Grouting and filling method for gangue slurry in pinniform directional drilling high-level mining subsidence area

Abstract

The invention discloses a pinniform directional drilling high-level mining subsidence area gangue slurry grouting filling method, which belongs to the technical field of slurry grouting, and comprises the following specific steps: S1, position determination: determining a grouting target layer position; a grouting position and a grouting track are determined, and a ground drilling position is selected; s2, drilling for the first time: drilling vertically downwards on the ground, inserting a surface casing, and cementing with cement; s3, drilling for the second time: continuously drilling at the well bottom of the vertical well section, inserting a well bottom technical casing, and cementing the well by cement; s31, drilling a plurality of hole sites in the side wall of the vertical well section in sequence, inserting a side wall technical casing into each hole site, and cementing the well with cement; and S4, third drilling is conducted, specifically, drilling is conducted in the bottom ends of the well bottom deflecting sections and the bottom ends of the side wall deflecting sections in sequence, production casing pipes are inserted, and grouting sections are formed. According to the high-position grouting device, stable filling of high-position grouting of the subsidence area can be conveniently achieved, and the filling effect of high-position grouting is guaranteed.

Description

Technical Field

[0001] The invention relates to the field of slurry grouting, in particular to a method for grouting and filling waste rock slurry in a feather-shaped directional drilling high-position goaf collapse area. Background Art

[0002] Underground coal mining inevitably triggers the subsidence and displacement of overlying rock strata. Further development of these geological changes can lead to a series of environmental problems, including water inrush, sand bursts, and surface collapse. Surface subsidence is particularly prominent among these problems, not only causing damage to farmland and buildings, but also leading to serious ecological and environmental issues such as soil erosion and desertification. Among current technical solutions, techniques such as high-level surface grouting and underground adjacent grouting, which can be implemented without interfering with normal underground mining operations, have become important remediation measures that have attracted considerable attention in the industry.

[0003] When faced with areas with thick coal seams, such as the mineable coal seam area in southern Ordos, the mineable coal seams are approximately 10 to 20 meters thick. During mining, the ground collapses and deforms rapidly, and the deformation lasts for a long time. Drilling platforms and grouting stations cannot be deployed within the collapse and deformation areas. At the same time, the amount of coal gangue produced is large, and the external discharge pressure is high. Therefore, the ortho-position coal gangue slurry grouting method is often used to dispose of the gangue. However, ortho-position grouting is carried out underground and requires grouting at an upward angle, which has poor grouting effects and the grouting volume per hole is too small, making it difficult to achieve stable grouting filling in the collapse area. Summary of the Invention

[0004] In order to facilitate the stable filling of high-position grouting in the subsidence area and ensure the filling effect of high-position grouting, the present application provides a method for grouting gangue slurry in high-position mined-out subsidence areas by feather-shaped directional drilling.

[0005] The present application provides a method for grouting and filling waste rock slurry in a high-position goaf subsidence area through feather-shaped directional drilling, which adopts the following technical solutions: A method for grouting and filling waste rock slurry in a high-position mined-out subsidence area with a feather-shaped directional drilling, comprising the following specific steps: S1, position determination: determining a grouting target layer; determining a grouting position and a grouting trajectory and selecting a ground drilling position, wherein the grouting position is located at the grouting target layer; S2: first drilling: drilling vertically downward on the ground and inserting a surface casing, cementing the well, and forming a vertical well section; S3: second drilling: continuing drilling at the bottom of the vertical well section and inserting a bottom well technical casing, cementing the well, and forming a bottom well deflection. S31: drilling multiple holes in the side wall of the vertical well section in sequence and inserting side wall technical casing into each hole, cementing the well to form multiple side wall deflecting sections, the lower end of each side wall deflecting section is inclined close to the grouting position; S4: three-hole drilling, drilling holes in the bottom end of each bottom well deflecting section and side wall deflecting section in sequence and inserting production casing to form a grouting section, the length direction of the grouting section is parallel to the formation, and the grouting section is located at the grouting position.

[0006] By adopting the above technical scheme, the coordination of the bottom inclination section, multiple side wall inclination sections and the grouting section facilitates the stable injection of coal gangue slurry into the required position in the coal mine, thereby facilitating the stable filling of high-position grouting in the collapse area and ensuring the filling effect of high-position grouting. At the same time, the provision of multiple side wall inclination sections facilitates the effective utilization of the straight hole section, increases the grouting volume of a single hole, reduces the grouting cost and is suitable for areas that do not have the opportunity to drill multiple straight hole sections, with strong applicability.

