A cable laying method

Abstract

The present application discloses a cable laying method, including the following steps: preparation before construction. Drilling a hole with a drilling tool according to the measured data, and expanding the hole to the required diameter with a hole reaming tool. Injecting the prepared mud into the guide hole to protect the inner wall of the guide hole, and part of the mud gathers at the bottom of the guide hole. Pulling the steel pipe with the blocked end back into the guide hole. After the steel pipe is laid, injecting a liquid with a volume of V1 into the steel pipe. Pulling the PE pipe with the blocked end back into the steel pipe. During the pulling process, the PE pipe located in the middle part of the steel pipe contacts the liquid in the steel pipe, and the PE pipe located in the middle part of the steel pipe floats on the liquid surface to reduce the friction generated by the PE pipe during the pulling process. Pulling the PE pipe back to the preset position. Cable laying. Pulling the cable back into the PE pipe by the pulling rope in the PE pipe. The present application solves the problem in the prior art that the pipeline is easily damaged during the cable laying process, thereby reducing the service life.

Description

Technical Field

[0001] The present application belongs to the technical field of trenchless directional drilling, and specifically relates to a cable laying method. Background Art

[0002] Trenchless directional drilling technology refers to a construction technology that uses less or no excavation to lay, repair, replace or detect underground pipelines and pipes. Trenchless directional drilling construction applies the principle of directional drilling technology, thereby reducing the impact of underground pipeline construction on traffic, environment, extrusion facilities, and residents' lives. Therefore, it is called an important part of the construction, construction, and management of modern urban technical facilities.

[0003] In the process of laying cables across the Yellow River, the long-distance cable laying increases the difficulty of construction. As the length and number of cables increase, the required back-pull force is greater during the laying process. In addition, during the back-pull process, the pipeline is easily damaged due to friction, which reduces the service life of the pipeline. Summary of the invention

[0004] The embodiment of the present application provides a cable laying method, thereby solving the problem in the prior art that the pipeline is easily damaged during the cable laying process, thereby reducing the service life.

[0005] In order to achieve the above object, an embodiment of the present invention provides a cable laying method, comprising the following steps:

[0006] Step 1: Preparation before construction;

[0007] Measure and lay out according to the design plan; weld steel pipes and weld PE pipes; test equipment; prepare mud;

[0008] Step 2: guide hole construction;

[0009] Drilling a hole using a drilling tool according to the measured data, and expanding the hole to the required diameter using an expanding tool;

[0010] The prepared mud is injected into the guide hole to protect the inner wall of the guide hole, and part of the mud is gathered at the bottom of the guide hole;

[0011] Step 3: Pipeline installation;

[0012] The steel pipe with the blocked end is pulled back into the guide hole, and the mud gathered at the bottom of the guide hole during the pulling back of the steel pipe reduces the friction generated during the pulling back of the steel pipe;

[0013] After the steel pipe is laid, a liquid with a volume of V1 is injected into the steel pipe;

[0014] The PE pipe with sealed ends is pulled back into the steel pipe. During the pulling back process, the PE pipe in the middle of the steel pipe is in contact with the liquid in the steel pipe. The PE pipe in the middle of the steel pipe floats on the liquid surface, which reduces the friction generated by the PE pipe during the pulling back process.

[0015] Drag the PE pipe back to the preset position;

[0016] Step 4: Cable laying;

[0017] The cable is pulled back into the PE pipe through the pulling rope inside the PE pipe.

[0018] In a possible implementation, step three includes injecting a liquid with a volume of V2 into the steel pipe before the steel pipe is pulled back, and plugging the end of the steel pipe;

[0019] During the process of pulling the steel pipe back, the liquid in the steel pipe causes the steel pipe to sink a certain distance in the mud gathered at the bottom of the guide hole, so that the steel pipe floats on the mud gathered at the bottom of the guide hole, and the side wall of the steel pipe maintains a certain distance from the top of the guide hole.

