Method for down-hole directional long hole hydraulic fracturing casing running

Abstract

The invention relates to the technical field of coal mining, and provides a method for hydraulic fracturing casing running of an underground directional long hole, which comprises the following steps of: cleaning the hole wall of a drill hole to ensure that the surface of the drill hole is clean; an inlet of the drill hole is determined, and subsequent casing pipe filling work is prepared; the interior of the drill hole is filled with a hot melting guide pipe till the bottom of the drill hole is filled with the hot melting guide pipe; the hot melting guide pipe is cured and formed, and a layer of sleeve supporting the hole wall is formed in the drill hole; the drilling hole is filled with the hot melting guide pipe in the underground drilling hole, the purpose of generating the casing pipe in the underground drilling hole is achieved, the hole wall can be effectively supported, the continuity and stability of the drilling hole are ensured, the success rate and efficiency of casing pipe running in the hydraulic fracturing drilling hole are improved, the risk and cost of hydraulic fracturing operation are reduced, and the production efficiency is improved. According to the hydraulic fracturing device, smooth fracturing operation is guaranteed, fracturing fluid can be accurately injected into a target stratum by forming a stable fracturing channel, and the directionality and the high efficiency of the hydraulic fracturing technology are improved.

Description

Technical Field

[0001] The invention relates to the technical field of coal mining, and in particular to a method for placing casing in underground directional long-hole hydraulic fracturing. Background Art

[0002] The application of hydraulic fracturing technology in the field of coal mining can be divided into the following aspects: First, coalbed methane extraction. Coalbed methane or coalbed gas is natural gas embedded in coal seams. Its extraction is one of the important ways to ensure coal mine safety and comprehensive resource utilization; hydraulic fracturing technology can form a crack network in the coal seam, improve the permeability of coalbed methane, and promote the release and extraction of coalbed methane; second, coal mine roof control. In coal mining, roof stability is an important link to ensure mine safety, especially the stability of thick and hard roof coal seams has an important impact on mine safety. Hydraulic fracturing technology can be used to weaken the roof, reduce its stability, make it more prone to collapse, and reduce the pressure on the mine; third, mine pressure control. In the process of coal mining, mine pressure is a common challenge , especially in the mining of thick and hard roof coal seams; hydraulic fracturing technology can slow down the release rate of mine pressure by weakening the coal rock mass, reduce the lateral support pressure of the surrounding rock by weakening the suspended roof through fracturing, improve the stress environment of the goaf area, and improve the stability of the goaf area, providing an important guarantee for the safe production of the mine; fourth, gas extraction. Coal mine gas is a dangerous flammable gas, and its extraction is crucial to mine safety. Hydraulic fracturing technology can improve the permeability of coal seams, increase the release rate and extraction efficiency of gas; fifth, mine geological disaster prevention and control. Hydraulic fracturing technology can also be used to prevent and control mine geological disasters, such as coal and gas outbursts, coal and gas explosions, etc., by changing the mechanical properties and permeability of coal rock mass, reducing the harm of geological disasters. In general, the application of hydraulic fracturing technology in the field of coal mines provides new technical means and ideas for improving coal mine safety, resource development and utilization, and environmental protection.

[0003] As the scale of underground coal mine rock transformation becomes larger and larger, the fracturing displacement and pressure increase accordingly, and the requirements for drilling depth, directional drilling construction, etc. are increased. In addition, when the target rock formation is dense and hard, traditional hydraulic fracturing technology may not be able to achieve the expected fracturing effect. In order to overcome this problem, some special technical means such as adding casing are needed to achieve directional and easy fracturing effects. The installation of traditional hydraulic fracturing drilling casing has the following problems: First, when there are many layers, when the hydraulic fracturing drilling needs to pass through multiple strata, the interface between the strata is unstable, which can easily lead to the collapse of the borehole or waste of the borehole; second, when the borehole is long, during the long hole drilling process, due to changes in the strata or the characteristics of the borehole itself, the borehole is prone to collapse.