[0007] Optionally, a plurality of water filtering holes distributed along the length direction of the production casing are opened on the side wall of the production casing, and a cone head is fixedly connected to one end of the production casing inserted into the grouting position.

[0008] By adopting the above technical solution, the grouting slurry enters the abscission layer through the water filter hole, and the diffusion range is more uniform. The setting of the cone head facilitates the smoother insertion of the production casing into the formation where the grouting position is located.

[0009] Optionally, the end of the technical casing is fixedly connected to a float shoe, and the end of the production casing away from the cone head is fixedly connected to a horn joint, and the end of the horn joint away from the production casing is a large-aperture end.

[0010] By adopting the above technical solution, the cooperation between the trumpet joint and the float shoe plays a role in limiting the position of the production casing, making it difficult for the production casing to slip off the technical casing, which is conducive to ensuring the position stability of the production casing during grouting.

[0011] Optionally, there is an overlapping section between the technical casing and the production casing, and the length of the overlapping section is 25% to 45% of the total length of the production casing. A buffer pad is fixedly provided on the inner wall of the technical casing, and the buffer pad is located in the overlapping section area. The outer peripheral surface of the horn joint contacts the buffer pad.

[0012] By adopting the above technical solution, the provision of the buffer pad causes the production casing to be subjected to resistance when sliding in the overlap section, which is beneficial to ensuring the stability of the overlap section area.

[0013] Optionally, a reinforcement ring is fixedly connected to the inner wall of the technical casing, the reinforcement ring is located in the overlapping section, and the production casing is passed through and abuts against the inner wall of the reinforcement ring.

[0014] By adopting the above technical solution, the provision of the reinforcement ring is conducive to further ensuring the position stability of the production casing, and facilitates stable grouting of the grouting area through the production casing.

[0015] Optionally, a check mechanism is provided at the free end of the production casing away from the cone head, and the check mechanism includes a check spring, a check fixing, a check sliding member and a check sealing gasket. The check fixing member is fixedly installed on the inner wall of the production casing, and the check sliding member slides and fits with the production casing. The check spring is provided on the check fixing member and is used to apply an elastic force to the check sliding member to move in a direction away from the cone head. The check sliding member is provided with a connecting hole for connecting the end of the production casing away from the cone head and the water filter hole. The check sealing gasket is fixedly installed on the check sliding member. Under normal circumstances, the check sealing gasket is pressed against the check fixing member under the elastic force of the check spring, and the check fixing member closes the connecting hole.

[0016] By adopting the above technical solution, when grouting is carried out, the grouting slurry presses the non-return sliding member, thereby connecting the connecting hole with the water filter hole. At this time, the non-return spring is in a compressed state, and the grouting slurry is grouting the grouting position through the connecting hole and the water filter hole. When the grouting is stopped, the non-return sliding member is reset under the elastic force of the command spring, the non-return fixing member closes the connecting hole, and the non-return sealing gasket presses against the non-return fixing member to isolate the connecting hole from the water filter hole, so that the grouting slurry is not easy to flow back, which is conducive to ensuring the grouting effect.

[0017] Optionally, a plurality of the communicating holes are circumferentially distributed around the axis of the non-return sliding member, and the non-return fixing member is provided with a partition portion for separating the communicating hole and the non-return spring.

[0018] By adopting the above technical solution, the provision of multiple connecting holes makes it easy to ensure the grouting efficiency of the grouting slurry, and the partition separates the check spring in the grouting and check conditions so that the grouting slurry is less likely to affect the check spring, which is beneficial to ensuring the stability and service life of the check spring, and thus facilitates the final more stable grouting.

[0019] Optionally, the horn joint has a joint connection portion, one end of the production casing is threadedly connected to the joint connection portion, the end of the cone head facing the production casing has a cone head connection portion, the cone head connection portion is threadedly connected to the end of the production casing away from the horn joint, and the joint connection portion and the cone head connection portion are both provided with a connecting sealing gasket to tighten the production casing.

[0020] By adopting the above technical solution, the separate setting of the trumpet joint, production casing and cone head enables each component to be produced separately, reducing processing costs. The setting of the connecting sealing gasket facilitates ensuring the transportation stability of the grouting slurry in the production casing, and by connecting the cone head connection part to different positions of the production casing, it is convenient to seal different water filter holes, thereby facilitating the adjustment of the grouting length according to different terrains, and has strong applicability.

