Prediction method and device for construction traction force for repairing long-distance corrosion pipeline based on multi-layer composite lining, medium and equipment

Abstract

The invention relates to a prediction method, device, medium and equipment for construction traction force for repairing a long-distance corroded pipeline based on a multi-layer composite lining, and the method comprises the steps: building a traction force prediction model of a single bending section based on an elastic mechanics theory; calculating traction force of the straight pipe section, including the influence of friction force and gravity; on the basis of a traction prediction model of a single bent section and traction calculation of a straight pipe section, a multi-bent pipeline traction calculation method is developed, a bent-straight pipe-bent structure is considered, the concept of the effective length of the straight pipe section is introduced, and the traction cumulative effect is corrected. The method can be suitable for repairing long-distance and multi-bend corrosion pipelines in the fields of oil and gas pipelines, municipal pipe networks and the like.

Description

Technical Field

[0001] The invention relates to the technical field of oil and gas pipeline maintenance and repair, and in particular to a method, device, medium and equipment for predicting the construction traction force of a long-distance corroded pipeline repair based on a multi-layer composite lining. Background Art

[0002] Steel pipes are widely considered the most economical carrier for transporting oil and gas due to their large capacity, high durability and relatively low cost. However, the internal environment of these pipes often leads to severe corrosion, mainly due to the presence of water, hydrogen sulfide and other corrosive substances in the transported fluids. This internal corrosion poses a significant risk to transportation safety and may lead to leaks or catastrophic failures.

[0003] Traditional methods of repairing pipeline corrosion typically involve replacing the damaged section. While effective, these methods are economically unviable and environmentally damaging. The high costs involved in replacement stem from the need for specialized equipment and long downtime, which can result in significant financial losses. In addition, such replacements have significant environmental impacts, including seabed disturbance, displacement of marine habitats, and sediment release that can endanger coral reefs and other sensitive ecosystems.

[0004] In light of these challenges, trenchless repair techniques have been widely used in the repair of aging pipelines due to their non-invasive nature. Among them, the sliding lining method involves inserting a new plastic pipe into the old pipeline to form a composite system, effectively restoring the mechanical and hydraulic properties of the pipeline, extending its service life and reducing maintenance costs. However, applying these technologies to submarine pipelines, especially those spanning long distances, presents unique challenges.

[0005] The underwater environment, especially in the ocean, presents several significant limitations. Long subsea pipelines cannot be easily disconnected, and repair operations are severely affected by severe marine conditions. The multiple bends in these pipelines further increase the complexity of the repair. When using the sliding lining method, the liner must be pulled through the old pipeline. Due to the length of the pipeline and the number of bends, this process requires a large amount of pulling force. High pulling forces may cause the liner to break, resulting in repair failure. Therefore, accurate prediction of the pulling force is crucial for the scientific design of the liner tensile strength.

[0006] Despite the importance of this aspect, there is currently no reliable method to predict the tensile forces involved in such repairs. The reason for this research gap is that long distances and multiple bends are not usually encountered when trenchless repair methods are applied on land, and the tensile strength of the liner is usually far greater than the tensile forces required during construction. Therefore, the development of a robust computational model for the tensile forces required for multi-bend pipelines is of great significance to improve the success rate and economics of long submarine pipeline repairs.

[0007] Existing theoretical models mainly focus on straight pipe sections or single bends, which makes it difficult to accurately describe complex multi-bend pipeline systems. In addition, these models often ignore the nonlinear characteristics of the lining material and the complex contact behavior with the inner wall of the pipeline, which may lead to significant errors in long-distance repairs.

[0008] In summary, there is an urgent need to develop a theoretical model that can accurately predict the traction force during the repair process of multi-bend and long-distance pipelines. Summary of the invention

[0009] In view of the above problems, the purpose of the present invention is to provide a method, device, medium and equipment for predicting the construction traction of long-distance corroded pipeline repair based on a multi-layer composite lining, which can be applied to the repair of long-distance, multi-bend corroded pipelines in the fields of oil and gas pipelines and municipal pipelines.

[0010] To achieve the above object, the present invention adopts the following technical solutions:

[0011] The method for predicting the traction force of long-distance corroded pipeline repair based on multi-layer composite lining of the present invention comprises the following steps:

[0012] Based on the theory of elastic mechanics, a traction force prediction model for a single bending segment is established;

[0013] Consider the traction calculation of the straight pipe section, including the effects of friction and gravity;

[0014] Based on the traction force prediction model of a single bend section and the traction force calculation of a straight pipe section, a traction force calculation method for multi-bend pipelines is developed. The "bend-straight pipe-bend" structure is considered, the concept of effective length of the straight pipe section is introduced, and the cumulative effect of traction is corrected.

