Coiled tubing body deformation tracking method based on key coordinates

Abstract

A coiled tubing operation pipe body deformation tracking method based on key coordinates, the method constructs an operation system dynamic geometric model by acquiring key coordinates of an operation site; a micro-element activation mechanism is established based on a time axis and truck-mounted lifting data, physical position tags are dynamically allocated for effective micro-elements; by monitoring position tag switching events, mechanical calculation of micro-elements is triggered as needed, equivalent plastic strain under the coupling effect of internal pressure and bending is calculated; state transition points are extracted to construct asymmetric fatigue cycles, and dynamic fatigue damage accumulation is performed. The present application effectively solves the problems of coiled tubing deformation leakage calculation and coordinate dislocation under complex working conditions such as local repeated tripping, realizes accurate quantitative tracking of fatigue damage of the whole pipe section, and provides reliable data basis for coiled tubing life management.

Description

Technical Field

[0001] This invention belongs to the field of image data processing technology, specifically relating to a method for tracking the deformation of tubing in continuous tubing operations based on key coordinates. Background Technology

[0002] A coiled tubing runner is a lightweight, hydraulically driven device primarily used for transporting and retrieving coiled tubing used in large-diameter tubing, casing, or wellbore operations. Its basic function is to raise and lower the coiled tubing during operations and, after completion, wind the raised tubing onto a drum for transport. In actual operating conditions, the coiled tubing typically contains high- or medium-pressure liquids or gases, making its operating environment complex and variable.

[0003] In the entire process of conventional surface handling and downhole operations, the coiled tubing string must sequentially pass through core surface components such as the workover rig drum, front beam, guide frame, and wellhead connection section, continuously enduring triaxial alternating loads of tension, bending, and internal pressure coupling. Within a complete "run-in-run-out" cycle, any fixed section of the coiled tubing undergoes at least six cycles of alternating "tension-bending" plastic deformation. Because the radii of curvature of the workover rig drum and guide frame are much smaller than the yield radius of curvature of the coiled tubing substrate, each bending deformation of the tubing results in irreversible plastic damage. Under the coupled effect of long-term cyclic plastic bending and the high-pressure medium inside the tubing, the coiled tubing is highly susceptible to low-cycle fatigue damage. According to engineering failure statistics, among various failures of coiled tubing, such as deformation failure, surface damage, and fracture failure, fatigue fracture caused by cyclic alternating stress accounts for the highest proportion and is the most destructive, being the main cause of premature tubing failure and operational safety accidents.

[0004] The industry has clearly defined the low-cycle fatigue evolution law and plastic deformation failure mechanism of coiled tubing. However, existing monitoring methods are insufficient to meet the precise detection requirements of complex operating conditions. Under complex dynamic conditions such as multiple partial tubing trips, repeated pressure tests, and multi-layer winding envelopes by rollers, traditional monitoring methods relying on sensor force measurement and mechanical counting cannot accurately distinguish the deformation frequency and stress state of each sub-segment of the coiled tubing. The existing technology system lacks high-precision, dynamic visual geometric information capture methods, making it difficult to solve the industry problem of segment sequence misalignment and positional deviation during multiple tubing trips. It cannot achieve precise spatial positioning of the tubing and full-cycle deformation history tracking. This monitoring blind spot makes it impossible to accurately assess the true fatigue state of each segment of the tubing, which can easily lead to premature failure or blind scrapping of the coiled tubing.

[0005] Therefore, developing a monitoring method based on image processing technology that can capture the dynamic geometric features of the operating system in real time, correct the tubing motion tracking model, and accurately quantify the cumulative fatigue damage of the entire tubing section has significant engineering value for improving the safety of coiled tubing operations and reducing maintenance costs. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to overcome the shortcomings of the prior art and provide a method for tracking the deformation of the continuous tubing operation based on key coordinates to accurately quantify the cumulative fatigue damage of the entire pipe section.

[0007] The technical solution adopted to solve the above-mentioned technical problems is: a method for tracking the deformation of coiled tubing based on key coordinates, comprising the following steps:

[0008] Step 1. Obtain the spatial coordinates of the drum center point and key points of the guide frame in the coiled tubing operation site. Combine the known parameters of the tubing, drum and guide frame to establish a spatial geometric model of the coiled tubing ground operation system and generate the spatial distribution parameters of each bending section.