[0004] Therefore, how to provide a method for casing installation suitable for downhole directional long hole drilling is a problem that technical personnel in this field need to solve urgently. Summary of the invention

[0005] The invention provides a method for inserting casing for downhole directional long hole hydraulic fracturing, which is used to solve the problem of easy hole collapse in hydraulic fracturing drilling in the prior art.

[0006] The present invention provides a method for casing downhole directional long hole hydraulic fracturing, comprising: Clean the hole wall to ensure the hole surface is clean; Determine the entrance of the borehole and prepare for subsequent casing filling work; Use hot melt conduit to fill the inside of the drill hole until the hot melt conduit fills to the bottom of the drill hole; The hot melt conduit solidifies and forms a casing in the drilled hole that supports the hole wall.

[0007] According to the method for downhole directional long hole hydraulic fracturing casing provided by the present invention, the use of hot melt conduit to fill the inside of the borehole comprises: Using a heating device to heat the hot melt conduit to above its softening point, so that it becomes flowable; Pneumatic pushing equipment is used to fill the heated hot melt conduit from the inlet into the borehole by means of pressurization until the hot melt conduit is filled to the bottom of the borehole.

[0008] According to the method for downhole directional long hole hydraulic fracturing casing provided by the present invention, the hole wall of the borehole is cleaned to ensure that the surface of the borehole is clean, which includes: Determine drilling parameters based on coal seam geological conditions and hydraulic fracturing requirements; Determine the drilling path and drilling area based on the formation conditions, downhole equipment and operating conditions.

[0009] The method for downhole directional long hole hydraulic fracturing casing provided by the present invention also includes: Directional drilling equipment is used to carry out directional drilling based on the determined drilling path to ensure that the target coal seam can be accurately penetrated and the predetermined hydraulic fracturing position can be reached.

[0010] According to the method for downhole directional long hole hydraulic fracturing casing provided by the present invention, the directional drilling is performed, and then the method comprises: Comprehensive mine information is used to monitor and evaluate the drilling in real time to ensure that the drilling quality, hole wall stability and inclination deviation meet the design requirements.

[0011] The method for downhole directional long hole hydraulic fracturing casing provided by the present invention also includes: Based on the assessment results, coal seam geological conditions, fracturing objectives and fracturing effect requirements, a fracturing design plan is formulated to ensure that the fracturing fluid formula, injection pressure and injection rate achieve the expected fracturing effect.

[0012] According to the method for downhole directional long hole hydraulic fracturing casing provided by the present invention, the hot melt pipe is solidified and formed to form a layer of casing supporting the hole wall in the borehole, and then includes: performing hydraulic fracturing, and after the hydraulic fracturing is completed, sealing and anti-seepage treatment of the wellhead.

[0013] According to the method for downhole directional long hole hydraulic fracturing casing provided by the present invention, the hydraulic fracturing further comprises: Use monitoring equipment to monitor and record fracturing parameters in real time during the fracturing process; Analyze the monitored data and evaluate the current fracturing effect; Adjust the fracturing parameters in time according to the analysis results to achieve the expected fracturing effect.

[0014] The method for downhole directional long hole hydraulic fracturing casing provided by the present invention further comprises: during the drilling process, when the rock formation is a dense rock formation, using a cutting technique to cut a predetermined crack in the rock.

[0015] The method for downhole directional long hole hydraulic fracturing casing provided by the present invention also includes: using directional perforating technology to drill directional holes in the wellbore so that the hydraulic fracturing fluid can be accurately injected into the target area.