[0015] The prediction method, preferably, the establishment of a traction prediction model for a single curved section specifically comprises the following steps:

[0016] The liner has three potential stress points at the bend, namely: outlet, midpoint and inlet. The normal forces exerted by the bend on the liner are denoted as F A 、F B and F C , the friction coefficient between the bend and the lining is μ, and the basic expression for the traction during construction is established as:

[0017] F 2 =F 1 +μ(F A +F B +F C )#(1)

[0018] Among them, F 1 is the tension of the liner before it enters the bend; F 2is the traction force of the liner pipe through bending; F A is the normal pressure between the inner and outer tubes at the curved outlet; F B is the normal pressure between the inner and outer tubes in the middle of the bend; F C is the normal pressure between the inner and outer tubes at the inlet end of the bend;

[0019] Using the small deflection theory for simply supported beams, the magnitudes of the three normal forces are determined to be:

[0020]

[0021] From the balanced equation we get:

[0022]

[0023] Where δ is the deflection of the liner; L is the distance between the inner and outer pipe interaction points at the bend; E j is the bending stiffness of the liner pipe; β is the bending angle;

[0024] In the prediction method, preferably, the traction force prediction model of the single curved section is:

[0025] When the liner passes through the bend, the tension at both ends is large enough to overcome the stiffness of the liner, resulting in only one contact point with the bend. By calculating F B The force balance on gives the first type of traction equation:

[0026]

[0027] When the liner passes through the bend, the inlet resistance is relatively small, which is not enough to overcome the stiffness of the liner, causing the liner to contact the bend inlet. On the contrary, the outlet traction force is large, which overcomes the stiffness of the liner and prevents the liner from contacting the bend outlet. At this time, there are two force points between the liner and the bend. Therefore, the calculation formula for the second type of traction force is:

[0028]

[0029] When the liner encounters the least resistance at the entrance and exit of the bend, due to the stiffness of the liner, there are three force points between the liner and the bend. The calculation formula for the third type of traction is:

[0030]

[0031] In the prediction method, preferably, the traction force of the straight pipe section is calculated as follows:

[0032] For the straight pipe section, considering the friction resistance between the lining and the old pipe and gravity, the traction formula is:

[0033] F 2=F 1 +ρl(μcosθ+sinθ)#(7)

[0034] Where ρ is the gravity density of the liner; l is the length of the straight section of the pipe; and θ is the rise angle of the straight section of the pipe.

[0035] The prediction method preferably considers the "bend-straight pipe-bend" structure and introduces the concept of effective length of the straight pipe section, and specifically includes the following steps:

[0036] According to structural mechanics, the cantilever beam under uniform load is 0 Deflection at As shown in formula (8), according to the deflection in the antisymmetric structure The relationship between the non-contact length 2L and the outer tube diameter D is as shown in formula (9): 0 The expression of is as formula (10), so the effective length of the straight pipe section Le is as formula (11), and the effective length is used to calculate the friction force of the straight pipe section and the subsequent calculation of the friction force of the elbow;

[0037]

[0038] in, is the deflection; ρ is the hose density; g is the gravitational acceleration; L 0 is the length of the non-contact zone; L is the length of the straight tube section; E is Young's modulus; I is the linear stiffness; D is the diameter of the outer tube; Le is the effective length; S is the cross-sectional area;

[0039] According to the angle relationship of the elbow on the same side, a method for determining the effective length of a straight pipe section is established. If the angles of two adjacent elbows β i With β i+1 If the relationship (12) is satisfied, it is determined to be a same-direction elbow, and the effective length of the straight pipe section is equal to the length of the straight pipe section. The rest are determined to be different-direction elbows, and the effective length of the straight pipe section is calculated according to the formula (11);

[0040]

[0041] The device for predicting the traction force of long-distance corroded pipeline repair based on multi-layer composite lining of the present invention comprises:

[0042] A first processing unit is used to establish a traction force prediction model of a single bending section based on elastic mechanics theory;

[0043] The second processing unit is used to calculate the traction force of the straight pipe section, including the influence of friction and gravity;

[0044] The third processing unit is used to develop a traction calculation method for multi-bend pipelines based on the traction prediction model of a single bend section and the traction calculation of a straight pipe section, taking into account the "bend-straight pipe-bend" structure, introducing the concept of the effective length of the straight pipe section, and correcting the cumulative effect of traction.

[0045] The present invention also provides a computer storage medium on which a computer program is stored. When the computer program is executed by a processor, the steps of the method for predicting the construction traction force of a long-distance corroded pipeline repair based on a multi-layer composite lining are implemented.

