIMP image processing software;

[0109] The edge detection algorithm is used to extract the edge and contour information of the threaded joint and the pipes on both sides of the threaded joint from the high-definition image of the threaded joint of the oil casing;

[0110] Perform three-dimensional reconstruction through three-dimensional modeling software to generate a three-dimensional model;

[0111] Extract the central axis of the pipes on both sides of the threaded joint in the 3D model. The central axis refers to the center line inside the pipe.

[0112] Detect the deviation angle between the central axis of the pipes on both sides of the threaded joint, and the distance between the two closest end points of the central axis of the pipes on both sides of the threaded joint;

[0113] The deviation of the center axis of the pipes on both sides of the threaded joint is evaluated based on the deviation angle between the center axis of the pipes on both sides of the threaded joint and the distance between the two closest end points of the center axis of the pipes on both sides of the threaded joint.

[0114] In one embodiment of the present invention, the deviation of the central axis of the pipes on both sides of the threaded joint is evaluated according to the deviation angle between the central axis of the pipes on both sides of the threaded joint and the distance between the two closest end points of the central axis of the pipes on both sides of the threaded joint, including the following steps:

[0115] Obtaining the distance between the pipes on both sides of the threaded joint in the generated three-dimensional model of the threaded joint of the oil casing and the pipes on both sides;

[0116] According to the distance between the pipes on both sides of the threaded joint, the deviation angle between the central axes of the pipes on both sides of the threaded joint, and the distance between the two closest endpoints of the central axes of the pipes on both sides of the threaded joint, the deviation of the central axes of the pipes on both sides of the threaded joint is evaluated by the following formula:

[0117]

[0118] Among them, K is the deviation of the central axis of the pipes on both sides of the threaded joint, θ is the deviation angle between the central axes of the pipes on both sides of the threaded joint, L1 is the distance between the pipes on both sides of the threaded joint, L2 is the distance between the two nearest endpoints of the central axis of the pipes on both sides of the threaded joint, and e is a natural constant.

[0119] In one embodiment of the present invention, based on the evaluation results of the deviation of the central axis of the pipes on both sides of the threaded joint and the high-definition image at the threaded joint, a central axis deviation damage model of the threaded joint of the oil casing is established to evaluate the deviation damage coefficient of the threaded joint, including the following steps:

[0120] Acquire historical data of high-definition images of threaded joints with surface defects, and mark defective parts in the high-definition images of the threaded joints;

[0121] The Mask R-CNN image segmentation model is trained through annotated images to mark the defects in high-definition images.

[0122] Obtain the collected high-definition images of the threaded joints, and annotate the defective parts in the high-definition images of the threaded joints using the trained Mask R-CNN image segmentation model;

[0123] Calculate the percentage of the defective part in the high-definition image of the threaded joint to the surface area of ​​the threaded joint;

[0124] Based on the evaluation results of the deviation of the central axis of the pipes on both sides of the threaded joint and the percentage of the defective part in the high-definition image of the threaded joint to the surface area of ​​the threaded joint, the central axis deviation damage model of the threaded joint of the oil casing is established by the following formula:

[0125]

[0126] Among them, β is the deviation loss coefficient of the central axis of the threaded joint of the oil casing, and f is the percentage of the defective part in the high-definition image of the threaded joint to the surface area of ​​the threaded joint.

[0127] In one embodiment of the present invention, the damage degree of the threaded joint of the oil casing is evaluated by the number of times the threaded joint of the oil casing has been tightened and the service time, the initial tightening force at each tightening, the operation stability coefficient of the threaded joint of the oil casing and the deviation loss coefficient of the threaded joint, including the following steps:

[0128] Obtain the number of times the threaded joint is tightened and the service time recorded by the data processing node, as well as the initial tightening force during each tightening;

[0129] Detect the number of times n that the threaded joint is tightened. If the number of times n that the threaded joint is tightened is an even number, divide the initial tightening force values ​​of the threaded joint at each tightening into two parts according to the order in which the initial tightening force values ​​of the threaded joint are recorded each time, and calculate the difference U between the sum of the initial tightening force values ​​of the first part and the sum of the initial tightening force values ​​of the second part;

[0130] If the number of times n of tightening the threaded joint is an odd number, remove the initial tightening force data at the (n+1) / 2nd tightening, divide the initial tightening force values ​​of the threaded joint at each tightening into two parts according to the order of recording the initial tightening force values ​​of the threaded joint at each tightening, and calculate the difference U between the sum of the initial tightening force values ​​of the first part and the sum of the initial tightening force values ​​of the second part;