[0016] The present invention provides a method for inserting casing for downhole directional long-hole hydraulic fracturing. The method uses a hot-melt conduit to fill the borehole inside the downhole borehole to form a layer of casing to support the borehole wall, thereby achieving the purpose of forming casing inside the downhole borehole. Through this scheme, on the one hand, it can effectively support the hole wall and prevent the hole wall from collapsing, ensure the continuity and stability of the borehole, improve the success rate and efficiency of hydraulic fracturing borehole casing, provide support and stabilize the hole wall, thereby preventing the occurrence of borehole collapse, reducing the occurrence of waste holes, and reducing the risk and cost of hydraulic fracturing operations; on the other hand, the addition of casing can provide additional support for the borehole wall, forming a stable hole wall composite structure, which can effectively resist the formation Pressure and deformation reduce the risk of borehole collapse and improve the stability and safety of downhole drilling; on the other hand, it can form a downhole fracturing channel. The addition of casing can effectively form a downhole fracturing channel, thereby providing a good channel for hydraulic fracturing operations, so that the fracturing fluid can be effectively injected into the target formation to maximize the fracturing effect; in addition, it can effectively seal the space around the borehole to prevent the leakage of the fracturing fluid, reduce the leakage and non-pressure maintenance caused by the borehole itself, and ensure the smooth progress of the fracturing operation. By forming a stable fracturing channel, the fracturing fluid can be accurately injected into the target formation, achieving the maximum fracturing effect, thereby improving the directionality and efficiency of hydraulic fracturing technology. This method of casing in downhole boreholes can be applied to different types of hydraulic fracturing operations, with a wide range of applications, and can effectively solve the common and difficult problems in downhole hydraulic fracturing operations. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0018] Figure 1 The present invention is a flowchart of a method for casing installation in downhole directional long hole hydraulic fracturing provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0019] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the drawings 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.

[0020] Combine the following Figure 1The present invention describes a method for casing downhole directional long hole hydraulic fracturing.

[0021] Figure 1 is a flow chart of a method for downhole directional long hole hydraulic fracturing casing provided by an embodiment of the present invention, such as Figure 1 As shown, the method includes: Step 101: Clean the borehole wall to ensure that the borehole surface is clean; that is, by thoroughly cleaning the debris and other obstacles in the borehole, ensure that the hole wall is clean and smooth so that the hot melt conduit can better adhere and can smoothly reach the bottom of the borehole from the entrance.

[0022] Step 102: Determine the entrance of the borehole and prepare for the subsequent casing filling work. The casing filling work may include determining the material and process of the hot melt casing. The process includes lowering the casing and pressurizing the filling to ensure that the casing can be stably filled into the borehole. Among them, the hot melt conduit material can be thermoplastic plastics such as polyethylene (PE), polypropylene (PP), and polyvinyl chloride (PVC). These materials have good processing properties and good resistance to a variety of chemicals. They are not easily corroded by substances such as acids, alkalis, and salt solutions. Compared with some traditional solvent-based materials, hot melt conduits do not contain volatile organic compounds (VOCs), which reduces pollution to the environment and meets modern environmental protection requirements. Choose a suitable heating method to ensure that the hot melt casing can be fully softened and filled into the borehole. Common heating methods include electric heating, infrared heating, etc. The heating temperature should be adjusted according to the melting point of the casing material to ensure that it softens at an appropriate temperature but does not overheat and decompose. During the filling process, use pressurizing equipment (such as high-pressure pumps, pneumatic systems, etc.) to apply a certain pressure to the casing to ensure that it can fit closely to the borehole wall to form a good sealing effect.

[0023] Step 103: Use the hot melt conduit to fill the inside of the drill hole until the hot melt conduit fills to the bottom of the drill hole.

[0024] Step 104: The hot melt conduit is solidified and formed into a casing in the drilled hole to support the hole wall.

[0025] In this embodiment, step 104 includes: performing hydraulic fracturing, and after the hydraulic fracturing is completed, sealing and waterproofing the wellhead to prevent fracturing fluid or other fluids from leaking from the wellhead, and preventing groundwater or other fluids from penetrating into the wellbore, thereby protecting the integrity of the wellbore.