[0020] In a possible implementation, step three includes adding a weight of G1 into the first PE pipe and sealing the end of the first PE pipe;

[0021] During the process of pulling back the first PE pipe, the counterweight with a weight of G1 in the first PE pipe makes the first PE pipe sink a certain distance in the liquid in the steel pipe, so that the first PE pipe floats on the liquid in the steel pipe, and the side wall of the first PE pipe maintains a certain distance from the top of the steel pipe;

[0022] After the first PE pipe is laid, take out the counterweight G1 inside the first PE pipe.

[0023] In a possible implementation, after the first PE pipe is laid, a weight of G2 is added to the first PE pipe, G1<G2; the first PE pipe with the weight of G2 sinks to the bottom of the liquid in the steel pipe;

[0024] Laying the second PE pipe; adding a weight of G3 into the second PE pipe, where G3 is less than G2, and sealing the end of the second PE pipe;

[0025] During the process of pulling back the second PE pipe, the counterweight G3 in the second PE pipe makes the second PE pipe sink a certain distance in the liquid in the steel pipe, so that the second PE pipe floats on the liquid in the steel pipe, and the side wall of the second PE pipe keeps a certain distance from the top of the steel pipe, and the side wall of the second PE pipe keeps a certain distance from the side wall of the first PE pipe;

[0026] Repeat the above steps until all PE pipes are laid, and then remove all the weights in the PE pipes.

[0027] In a possible implementation, after adding a counterweight with a weight of G2 into the first PE pipe, a liquid with a volume of V3 is added into the steel pipe, and V3<V1, and then the second PE pipe is pulled back.

[0028] In a possible implementation, a miniature waterproof camera is installed at one end of the PE pipe that is pulled back into the steel pipe;

[0029] The miniature waterproof camera uploads the images during the towing process to the display outside the guide hole;

[0030] The amount of liquid added to the steel pipe is further controlled during the backhaul process according to the content on the display.

[0031] In a possible implementation, step three includes injecting a volume of liquid V1 into the steel pipe, and calculating the height of the liquid in the steel pipe and the height required for the PE pipe to float in the liquid during the backhaul process, thereby obtaining a numerical range of the liquid replenishment amount V3 in the steel pipe;

[0032] The required height is the height that creates a distance from both the upper wall of the steel pipe and the height that creates a distance from the PE pipe filled with liquid.

[0033] In a possible implementation, step one includes preparing mud with 0.03% to 0.1% of a horizontal directional drilling carrier agent SDX and 0.05% to 0.3% of a horizontal directional drilling viscosity increasing fluid loss reducing agent SDJ.

[0034] In a possible implementation, the mud is prepared to contain 0.1% of the horizontal directional drilling carrier SDX and 0.3% of the horizontal directional drilling viscosity increasing fluid loss reducing agent SDJ.

[0035] In a possible implementation, step three includes, in the process of pulling the steel pipe with the blocked end back into the guide hole, using a drilling rig to pull the steel pipe back, and judging whether the pulling back of the steel pipe is normal by the torque force;

[0036] When the torque exceeds the preset range, the steel pipe is pulled out from the other end;

[0037] When the torque is within the preset range, the drilling rig continues to pull back the steel pipe.

[0038] One or more technical solutions provided in the embodiments of the present invention have at least the following technical effects or advantages:

[0039] An embodiment of the present invention provides a cable laying method. During the actual construction process, the steel pipe with blocked ends is pulled back into the guide hole. During the pulling back process, the mud gathered at the bottom of the guide hole reduces the friction generated during the pulling back process of the steel pipe, thereby reducing the difficulty of laying the steel pipe. After the laying of the steel pipe is completed, a liquid with a volume of V1 is injected into the steel pipe, wherein the liquid in the steel pipe is oil, water or a water-oil mixture. The PE pipe with blocked ends is pulled back into the steel pipe, and during the pulling back process, the PE pipe located in the middle part of the steel pipe is in contact with the liquid in the steel pipe. The PE pipe located in the middle part of the steel pipe floats on the liquid surface, reducing the friction generated by the PE pipe during the pulling back process, thereby avoiding the increase of the pulling back force due to excessive friction between the PE pipe and the steel pipe during the pulling back process, and even scratching the outer wall of the PE pipe. The PE pipe is pulled back to a preset position. Specifically, during the process of pulling the PE pipe back inside the steel pipe, the buoyancy of water is used to float the PE pipe on the liquid surface inside the steel pipe, and the side wall of the PE pipe is kept at a certain distance from the inner wall of the steel pipe, thereby reducing the friction generated when the PE pipe is pulled back inside the steel pipe. Finally, the cable is pulled back into the PE pipe by the pulling rope inside the PE pipe. The present invention solves the problem in the prior art that the pipeline is easily damaged during the cable laying process, thereby reducing the service life. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments recorded in the present application, and for ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0041] Figure 1 An installation flow chart of the cable laying method provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0042] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0043] In the description of the embodiments of the present invention, it should be noted that the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the embodiments of the present invention and simplifying the description, rather than indicating or implying that the devices or elements referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limitations on the present invention. The terms "first", "second", and "third" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance. In addition, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be a connection between the two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present invention can be understood according to the specific circumstances.

[0044] like Figure 1 The embodiment of the present invention provides a cable laying method, comprising the following steps:

[0045] Step 1: Preparation before construction.

[0046] Measure and lay out according to the design plan. Weld steel pipes and weld PE pipes. Test equipment. Prepare mud.

[0047] Step 2: Construction of guide holes.

[0048] The drill bit is used to drill a hole according to the measured data, and the hole is enlarged to the required diameter using an expansion tool.

[0049] The prepared mud is injected into the guide hole to protect the inner wall of the guide hole, and part of the mud is gathered at the bottom of the guide hole.

[0050] Step 3: Pipeline installation.

[0051] The steel pipe with the sealed end is pulled back into the guide hole, and the mud gathered at the bottom of the guide hole during the pulling back of the steel pipe reduces the friction generated during the pulling back of the steel pipe.

[0052] After the steel pipe is laid, a liquid with a volume of V1 is injected into the steel pipe.

[0053] The PE pipe with sealed ends is pulled back into the steel pipe. During the pulling back process, the PE pipe located in the middle part of the steel pipe comes into contact with the liquid in the steel pipe. The PE pipe located in the middle part of the steel pipe floats on the liquid surface, reducing the friction generated by the PE pipe during the pulling back process.

[0054] Drag the PE pipe back to the preset position.

[0055] Step 4: Cable laying.

[0056] The cable is pulled back into the PE pipe through the pulling rope inside the PE pipe.

[0057] It should be noted that the survey and layout are carried out according to the design plan, including laying out the drilling site control line and equipment placement line according to the design briefing and construction drawings, ensuring that the center line of the drilling rig is in a straight line with the entry and exit points. Specifically, GPS is used for survey and layout, and the coordinate points are located according to the design document positioning piles, and the relative coordinate points and elevations are derived. The entry angle and exit angle are measured, and the angle between the pull pipe and the main channel of the Yellow River is measured. The control parameters are measured and calibrated according to the operating procedures. To ensure the accuracy of the data, the data are measured at different positions across the axis, and each position is measured at least three or four times and compared and recorded. The effective average value is taken as the control Line Az value. When the drilling rig is tested, the measurement data is checked, and construction continues after it is normal. The steel pipe is welded, and the steps of pre-welding preparation, welding, and quality control of welding are carried out.

[0058] PE pipe welding, including PE pipe welding pliers, need to check the PE pipe material, and remove stains, dirt, water and other foreign matter inside the pipe and on the interface surface. The non-welding port of the pipe is blocked to prevent foreign matter from entering the pipe during the welding process. PE pipe welding also includes the steps of pipe clamping, pipe cutting, pipe centering, pipe heating, switching, melting and docking, cooling, and inspection.

[0059] The equipment is tested. Before the pilot hole is constructed, the equipment is debugged and installed according to the measurement data. After one or two drill rods are drilled, it is determined whether the drilling rig, mud, and guiding system are operating normally. When the drilling rig, mud, and guiding system can operate normally, test drilling is carried out according to the construction drawings and construction acceptance specifications. When the drilling rig drills 15 to 25 meters, the operation of each part is checked. If the parameters of each part are normal, drilling can be carried out normally.