[0131] According to the acquired data, the running stability coefficient of the threaded joint of the oil casing and the deviation loss coefficient of the threaded joint, the damage degree of the threaded joint of the oil casing and the casing is evaluated:

[0132]

[0133] Among them, E is the damage evaluation value of the oil casing threaded joint, ft is the percentage of the service life of the oil casing threaded joint in the total service life, Fz is the sum of the initial tightening force of the threaded joint each time it is tightened, and S0 is the variance of the initial tightening force of the threaded joint each time it is tightened;

[0134] If the damage degree evaluation value of the oil casing threaded joint exceeds the preset threshold, the corresponding threaded joint is damaged and the corresponding threaded joint is replaced.

[0135] Specifically, in this embodiment, by statistics on the damage degree evaluation values ​​of the oil casing threaded joints of a large amount of experimental data, when the damage degree evaluation value of the oil casing threaded joints is set to be greater than 1.2, the corresponding threaded joint is damaged and the corresponding threaded joint is replaced; when the damage degree evaluation value of the oil casing threaded joints is set to be less than or equal to 1.2 and greater than 1, a damage warning is issued for the corresponding threaded joint.

[0136] In another embodiment of the present invention, a system for identifying and evaluating damage of oil casing threaded joints is provided. The system adopts a method for identifying and evaluating damage of oil casing threaded joints as described above to implement damage identification and evaluation of oil casing threaded joints.

[0137] The above embodiments are only used to illustrate the technical method of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical method of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical method of the present invention.

Claims

1. A method for identifying and evaluating damage of oil casing threaded joints, characterized in that: The following steps are involved: According to the positions of the threaded joints of the oil casing in the management area, the threaded joints of the oil casing are allocated to different management blocks, and the basic parameters of the threaded joints in each threaded joint management block are collected; The threaded joints in the threaded joint management area are classified into high-temperature threaded joints, high-pressure threaded joints and ordinary threaded joints. For the high-temperature threaded joints, the internal and external temperatures of the threaded joints and the temperature data of the threaded joints themselves are detected. For the high-pressure threaded joints, the internal and external pressure data of the threaded joints are detected. Based on the detected data and the basic parameters of the threaded joints, the operating stability coefficient of the threaded joints of the oil casing is evaluated; Based on the high-definition images of the threaded joints of the oil casing and tubing, a three-dimensional model of the threaded joints of the oil casing and tubing is established, the central axis of the pipes on both sides of the threaded joint is detected, and the deviation of the central axis of the pipes on both sides of the threaded joint is evaluated; Based on the evaluation results of the deviation of the central axis of the pipes on both sides of the threaded joint and the high-definition images of the threaded joint, a central axis deviation damage model of the threaded joint of the oil casing is established to evaluate the deviation damage coefficient of the threaded joint; The damage degree of the threaded joints of the oil casing and tubing is evaluated by the number of times the threaded joints of the oil casing and tubing have been tightened and the service time, the initial tightening force at each tightening, the operating stability coefficient of the threaded joints of the oil casing and tubing and the deviation loss coefficient of the threaded joints.

2. The damage identification and assessment method of oil casing threaded joint according to claim 1 is characterized in that: According to the positions of the threaded joints of the oil casing in the management area, the threaded joints of the oil casing are allocated to different management blocks, and the basic parameters of the threaded joints in each threaded joint management block are collected, including the following steps: Obtain the layout of the oil casing and tubing in the management area, as well as the locations of the threaded joints of the oil casing and tubing; Code the oil casing and tubing in the management area, and code the threaded joints on the oil casing and tubing according to the codes of the oil casing and tubing; Divide the management blocks from the initial fluid inlet on the layout diagram of the oil casing to the fluid outlet, so that each management block includes a certain number of threaded joints; A data processing node is set in each threaded joint management block, and the number of times the threaded joint is tightened and the service time, as well as the initial tightening force at each tightening, are recorded through the data processing node, so as to collect the basic parameters of the threaded joint in the threaded joint management block; The data processing node cleans and denoises the basic parameters of the threaded joint, adds the code of the threaded joint as a label to the basic parameters, and adds the basic parameters after the label is added.

3. The damage identification and assessment method of oil casing threaded joint according to claim 2 is characterized in that: Collecting the basic parameters of the threaded joint in the threaded joint management block includes the following steps: A plurality of stress detection sheets are arranged at the threads of the threaded joint, and the stress detection sheets are arranged in a ring array along the central axis of the threaded joint; Collect stress data at the thread of the threaded joint, and collect thickness data at the thread of the threaded joint through ultrasonic testing technology; The collected stress data at the threads of the threaded joint and the thickness data at the threads of the threaded joint are used as the basic parameters of the threaded joint.

