A method for fixed-point treatment of water leakage in a water-rich stratum inclined shaft wellbore

Abstract

This invention discloses a method for targeted treatment of leakage in inclined wells in water-rich formations. The method includes: determining the area to be treated based on obtained physical characteristic data of the surrounding rock and water inflow data of the inclined well; determining the radius and boundary of the loosened zone of the surrounding rock; determining the radial distance from the outer boundary of the annular void around the inclined well to the boundary of the loosened zone; determining the range of values ​​for the horizontal distance between the to-be-constructed closed grouting anti-seepage zone and the center point of the inclined well, as well as the range of values ​​for the horizontal distance between the to-be-constructed grouting external seepage reinforcement zone and the center point of the inclined well; determining the spatial location of the leakage point in a three-dimensional rectangular coordinate system; drilling vertically from the construction surface to the boundary of the loosened zone of the surrounding rock of the inclined well; determining the opening position of the micro-grouting holes in the inclined well and completing the opening; and combining the "upward extraction and downward injection" and "downward drainage and upward injection" treatment methods to complete the treatment of leakage at the leakage point, protecting the safety and structural integrity of the inclined well.

Description

Technical Field

[0001] This invention belongs to the technical field of coal mine water hazard prevention, water resource protection and wellbore reinforcement, and relates to a method for targeted treatment of water leakage in inclined wells in water-rich strata. Background Technology

[0002] When coal seams are shallow, topsoil is thin, hydrogeological conditions are relatively simple, and the seam dip angle is small, inclined shafts are often used for development. These inclined shafts establish a connection between the upper and lower parts of the coal mine, making them crucial for coal mine development, tunneling, and production. In western my country, mine shafts are characterized by large diameters, shallow alluvial deposits, thin alluvial layers, and numerous porous and fractured aquifers. Currently, the main methods used for inclined shaft tunneling include freezing, conventional methods, and tunneling machine methods. When an inclined shaft traverses an aquifer, methods such as freezing, dewatering, and pre-grouting are often employed to allow the shaft to pass through the aquifer section. After the inclined shaft is formed, it connects different aquifer sections from top to bottom, including the surface, Quaternary loose aquifers, weathered bedrock, and porous and fractured rock layers. Water from each aquifer collects and infiltrates through pores and fractures into the annular space outside the inclined shaft and the surrounding rock mass, resulting in a saturated state around the inclined shaft. When cracks or undesirable pores appear in the inclined shaft, they become points where a large amount of water from the underground aquifer rushes into the shaft, causing a rapid increase in the mine's water inflow in a short period of time. Moreover, after the actual construction of the inclined shaft, there will be various leakage points such as joints, construction joints, and undesirable pores. Therefore, most inclined shafts have water leakage. Prolonged water leakage will cause the mud and sand in the surrounding strata to be washed away by the water inflow, the water passage to gradually enlarge, the foundation of the inclined shaft to become unstable, and the shaft to deform and crack, resulting in accidents such as water inrush and shaft breakage. This seriously disrupts the normal transportation and production of the inclined shaft and threatens the lives and property of miners.

[0003] Existing technologies mainly employ methods such as grouting behind the well wall, pre-grouting on the ground, and grouting at the working face to block water leakage in inclined wells. However, these methods have several drawbacks: grouting behind the well wall easily damages the reinforcing steel bars, disrupts the well structure, reduces the well's strength, and can lead to well instability and failure. Ground grouting involves drilling a hole above the leakage point to the location of the leak and inserting a grouting pipe to seal the loose layer outside the leakage point. However, existing engineering examples show that the loose layer has well-developed pores and rock strata with pores and fractures, making the direction and range of grout diffusion uncontrollable. Cement grout and chemical grout are both insufficient to form an effective anti-seepage barrier that can completely seal the seepage channels. Furthermore, methods such as grouting behind the well wall and ground grouting have poor treatment effects and unsatisfactory water-blocking results. Summary of the Invention