[0060] Mud preparation includes comprehensive analysis of relevant geological survey data, geological conditions of the drilling points, and mud formula to meet the requirements of wall consolidation and collapse prevention. It should also have good sand carrying and lubrication properties, and can also prevent mud from packing the cutter with strong suppression ability.

[0061] The pilot hole construction uses the ABS geomagnetic wired steering instrument for guiding construction because the distance of crossing the Yellow River is long. Lay the AC cable coil, set up the AC and loop cables on the surface above the crossing center line, and form a closed AC cable coil, which will serve as the magnetic signal source of the ABS geomagnetic wired steering system for the pilot hole during the crossing process, and then accurately locate the pilot hole through the artificial magnetic field. Among them, the signal line uses a special thickened double-layer insulation signal line, and a clip is added to the guide construction drill rod to prevent the signal line from being washed and entangled by mud; the pilot hole construction includes hole expansion, hole washing and mud wall protection.

[0062] In the actual construction process, the preparatory work before construction is first carried out. Specifically, the survey and layout are carried out according to the relevant plan to determine the placement of the drilling rig, the position and angle of the drilling rig entering the soil, and the position and angle of the drilling rig emerging from the soil; the steel pipes are welded and the PE pipes are welded as needed; the equipment is tested before drilling and the operation of the equipment is adjusted in time; and a certain amount of mud is prepared before construction. Secondly, the construction of the guide hole is carried out. Specifically, according to the measured data, the drill is drilled through the guide hole through the drilling tool. During the drilling process, in order to prevent the drill rod from being clamped or locked by the soil layer, the mud pump pumps out expanded cement or mud through the drill rod and the drill bit. Expanded cement or mud can also play a role in solidifying the channel and preventing the collapse of the pipeline. When the guide hole is completed, the mud motor and the guide drill bit are removed, and the pre-cleaned drill tool is replaced and slurry is used to clean it again. When it is ensured that the slurry discharge of the drill tool is normal, the reamer is connected and the step-by-step reaming operation is started. The drill tool must be cleaned in each subsequent process to ensure that the mud channel of the drill tool is normal. After the reaming is completed, the hole is washed with an extrusion-expansion back reamer to clean the guide hole. When the guide hole is drilled and expanded to the preset hole diameter and length, mud is used to protect the wall. Next, the steel pipe with blocked ends is pulled back into the guide hole. During the pulling back process, the mud gathered at the bottom of the guide hole reduces the friction generated during the pulling back process, thereby reducing the difficulty of laying the steel pipe. After the steel pipe is laid, a liquid with a volume of V1 is injected into the steel pipe, wherein the liquid in the steel pipe is oil, water or a water-oil mixture. The PE pipe with blocked ends is pulled back into the steel pipe, and during the pulling back process, the PE pipe located in the middle part of the steel pipe contacts the liquid in the steel pipe. The PE pipe located in the middle part of the steel pipe floats on the liquid surface, reducing the friction generated by the PE pipe during the pulling back process, thereby avoiding the increase of the pulling back force due to excessive friction between the PE pipe and the steel pipe during the pulling back process, and even scratching the outer wall of the PE pipe. The PE pipe is pulled back to the preset position. Specifically, during the pulling back process of the PE pipe in the steel pipe, the buoyancy of the water is used to float the PE pipe on the liquid surface in the steel pipe, and the side wall of the PE pipe is kept at a certain distance from the inner wall of the steel pipe, thereby reducing the friction generated when the PE pipe is pulled back in the steel pipe. Finally, the cable is pulled back into the PE pipe by the pulling rope in the PE pipe. The present invention solves the problem in the prior art that the pipe is easily damaged during the cable laying process, thereby reducing the service life.

[0063] In this embodiment, step three includes injecting a liquid with a volume of V2 into the steel pipe before the steel pipe is pulled back, and sealing the end of the steel pipe.

[0064] During the process of pulling the steel pipe back, the liquid in the steel pipe causes the steel pipe to sink a certain distance in the mud gathered at the bottom of the guide hole, so that the steel pipe floats on the mud gathered at the bottom of the guide hole, and the side wall of the steel pipe maintains a certain distance from the top of the guide hole.