[0046] The present invention also provides a computer device, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, the method steps for predicting the construction traction of a long-distance corroded pipeline repaired based on a multi-layer composite lining are implemented.

[0047] The present invention adopts the above technical solution, which has the following advantages:

[0048] The present invention systematically solves the problem of traction force prediction in long-distance, multi-bend pipeline repair for the first time, filling an important gap in existing research;

[0049] The present invention provides a more accurate prediction of traction force by considering multiple complex factors, such as bending angle, friction coefficient of the inner wall of the pipe and reverse tension.

[0050] The "bend-straight pipe-bend" structural calculation method and the concept of effective length of straight pipe section innovatively introduced in the present invention provide new ideas for mechanical analysis of complex piping systems;

[0051] The present invention provides important technical support for the sustainable development of energy, municipal administration, industry and other fields, and has broad application prospects and significant social and economic benefits.

[0052] By providing a reliable theoretical basis and practical engineering guidance, the present invention is expected to trigger innovation in the field of pipeline maintenance and repair, and promote the progress of related technologies and the development of the industry. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] Various other advantages and benefits will become apparent to those of ordinary skill in the art by reading the detailed description of the preferred embodiments below. The accompanying drawings are only for the purpose of illustrating the preferred embodiments and are not to be considered as limiting the present invention. Throughout the accompanying drawings, the same reference numerals are used to represent the same components. In the accompanying drawings:

[0054] Figure 1The present invention is a flow chart of developing a method for calculating the traction force of a multi-bend pipeline, taking into account a "bend-straight pipe-bend" structure, introducing the concept of effective length of a straight pipe section, and correcting the cumulative effect of traction force.

[0055] Figure 2 This is the first (Type 1) contact form between the inner lining of the present invention and the inner wall of the old pipe;

[0056] Figure 3 This is the second (Type 2) contact form between the inner lining of the present invention and the inner wall of the old pipe;

[0057] Figure 4 This is the third (Type 3) contact form between the liner of the present invention and the inner wall of the old pipe. DETAILED DESCRIPTION

[0058] The exemplary embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. Although the exemplary embodiments of the present invention are shown in the accompanying drawings, it should be understood that the present invention can be implemented in various forms and should not be limited by the embodiments described herein. On the contrary, these embodiments are provided in order to enable a more thorough understanding of the present invention and to fully convey the scope of the present invention to those skilled in the art.

[0059] The present invention provides a method for predicting the construction traction force of long-distance corroded pipeline repair based on multi-layer composite lining, and establishes a comprehensive and accurate theoretical model for predicting the construction traction force, taking into account the complex geometric characteristics of multi-bend pipelines, the mechanical properties of lining materials, and the complex contact behavior between the lining and the inner wall of the pipeline. The method provides a reliable theoretical basis for the non-excavation repair of long-distance, multi-bend corroded pipelines, and has wide applicability and significant engineering application value.

[0060] The present invention provides a method for predicting the traction force of long-distance corroded pipeline repair construction based on a multi-layer composite lining, comprising the following steps:

[0061] S1. Based on the theory of elastic mechanics, a traction force prediction model for a single bending segment is established;

[0062] S2. Calculation of traction force of straight pipe section, including the influence of friction and gravity;

[0063] S3. Based on the traction prediction model of a single bend section and the traction calculation of a straight pipe section, a traction calculation method for multi-bend pipelines is developed, taking into account the "bend-straight pipe-bend" structure, introducing the concept of effective length of the straight pipe section, and correcting the cumulative effect of traction.

[0064] In the above embodiment, preferably, the establishing of the traction force prediction model of a single curved section specifically includes the following steps:

[0065] The liner has three potential stress points at the bend, namely: outlet, midpoint and inlet. The normal forces exerted by the bend on the liner are denoted as F A 、F B and F C , the friction coefficient between the bend and the lining is μ, and the basic expression for the traction during construction is established as:

[0066] F 2 =F 1 +μ(F A +F B +F C )#(1)

[0067] Among them, F 1 is the tension of the liner before it enters the bend; F 2 is the traction force of the liner pipe through bending; F A is the normal pressure between the inner and outer tubes at the curved outlet; F B is the normal pressure between the inner and outer tubes in the middle of the bend; F C is the normal pressure between the inner and outer tubes at the inlet end of the bend;

[0068] Using the small deflection theory for simply supported beams, the magnitudes of the three normal forces are determined to be:

[0069]

[0070] From the balanced equation we get:

[0071]