[0009] Step 2. Obtain the length of the continuous tubing in the on-board operation record and discretize it according to the time axis. Based on the actual cumulative length of the tubing at each moment, perform validity activation judgment on the tubing material micro-element of the preset unit length, filter out the valid tubing material micro-element, and dynamically assign physical position labels to the valid tubing material micro-element through spatial distribution parameters.

[0010] Step 3. Based on the physical location label, call the corresponding spatial sub-coordinate solution model to dynamically analyze the spatial sub-coordinates of the effective tube material micro-element at the current moment;

[0011] Step 4. Monitor the physical position label switching events of each effective pipe material micro-element in real time. When the effective pipe material micro-element undergoes cross-section displacement, trigger the mechanical calculation. Combine the internal pressure data to invert and calculate the equivalent plastic strain of the effective pipe material micro-element under the action of internal pressure bending coupling.

[0012] Step 5. Detect the state transition point based on the equivalent plastic strain sequence of the effective pipe material micro-element, construct an asymmetric fatigue strain cycle, perform dynamic damage accumulation based on event flow based on the fatigue damage model with average stress correction, and output the cumulative fatigue damage value of the entire pipe segment micro-element.

[0013] As a preferred technical solution, the method for determining the effective activation of a pre-set unit length tube material micro-element based on the actual cumulative release length at each moment is as follows: if the absolute number of the tube material micro-element is less than or equal to the actual cumulative release length at the current moment, then the tube material micro-element is in an effective activation state.

[0014] As a preferred technical solution, the method for inverting and calculating the equivalent plastic strain of the effective pipe material micro-element under the strong coupling of internal pressure and bending in step 4 is as follows:

[0015] Step 4.1. Based on the internal pressure, generate the surface radial stress, surface circumferential stress, and initial axial stress generated by the end sealing effect through the thick-walled tube stress model;

[0016] Step 4.2. Ignore the elastic strain component and treat the total geometric bending strain as an equivalent plastic strain in the cyclic strain hardening model of the material to generate the bending axial stress component under pure bending action.

[0017] Step 4.3. The initial axial stress and the bending axial stress components are superimposed by scalar to obtain the total axial stress;

[0018] Step 4.4. Generate the comprehensive equivalent stress using the Mises yield criterion, and then invert the equivalent plastic strain under the coupling of internal pressure and bending through nonlinear constitutive relations.

[0019] As a preferred technical solution, step 5 specifically involves the following steps:

[0020] Step 5.1. Detect the state transition points of "straight line, bending extreme value, straight line", match this complete physical deformation process as an independent effective fatigue cycle, extract the alternating strain amplitude of the independent effective fatigue cycle, and generate the average stress of asymmetric fatigue by combining the initial axial stress of internal pressure in the straight line state.

[0021] Step 5.2. Based on the mean stress of asymmetric fatigue, the theoretical fatigue failure life of a single cycle is generated using the Manson-Coffin model modified by Morrow mean stress.

[0022] Step 5.3. Generate single-cycle damage weights according to Miner's rule, establish a dynamically extended accumulator to linearly superimpose the damage weights of the actual strain cycles, generate the cumulative fatigue damage value of the entire pipe segment micro-element and output it.

[0023] As a preferred technical solution, the working section corresponding to the physical location label includes: the drum envelope area, the front beam area, the guide frame area, and the wellhead connection area.

[0024] As a preferred technical solution, in step 2, the preset unit length is 0.5 meters to 2.0 meters.

[0025] The beneficial effects of this invention are as follows:

[0026] (1) This invention discretizes the coiled tubing into micro-elements of tubing material of a preset unit length. Combining the acquired key coordinates of the work site and the actual cumulative length of tubing deployed, it assigns physical position labels to effective micro-elements of tubing material and resolves spatial sub-coordinates. This tracking mechanism ensures the consistency of spatial coordinates when the same tubing segment returns to its original position after multiple reciprocating movements, thereby achieving precise positioning of each tubing segment and tracking of its full-cycle deformation history. This solves the problem of existing technologies lacking high-precision visual geometric information capture methods, making it difficult to address the issues of misalignment and positional shift of tubing segments during multiple deployments and local retrieval operations.