[0065] It should be noted that after the mud wall protection, a certain amount of mud is injected into the guide hole, or during the mud wall protection process, more mud than that used for wall protection is injected into the guide hole, thereby reducing the friction between the steel pipe and the guide hole.

[0066] During the process of pulling the steel pipe back, the liquid in the steel pipe makes the steel pipe obtain a certain gravity, and makes the steel pipe sink a certain distance in the mud, so that the position of the steel pipe floating in the mud can be controlled. Furthermore, it prevents the steel pipe from generating a large friction force with the inner wall of the guide hole during the process of pulling back, and makes the pulling back of the steel pipe require a relatively small friction force, thereby reducing the difficulty of pulling back the steel pipe.

[0067] In this embodiment, a counterweight with a weight of G1 is added into the first PE pipe, and the end of the first PE pipe is sealed.

[0068] During the process of pulling back the first PE pipe, the counterweight with a weight of G1 in the first PE pipe makes the first PE pipe sink a certain distance in the liquid in the steel pipe, so that the first PE pipe floats on the liquid in the steel pipe, and the side wall of the first PE pipe maintains a certain distance from the top of the steel pipe.

[0069] After the first PE pipe is laid, take out the counterweight G1 inside the first PE pipe.

[0070] It should be noted that the counterweight in this embodiment is solid, and the pulling rope set in the first PE tube drags the counterweight with a weight of G1 into the PE tube, and an oil lubricant is applied between the counterweight and the inner wall of the first PE tube. During the process of pulling back the first PE tube, the first PE tube with a counterweight with a weight of G1 sinks a certain distance in the liquid in the steel tube, and the first PE tube floats in the liquid in the steel tube, and reduces the friction of the side wall of the first PE tube in the steel tube, thereby preventing the outer wall of the first PE tube from being damaged during the laying of the first PE tube. The oil lubricant is applied between the counterweight and the inner wall of the first PE tube, so that the inner wall of the PE tube is not easily damaged during the process of dragging in or out the counterweight, thereby relatively extending the service life of the PE tube, and further protecting the cable laid in the PE tube from damage.

[0071] In the second embodiment, a liquid with a volume of V4 is injected into the first PE pipe, and the end of the first PE pipe is sealed. During the process of pulling back the first PE pipe, the liquid with a volume of V4 in the PE pipe causes the first PE pipe to sink a certain distance in the liquid in the steel pipe, so that the first PE pipe is loaded on the liquid in the steel pipe, and the side wall of the first PE pipe maintains a certain distance from the top of the steel pipe.

[0072] In Example 3, a liquid weight with a volume of V5 is injected into the first PE pipe, and after calculating the weight of the liquid weight with a volume of V5, a solid weight with a weight of G5 is added, and the end of the first PE pipe is sealed. During the process of pulling back the first PE pipe, the liquid weight and the solid weight in the PE pipe together make the first PE pipe sink a certain distance in the liquid in the steel pipe, so that the first PE pipe is loaded on the liquid in the steel pipe, and the side wall of the first PE pipe maintains a certain distance from the top of the steel pipe.

[0073] In this embodiment, after the first PE pipe is laid, a weight of G2 is added to the first PE pipe, G1 < G2. The first PE pipe with the weight of G2 sinks to the bottom of the liquid in the steel pipe.

[0074] The second PE pipe is laid. A counterweight of G3 is added into the second PE pipe, with G3 < G2, and the end of the second PE pipe is sealed.

[0075] During the process of pulling back the second PE pipe, the counterweight with a weight of G3 in the second PE pipe makes the second PE pipe sink a certain distance in the liquid in the steel pipe, so that the second PE pipe floats on the liquid in the steel pipe, and the side wall of the second PE pipe maintains a certain distance from the top of the steel pipe, and the side wall of the second PE pipe maintains a certain distance from the side wall of the first PE pipe.

[0076] Repeat the above steps until all PE pipes are laid, and then remove all the weights in the PE pipes.