[0026] Furthermore, the hydraulic fracturing also includes: using monitoring equipment to monitor and record the fracturing parameters in real time during the fracturing process; analyzing the monitored data to evaluate the current fracturing effect; Adjust the fracturing parameters in time according to the analysis results to achieve the expected fracturing effect.

[0027] With such a setting, through real-time monitoring and parameter adjustment, it can be ensured that the fracturing fluid can be evenly distributed throughout the coal seam, forming an ideal fracture network and improving the efficiency of fracture expansion. Through real-time monitoring and dynamic adjustment, potential safety hazards can be discovered and dealt with in a timely manner, reducing the occurrence of construction accidents and ensuring the safety of construction personnel.

[0028] It can be seen from the above scheme that the present invention uses a hot melt conduit to fill the borehole inside the downhole borehole to form a layer of casing to support the borehole wall, thereby achieving the purpose of forming the casing inside the downhole borehole. Through this solution, on the one hand, it can effectively support the hole wall, prevent the hole wall from collapsing, ensure the continuity and stability of the borehole, improve the success rate and efficiency of casing in hydraulic fracturing drilling, provide support and stabilize the hole wall, thereby preventing the occurrence of hole collapse, reducing the occurrence of waste holes, and reducing the risk and cost of hydraulic fracturing operations; on the other hand, the addition of casing can provide additional support for the hole wall, forming a stable hole wall composite structure, which can effectively resist the pressure and deformation of the formation, reduce the risk of hole collapse, and improve the stability and safety of downhole drilling; on the other hand, it can Forming a downhole fracturing channel, the addition of casing can effectively form a downhole fracturing channel, thereby providing a good channel for hydraulic fracturing operations, so that the fracturing fluid can be effectively injected into the target formation to maximize the fracturing effect; in addition, it can effectively seal the space around the borehole to prevent the leakage of the fracturing fluid, reduce the leakage and non-pressure maintenance caused by the borehole itself, and ensure the smooth progress of the fracturing operation. By forming a stable fracturing channel, the fracturing fluid can be accurately injected into the target formation, achieving the maximum fracturing effect, thereby improving the directionality and efficiency of the hydraulic fracturing technology. This method of casing in a downhole borehole can be applied to different types of hydraulic fracturing operations, with a wide range of applications, and can effectively solve the common and difficult problems in downhole hydraulic fracturing operations.

[0029] In this embodiment, the use of hot melt conduit to fill the interior of the borehole in step 103 includes: using a heating device to heat the hot melt conduit to above its softening point to make it flowable; and using a pneumatic pushing device to fill the heated hot melt conduit from the entrance into the interior of the borehole by means of pressurization until the hot melt conduit is filled to the bottom of the borehole.

[0030] Among them, the heating equipment can be an electric heating equipment, which generates heat through a resistance wire or a heating element to directly heat the hot melt conduit so that the hot melt conduit reaches an appropriate temperature, and then it is slowly and steadily sent into the borehole through a pneumatic pushing device until it is filled to a predetermined position (usually the bottom of the borehole). During the entire filling process, an appropriate filling pressure is maintained to ensure that the hot melt conduit can evenly fill the entire space and is in close contact with the hole wall; once the hot melt conduit is filled in place, the material of the hot melt conduit is quickly hardened and a stable structure is formed through forced cooling such as air cooling and water cooling. The cooled hot melt conduit usually has a higher hardness and pressure resistance, can effectively support the pressure of the surrounding environment of the borehole, and maintain the shape of the borehole.

[0031] In a further embodiment, step 101 includes step 100: determining drilling parameters according to coal seam geological conditions and hydraulic fracturing requirements; and determining the drilling path and drilling area according to formation conditions, downhole equipment and operating conditions.

[0032] Among them, the drilling parameters include the diameter, length, inclination and other parameters of the borehole. A reasonable diameter can accommodate more fracturing fluid and proppant, a longer borehole can cover a larger area, and a reasonable inclination can make the borehole fit the coal seam better, reduce deviation, and improve the fracturing effect.