[0027] (2) This invention discretizes the entire continuous tubing into pipe material micro-elements of a preset unit length. By monitoring the switching events of physical position labels, it accurately captures each "straight-bend" or "bend-straight" physical deformation experienced by each pipe material micro-element. By deeply integrating the thick-walled pipe stress model, the material cyclic strain hardening model, and the Mises yield criterion, this invention fully considers the coupling effect of internal pressure and bending load, accurately calculates the equivalent plastic strain extreme value of each pipe material micro-element at the current moment, and significantly improves the microscopic precision and accuracy of mechanical analysis.

[0028] (3) This invention accurately matches independent asymmetric fatigue cycles that truly reflect the working conditions by detecting state transition points such as "straight line, bending extreme value, and straight line" in the extreme plastic strain sequence; and further combines the Manson-Coffin model with Morrow mean stress correction and Miner's rule to construct a damage accumulator with dynamic extension characteristics, which linearly superimposes the damage weights of the real strain cycles. This system effectively solves the problems of missed calculation of coiled tubing deformation and coordinate misalignment under complex working conditions such as local repeated start-up and shutdown, and realizes accurate quantitative tracking of cumulative fatigue damage of micro-elements in the entire pipe section, providing data basis for coiled tubing life assessment, operation and maintenance cost control, and prevention of operational safety accidents. Attached Figure Description

[0029] Figure 1 This is a flowchart illustrating the method for tracking tubing deformation in continuous tubing operations based on key coordinates, as described in this invention.

[0030] Figure 2 This is a three-dimensional coordinate schematic diagram of the spatial geometry of the coiled tubing surface operation system of the present invention.

[0031] Figure 3 This is a schematic diagram of the material coordinate system construction and job sequence mapping and tracking process of the present invention.

[0032] Figure 4 This is a schematic diagram of the stress-strain calculation process under the coupling effect of internal pressure and bending according to the present invention.

[0033] Figure 5 This is a schematic diagram of the fatigue cycle identification and cumulative damage calculation process of the present invention. Detailed Implementation

[0034] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments, but the present invention is not limited to the following embodiments.

[0035] Example

[0036] exist Figure 1 The coiled tubing deformation tracking method based on key coordinates in this embodiment includes the following steps:

[0037] Step 1. Spatial geometric modeling of the ground operation system

[0038] By deploying machine vision devices at the work site, the spatial coordinates of the drum center point and key points of the guide frame in the coiled tubing operation are acquired. Combined with known parameters of the tubing, drum, and guide frame, a spatial geometric model of the coiled tubing surface operation system is established, including the drum envelope area, the front beam area, the guide frame area, and the wellhead connection area. This model generates spatial distribution parameters for each curved section, such as... Figure 2 ;

[0039] Wherein: the length of the beam between roller 101 and guide frame 102 :

[0040]

[0041] In the formula, This refers to the horizontal distance between the drum and the wellhead. For the guide frame radius, The total height of the roller center. Total height of the wellhead Where is the radius of the roller;

[0042] included angle of guide frame tangent for:

[0043]

[0044] In the formula, This is a correction factor;

[0045] Guide frame arc length :

[0046]

[0047] No. Equivalent envelope radius of the layer :

[0048]

[0049] In the formula, The radius of the roller mandrel or the initial wrapping radius. Let be the equivalent radius of the coiled tubing. This refers to the number of winding layers;

[0050] Maximum capacity length of a single layer :

[0051]

[0052] In the formula, π represents the effective number of rings that can be arranged along the roller axis in the nth layer, and π is the circumference ratio.

[0053] Step 2. Construct a material coordinate system and track the job sequence mapping.

