Trenchless pipeline obstacle removing method

Abstract

The invention belongs to the technical field of underground engineering, and discloses a trenchless pipeline obstacle removing method which comprises the following steps: S1, arranging a working well at each of two ends of a waste steel pipe, and arranging a tractor beside one working well; s2, an antifriction agent is injected to the waste steel pipe on the surface of the stratum at intervals; s3, a temporary valve is installed at one end of the waste steel pipe, the interior of the waste steel pipe is purged, and the temporary valve is taken down after purging is completed; s4, the casing milling pipe is connected with a traction machine, the casing milling pipe and the waste steel pipe are connected through a connecting ring, the exterior of the waste steel pipe is cleaned, and the casing milling pipe is taken down after cleaning is completed; and S5, the pipe drawing device is connected with a traction machine, the waste steel pipe and the pipe drawing device are connected, and the waste steel pipe is dragged back in a segmented mode. On the premise of non-excavation, the method is suitable for different soil layer geological conditions and can be flexibly implemented, the cleaning period is shortened, the construction difficulty is reduced, and smooth obstacle removal of various pipelines is guaranteed.

Description

Technical Field

[0001] The invention relates to the technical field of underground engineering, and in particular to a trenchless pipeline obstacle clearing method. Background Art

[0002] At present, for the clearance of underground pipelines, traditional process methods mostly use open excavation methods or conventional dragging schemes. However, the open excavation method is difficult to implement when there are other pipelines above or the pipelines in the construction area are relatively complex. At the same time, pipelines buried in deeper soil layers and for a long time have good compaction, the pipelines are tightly wrapped with the outer grouting layer, there is a large friction, the pipeline joints are of poor quality and are easy to break, etc. It is difficult to use conventional dragging schemes for clearance. The clearance of ultra-long and ultra-deep pipelines is even more difficult. Therefore, how to flexibly implement and shorten the cleaning period and reduce the construction difficulty under the premise of non-excavation to ensure the smooth clearance of various types of pipelines is a problem that people in this field need to solve. Summary of the invention

[0003] The purpose of the present invention is to provide a trenchless pipeline clearing method, which is applicable to different soil geological conditions without excavation, can be flexibly implemented and shorten the cleaning period, reduce the construction difficulty, so as to ensure the smooth clearing of various types of pipelines.

[0004] To achieve this object, the present invention adopts the following technical solutions:

[0005] A trenchless pipeline clearing method, comprising the following steps:

[0006] S1. A working well is set at each end of the scrapped steel pipe, and a traction machine is set next to one of the working wells;

[0007] S2. Inject friction reducer at intervals on the formation surface until the steel pipe is removed;

[0008] S3. Install a temporary valve at one end of the scrapped steel pipe, purge the inside of the scrapped steel pipe, and remove the temporary valve after the purge is completed;

[0009] S4, connecting the casing milling pipe to the traction machine, and connecting the casing milling pipe to the scrapped steel pipe through a connecting ring, cleaning the outside of the scrapped steel pipe, and removing the casing milling pipe after the cleaning is completed;

[0010] S5. Connect the pipe puller to the traction machine, and connect the scrapped steel pipe to the pipe puller to pull back the scrapped steel pipe in sections.

[0011] Optionally, step S2 includes:

[0012] S2.1. Drill several grouting holes at intervals and throughout the ground surface;

[0013] S2.2. An observation hole is set between two adjacent grouting holes;

[0014] S2.3. Inject the friction reducer through the grouting hole to the abandoned steel pipe and stop injecting when grout emerges from the hole.

[0015] As an option, the distance between two adjacent grouting holes is set to 10m.

[0016] As an option, the injection amount of the friction reducer ranges from 500kg to 1000kg.