[0033] Such settings ensure that the borehole can effectively reach the target coal seam and provide the best physical channel for hydraulic fracturing; by reasonably selecting drilling parameters, the starting pressure can be reduced, the efficiency of crack expansion can be increased, and thus the resource recovery rate can be improved; choosing appropriate drilling paths and areas can avoid crossing unstable formations or obstacles and reduce safety hazards during construction. According to the capabilities of existing downhole equipment (such as drilling rig power, conveying system, etc.), choose a suitable drilling path to ensure that the equipment can work normally. Reasonable path planning can shorten construction time, reduce equipment load, and improve overall construction efficiency.

[0034] Furthermore, between step 100 and step 101, the process also includes: using directional drilling equipment to perform directional drilling based on the determined drilling path to ensure that the target coal seam can be accurately penetrated and a predetermined hydraulic fracturing position can be reached.

[0035] Such a setting can ensure that the borehole can accurately pass through the target coal seam, thereby improving the success rate of hydraulic fracturing. Through precise path planning and real-time adjustment, the borehole can smoothly reach the predetermined fracturing position, ensuring that the fracturing fluid can be effectively injected into the target area, forming an ideal crack and improving the efficiency of crack expansion.

[0036] In some embodiments, during the drilling process, when the rock formation is a dense rock formation, a cutting technique is used to cut a predetermined crack in the rock. In this way, since it may be difficult for traditional drilling and fracturing methods to form sufficient cracks or channels in a dense rock formation, the cutting technique can be used to pre-create a predetermined crack or channel in the rock, providing an "entrance" for subsequent hydraulic fracturing. The cut cracks can be used as a channel for the fracturing fluid to enter the rock formation, reducing the initial pressure required for hydraulic fracturing, reducing energy consumption and equipment load, and improving fracturing efficiency.

[0037] Furthermore, it also includes: using directional perforating technology to drill directional holes in the wellbore so that the hydraulic fracturing fluid can be accurately injected into the target area. Specifically, a directional perforating gun can be used to accurately punch small holes on the wellbore wall according to the pre-designed path and angle. The perforating gun is usually equipped with GPS positioning systems, gyroscopes, magnetic locators and other sensors, which can monitor the position and angle of the perforation in real time to ensure accuracy. The perforating gun can be lowered into the wellbore through a cable or oil pipe, and after reaching the predetermined depth, perforation is performed according to the design requirements. In order to achieve directional perforation, guide tools (such as elbows, stabilizers, etc.) are usually installed on the perforating gun to control the posture and direction of the perforating gun. These tools can be adjusted in real time through the ground control system to ensure that the perforating gun moves along the predetermined path.

[0038] With this setup, directional perforation technology can drill directional holes in the wellbore, allowing the fracturing fluid to be precisely injected into the target area, avoiding unnecessary diffusion, and improving the efficiency of fracture formation. By controlling the direction and position of the perforations, the fractures can be evenly distributed in the network, which can optimize the fracture network, improve the success rate of fracturing, reduce costs, and protect the environment.

[0039] In this embodiment, directional drilling is carried out, followed by: comprehensive mine information, real-time monitoring and evaluation of the borehole to ensure that the borehole quality, hole wall stability and inclination deviation meet the design requirements, wherein the comprehensive mine information may include tunnel structure, spatial layout, overburden characteristics, geological structure and support, etc.

[0040] That is to say, during the drilling process, mid-course measurements (such as logging, imaging, etc.) are carried out regularly. These data can be obtained through geological radar, core drilling, etc. to verify whether the borehole is advancing along the predetermined path. If deviations are found, the drilling parameters are adjusted in time. Based on the mid-course measurement results, the subsequent drilling path is optimized to ensure that the borehole can smoothly reach the predetermined hydraulic fracturing position. If necessary, the angle of the drill bit can be adjusted or part of the path can be replanned.