[0004] In view of the defects and deficiencies in the prior art, the present invention provides a method for targeted treatment of water leakage in inclined wells in water-rich formations, so as to solve the technical problems of uncontrollable slurry diffusion and unsatisfactory sealing of leakage points caused by the lack of effective methods to block water leakage in inclined wells.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] A method for targeted treatment of water leakage in inclined wells in water-rich formations includes the following steps:

[0007] Step 1: Obtain geological data and well construction data of the inclined shaft. Based on the obtained data, determine the physical characteristics of the surrounding rock and the water inflow data of the inclined shaft. Based on the obtained physical characteristics of the surrounding rock and the water inflow data of the inclined shaft, determine the area to be treated.

[0008] The physical characteristic data of the surrounding rock of the inclined shaft include the stratification location of the surrounding rock of the inclined shaft, the cohesion and internal friction angle of each stratification of the surrounding rock of the inclined shaft, the width of the annular void around the inclined shaft, and the measured radius of the loosened zone of the surrounding rock of the inclined shaft.

[0009] The water inflow data of the inclined shaft includes the location of the leakage point, the number of leakage points, and the total water inflow of the inclined shaft.

[0010] Step 2: Based on the data obtained in Step 1, the theoretical radius of the loosened zone of the surrounding rock of the inclined shaft is calculated using theoretical calculation methods;

[0011] Step 3: Based on the data obtained in Step 1, a numerical simulation method is used to construct a model of the coal mine inclined shaft and surrounding rock structure, and then the simulated radius of the loosened zone of the surrounding rock of the inclined shaft is calculated.

[0012] Step 4: Take the maximum value among the measured radius obtained in Step 1, the theoretical radius obtained in Step 2, and the simulated radius obtained in Step 3 as the radius of the loosened zone of the surrounding rock in the inclined shaft, and determine the boundary of the loosened zone of the surrounding rock.

[0013] Step 5: Determine the radial distance from the outer boundary of the annular void around the inclined shaft to the outer boundary of the loosened zone of the surrounding rock;

[0014] Step 6: Determine the range of values ​​for the horizontal distance between the closed grouting anti-seepage zone to be constructed and the center point of the inclined well, as well as the range of values ​​for the horizontal distance between the grouting external seepage reinforcement zone to be constructed and the center point of the inclined well.

[0015] Step 7: Based on the determined range of horizontal distances between the closed grouting anti-seepage zone to be constructed and the center point of the inclined well, the range of horizontal distances between the grouting external seepage reinforcement zone to be constructed and the center point of the inclined well, and the location of the inclined well to be treated, determine the spatial location of the leakage point in the three-dimensional rectangular coordinate system.

[0016] Step 8: Determine the corresponding ground location of the seepage point based on its spatial location in the three-dimensional rectangular coordinate system. Use the ground location corresponding to the seepage point as the opening position for vertical drilling on the ground. Drill vertically on the ground until the outer boundary of the loosened zone of the surrounding rock of the inclined shaft is reached.

[0017] Step 9: Obtain the spatial distribution of the reinforcing bars around the leakage point and the location of the gaps between the longitudinal and transverse reinforcing bars, and then determine the opening location of the micro-grouting holes in the inclined shaft and complete the opening.

[0018] Step 10: Complete the treatment of water leakage in the inclined shaft.

[0019] The present invention also has the following technical features:

[0020] Specifically, the radial distance from the outer boundary of the annular void around the inclined shaft to the boundary of the loosened zone of the surrounding rock, as described in step 5, is determined by the following formula:

[0021] D 外 =R b -R0-D 内 ;

[0022] In the formula:

[0023] D 外 The radial distance, in meters, is from the outer boundary of the annular void around the inclined shaft to the outer boundary of the loosened zone of the surrounding rock.

[0024] R b The radius of the loosened zone of the surrounding rock of the inclined shaft is in meters.

[0025] R0 is the equivalent radius of the inclined shaft, in meters (m).