[0017] Optionally, step S3 includes:

[0018] S3.1. Select an open area that allows the discharge of dirt and debris as the purge port;

[0019] S3.2. Install a temporary valve at one end of the scrapped steel pipe, and place the temporary valve close to the purge port;

[0020] S3.3. Use compressed air to purge the inside of the scrapped steel pipe. When the pressure inside the scrapped steel pipe reaches the preset pressure during the purge, quickly open the temporary valve to discharge the dirt and debris.

[0021] S3.4. After completing the internal cleaning of the scrapped steel pipe, remove the temporary valve.

[0022] As an option, the outlet centerline of the temporary valve is installed upward at a 30° deviation from the vertical line.

[0023] As an option, the preset pressure is set to 1.5 MPa.

[0024] As an option, the sleeve milling pipe includes a pipe body and a milling head, the connecting ring is sleeved on the outside of the scrapped steel pipe and the pipe body, and there is a gap between the connecting ring and both, and during the cleaning process, the connecting ring can move synchronously with the pipe body along the outside of the scrapped steel pipe, and the milling head is used to clean the outside of the scrapped steel pipe.

[0025] Optionally, when the milling tube performs external cleaning on the scrapped steel pipe, bentonite is injected onto the outside of the scrapped steel pipe to enhance lubrication.

[0026] Optionally, step S5 includes:

[0027] S5.1. Connect one end of the pipe puller to the traction machine and the other end to the scrapped steel pipe. The other end of the scrapped steel pipe is operated with the pipe puller by a rammer;

[0028] S5.2. Drag the scrapped steel pipe back in sections of 10 m, and cut off each section from the undragged part after it is dragged out, and then reconnect the pipe puller to the undragged part and drag it back;

[0029] S5.3. After all the steel pipes have been pulled back, remove the pipe puller and inject cement slurry into the holes to fill them.

[0030] Beneficial effects of the present invention:

[0031] The present invention uses two working wells to facilitate the placement of subsequent sleeve milling equipment and pipe pulling equipment, and to facilitate the cleaning of exhaust gas inside the scrapped steel pipe. Injecting a friction reducer before internal and external cleaning can improve the efficiency of subsequent scrapped steel pipe pullback. Furthermore, by controlling the temporary valve to blow the inside of the scrapped steel pipe and using the sleeve milling pipe to clean the outside of the scrapped steel pipe, it can effectively avoid explosions caused by static electricity generated during the dismantling process, and can avoid interference in the scrapped steel pipe's pullback movement, thereby improving the pullback efficiency. Furthermore, by using the pipe puller to pull back the scrapped steel pipe in sections, not only can the effect of rapid pullback be achieved in a limited space, but it can also improve the obstacle clearance efficiency of long pipelines and reduce safety risks. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 is a schematic diagram of step S1 in the trenchless pipeline obstacle clearing method according to an embodiment of the present invention;

[0033] Figure 2 is a schematic diagram of step S4 of the trenchless pipeline obstacle clearing method according to an embodiment of the present invention;

[0034] Figure 3 It is a partial enlarged schematic diagram of the connection between the sleeve milling pipe and the abandoned steel pipe in the trenchless pipeline obstacle removal method according to an embodiment of the present invention;

[0035] Figure 4 It is a schematic diagram of step S5 of the trenchless pipeline obstacle clearing method described in an embodiment of the present invention.

[0036] In the figure:

[0037] 100-abandoned steel pipe; 101-hole; 200-stratum surface; 10-working well; 20-traction machine; 30-milling pipe; 31-pipe body; 32-milling head; 40-connecting ring; 50-pipe puller. DETAILED DESCRIPTION

[0038] The embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar parts or parts having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and should not be construed as limiting the present invention.

[0039] In the description of the present invention, unless otherwise clearly specified and limited, the terms "connected", "connected", and "fixed" should be understood in a broad sense, for example, it can be a fixed connection or a detachable connection, it can be a mechanical connection or an electrical connection, it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0040] In the description of the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include the first feature being in direct contact with the second feature, or may include the first feature being in contact with the second feature through another feature between them instead of being in direct contact. Moreover, a first feature being "above", "above" and "above" a second feature includes the first feature being directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes the first feature being directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0041] The technical solution of this embodiment is further explained below with reference to the accompanying drawings and through specific implementation methods.