[0021] Optionally, a method for grouting gangue slurry in a high-position mined-out subsidence area with feather-shaped directional drilling can also include the following specific steps: S1, position determination: determining the grouting target layer; determining the grouting position and grouting trajectory and selecting the ground drilling position, wherein the grouting position is located at the grouting target layer; S2: first drilling: drilling vertically downward on the ground and inserting the surface casing, cementing the well, and forming a vertical well section; S3: second drilling: continuing to drill at the bottom of the vertical well section and inserting the bottom hole technical casing, cementing the well , forming a bottom hole inclination section, the lower end of the bottom hole inclination section is inclined close to the grouting position; S4: three drillings, drilling at the bottom end of the bottom hole inclination section and inserting a bottom hole production casing to form a bottom hole grouting section, the length direction of the bottom hole grouting section is parallel to the formation, and the bottom hole grouting section is located at the grouting position; S41, drilling multiple holes in the side wall of the bottom hole inclination section in sequence and inserting a side wall production casing into each hole position to form multiple side wall grouting sections, each of the side wall grouting sections is located at the grouting position.

[0022] By adopting the above technical scheme, the coordination of the bottom-hole deflection section, the bottom-hole grouting section and multiple side-wall grouting sections facilitates the stable injection of coal gangue slurry to the required position in the coal mine, thereby facilitating the effective guarantee of the gangue disposal volume. At the same time, the provision of multiple side-wall grouting sections facilitates the effective utilization of the bottom-hole deflection section, increases the single-hole grouting volume, reduces the grouting cost and is suitable for areas that do not have the opportunity to drill multiple deflection sections, with strong applicability.

[0023] Optionally, in step S1, the boundary angle value applicable to the working face is determined, and the boundary angle influence surface is determined by connecting the coal seam roof at the working face boundary and the ground boundary angle influence boundary at the corresponding position, and then the ground influence zone boundary is determined, and the ground drilling position is located outside the ground influence zone.

[0024] By adopting the above technical solution, the surface casing in the first drilling step and the technical casing in the second drilling step are basically located in a stable stratum where no settlement occurs, reducing the probability of grouting pipe damage due to settlement of gradual rock strata, which is beneficial to ensuring the service life of the surface casing and the technical casing.

[0025] In summary, this application includes at least one of the following beneficial technical effects: 1. The coordination of the bottom slope section, multiple side wall slope sections and the grouting section facilitates the stable injection of coal gangue slurry into the required position in the coal mine, thereby facilitating the stable filling of high-position grouting in the subsidence area and ensuring the filling effect of high-position grouting. At the same time, the setting of multiple side wall slope sections facilitates the effective utilization of the straight hole section, increases the grouting volume of a single hole, reduces the grouting cost and is suitable for areas where multiple straight hole sections are not available, with strong applicability.

[0026] 2. The cooperation between the horn joint and the float shoe limits the position of the production casing, making it difficult for the production casing to slip off the technical casing, which is conducive to ensuring the position stability of the production casing during grouting.

[0027] 3. When grouting is stopped, the non-return sliding part is reset under the elastic force of the command spring, the non-return fixing part closes the connecting hole, and the non-return sealing gasket presses against the non-return fixing part to isolate the connecting hole and the water filter hole, so that the grouting slurry is not easy to flow back, which is conducive to ensuring the grouting effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a structural schematic diagram of the formation structure and drilling trajectory in Example 1 of the present application.

[0029] Figure 2 It is a schematic diagram of the top view of the drilling position and grouting diffusion in Example 1 of the present application.

[0030] Figure 3 It is a structural schematic diagram of the overlapping state of the technical casing and the production casing in Example 1 of the present application.

[0031] Figure 4 It is a structural schematic diagram of another stratum structure and drilling trajectory in Example 1 of the present application.

[0032] Figure 5 It is a three-dimensional structural schematic diagram of the stratum structure and drilling trajectory in Example 2 of the present application.

[0033] Figure 6 It is a three-dimensional structural schematic diagram of the stratum structure and drilling trajectory in Example 3 of the present application.

[0034] Figure 7 It is a structural schematic diagram of the overlapping state of the technical casing and the production casing in Example 4 of the present application.

[0035] Figure 8 yes Figure 7 A partial enlarged schematic diagram of part A.

[0036] Description of reference numerals: 1. Grouting position; 11. Boundary angle influencing surface; 2. Vertical well section; 21. Surface casing; 3. Deflection section; 301. Bottom hole deflection section; 302. Side wall deflection section; 31. Technical casing; 311. Float shoe; 311. Overlap section; 4. Grouting section; 41. Bottom hole grouting section; 42. Side wall grouting section; 5. Production casing; 51. Drain hole; 52. Trumpet joint; 521. Joint connection; 53. Cone head; 531. Cone head connection; 6. Connection gasket; 7. Buffer pad; 8. Reinforcement ring; 9. Check spring; 10. Check fixing; 11. Check sliding member; 12. Check gasket; 13. Connecting hole; 14. Partition. DETAILED DESCRIPTION

[0037] The following is combined with Figure 1-7 This application is described in further detail.