[0041] Optionally, during the drilling process, a logging while drilling system is used to monitor the drill bit's position, depth, inclination, pressure and other parameters in real time. These data can help operators adjust the direction and angle of the drill bit in a timely manner to ensure that the drilling proceeds along the predetermined path. Acoustic sensors can be used to monitor the integrity of the hole wall and detect whether there are cracks or looseness. Acoustic sensors can provide high-resolution hole wall images to help evaluate the stability of the hole wall.

[0042] The data collected by the monitoring equipment is transmitted to the ground control center in real time through a wireless or wired network. The data transmission should be highly reliable to ensure that there is no data loss or delay. The collected data is analyzed and processed at the ground control center. Through data visualization technology, the various parameters of the drilling can be displayed intuitively to help operators make decisions quickly.

[0043] Based on the monitoring data, the drilling parameters are adjusted in real time to ensure that the drilling quality meets the design requirements.

[0044] Optionally, the integrity and stability of the borehole wall can be evaluated through acoustic imaging, video monitoring and other means, and the inclination and azimuth of the borehole can be accurately measured by using equipment such as gyroscopes and magnetic positioning to ensure that it meets the design requirements.

[0045] Preferably, after the drilling is completed, a comprehensive end-hole measurement is performed to confirm whether the borehole has accurately passed through the target coal seam and reached the predetermined fracturing position. The end-hole measurement should include parameters such as the diameter, length, inclination, and offset of the borehole.

[0046] In some embodiments, it also includes: formulating a fracturing design plan based on the evaluation results, coal seam geological conditions, fracturing objectives and fracturing effect requirements to ensure that the fracturing fluid formula, injection pressure and injection speed achieve the expected fracturing effect.

[0047] Specifically, based on the final hole measurement and hole wall stability assessment results of the borehole, confirm whether the borehole meets the design requirements and whether there are potential risk points (such as cracks, looseness, etc.). If problems are found, timely remedial measures such as casing are taken to ensure the integrity and stability of the borehole; by combining the geological conditions of the coal seam such as coal seam thickness, strike, inclination, crack development, stratum lithology, etc., analyze the physical and mechanical properties of the formation to determine its impact on the fracturing effect; and select appropriate fracturing fluid according to the geological conditions and fracturing targets of the coal seam; determine the appropriate injection pressure according to the compressive strength and crack development of the coal seam to break through the natural cracks of the coal seam, while avoiding unnecessary equipment load or formation damage, and the maximum injection pressure should be lower than the fracture pressure of the coal seam to avoid excessive fracturing leading to formation instability or cracks extending to non-target areas; set an appropriate injection speed according to the permeability and fracturing targets of the coal seam to ensure that the fracturing fluid can quickly enter the coal seam and avoid crack closure or fluid loss due to too fast injection.

[0048] With such settings, through reasonable fracturing fluid formulation and injection parameters, an ideal fracture network can be formed, ensuring that the fracturing fluid can be evenly distributed throughout the coal seam, improving the efficiency of fracture expansion, and through reasonable injection pressure and speed settings, excessive equipment load can be avoided, extending the service life of the equipment and reducing maintenance costs.

[0049] The present invention combines directional drilling, hydraulic fracturing technology and adding casing in the borehole to establish a coal mine hydraulic fracturing directional drilling casing technology. This method can improve the efficiency and success rate of hydraulic fracturing operations, thereby further improving the effect of hydraulic fracturing. The specific effects are as follows: 1. Adding casing during the drilling process can effectively support the hole wall, prevent the hole wall from collapsing, ensure the continuity and stability of the drilling, and thus improve the drilling rate.

[0050] 2. The addition of casing can provide additional support for the borehole wall, forming a stable combined structure of the borehole wall, effectively resisting the pressure and deformation of the formation, reducing the risk of borehole collapse, and improving the stability and safety of downhole drilling.