[0054] like Figure 3 The system obtains the length of the continuous tubing released from the on-board operation record, discretizes it along the time axis, and performs validity activation judgment on the tubing material micro-elements of a preset unit length based on the actual cumulative release length at each moment. Valid tubing material micro-elements are selected, and physical location labels are dynamically assigned to them using spatial distribution parameters. Specifically:

[0055] Step 2.1. Discretize the on-board operation record into a continuous time series according to the preset time step. The cumulative actual length of the coiled tubing leaving the drum is synchronously acquired at each discrete time t. Discretize the entire continuous tubing into preset unit lengths. The pipe body material is micro-element, It can be 0.5m or 2m, and with the pipe head as the zero point, each pipe material micro-element is assigned a unique absolute material number j;

[0056] Step 2.2. At any time t on the operation time axis, for any pipe material element numbered j in the entire pipe sequence, according to... Determine whether the activation is effective in participating in surface or downhole path deformation:

[0057] If the conditions are met, then the micro-element j of the tube material is determined to be in an "effectively activated" state at time t, that is, it has left the drum body, and its position parameter is set. ;

[0058] If the conditions are not met, such as if the micro-element of the tube material is rewound to the depth of the drum during the retrieval operation, it is judged as an "invalid departure" state.

[0059] Step 2.3. Based on the cumulative length geometric threshold of each working section of the system's built-in ground equipment, where the upper limit of the cumulative length in the wellhead area is... The cumulative upper limit of the guide frame area is The cumulative upper limit of the pre-positioned beam area is The relative positions of all tube material micro-elements in the "effectively activated" state Real-time comparison with the above intervals is performed to complete the physical location allocation:

[0060] like The location label for this micro-element is assigned as "wellhead";

[0061] like The position label for this micro-element is assigned as "guide frame";

[0062] like The position label for this micro-element is assigned as "front beam";

[0063] like If so, the assigned location label is "roller";

[0064] For pipe material micro-elements that are determined to be "invalid departure", their location labels are marked as empty.

[0065] Step 2.4. Output the state matrix of all discrete tube material elements in the entire tube column at any time t, including: the validity identification sequence of the tube material elements, and the absolute physical position label of each valid element.

[0066] Step 3. Based on the physical location label, call the corresponding spatial sub-coordinate solution model to dynamically analyze the spatial sub-coordinates of the effective pipe material micro-element at the current moment;

[0067] Step 3.1. Generate the sub-coordinates of the roller section

[0068] If the physical location label of the effective tube material micro-element is "roller", then the micro-element location parameters With the maximum capacity length of a single layer By comparing each layer, the winding layer number m and the coil number n are determined, based on the equivalent radius. With the radius of the roller Use the hexagonal stacked model to generate the roller sub-coordinates:

[0069]

[0070]

[0071] Step 3.2. Generate the coordinates of the pre-beam section.

[0072] If the physical location label of the micro-element is "pre-positioned beam", then based on its number j and the starting datum of the pre-positioned beam. Generate horizontal linear coordinates:

[0073]

[0074]

[0075] Step 3.3. Generate the coordinates of the guide frame section

[0076] If the physical location label of the infinitesimal element is "guide frame", extract the radius of the guide frame established in step 1. Angle with tangent The polar coordinate circular arc transformation formula is used to map its three-dimensional coordinates:

[0077]

[0078]

[0079] in, This is the starting absolute length of the guide frame area;

[0080] Step 3.4. Generate wellhead coordinates

[0081] If the physical label of the micro-element location is "wellhead", the vertical downward formula is called to generate the vertically downward three-dimensional coordinate components:

[0082]

[0083]

[0084] in, The length of the vertical reference point at the wellhead;

[0085] Step 3.5. When a certain micro-element of pipe material is reassigned to the same physical location label in a subsequent time step due to the "recovery and re-deployment" operation, the spatial coordinate dynamic analytical function is used. The recalculated sub-coordinates will strictly coincide with the historical coordinates of the same position, realizing the restoration of the coordinates along the physical movement trajectory, thus ensuring the absolute consistency of the spatial coordinates when the same pipe segment returns to its original position after multiple reciprocating movements.