[0038] Example 1.

[0039] The embodiment of the present application discloses a method for grouting and filling gangue slurry in a high-position goaf subsidence area through feather-shaped directional drilling.

[0040] Reference Figure 1 The feather-shaped directional drilling high-position goaf subsidence area grouting method of gangue slurry includes the following specific steps: S1, position determination: determine the grouting target layer, determine the grouting position 1 and the grouting trajectory and select the ground drilling position, the grouting position 1 is located at the grouting target layer; determine the boundary angle value applicable to the working face, by connecting the working face boundary coal seam roof and the ground boundary angle influence boundary at the corresponding position, determine the boundary angle influence surface 11, and then determine the ground influence zone boundary, the ground drilling position is located outside the ground influence zone.

[0041] S2: First drilling: Drill vertically downward at the selected drilling position on the ground, using a φ444.5mm drill bit to drill 10m to 25m below the intact bedrock, and insert surface casing 21. The surface casing 21 is a φ339.7mm, 10.16mm wall thickness, J55 grade steel pipe. Cement the well for 48 hours to form a vertical well section 2.

[0042] S3: Secondary drilling: Drilling continues at the bottom of the vertical well section 2. When drilling to a depth of 48 to 52 m using a φ269.9 mm drill bit according to the designed trajectory, inclination is started and the bottomhole technical casing 31 is inserted. The bottomhole technical casing 31 is a φ219 mm, 10.16 mm thick, N80 grade steel pipe. Cementing is performed for 72 hours to form a bottomhole inclination section 301. The lower end of the bottomhole inclination section 301 is inclined near the grouting position 1.

[0043] S31: Continue to use the φ269.9mm drill bit to drill multiple holes in the side wall extending from bottom to top in the vertical direction. The distance between two adjacent holes in the vertical direction is between 4m and 6m, and multiple holes can be distributed circumferentially around the axis of the vertical well section 2 at the same horizontal position. The number of holes at the same horizontal position is less than or equal to three. After the drilling of each hole is completed, the side wall technical casing 31 is inserted into each hole in turn. The side wall technical casing 31 is φ219mm, 10.16mm thick, and N80 grade steel pipe. Cement is cemented for 72 hours to form a side wall deflection section 302. The lower end of the side wall deflection section 302 is inclined close to the grouting position 1.

[0044] S4: Three holes are drilled. A φ190.5mm drill bit is used to drill holes in the bottom of the well inclination section 301 and the bottom of each sidewall inclination section 302, and production casing 5 is inserted to form a grouting section 4. The production casing 54 is a φ139.7mm, 9.17mm thick, N80 grade steel pipe. The length direction of the grouting section 4 is parallel to the local formation. The grouting section 4 is located at the grouting position 1.

[0045] Reference Figure 1 and Figure 2 , assuming that the coal seam depth is H, the mining width at the coal seam is L, and the boundary angle is α, then the extension width of the ground influence zone is L1=Htanα; there are multiple grouting points, and the spacing between two adjacent vertical well sections 2 is equal to L. The slurry diffusion radius is r, L=√(r^2-〖(L / 2)〗^2).

[0046] Reference Figure 3 The side wall of the production casing 5 is provided with a plurality of groups of drainage holes 51 along its length, and each group of drainage holes 51 has a plurality of holes distributed circumferentially around its axis. The end of the production casing 5 inserted into the grouting position 1 is fixedly connected to a cone head 53, so that the flower pipe can be more smoothly inserted into the stratum at the grouting position 1. The end of the technical casing 31 away from the surface casing 21 is fixedly connected to a float shoe 311, and the end of the technical casing 31 away from the cone head 53 is fixedly connected to a horn joint 52, and the large-diameter end of the horn joint 52 is located on the side away from the production casing 5; during grouting, the slurry passes through the surface casing 21, the technical casing 31 in turn, and then enters the production casing 5 through the horn joint 52, and finally enters the abscission stratum through the drainage holes 51.

[0047] The implementation principle of Example 1 is: during the grouting process, the cooperation of the bottom well inclination section 301, multiple side wall inclination sections 302 and the grouting section 4 facilitates the stable injection of coal gangue slurry into the required position in the coal mine, thereby facilitating the stable filling of high-position grouting in the collapse area and ensuring the filling effect of high-position grouting. At the same time, the setting of multiple side wall inclination sections 302 facilitates the effective utilization of the straight hole section, increases the grouting volume of a single hole, reduces the grouting cost and is suitable for areas that do not have the opportunity to drill multiple straight hole sections, and has strong applicability.