[0072] Where δ is the deflection of the liner; L is the distance between the inner and outer pipe interaction points at the bend; E j is the bending stiffness of the liner pipe; β is the bending angle;

[0073] In the above embodiment, preferably, the traction force prediction model of the single curved section is:

[0074] When the liner passes through the bend, the tension at both ends is large enough to overcome the stiffness of the liner, resulting in only one contact point with the bend. By calculating F B The force balance on gives the first type of traction equation:

[0075]

[0076] When the liner passes through the bend, the inlet resistance is relatively small, which is not enough to overcome the stiffness of the liner, causing the liner to contact the bend inlet. On the contrary, the outlet traction force is large, which overcomes the stiffness of the liner and prevents the liner from contacting the bend outlet. At this time, there are two force points between the liner and the bend. Therefore, the calculation formula for the second type of traction force is:

[0077]

[0078] When the liner encounters the least resistance at the entrance and exit of the bend, due to the stiffness of the liner, there are three force points between the liner and the bend. The calculation formula for the third type of traction is:

[0079]

[0080] Among them, the three contact modes between the lining and the inner wall of the old pipe are shown in Table 1.

[0081] Table 1: Three contact modes between the lining and the inner wall of the old pipe.

[0082]

[0083] In the above embodiment, preferably, the traction force of the straight pipe section is calculated as follows:

[0084] For the straight pipe section, considering the friction resistance between the lining and the old pipe and gravity, the traction formula is:

[0085] F 2 =F 1 +ρl(μcosθ+sinθ)#(7)

[0086] Where ρ is the gravity density of the liner; l is the length of the straight section of the pipe; and θ is the rise angle of the straight section of the pipe.

[0087] In the above embodiment, preferably, the “bend-straight pipe-bend” structure is considered, and the concept of effective length of the straight pipe section is introduced, which specifically includes the following steps:

[0088] According to structural mechanics, the cantilever beam under uniform load is 0 Deflection at As shown in formula (8), according to the deflection in the antisymmetric structure The relationship between the non-contact length 2L and the outer tube diameter D is as shown in formula (9): 0 The expression of is as formula (10), so the effective length of the straight pipe section Le is as formula (11), and the effective length is used to calculate the friction force of the straight pipe section and the subsequent calculation of the friction force of the elbow;

[0089]

[0090]

[0091] in, is the deflection; ρ is the hose density; g is the gravitational acceleration; L 0is the length of the non-contact zone; L is the length of the straight tube section; E is Young's modulus; I is the linear stiffness; D is the diameter of the outer tube; Le is the effective length; S is the cross-sectional area;

[0092] According to the angle relationship of the elbow on the same side, a method for determining the effective length of a straight pipe section is established. If the angles of two adjacent elbows β i With β i+1 If the relationship (12) is satisfied, it is determined to be a same-direction elbow, and the effective length of the straight pipe section is equal to the length of the straight pipe section. The rest are determined to be different-direction elbows, and the effective length of the straight pipe section is calculated according to the formula (11);

[0093]

[0094] The specific process of correcting the cumulative effect of traction is as follows: Figure 1 shown.

[0095] The present invention also provides a device for predicting the traction force of long-distance corroded pipeline repair construction based on a multi-layer composite lining, comprising:

[0096] A first processing unit is used to establish a traction force prediction model of a single bending section based on elastic mechanics theory;

[0097] The second processing unit is used to calculate the traction force of the straight pipe section, including the influence of friction and gravity;

[0098] The third processing unit is used to develop a traction calculation method for multi-bend pipelines based on the traction prediction model of a single bend section and the traction calculation of a straight pipe section, taking into account the "bend-straight pipe-bend" structure, introducing the concept of the effective length of the straight pipe section, and correcting the cumulative effect of traction.

[0099] The present invention also provides a computer storage medium on which a computer program is stored. When the computer program is executed by a processor, the steps of the method for predicting the construction traction force of a long-distance corroded pipeline repair based on a multi-layer composite lining are implemented.

[0100] The present invention also provides a computer device, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, the method steps for predicting the construction traction of a long-distance corroded pipeline repaired based on a multi-layer composite lining are implemented.

[0101] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for predicting the traction force of long-distance corroded pipeline repair based on multi-layer composite lining, characterized in that: The steps include: Based on the theory of elastic mechanics, a traction force prediction model for a single bending segment is established; Consider the traction calculation of the straight pipe section, including the effects of friction and gravity; Based on the traction force prediction model of a single bend section and the traction force calculation of a straight pipe section, a traction force calculation method for multi-bend pipelines is developed. The "bend-straight pipe-bend" structure is considered, the concept of effective length of the straight pipe section is introduced, and the cumulative effect of traction force is corrected.