[0051] 3. By forming a casing in the borehole, a downhole fracturing channel can be effectively formed. This fracturing channel can provide a good channel for hydraulic fracturing operations, so that the fracturing fluid can be effectively injected into the target formation, thereby maximizing the fracturing effect.

[0052] 4. The addition of casing can effectively seal the space around the borehole, prevent the leakage of fracturing fluid, effectively reduce the leakage and non-pressure maintenance caused by the borehole itself, and ensure the smooth progress of the fracturing operation.

[0053] 5. By forming a stable fracturing channel, the fracturing fluid can be accurately injected into the target formation, maximizing the fracturing effect, thereby improving the directionality and efficiency of hydraulic fracturing technology.

[0054] 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 downhole directional long hole hydraulic fracturing casing, characterized in that: include: Clean the hole wall to ensure the hole surface is clean; Determine the entrance of the borehole and prepare for subsequent casing filling work; Use hot melt conduit to fill the inside of the drill hole until the hot melt conduit fills to the bottom of the drill hole; The hot melt conduit solidifies and forms a casing in the drilled hole that supports the hole wall.

2. The method for casing installation for downhole directional long hole hydraulic fracturing according to claim 1, characterized in that: The method of filling the inside of the drill hole with a hot melt conduit comprises: Using a heating device to heat the hot melt conduit to above its softening point, so that it becomes flowable; Pneumatic pushing equipment is used to fill the heated hot melt conduit from the inlet into the borehole by means of pressurization until the hot melt conduit is filled to the bottom of the borehole.

3. The method for casing installation for downhole directional long hole hydraulic fracturing according to claim 1, characterized in that: The hole wall of the drilled hole is cleaned to ensure the surface of the drilled hole is clean, which includes: Determine drilling parameters based on coal seam geological conditions and hydraulic fracturing requirements; Determine the drilling path and drilling area based on the formation conditions, downhole equipment and operating conditions.

4. The method for casing installation for downhole directional long hole hydraulic fracturing according to claim 3, characterized in that: Also includes: Directional drilling equipment is used to carry out directional drilling based on the determined drilling path to ensure that the target coal seam can be accurately penetrated and the predetermined hydraulic fracturing position can be reached.

5. The method for casing installation for downhole directional long hole hydraulic fracturing according to claim 4, characterized in that: The directional drilling is then performed including: Comprehensive mine information is used to monitor and evaluate the drilling in real time to ensure that the drilling quality, hole wall stability and inclination deviation meet the design requirements.

6. The method for casing installation for downhole directional long hole hydraulic fracturing according to claim 5, characterized in that: Also includes: Based on the assessment results, coal seam geological conditions, fracturing objectives and fracturing effect requirements, a fracturing design plan is formulated to ensure that the fracturing fluid formula, injection pressure and injection rate achieve the expected fracturing effect.

7. The method for casing downhole directional long hole hydraulic fracturing according to claim 6, characterized in that: The hot-melt conduit is solidified and formed into a layer of casing in the borehole to support the borehole wall, followed by: hydraulic fracturing, and after the hydraulic fracturing is completed, the wellhead is sealed and anti-seepage treated.

8. The method for casing installation for downhole directional long hole hydraulic fracturing according to claim 7, characterized in that: The hydraulic fracturing further comprises: Use monitoring equipment to monitor and record fracturing parameters in real time during the fracturing process; Analyze the monitored data and evaluate the current fracturing effect; Adjust the fracturing parameters in time according to the analysis results to achieve the expected fracturing effect.

9. The method for casing installation for downhole directional long hole hydraulic fracturing according to claim 4, characterized in that: Also includes: During the drilling process, when the rock formation is a dense rock formation, a cutting technique is used to cut a predetermined crack in the rock.

10. The method for casing installation for downhole directional long hole hydraulic fracturing according to claim 9, characterized in that: Also includes: Directional perforating technology is used to drill directional holes in the wellbore so that the hydraulic fracturing fluid can be accurately injected into the target area.

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