[0048] In addition, refer to Figure 1 and Figure 4 When the underground coal seam collapse degree is small and there is only one grouting target layer, the grouting position 1 is also located at the same depth of the formation. At this time, it is convenient to pass through the bottom well deflection section 301 with different inclination angles to the grouting position 1 for multi-point grouting; when the underground coal seam collapse degree is large and there are multiple grouting target layers, there are multiple grouting positions 1 corresponding to the grouting target layers. At this time, it is convenient to realize grouting treatment of grouting positions 1 at different depths of formations by setting the bottom well deflection section 301 at different depths.

[0049] Example 2.

[0050] Reference Figure 5 The main difference between this embodiment and embodiment 1 is that steps S3 and S4 are different. In the feather-shaped directional drilling high-position goaf subsidence area grouting method, S3 and S4 include the following specific steps: S3: Secondary drilling: Drilling continues at the bottom of the vertical well section 2. When drilling to a depth of 48 to 52 m using a φ269.9 mm drill bit according to the designed trajectory, inclination is started and the bottomhole technical casing 31 is inserted. The bottomhole technical casing 31 is a φ219 mm, 10.16 mm thick, N80 grade steel pipe. Cementing is performed for 72 hours to form a bottomhole inclination section 301. The lower end of the bottomhole inclination section 301 is inclined near the grouting position 1.

[0051] S4: Three-hole drilling: A φ190.5mm drill bit is used to drill a hole at the bottom end of the bottomhole deflection section 301 and insert a production casing 5 to form a bottomhole grouting section 41. The production casing 5 is a φ139.7mm, 9.17mm thick, N80 grade steel pipe. The length direction of the bottomhole grouting section 41 is parallel to the local formation and is located at grouting position 1.

[0052] S41, continue to use the φ190.5mm drill bit to drill holes in sequence at the free end of the bottom of the well inclination section 301 near the bottom. Multiple hole positions can be distributed circumferentially around the axis of the bottom of the well inclination section 301 at the same length position of the bottom of the well inclination section 301. The number of hole positions at the same length position of the bottom of the well inclination section 301 is less than or equal to three, and the distance between two adjacent hole positions is between 4m and 5m. Insert the production casing 5 into each hole position in turn to form a bottom of the well grouting section 42. The production casing 54 is a φ139.7mm, 9.17mm wall thickness, N80 grade steel pipe. The length direction of each bottom of the well grouting section 42 is parallel to the local formation. The bottom of the well grouting section 42 is located at the grouting position 1.

[0053] The implementation principle of Example 2 is as follows: during the grouting process, the coordination of the bottom hole deflection section 301 with the bottom hole grouting section 41 and the bottom hole grouting section 42 facilitates the stable injection of the coal gangue slurry into the desired position in the coal mine, thereby facilitating the stable filling of the high-position grouting in the subsidence area and ensuring the filling effect of the high-position grouting. At the same time, the provision of multiple side wall deflection sections 302 facilitates the effective utilization of the straight hole section, increases the grouting volume of a single hole, reduces the grouting cost, and is applicable to areas where multiple straight hole sections are not drilled, with strong applicability. The embodiment of the present application is mainly applicable to situations where the degree of underground coal subsidence is small, there is only one target grouting layer, and the grouting positions 1 are all located in the same depth stratum, so that multi-point grouting of the target grouting layer can be achieved through multiple bottom hole grouting sections 42.

[0054] Example 3.

[0055] Reference Figure 6 The difference between the embodiment of the present application and embodiment 1 is mainly that the steps S3 and S4 are different. In the feather directional drilling high-position goaf subsidence area grouting filling method S3 and S4 in the embodiment of the present application include the following specific steps: S3: Secondary drilling: Drilling continues at the bottom of the vertical well section 2. When drilling to a depth of 48 to 52 m using a φ269.9 mm drill bit according to the designed trajectory, inclination is started and the bottomhole technical casing 31 is inserted. The bottomhole technical casing 31 is a φ219 mm, 10.16 mm thick, N80 grade steel pipe. Cementing is performed for 72 hours to form a bottomhole inclination section 301. The lower end of the bottomhole inclination section 301 is inclined near the grouting position 1.

[0056] S31: Continue to use the φ269.9mm drill bit to drill multiple holes in the side wall extending from bottom to top in the vertical direction. The distance between two adjacent holes in the vertical direction is between 4m and 6m, and multiple holes can be distributed circumferentially around the axis of the vertical well section 2 at the same horizontal position. The number of holes at the same horizontal position is less than or equal to three. After the drilling of each hole is completed, the side wall technical casing 31 is inserted into each hole in turn. The side wall technical casing 31 is φ219mm, 10.16mm thick, and N80 grade steel pipe. Cement is cemented for 72 hours to form a side wall deflection section 302. The lower end of the side wall deflection section 302 is inclined close to the grouting position 1.