[0042] like Figure 1-Figure 4 As shown, this embodiment provides a trenchless pipeline obstacle removal method, comprising the following steps:

[0043] S1. A working well 10 is respectively provided at both ends of the scrapped steel pipe 100, and a traction machine 20 is provided next to one of the working wells 10;

[0044] S2, injecting friction reducer at intervals on the formation surface 200 to the place where the steel pipe 100 is abandoned;

[0045] S3, installing a temporary valve at one end of the scrapped steel pipe 100, purging the inside of the scrapped steel pipe 100, and removing the temporary valve after the purging is completed;

[0046] S4, connecting the casing milling tube 30 to the traction machine 20, and connecting the casing milling tube 30 to the scrapped steel tube 100 through the connecting ring 40, cleaning the outside of the scrapped steel tube 100, and removing the casing milling tube 30 after the cleaning is completed;

[0047] S5, connecting the pipe puller 50 to the traction machine 20, and connecting the scrapped steel pipe 100 to the pipe puller 50, and pulling the scrapped steel pipe 100 back in sections.

[0048] Specifically, the two working wells 10 used in this embodiment are convenient for the placement of subsequent sleeve milling equipment and pipe pulling equipment, and for cleaning the exhaust gas inside the scrapped steel pipe 100. Injecting a friction reducer before internal and external cleaning can improve the subsequent pull-back efficiency of the scrapped steel pipe 100. Furthermore, by controlling the temporary valve to blow the inside of the scrapped steel pipe 100, and using the sleeve milling pipe 30 to clean the outside of the scrapped steel pipe 100, it can effectively avoid explosions caused by static electricity generated during the dismantling process, and can avoid interference in the pull-back movement of the scrapped steel pipe 100, thereby improving the pull-back efficiency. Furthermore, by using the pipe puller 50 to pull the scrapped steel pipe 100 back in sections, it can not only achieve the effect of rapid pull-back in a limited space, but also improve the obstacle clearance efficiency of long pipelines and reduce safety risks.

[0049] The specific process of the trenchless pipeline obstacle clearing method in this embodiment is described below.

[0050] Combination Figure 1-Figure 4 As shown, the pipeline excavation and obstacle removal method in this embodiment includes:

[0051] S1. A working well 10 is respectively provided at both ends of the scrapped steel pipe 100, and a traction machine 20 is provided next to one of the working wells 10;

[0052] S2, injecting friction reducer at intervals on the formation surface 200 to the place where the steel pipe 100 is abandoned;

[0053] S3, installing a temporary valve at one end of the scrapped steel pipe 100, purging the inside of the scrapped steel pipe 100, and removing the temporary valve after the purging is completed;

[0054] S4, connecting the casing milling tube 30 to the traction machine 20, and connecting the casing milling tube 30 to the scrapped steel tube 100 through the connecting ring 40, cleaning the outside of the scrapped steel tube 100, and removing the casing milling tube 30 after the cleaning is completed;

[0055] S5, connecting the pipe puller 50 to the traction machine 20, and connecting the scrapped steel pipe 100 to the pipe puller 50, and pulling the scrapped steel pipe 100 back in sections.