[0077] It should be noted that the counterweight in this embodiment is a solid counterweight. During the PE pipe laying process, the first PE pipe that has been pulled back into the guide hole is easy to be entangled with the second PE pipe that is being pulled back. Therefore, a counterweight with a weight of G2 is dragged into the first PE pipe, and the first PE pipe is allowed to sink to the bottom of the liquid in the steel pipe, thereby maintaining a certain distance from the second PE pipe floating in the liquid in the steel pipe. In addition, a counterweight with a weight of G3 is dragged into the second PE pipe, so that the second PE pipe sinks a certain distance in the liquid in the steel pipe, so that the second PE pipe floats on the liquid in the steel pipe, and maintains a certain distance from the top of the steel pipe and the first PE pipe, thereby reducing the friction between the second PE pipe and the steel pipe while preventing entanglement with the first PE pipe, further reducing the difficulty of PE pipe laying. In addition, G1<G3<G2, the height space inside the steel pipe decreases as the number of PE pipes laid increases. Therefore, the counterweight required for laying the first PE pipe is smaller than the counterweight required for laying the second PE pipe, which increases the distance that the PE pipe sinks in the liquid inside the steel pipe, further preventing the PE pipe from rubbing against the upper wall inside the steel pipe due to too small counterweight.

[0078] In Example 4, a liquid weight with a volume of V4 is injected into the first PE pipe, and the end of the first PE pipe is sealed, so that the first PE pipe sinks to the bottom of the liquid in the steel pipe. A solid weight with a weight of G3 is dragged into the second steel pipe. When all PE pipes are laid, the first PE pipe is pulled out and a liquid weight with a volume of V4 is injected, and the first PE pipe is dried. The liquid injected into the first PE pipe is used to prevent the counterweight required for the sinking of the first PE pipe from being too large, thereby causing the counterweight to damage the inner wall of the first PE pipe during the process of dragging in or out. A solid weight of G3 is added to the second PE pipe to add a weight of G3. During the process of pulling back the second PE pipe, the solid weight of G3 in the PE pipe makes the second PE pipe sink a certain distance in the liquid in the steel pipe, so that the second PE pipe floats on the liquid in the steel pipe, and the side wall of the second PE pipe keeps a certain distance from the top of the steel pipe, and the side wall of the second PE pipe keeps a certain distance from the side wall of the first PE pipe. When all PE pipes are laid, all the weights in the PE pipes are removed.

[0079] In the fifth embodiment, this method can be used to lay multiple PE pipes in one steel pipe. During the laying of the PE pipes, the weight can be added by injecting liquid into the PE pipes to control the distance between the multiple PE pipes.

[0080] In this embodiment, after adding a solid weight of G2 into the first PE pipe, a liquid weight of V3 is added into the steel pipe, and V3<V1, and then the second PE pipe is pulled back.

[0081] It should be noted that during the laying of the PE pipe, the liquid in the steel pipe will be lost. When the amount of liquid in the steel pipe decreases, the surface of the PE pipe in contact with the liquid or the volume of the water displaced will decrease, which will affect the buoyancy of the PE pipe. Therefore, when the amount of liquid in the steel pipe decreases, it is necessary to add a liquid weight with a volume of V3 to the steel pipe and ensure that the friction of the PE pipe is reduced during the laying process, so that the side wall of the PE pipe is not damaged as much as possible.

[0082] Furthermore, a miniature waterproof camera is installed at one end of the PE pipe that is pulled back into the steel pipe.

[0083] The miniature waterproof camera uploads the images during the towing process to the display outside the guide hole.

[0084] The amount of liquid added to the steel pipe is further controlled during the backhaul process according to the content on the display.

[0085] It should be noted that an LED fill light is installed on the PE tube near the miniature waterproof camera.

[0086] The miniature waterproof camera records the images in the guide hole and uploads them to the display outside the guide hole. The construction personnel can understand the liquid height and working environment in the steel pipe by observing and analyzing the images on the display, and further determine the extraction or replenishment of the liquid in the steel pipe. In addition, the miniature waterproof camera is used to shoot and monitor the inner wall of the steel pipe that has been pulled back into the guide hole.