[0057] S4: Three-hole drilling: A φ190.5mm drill bit is used to drill holes in the bottom of the well bottom inclination section 301 and the bottom of the side wall inclination section 302 in sequence and insert production casing 5 to form multiple bottom grouting sections 41. The production casing 5 is a φ139.7mm, 9.17mm thick, N80 grade steel pipe. The length direction of each bottom grouting section 41 is parallel to the local formation. The bottom grouting section 41 is located at grouting position 1.

[0058] S41, continue to use the φ190.5mm drill bit to drill holes in turn at the free end near the bottom of each bottom well inclination section 301. The same length position of the bottom well inclination section 301 can have multiple hole positions distributed circumferentially around the axis of the bottom well inclination section 301. The number of hole positions at the same length position of the bottom well inclination section 301 is less than or equal to three, and the distance between two adjacent hole positions is between 4m and 5m. Insert the production casing 5 into each hole position in turn to form a bottom well grouting section 42. The production casing 54 is a φ139.7mm, 9.17mm wall thickness, N80 grade steel pipe. The length direction of each bottom well grouting section 42 is parallel to the local formation. The bottom well grouting section 42 is located at grouting position 1.

[0059] The implementation principle of Example 3 is: during the grouting process, the coordination of the bottom hole inclination section 301, each side wall inclination section 302, each bottom hole grouting section 41 and each bottom hole grouting section 42 facilitates the stable injection of coal gangue slurry into the required position in the coal mine, thereby facilitating the stable filling of high-position grouting in the collapse area and ensuring the filling effect of high-position grouting. At the same time, the provision of multiple side wall inclination sections 302 facilitates the effective utilization of the straight hole section, increases the grouting volume of a single hole, reduces the grouting cost, and is suitable for areas where multiple straight hole sections are not drilled, and has strong applicability.

[0060] The situation shown in the embodiment of the present application is mainly when the underground coal subsidence is small and there is only one target grouting layer. The grouting positions 1 are also all located at the same depth. In this case, it is convenient to achieve multi-point grouting at the grouting positions 1 by coordinating the bottom hole deflection sections 301 with different inclination angles and multiple bottom hole grouting sections 42. In addition, when the underground coal seam subsidence is large and there are multiple target grouting layers, there are multiple grouting positions 1 corresponding to the grouting target layers. In this case, it is convenient to achieve multi-point grouting at the grouting positions 1 at different depths by coordinating the bottom hole deflection sections 301 with multiple bottom hole grouting sections 42.

[0061] Example 4.

[0062] Reference Figure 7 and Figure 8 The difference between the embodiment of the present application and embodiment 1 mainly lies in the specific structures of the technical casing 31 and the production casing 5. Specifically, when the production casing 5 is installed in place, there is an overlapping section 311 between the technical casing 31 and the production casing 5. The length of the overlapping section 311 is 25% to 45% of the total length of the production casing 5, so that the production casing 5 has a certain sliding margin relative to the technical casing 31, which is convenient for protecting the production casing 5.

[0063] Reference Figure 7 In the embodiment of the present application, the production casing 5 is provided with an internal thread at one end and an external thread at the other end. The end with the smaller opening of the flare joint 52 has a cylindrical joint connection portion 521. The end of the production casing 5 provided with the external thread is threadedly connected to the joint connection portion 521 to achieve a stable connection between the flare joint 52 and the production casing 5. The end of the cone head 53 facing the production casing 5 has a cylindrical cone head connection portion 531. The end of the production casing 5 provided with the internal thread is threadedly connected to the joint connection portion 521 to achieve a stable connection between the production casing 5 and the cone head 53.

[0064] Reference Figure 7 and Figure 8 The inner side of the joint connection part 521 and the outer side of the cone head connection part 531 are fixedly provided with a connection sealing gasket 6 for tightening the production casing 5. In the embodiment of the present application, the material of the buffer pad 7 is selected as rubber to ensure the sealing of the production casing 5 after the connection with the horn joint 52 and the cone head 53. At the same time, by rotating the cone head connection part 531, the cone head connection part 531 can be fixed at different length positions of the production casing 5 to facilitate the blocking of different numbers of water filter holes 51, and then facilitate the adjustment of the grouting length according to different terrains, and has strong applicability.