[0086] Step 3.6. On the operation timeline, output the high-precision three-dimensional spatial coordinates of all effective pipe material micro-elements at their assigned positions. Dynamic sequence matrix;

[0087] Step 4. Monitor the physical position label switching events of each effective pipe material micro-element in real time. When an effective pipe material micro-element undergoes cross-segment displacement, trigger the mechanical calculation. Combined with the internal pressure data, calculate the equivalent plastic strain of the effective pipe material micro-element under the coupling effect of internal pressure and bending. Figure 4 ;

[0088] Step 4.1. On the operation timeline, extract the physical position labels of each effective pipe material micro-element j in Step 2 at adjacent time points in real time. and ,like If the effective pipe material element j has undergone a cross-section displacement, the system will mark this as the i-th "straight-bending" or "bending-straight" deformation event of the effective pipe material element j and automatically extract the pipe pressure P at time t.

[0089] When event i determines that element j has entered the bending section, i.e., the roller or guide frame, it is based on the outer diameter of the effective tube material element. Calculate geometric bending strain:

[0090] If the drum section is entered, the equivalent envelope diameter of that layer is extracted. Calculate the maximum bending strain : Enter the guide frame section and extract the guide frame diameter. Calculate the maximum bending strain : ;

[0091] Based on the obtained pipe pressure The effective pipe material element's inner diameter d and outer diameter D are used to generate the surface radial stress generated by the internal pressure of this effective pipe material element according to the following formula. Surface circumferential stress Initial axial stress components generated solely by the internal pressure sealing effect :

[0092]

[0093]

[0094]

[0095] Step 4.2. Ignoring the elastic strain components, the total geometric bending strain is treated as an equivalent plastic strain and substituted into the cyclic strain hardening model of the material to generate the axial bending stress components under pure bending action. : ;

[0096] In the formula, Based on the cyclic strain hardening coefficient of the material, The cyclic strain hardening index;

[0097] Step 4.3. Scalar superposition of the initial axial stress and the bending axial stress components yields the total axial stress. , ;

[0098] Step 4.4. Use the Mises yield criterion to generate the comprehensive equivalent stress according to the following formula. :

[0099]

[0100] Furthermore, the equivalent plastic strain under the coupling of internal pressure and bending is inverted through nonlinear constitutive relations. :

[0101]

[0102] The output is the extreme plastic strain sequence of all continuous tubing material micro-elements that triggered position state switching events on the entire operation timeline;

[0103] Step 5. Detect state transition points based on the equivalent plastic strain sequence of the effective pipe material micro-elements, construct an asymmetric fatigue strain cycle, perform dynamic damage accumulation based on event flow using a fatigue damage model with mean stress correction, and output the cumulative fatigue damage value of the entire pipe segment micro-elements, such as... Figure 5 ;

[0104] Step 5.1. Based on the extreme value plastic strain sequence output in Step 4, detect the state transition points of the effective tube material micro-element j from "straight line, bending extreme value, straight line" and match this complete physical deformation process as an independent effective fatigue cycle. Extract the alternating strain amplitude of this independent effective fatigue cycle and combine it with the initial axial stress of the internal pressure in the straight line state to generate the average stress of asymmetric fatigue. :

[0105]

[0106] In the formula, The effective tube material element of a continuous tubing is subjected to only the axial stress component caused by the high pressure inside the tube when in a straight state.

[0107] Step 5.2. Average stress based on asymmetric fatigue The theoretical fatigue failure life for a single cycle is generated using the Manson-Coffin model corrected for Morrow mean stress. ;

[0108] The Morrow mean stress corrected Manson-Coffin model is as follows:

[0109]

[0110] In the formula, The alternating strain amplitude represents the independent and effective fatigue cycle, and E represents the elastic modulus of the coiled tubing material. denoted as σf, where σb is the fatigue strength coefficient of the material, and σf is the fatigue strength index of the material. is the fatigue ductility coefficient of the material, and c is the fatigue ductility index of the material;

[0111] Step 5.3. Generate single-cycle damage weights according to Miner's rule, establish a dynamically extended accumulator to linearly superimpose the damage weights of the actual strain cycles, and generate the cumulative fatigue damage value of the entire pipe segment micro-element. And output;

[0112] Among them, the cumulative fatigue damage value of the micro-element of the entire pipe section for:

[0113]

[0114]

[0115] when When the time is right, the micro-element is determined to have suffered fatigue fracture failure.