[0087] In this embodiment, after a volume of liquid V1 is injected into the steel pipe, the height of the liquid in the steel pipe and the height required for the PE pipe to float in the liquid during the back-pulling process are calculated, thereby obtaining the numerical range of the liquid replenishment amount V3 in the steel pipe.

[0088] The required height is the height that creates a distance from both the upper wall of the steel pipe and the height that creates a distance from the PE pipe filled with liquid.

[0089] It should be noted that the numerical range of the amount V3 of liquid that needs to be replenished or extracted from the steel pipe is obtained by calculating the height of the liquid in the steel pipe based on the volume of liquid that has been injected into the steel pipe.

[0090] In the sixth embodiment, the pages in the steel pipe are observed by a miniature waterproof camera, and the volume of liquid required in the steel pipe is calculated, and the required amount of liquid is injected into the steel pipe.

[0091] In this embodiment, step one includes preparing mud with 0.03% to 0.1% of a horizontal directional drilling carrier SDX and 0.05% to 0.3% of a horizontal directional drilling viscosity increasing and fluid loss reducing agent SDJ.

[0092] It should be noted that due to the long crossing distance and time, the probability of drill pipe torque, separation and tension increase increases, so it is necessary to increase the lubricity of mud and its long-distance fluidity and portability. Therefore, horizontal directional drilling carrier SDX and horizontal directional drilling viscosity increasing and fluid loss reducing agent SDJ are selected, among which SDX has good floating shear ability and SDJ has good wall building and plugging ability.

[0093] In this embodiment, the mud is prepared to contain 0.1% of the horizontal directional drilling carrier agent SDX and 0.3% of the horizontal directional drilling viscosity increasing fluid loss reducing agent SDJ.

[0094] It should be noted that, as shown in Table 1, according to the experimental results, the effect of preparing mud with 0.1% of horizontal directional drilling carrier SDX and 0.3% of horizontal directional drilling viscosity increasing fluid loss reducing agent SDJ is relatively obvious.

[0095] Table 1

[0096]

[0097] In this embodiment, during the process of pulling the steel pipe with the sealed end back into the guide hole, a drilling rig is used to pull the steel pipe back, and whether the pulling back of the steel pipe is normal is determined by the torque force.

[0098] When the torque exceeds the preset range, the steel pipe is pulled out from the other end.

[0099] When the torque is within the preset range, the drilling rig continues to pull back the steel pipe.

[0100] It should be noted that the drilling rig improves the pulling efficiency and reduces the deformation of the pipe during the pulling process. The torque force is used to judge whether the pulling of the steel pipe is normal. Specifically, if the torque of the drilling rig increases continuously and has no downward trend in a short period of time during the pulling process, the pulling is stopped immediately, and the pulling is restarted through torque force analysis and calculation.

[0101] In this embodiment, it is obvious to those skilled in the art that the present invention is not limited to the details of the above exemplary embodiments, and that the present invention can be implemented in other specific forms without departing from the spirit or essential features of the present invention. Therefore, no matter from which point of view, the embodiments should be regarded as exemplary and non-restrictive, and the scope of the present invention is defined by the appended claims rather than the above description, and therefore it is intended that all changes falling within the meaning and scope of the equivalent elements of the claims are included in the present invention.