4. The damage identification and assessment method for oil casing threaded joints according to claim 1 is characterized in that: Classifying the threaded joints in the threaded joint management block into high temperature threaded joints, high pressure threaded joints and common threaded joints includes the following steps: The temperature and pressure of the fluid medium inside the threaded joints of the oil casing in the collection management area; If the temperature of the fluid medium inside the threaded joint of the oil casing is greater than 200°C, the threaded joint of the oil casing is classified as a high-temperature threaded joint; If the pressure of the fluid medium inside the threaded joint of the oil casing is greater than 10MPa, the threaded joint of the oil casing is classified as a high-pressure threaded joint.

5. The damage identification and assessment method for oil casing threaded joints according to claim 1 is characterized in that: According to the detected data combined with the basic parameters of the threaded joint, the running stability coefficient of the threaded joint of the oil casing is evaluated, including the following steps: For high-temperature threaded joints, the preset detection time interval is obtained. The temperature inside and outside the high-temperature threaded joint is detected, as well as the temperature data of the threaded joint itself. The temperature data of the threaded joint itself within the detection time interval is normalized so that the temperature data of the threaded joint itself is within the interval [0,1]. Combined with the basic parameters of the threaded joint, the operation stability coefficient of the threaded joint of the oil casing is evaluated by the following formula: Among them, α1 is the operation stability coefficient of the threaded joint of the high-temperature threaded joint type, St is the variance of the temperature change of the threaded joint itself within the detection time interval, Sn is the variance of the temperature change inside the threaded joint within the detection time interval, Sw is the variance of the temperature change inside the threaded joint within the detection time interval, Sh is the variance of the thickness change at the thread of the threaded joint within the detection time interval, Sf is the variance of all stress detection values ​​at the thread of the threaded joint within the detection time interval, μ1 is the average value of the temperature change of the threaded joint itself within the detection time interval, μ2 is the average value of the temperature change inside the threaded joint within the detection time interval, μ3 is the average value of the thickness change at the thread of the threaded joint within the detection time interval, and μ4 is the average value of all stress detection values ​​at the thread of the threaded joint within the detection time interval; For high-pressure threaded joints, obtain the pressure data inside and outside the high-pressure threaded joints, combine the basic parameters of the threaded joints, and use the following formula to evaluate the operating stability coefficient of the threaded joints of the oil casing: Among them, α1 is the operation stability coefficient of the threaded joint of the high-temperature threaded joint type, St is the variance of the temperature change of the threaded joint itself within the detection time interval, Spn is the variance of the pressure change inside the threaded joint within the detection time interval, and Spw is the variance of the pressure change outside the threaded joint within the detection time interval; For common threaded joints, the running stability coefficient of the threaded joints of oil casing is evaluated according to the basic parameters of the threaded joints: Among them, α3 is the operating stability coefficient of the threaded joint of the ordinary threaded joint type.

6. A method for identifying and evaluating damage of oil casing threaded joints according to claim 5, characterized in that: According to the high-definition image of the threaded joint of the oil casing, a three-dimensional model of the threaded joint of the oil casing is established, the central axis of the pipes on both sides of the threaded joint is detected, and the deviation of the central axis of the pipes on both sides of the threaded joint is evaluated, including the following steps: The high-definition images of the threaded joints of the oil casing were de-noised and contrast enhanced using GIMP image processing software; The edge detection algorithm is used to extract the edge and contour information of the threaded joint and the pipes on both sides of the threaded joint from the high-definition image of the threaded joint of the oil casing; Perform three-dimensional reconstruction through three-dimensional modeling software to generate a three-dimensional model; Extract the central axis of the pipes on both sides of the threaded joint in the 3D model. The central axis refers to the center line inside the pipe. Detect the deviation angle between the central axis of the pipes on both sides of the threaded joint, and the distance between the two closest end points of the central axis of the pipes on both sides of the threaded joint; The deviation of the center axis of the pipes on both sides of the threaded joint is evaluated based on the deviation angle between the center axis of the pipes on both sides of the threaded joint and the distance between the two closest end points of the center axis of the pipes on both sides of the threaded joint.