[0056] Specifically, in this embodiment, working wells 10 are respectively provided at both ends of the scrapped steel pipe 100. The two working wells 10 can ensure the smooth placement of subsequent sleeve milling equipment and pipe pulling equipment, and facilitate the removal of exhaust gas inside the scrapped steel pipe 100. For example, in the prior art, during construction operations in shallow soil, well leakage often occurs due to loose formations, that is, mud leakage occurs during drilling. If it cannot be effectively suppressed, a large amount of mud may directly enter the formation and flow in the formation, taking away a large amount of filling materials in the formation, thereby causing the formation to lose support and cause serious hole collapse, so timely plugging is necessary. Combined with Figure 1 As shown, in this embodiment, a "two highs and one appropriate" mud plugging scheme can be adopted during the construction process, wherein the two highs are high viscosity and high soil content, and the one appropriate is a plugging material of appropriate concentration, so that a dense plugging layer can be formed on the well wall in time. For example, this kind of mud can be used in the working well 10 for wall plugging. Furthermore, after entering the formation, this kind of mud can still effectively block the pores in the formation to prevent the mud from further entering the formation, thereby avoiding the collapse caused by the mud channeling and hollowing out the formation. In this embodiment, the use of this kind of mud for plugging can also ensure the stability of the subsequent cleaning and scrapping of the steel pipe 100 and the smooth progress of the pipe pulling operation.

[0057] Further, step S2 includes:

[0058] S2.1, drilling a number of grouting holes at intervals and throughout the stratum surface 200;

[0059] S2.2. An observation hole is set between two adjacent grouting holes;

[0060] S2.3. Inject the friction reducer through the grouting hole to the abandoned steel pipe 100, and stop injecting when grout emerges from the observation hole.

[0061] Optionally, in this embodiment, the distance between two adjacent grouting holes is set to 10m, and the injection amount of the friction reducer ranges from 500kg to 1000kg, thereby ensuring smooth pipe removal and reducing the friction between the scrapped steel pipe 100 and the surrounding soil. Exemplarily, in this embodiment, the friction reducer can be the mud in step S1, so that the mud is injected into the grouting hole so that the mud is wrapped around the outside of the scrapped steel pipe 100 to reduce friction.

[0062] Further, step S3 includes:

[0063] S3.1. Select an open area that allows the discharge of dirt and debris as the purge port;

[0064] S3.2. Install a temporary valve at one end of the scrapped steel pipe 100, and the temporary valve is set close to the purge port;

[0065] S3.3, use a compressed air machine to purge the inside of the scrapped steel pipe 100, and when the pressure inside the scrapped steel pipe 100 reaches a preset pressure during the purge, quickly open a temporary valve to discharge dirt and debris;

[0066] S3.4. After completing the cleaning of the interior of the scrap steel pipe 100, remove the temporary valve.

[0067] Specifically, in this embodiment, the outlet center line of the temporary valve is installed upward at a 30° deviation from the vertical line, and the outlet of the temporary valve is higher than the top of the scrapped steel pipe 100, so as to ensure that the inside of the scrapped steel pipe 100 is fully cleaned and to prevent debris from falling back. Furthermore, the preset pressure is set to 1.5MPa, and it can also be set as needed in other embodiments. Specifically, in this embodiment, the position of the purge port is set in an open area that allows the discharge of dirt and debris, and does not threaten the safety of people and objects around, thereby reducing the operational risks and achieving environmental protection effects. Furthermore, in this embodiment, a compressed air machine is used to provide dry and clean air to purge the inside of the scrapped steel pipe 100, so as to ensure that the inside of the scrapped steel pipe 100 is fully cleaned, thereby improving the removal efficiency and avoiding affecting the subsequent pipe removal and cutting operations. At the same time, it can also ensure the safety and smooth progress of the entire removal work, and avoid the generation of static electricity during the removal process to cause explosions.