Claims

1. A method for tracking tubing deformation in coiled tubing operations based on key coordinates, characterized in that, Includes the following steps: Step 1. Obtain the spatial coordinates of the drum center point and key points of the guide frame in the coiled tubing operation site. Combine the known parameters of the tubing, drum and guide frame to establish a spatial geometric model of the coiled tubing ground operation system and generate the spatial distribution parameters of each bending section. Step 2. Obtain the length of the continuous tubing in the on-board operation record and discretize it according to the time axis. Based on the actual cumulative length of the tubing at each moment, perform validity activation judgment on the tubing material micro-element of the preset unit length, filter out the valid tubing material micro-element, and dynamically assign physical position labels to the valid tubing material micro-element through spatial distribution parameters. Step 3. Based on the physical location label, call the corresponding spatial sub-coordinate solution model to dynamically analyze the spatial sub-coordinates of the effective tube material micro-element at the current moment; Step 4. Monitor the physical position label switching events of each effective pipe material micro-element in real time. When the effective pipe material micro-element undergoes cross-section displacement, trigger the mechanical calculation. Combine the internal pressure data to invert and calculate the equivalent plastic strain of the effective pipe material micro-element under the action of internal pressure bending coupling. Step 5. Detect the state transition point based on the equivalent plastic strain sequence of the effective pipe material micro-element, construct an asymmetric fatigue strain cycle, perform dynamic damage accumulation based on event flow based on the fatigue damage model with average stress correction, and output the cumulative fatigue damage value of the entire pipe segment micro-element.

2. The method for tracking tubing deformation in continuous tubing operations based on key coordinates according to claim 1, characterized in that, In step 2, the method for determining the effective activation of the pre-set unit length tube material micro-element based on the actual cumulative release length at each moment is as follows: if the absolute number of the tube material micro-element is less than or equal to the actual cumulative release length at the current moment, then the tube material micro-element is in an effective activation state.

3. The method for tracking tubing deformation in continuous tubing operations based on key coordinates according to claim 1, characterized in that, The method for inverting and calculating the equivalent plastic strain of the effective tube material element under the strong coupling of internal pressure and bending, as described in step 4, is as follows: Step 4.

1. Based on the internal pressure, generate the surface radial stress, surface circumferential stress, and initial axial stress generated by the end sealing effect through the thick-walled tube stress model; Step 4.

2. Ignore the elastic strain component and treat the total geometric bending strain as an equivalent plastic strain in the cyclic strain hardening model of the material to generate the bending axial stress component under pure bending action. Step 4.

3. The initial axial stress and the bending axial stress components are superimposed by scalar to obtain the total axial stress; Step 4.

4. Generate the comprehensive equivalent stress using the Mises yield criterion, and then invert the equivalent plastic strain under the coupling of internal pressure and bending through nonlinear constitutive relations.

4. The method for tracking tubing deformation in continuous tubing operations based on key coordinates according to claim 1, characterized in that, The specific operation of step 5 is as follows: Step 5.

1. Detect the state transition points of "straight line, bending extreme value, straight line", match this complete physical deformation process as an independent effective fatigue cycle, extract the alternating strain amplitude of the independent effective fatigue cycle, and combine it with the initial axial stress of internal pressure in the straight line state to generate the average stress of asymmetric fatigue. Step 5.

2. Based on the mean stress of asymmetric fatigue, the theoretical fatigue failure life of a single cycle is generated using the Manson-Coffin model modified by Morrow mean stress. Step 5.

3. Generate single-cycle damage weights according to Miner's rule, establish a dynamically extended accumulator to linearly superimpose the damage weights of the actual strain cycles, generate the cumulative fatigue damage value of the entire pipe segment micro-element and output it.

5. The method for tracking tubing deformation in continuous tubing operations based on key coordinates according to claim 1, characterized in that, The operating sections corresponding to the physical location labels include: the drum envelope area, the front beam area, the guide frame area, and the wellhead connection area.

6. The method for tracking tubing deformation in continuous tubing operations based on key coordinates according to claim 1, characterized in that, In step 2, the preset unit length is 0.5 meters to 2.0 meters.

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