[0065] Continue to refer to Figure 7 and Figure 8A buffer pad 7 and a reinforcement ring are fixedly installed on the inner wall of the technical casing 31. Both the buffer pad 7 and the reinforcement ring 8 are located within the overlap section 311. The outer peripheral surface of the horn joint 52 contacts the buffer pad 7, so that the production casing 5 is resisted by the buffer pad 7 when sliding within the overlap section 311, which helps to ensure the stability of the relative positions of the technical casing 31 and the production casing 5. The production casing 5 passes through and contacts the inner wall of the reinforcement ring 8, so that the reinforcement ring 8 further supports the production casing 5, which helps to further ensure the stability of the position of the production casing 5.

[0066] Continue to refer to Figure 7 and Figure 8 A non-return mechanism is provided at the free end of the production casing 5 away from the cone head 53, that is, the free end close to the horn joint 52, wherein the non-return mechanism includes a non-return spring 9, a non-return fixing part 10, a non-return sliding part 11 and a non-return sealing gasket 12. Specifically, the non-return fixing part 10 is annular and fixedly installed on the inner wall of the production casing 5. One end of the non-return spring 9 is fixedly connected to the non-return fixing part 10, and the other end is fixedly connected to the non-return sliding part 11, so as to apply an elastic force to the non-return sliding part 11 to move toward one end away from the cone head 53.

[0067] Reference Figure 8 The non-return sliding member 11 is slidably engaged with the production casing 5. The non-return sliding member 11 is provided with a connecting hole 13 for connecting the end of the production casing 5 away from the cone head 53 with the water filter hole 51. There are multiple connecting holes 13 distributed circumferentially around the axis of the non-return sliding member 11. The non-return sealing gasket 12 is fixedly installed on the non-return sliding member 11. In the embodiment of the present application, the material of the non-return sealing gasket 12 is selected to be rubber. Under normal conditions, the non-return sealing gasket 12 is pressed against the non-return fixing member 10 by the elastic force of the non-return spring 9. The non-return fixing member 10 closes the connecting hole 13, thereby preventing the grouting slurry from flowing back and ensuring the grouting effect. During grouting, the non-return sliding member 11 moves toward the cone head 53, and the connecting hole 13 is connected to each water filter hole 51, thereby facilitating the grouting slurry to pass through the connecting hole 13 and the water filter hole 51 to achieve grouting of the grouting position 1. The non-return fixing member 10 is fixed with a partition 14 that separates the communicating hole 13 and the non-return spring 9, so that the grouting slurry is not easy to interfere with the water-stop spring, thereby ensuring the elastic stability of the non-return spring 9.

[0068] The implementation principle of Example 4 is the same as that of Example 1 and will not be repeated here.

[0069] The above are all preferred embodiments of the present application, and are not intended to limit the scope of protection of the present application. Therefore, any equivalent changes made based on the structure, shape, and principle of the present application should be included in the scope of protection of the present application.

Claims

1. A method for grouting and filling high-level mined-out subsidence areas with waste rock slurry by feather-shaped directional drilling, characterized by: The method comprises the following specific steps: S1, position determination: determining the target grouting layer; determining the grouting position (1) and the grouting trajectory and selecting the ground drilling position, wherein the grouting position (1) is located at the target grouting layer; S2: First drilling: Drilling vertically downwards on the ground and inserting surface casing (21), cementing the well to form a vertical well section (2); S3: Secondary drilling: Continue drilling at the bottom of the vertical well section (2) and insert the bottom well casing (31), cement the well, and form a bottom well inclination section (301). The lower end of the bottom well inclination section (301) is inclined close to the grouting position; S31: drilling multiple holes in the side wall of the vertical well section (2) in sequence and inserting side wall technical casing (31) into each hole, cementing the well, and forming multiple side wall deflection sections (302), wherein the lower end of each side wall deflection section (302) is inclined close to the grouting position (1); S4: three-hole drilling, drilling in sequence at the bottom end of each well bottom deflection section (301) and side wall deflection section (302) and inserting a production casing (5) to form a grouting section (4), wherein the length direction of the grouting section (4) is parallel to the formation, and the grouting section (4) is located at the grouting position (1).

2. The method for grouting and filling waste rock slurry in a high-level mined-out subsidence area by feather-shaped directional drilling according to claim 1, characterized in that: The side wall of the production casing (5) is provided with a plurality of water filtering holes (51) distributed along its length direction, and one end of the production casing (5) inserted into the grouting position (1) is fixedly connected with a cone head (53).

3. The method for grouting and filling waste rock slurry in high-level mined-out subsidence areas by feather-shaped directional drilling according to claim 2, characterized in that: The end of the technical casing (31) is fixedly connected to a float shoe (311), and the end of the production casing (5) away from the cone head (53) is fixedly connected to a horn joint (52), and the end of the horn joint (52) away from the production casing (5) is a large-aperture end.