[0068] Combination Figure 2 and Figure 3 As shown, in this embodiment, the sleeve milling pipe 30 includes a pipe body 31 and a milling head 32. Specifically, one end of the pipe body 31 can be connected to the traction machine 20, and the other end is connected to the milling head 32, and the connecting ring 40 is sleeved on the outside of the scrapped steel pipe 100 and the pipe body 31, and there is a gap between the connecting pipe 40 and the scrapped steel pipe 100 and the pipe body 31, so that during the cleaning process, the milling head 32 can be driven by the traction machine 20 and the pipe body 31 to move outside the scrapped steel pipe 100 for cleaning, and during this cleaning process, the connecting ring 40 can move synchronously with the pipe body 31 outside the scrapped steel pipe 100, so as to ensure that the sleeve milling pipe 30 always moves outside the scrapped steel pipe 100 and will not fall off. For example, when the milling tube 30 performs external cleaning on the scrapped steel pipe 100, the gap between the outside of the scrapped steel pipe 100 and the soil is increased to form a hole 101, so that bentonite is injected into the outside of the scrapped steel pipe 100, that is, the hole 101, during cleaning, so as to reinforce the load-bearing soil around the scrapped steel pipe 100 and lubricate the movement of the milling tube 30 to improve the cleaning efficiency. For example, in this embodiment, the bentonite can also be the mud in step S1, so as to inject mud into the hole 101, reinforce and lubricate the inner wall of the hole 101, and ensure the smooth movement of the milling tube 30.

[0069] Further, step S5 includes:

[0070] S5.1. Connect one end of the pipe puller 50 to the traction machine 20, and the other end to the scrapped steel pipe 100. The other end of the scrapped steel pipe 100 is operated by a rammer in cooperation with the pipe puller 50.

[0071] S5.2, the scrapped steel pipe 100 is towed back in sections of 10 m, and after each section is towed out, it is cut off from the untowed part, and then the pipe puller 50 is reconnected to the untowed part to tow back;

[0072] S5.3. After all the steel pipes 100 have been pulled back, the pipe puller 50 is removed and cement slurry is injected into the hole 101 to fill it.

[0073] Specifically, when a rammer is used in conjunction with the pipe puller 50, 2-3 workers can be arranged to provide protection nearby to ensure the safety of the entire back-dragging operation. Furthermore, the pipe puller 50 is connected to the scrapped steel pipe 100 by welding to ensure the stability of the back-dragging. Exemplarily, after each scrapped steel pipe 100 is back-dragged out of the hole 101, the back-dragged pipe can be directly cut off by a welder, and the pipe puller 50 and the unback-dragged pipe can be re-welded to carry out the next back-dragging operation. Exemplarily, after all scrapped steel pipes 100 are back-dragged, cement slurry needs to be injected into the hole 101 to fill it, so as to avoid slurry leakage during future shield advancement operations. Specifically, the cement slurry requires a slurry density greater than 1.8g / cm 3 , water seepage rate is less than 5%, slump is 12-16cm, yield strength after 20 hours is greater than 800Pa, compressive strength after 28 days R28>0.5MPa, and permeability coefficient is <5x10-5cm / s.

[0074] Exemplarily, the trenchless pipeline clearing method in this embodiment can be directly used for the treatment of medium-pressure natural gas pipelines. Specifically, the diameter of the medium-pressure natural gas pipeline is 300mm, the material is steel pipe, and the wall thickness of the steel pipe is 1cm. The maximum burial depth is about 11m, and the actual burial depth is 12.5m. Furthermore, the plane position of the medium-pressure natural gas pipeline tends to be parallel and cross-sectional with the interval tunnel, and the affected range is about 140m. Most of the pipeline is in the medium sand and silty clay layer. The length of the abandoned pipeline is about 170m, and the burial depth is in the range of 3-11m. The tunnel range elevation of the shield interval is -5.45 to -6.586m, and the center of gravity elevation of the shield is -7.47m. Specifically, the trenchless pipeline obstacle clearing method in this embodiment sequentially carries out the construction of the working well 10, the injection of the friction reducer, the pipeline purging, the installation of the sleeve milling pipe 30, the welding of the pipe puller 50 to abolish the steel pipe 100, the pipeline pulling back and the filling of the channel 101, thereby ensuring the purpose of trenchless removal of long pipelines and avoiding the occurrence of other accidents such as landslides.