Claims

1. A cable laying method, characterized in that: The following steps are included: Step 1: Preparation before construction; Measure and lay out according to the design plan; weld steel pipes and weld PE pipes; test equipment; prepare mud; Step 2: guide hole construction; Drilling a hole using a drilling tool according to the measured data, and expanding the hole to the required diameter using an expanding tool; The prepared mud is injected into the guide hole to protect the inner wall of the guide hole, and part of the mud is gathered at the bottom of the guide hole; Step 3: Pipeline installation; The steel pipe with the blocked end is pulled back into the guide hole, and the mud gathered at the bottom of the guide hole during the pulling back of the steel pipe reduces the friction generated during the pulling back of the steel pipe; After the steel pipe is laid, a liquid with a volume of V1 is injected into the steel pipe; The PE pipe with sealed ends is pulled back into the steel pipe. During the pulling back process, the PE pipe in the middle of the steel pipe is in contact with the liquid in the steel pipe. The PE pipe in the middle of the steel pipe floats on the liquid surface, which reduces the friction generated by the PE pipe during the pulling back process. Drag the PE pipe back to the preset position; The method also includes adding a weight of G1 into the first PE pipe and plugging and sealing the end of the first PE pipe; During the process of pulling back the first PE pipe, the counterweight with a weight of G1 in the first PE pipe makes the first PE pipe sink a certain distance in the liquid in the steel pipe, so that the first PE pipe floats on the liquid in the steel pipe, and the side wall of the first PE pipe maintains a certain distance from the top of the steel pipe; When the first PE pipe is laid, take out the weight G1 from the first PE pipe; When the first PE pipe is laid, a weight of G2 is added to the first PE pipe, G1<G2; the first PE pipe with the weight of G2 sinks to the bottom of the liquid in the steel pipe; Laying the second PE pipe; adding a weight of G3 into the second PE pipe, where G3 is less than G2, and sealing the end of the second PE pipe; During the process of pulling back the second PE pipe, the counterweight G3 in the second PE pipe makes the second PE pipe sink a certain distance in the liquid in the steel pipe, so that the second PE pipe floats on the liquid in the steel pipe, and the side wall of the second PE pipe keeps a certain distance from the top of the steel pipe, and the side wall of the second PE pipe keeps a certain distance from the side wall of the first PE pipe; Repeat the above steps until all PE pipes are laid, and then remove all the weights in the PE pipes; Step 4: Cable laying; The cable is pulled back into the PE pipe through the pulling rope inside the PE pipe.

2. The cable laying method according to claim 1, characterized in that: Step three includes injecting a volume of liquid V2 into the steel pipe before the steel pipe is pulled back, and plugging the end of the steel pipe; During the process of pulling the steel pipe back, the liquid in the steel pipe causes the steel pipe to sink a certain distance in the mud gathered at the bottom of the guide hole, so that the steel pipe floats on the mud gathered at the bottom of the guide hole, and the side wall of the steel pipe maintains a certain distance from the top of the guide hole.

3. The cable laying method according to claim 1, characterized in that: After adding a counterweight of G2 into the first PE pipe, a liquid of V3 in volume is added into the steel pipe, and V3 < V1, and then the second PE pipe is pulled back.

4. The cable laying method according to claim 3, characterized in that: A miniature waterproof camera is installed on the end of the PE pipe that is pulled back into the steel pipe; The miniature waterproof camera uploads the images during the towing process to the display outside the guide hole; The amount of liquid added to the steel pipe is further controlled during the backhaul process according to the content on the display.

5. The cable laying method according to claim 4, characterized in that: Step three includes injecting a volume of liquid V1 into the steel pipe, and calculating the height of the liquid in the steel pipe and the height required for the PE pipe to float in the liquid during the backhaul process, thereby obtaining a numerical range of the liquid replenishment amount V3 in the steel pipe; The required height is the height that creates a distance from both the upper wall of the steel pipe and the height that creates a distance from the PE pipe filled with liquid.

6. The cable laying method according to claim 1, characterized in that: Step one includes preparing mud with 0.03% to 0.1% of a horizontal directional drilling carrier SDX and 0.05% to 0.3% of a horizontal directional drilling viscosity increasing and fluid loss reducing agent SDJ.

7. The cable laying method according to claim 6, characterized in that: The prepared mud contains 0.1% of the horizontal directional drilling carrier SDX and 0.3% of the horizontal directional drilling viscosity increasing and fluid loss reducing agent SDJ.

8. The cable laying method according to claim 1, characterized in that: Step three includes, in the process of pulling the steel pipe with the blocked end back into the guide hole, using a drilling rig to pull the steel pipe back, and judging whether the pulling back of the steel pipe is normal by the torque force; When the torque exceeds the preset range, the steel pipe is pulled out from the other end; When the torque is within the preset range, the drilling rig continues to pull back the steel pipe.

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