4. The method for grouting and filling high-level mined-out subsidence areas with waste rock slurry by feather-shaped directional drilling according to claim 3, characterized in that: An overlapping section (311) is provided between the technical casing (31) and the production casing (5), and the length of the overlapping section (311) is 25% to 45% of the total length of the production casing (5). A buffer pad (7) is fixedly provided on the inner wall of the technical casing (31), and the buffer pad (7) is located in the overlapping section (311) area. The outer peripheral surface of the horn joint (52) contacts the buffer pad (7).

5. The method for grouting and filling high-level mined-out subsidence areas with waste rock slurry by feather-shaped directional drilling according to claim 4, characterized in that: The inner wall of the technical casing (31) is fixedly connected with a reinforcement ring (8), the reinforcement ring (8) is located in the overlapping section (311), and the production casing (5) is passed through and abuts against the inner wall of the reinforcement ring (8).

6. The method for grouting and filling high-level mined-out subsidence areas with waste rock slurry by feather-shaped directional drilling according to claim 2, characterized in that: The free end of the production casing (5) away from the cone head (53) is provided with a non-return mechanism, the non-return mechanism comprising a non-return spring (9), a non-return fixing member (10), a non-return sliding member (11) and a non-return sealing gasket (12), the non-return fixing member (10) is fixedly mounted on the inner wall of the production casing (5), the non-return sliding member (11) is slidably fitted on the production casing (5), the non-return spring (9) is provided on the non-return fixing member (10) and is used to apply a force to the non-return sliding member (11) The non-return sliding member (11) is provided with a connecting hole (13) for connecting the end of the production casing (5) away from the cone head (53) and the water filter hole (51). The non-return sealing gasket (12) is fixedly installed on the non-return sliding member (11). In normal state, the non-return sealing gasket (12) presses against the non-return fixing member (10) under the elastic force of the non-return spring (9), and the non-return fixing member (10) closes the connecting hole (13).

7. The method for grouting and filling high-level mined-out subsidence areas with waste rock slurry by feather-shaped directional drilling according to claim 6, characterized in that: A plurality of the communication holes (13) are circumferentially distributed around the axis of the non-return sliding member (11), and the non-return fixing member (10) is provided with a partition (14) for separating the communication hole (13) and the non-return spring (9).

8. The method for grouting and filling high-level mined-out subsidence areas with waste rock slurry by feather-shaped directional drilling according to claim 3, characterized in that: The horn joint (52) has a joint connection portion (521), one end of the production casing (5) is threadedly connected to the joint connection portion (521), the end of the cone head (53) facing the production casing (5) has a cone head (53) connection portion, the cone head (53) connection portion is threadedly connected to the end of the production casing (5) away from the horn joint (52), and the joint connection portion (521) and the cone head (53) connection portion are both provided with a connection sealing gasket (6) for pressing against the production casing (5).

9. A method for grouting and filling high-level mined-out subsidence areas with waste rock slurry by feather-shaped directional drilling, characterized by: S1, position determination: determining the grouting target layer; determining the grouting position (1) and the grouting trajectory and selecting the ground drilling position, wherein the grouting position (1) is located at the grouting target layer; S2: First drilling: Drilling vertically downwards on the ground and inserting surface casing (21), cementing the well to form a vertical well section (2); S3: Secondary drilling: Continue drilling at the bottom of the vertical well section (2) and insert the bottom well casing (31), cement the well, and form a bottom well inclination section (301). The lower end of the bottom well inclination section (301) is inclined close to the grouting position (1); S4: three-hole drilling, drilling at the bottom end of the bottom-hole deflection section (301) and inserting the bottom-hole production casing (5) to form a bottom-hole grouting section (41), wherein the length direction of the bottom-hole grouting section (41) is parallel to the formation, and the bottom-hole grouting section (41) is located at the grouting position (1); S41, drilling multiple holes in the side wall of the bottom well deflection section (301) in sequence and inserting a side wall production casing (5) into each hole to form multiple side wall grouting sections (42), each of the side wall grouting sections (42) is located at a grouting position (1).

10. A method for grouting and filling waste rock slurry in a high-position mined-out subsidence area with feather-shaped directional drilling according to any one of claims 1 to 9, characterized in that: In step S1, the boundary angle value applicable to the working face is determined, and the boundary angle influence surface (11) is determined by connecting the coal seam roof at the working face boundary and the ground boundary angle influence boundary at the corresponding position, thereby determining the boundary of the ground influence zone, and the ground drilling position is located outside the ground influence zone.

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