[0075] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the embodiments here. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. A trenchless pipeline clearing method, characterized in that: The following steps are involved: S1. A working well (10) is respectively provided at both ends of the scrapped steel pipe (100), and a traction machine (20) is provided next to one of the working wells (10); S2, injecting friction reducer at intervals on the formation surface (200) to the point where the steel pipe (100) is abandoned; S3, installing a temporary valve at one end of the scrapped steel pipe (100), purging the inside of the scrapped steel pipe (100), and removing the temporary valve after the purging is completed; S4, connecting the casing milling tube (30) to the traction machine (20), and connecting the casing milling tube (30) to the scrap steel tube (100) through the connecting ring (40), cleaning the outside of the scrap steel tube (100), and removing the casing milling tube (30) after the cleaning is completed; S5, connecting the pipe puller (50) to the traction machine (20), and connecting the scrapped steel pipe (100) to the pipe puller (50), and pulling the scrapped steel pipe (100) back in sections.

2. The trenchless pipeline obstacle removal method according to claim 1, characterized in that: The step S2 comprises: S2.1, drilling a plurality of grouting holes at intervals and throughout the formation surface (200); S2.

2. An observation hole is set between two adjacent grouting holes; S2.

3. Inject the friction reducer into the scrapped steel pipe (100) through the grouting hole, and stop injecting when grout is observed to be coming out of the hole.

3. The trenchless pipeline clearing method according to claim 2, characterized in that: The distance between two adjacent grouting holes is set to 10m.

4. The trenchless pipeline clearing method according to claim 2, characterized in that: The injection amount of the friction reducer ranges from 500kg to 1000kg.

5. The trenchless pipeline clearing method according to claim 1, characterized in that: The step S3 comprises: S3.

1. Select an open area that allows the discharge of dirt and debris as the purge port; S3.

2. Install a temporary valve at one end of the scrapped steel pipe (100), and the temporary valve is located close to the purge port; S3.3, using a compressed air machine to blow the inside of the scrapped steel pipe (100), and when the pressure inside the scrapped steel pipe (100) reaches a preset pressure during blowing, quickly open a temporary valve to discharge dirt and debris; S3.

4. After cleaning the interior of the scrap steel pipe (100), remove the temporary valve.

6. The trenchless pipeline obstacle removal method according to claim 5, characterized in that: The outlet center line of the temporary valve is installed upwards at a 30° deviation from the vertical line.

7. The trenchless pipeline clearing method according to claim 5, characterized in that: The preset pressure is set to 1.5 MPa.

8. The trenchless pipeline obstacle removal method according to claim 1, characterized in that: The sleeve milling pipe (30) comprises a pipe body (31) and a milling head (32); the connecting ring (40) is sleeved on the outer sides of the scrapped steel pipe (100) and the pipe body (31); and there is a gap between the connecting ring (40) and both of them; and during the cleaning process, the connecting ring (40) can move synchronously with the pipe body (31) on the outer side of the scrapped steel pipe (100); and the milling head (32) is used to clean the outer side of the scrapped steel pipe (100).

9. The trenchless pipeline obstacle removal method according to claim 1, characterized in that: When the sleeve milling pipe (30) cleans the exterior of the scrapped steel pipe (100), bentonite is injected into the exterior of the scrapped steel pipe (100) to enhance lubrication.

10. The trenchless pipeline obstacle removal method according to claim 1, characterized in that: The step S5 comprises: S5.

1. Connect one end of the pipe puller (50) to the traction machine (20), and the other end to the scrapped steel pipe (100). The other end of the scrapped steel pipe (100) is operated by a rammer in cooperation with the pipe puller (50); S5.2, the scrapped steel pipe (100) is towed back in sections of 10 m, and after each section is towed out, it is cut off from the untowed part, and then the pipe puller (50) is reconnected to the untowed part to tow back; S5.

3. After all the steel pipes (100) have been pulled back, the pipe puller (50) is removed and cement slurry is injected into the hole (101) to fill it.

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