7. A method for identifying and evaluating damage of oil casing threaded joints according to claim 6, characterized in that: According to the deviation angle between the central axes of the pipes on both sides of the threaded joint and the distance between the two closest end points of the central axes of the pipes on both sides of the threaded joint, the deviation of the central axes of the pipes on both sides of the threaded joint is evaluated, including the following steps: Obtaining the distance between the pipes on both sides of the threaded joint in the generated three-dimensional model of the threaded joint of the oil casing and the pipes on both sides; According to the distance between the pipes on both sides of the threaded joint, the deviation angle between the central axes of the pipes on both sides of the threaded joint, and the distance between the two closest endpoints of the central axes of the pipes on both sides of the threaded joint, the deviation of the central axes of the pipes on both sides of the threaded joint is evaluated by the following formula: Among them, K is the deviation of the central axis of the pipes on both sides of the threaded joint, θ is the deviation angle between the central axes of the pipes on both sides of the threaded joint, L1 is the distance between the pipes on both sides of the threaded joint, L2 is the distance between the two nearest endpoints of the central axis of the pipes on both sides of the threaded joint, and e is a natural constant.

8. The damage identification and assessment method for oil casing threaded joints according to claim 7 is characterized in that: Based on the evaluation results of the deviation of the central axis of the pipes on both sides of the threaded joint and the high-definition image at the threaded joint, a central axis deviation damage model of the threaded joint of the oil casing is established to evaluate the deviation damage coefficient of the threaded joint, including the following steps: Acquire historical data of high-definition images of threaded joints with surface defects, and mark defective parts in the high-definition images of the threaded joints; The Mask R-CNN image segmentation model is trained through annotated images to mark the defects in high-definition images. Obtain the collected high-definition images of the threaded joints, and annotate the defective parts in the high-definition images of the threaded joints using the trained Mask R-CNN image segmentation model; Calculate the percentage of the defective part in the high-definition image of the threaded joint to the surface area of ​​the threaded joint; Based on the evaluation results of the deviation of the central axis of the pipes on both sides of the threaded joint and the percentage of the defective part in the high-definition image of the threaded joint to the surface area of ​​the threaded joint, the central axis deviation damage model of the threaded joint of the oil casing is established by the following formula: Among them, β is the deviation loss coefficient of the central axis of the threaded joint of the oil casing, and f is the percentage of the defective part in the high-definition image of the threaded joint to the surface area of ​​the threaded joint.

9. The damage identification and assessment method for oil casing threaded joints according to claim 8 is characterized in that: The damage degree of the threaded joints of the oil casing and tubing is evaluated by the number of times the threaded joints of the oil casing and tubing have been tightened and the service time, the initial tightening force at each tightening, the running stability coefficient of the threaded joints of the oil casing and tubing and the deviation loss coefficient of the threaded joints, including the following steps: Obtain the number of times the threaded joint is tightened and the service time recorded by the data processing node, as well as the initial tightening force during each tightening; Detect the number of times n that the threaded joint is tightened. If the number of times n that the threaded joint is tightened is an even number, divide the initial tightening force values ​​of the threaded joint at each tightening into two parts according to the order in which the initial tightening force values ​​of the threaded joint are recorded each time, and calculate the difference U between the sum of the initial tightening force values ​​of the first part and the sum of the initial tightening force values ​​of the second part; If the number of times n of tightening the threaded joint is an odd number, remove the initial tightening force data at the (n+1) / 2nd tightening, divide the initial tightening force values ​​of the threaded joint at each tightening into two parts according to the order of recording the initial tightening force values ​​of the threaded joint at each tightening, and calculate the difference U between the sum of the initial tightening force values ​​of the first part and the sum of the initial tightening force values ​​of the second part; According to the acquired data, the running stability coefficient of the threaded joint of the oil casing and the deviation loss coefficient of the threaded joint, the damage degree of the threaded joint of the oil casing and the casing is evaluated: Among them, E is the damage evaluation value of the oil casing threaded joint, ft is the percentage of the service life of the oil casing threaded joint in the total service life, Fz is the sum of the initial tightening force of the threaded joint each time it is tightened, and S0 is the variance of the initial tightening force of the threaded joint each time it is tightened; If the damage degree evaluation value of the oil casing threaded joint exceeds the preset threshold, the corresponding threaded joint is damaged and the corresponding threaded joint is replaced.

10. A damage identification and assessment system for oil casing threaded joints, characterized in that: The system adopts a damage identification and evaluation method for oil casing threaded joints as described in any one of claims 1 to 9 to realize damage identification and evaluation of oil casing threaded joints.

Images