2. The prediction method according to claim 1, characterized in that: The establishment of the traction force prediction model for a single curved section specifically includes the following steps: The liner has three potential stress points at the bend, namely: outlet, midpoint and inlet. The normal forces exerted by the bend on the liner are denoted as F A 、F B and F C , the friction coefficient between the bend and the lining is μ, and the basic expression for the traction during construction is established as: F2=F1+μ(F A +F B +F C )#(1) Among them, F1 is the pulling force of the liner before entering the bend; F2 is the pulling force of the liner through the bend; F A is the normal pressure between the inner and outer tubes at the curved outlet; F B is the normal pressure between the inner and outer tubes in the middle of the bend; F C is the normal pressure between the inner and outer tubes at the inlet end of the bend; Using the small deflection theory for simply supported beams, the magnitudes of the three normal forces are determined to be: From the balanced equation we get: Where δ is the deflection of the liner; L is the distance between the inner and outer pipe interaction points at the bend; E j is the bending stiffness of the liner pipe; β is the bending angle.

3. The prediction method according to claim 2, characterized in that: The traction force prediction model of the single curved section is: When the liner passes through the bend, the tension at both ends is large enough to overcome the stiffness of the liner, resulting in only one contact point with the bend. By calculating F B The force balance on gives the first type of traction equation: When the liner passes through the bend, the inlet resistance is relatively small, which is not enough to overcome the stiffness of the liner, causing the liner to contact the bend inlet. On the contrary, the outlet traction force is large, which overcomes the stiffness of the liner and prevents the liner from contacting the bend outlet. At this time, there are two force points between the liner and the bend. Therefore, the calculation formula for the second type of traction force is: When the liner encounters the least resistance at the entrance and exit of the bend, due to the stiffness of the liner, there are three force points between the liner and the bend. The calculation formula for the third type of traction is:

4. The prediction method according to claim 1, characterized in that: The traction force calculation of the straight pipe section is specifically as follows: For the straight pipe section, considering the friction resistance between the lining and the old pipe and gravity, the traction formula is: F2=F1+ρl(μcosθ+sinθ)#(7) Where ρ is the gravity density of the liner; l is the length of the straight section of the pipe; and θ is the rise angle of the straight section of the pipe.

5. The prediction method according to claim 1, characterized in that: The "bend-straight pipe-bend" structure is considered, and the concept of effective length of the straight pipe section is introduced, which specifically includes the following steps: According to structural mechanics, the deflection of the cantilever beam at L0 under uniformly distributed load is obtained As shown in formula (8), according to the deflection in the antisymmetric structure The relationship between the diameter of the outer pipe D is as shown in formula (9), and the expression of the non-contact length 2L0 is obtained as shown in formula (10). Therefore, the effective length Le of the straight pipe section is as shown in formula (11), and the friction force of the straight pipe section and the subsequent elbow friction force are calculated based on the effective length; in, is the deflection; ρ is the hose density; g is the gravitational acceleration; L0 is the length of the non-contact area; L is the length of the straight pipe section; E is the Young's modulus; I is the linear stiffness; D is the outer tube diameter; Le is the effective length; S is the cross-sectional area; According to the angle relationship of the elbow on the same side, a method for determining the effective length of a straight pipe section is established. If the angles of two adjacent elbows β i With β i+1 If the relationship (12) is satisfied, it is determined to be a same-direction elbow, and the effective length of the straight pipe section is equal to the length of the straight pipe section. The rest are determined to be different-direction elbows, and the effective length of the straight pipe section is calculated according to the formula (11); 6. A device for predicting traction force for repairing long-distance corroded pipelines based on multi-layer composite lining, characterized in that: include: A first processing unit is used to establish a traction force prediction model of a single bending section based on elastic mechanics theory; The second processing unit is used to calculate the traction force of the straight pipe section, including the influence of friction and gravity; The third processing unit is used to develop a traction calculation method for multi-bend pipelines based on the traction prediction model of a single bend section and the traction calculation of a straight pipe section, taking into account the "bend-straight pipe-bend" structure, introducing the concept of effective length of a straight pipe section, and correcting the cumulative effect of traction.

7. A computer storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the method for predicting the construction traction of a long-distance corroded pipeline repair based on a multi-layer composite lining according to any one of claims 1 to 5 are implemented.

8. A computer device comprising a memory, a processor and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the computer program, the steps of the method for predicting the construction traction of a long-distance corroded pipeline repair based on a multi-layer composite lining as described in any one of claims 1 to 5 are implemented.

Images