[0026] D 内 The width of the annular void around the inclined shaft is measured in meters (m).

[0027] Furthermore, the range of values ​​for the horizontal distance between the closed grouting seepage-proof zone to be constructed and the center point of the inclined well shaft, as described in step 6, is determined by the following formula:

[0028] S 内 ∈(b / 2,b / 2+D 内 )

[0029] In the formula:

[0030] S 内 The range of values ​​for the horizontal distance between the closed grouting seepage prevention zone to be constructed and the center point of the inclined well shaft is given in meters.

[0031] D 内 The width of the annular void surrounding the inclined shaft, in meters;

[0032] b represents the width of the inclined shaft, in meters (m).

[0033] Furthermore, the range of values ​​for the horizontal distance between the grouting and seepage reinforcement zone to be constructed and the center point of the inclined well shaft, as described in step 6, is determined by the following formula:

[0034] S 外 ∈(b / 2+D 内 ,b / 2+D 内 +D 外 )

[0035] In the formula:

[0036] S 外 The range of values ​​for the horizontal distance between the grouting and seepage reinforcement zone to be constructed and the center point of the inclined well shaft, in meters;

[0037] b is the width of the inclined shaft, in meters (m).

[0038] D 内 The width of the annular void surrounding the inclined shaft, in meters;

[0039] D 外 It is the radial distance from the outer boundary of the annular void around the inclined shaft to the outer boundary of the loosened zone of the surrounding rock, in meters.

[0040] Furthermore, the opening position of the micro-grouting hole in the inclined shaft described in step 9 is the center point of the gap between the longitudinal and transverse reinforcing bars.

[0041] Furthermore, step 10, which describes the treatment of leakage in the inclined well shaft, specifically includes the following sub-steps:

[0042] Step 10.1: Lower a water pump into a vertical borehole in the ground to pump the water outside the seepage point to the surface, forming an underground flow field near the seepage point;

[0043] Step 10.2: Inject the first cement grout into the annular gap between the inclined shaft and the surrounding rock through the micro-grouting holes in the shaft to form a closed grouting anti-seepage zone in the annular gap between the inclined shaft and the loosened surrounding rock.

[0044] Step 10.3: Before the final setting of the closed grouting anti-seepage zone, insert an extension screen pipe into the micro grouting hole of the inclined shaft, extending into the surrounding rock within the loosened zone of the inclined shaft. The extension screen pipe serves as a drainage channel for water outside the loosened zone of the inclined shaft.

[0045] Step 10.4: Water from the outside of the loosened zone of the surrounding rock of the inclined shaft is introduced into the inclined shaft through the extended screen pipe, and a second cement grout is injected into the vertical borehole on the ground to form a seepage prevention and reinforcement zone outside the closed grouting seepage prevention zone.

[0046] Furthermore, the water-cement ratio of the first cement slurry described in step 10.2 is 0.8 to 1.5, the setting time is 20 to 40 minutes, the fluidity is 20 to 25 cm, and the 28-day strength is 8 to 20 MPa.

[0047] Furthermore, in step 10.4, the water-cement ratio of the second cement slurry is 0.9 to 1.8, the fly ash content is 30% to 90%, the setting time is 30 min to 90 min, the fluidity is 21 to 26 cm, and the 28-day strength is 4 MPa to 13 MPa.

[0048] Furthermore, the spatial distribution of the reinforcing bars around the leakage point and the location of the gaps between the longitudinal and transverse reinforcing bars are obtained using detection instruments installed on the wall of the inclined shaft.

[0049] Compared with the prior art, the beneficial technical effects of this invention are:

[0050] (1) The method of the present invention can scientifically, rationally and efficiently determine the treatment area of ​​the seepage point in the inclined well, determine the range of horizontal distance between the closed grouting anti-seepage zone to be constructed and the center point of the inclined well, and the range of horizontal distance between the grouting external seepage reinforcement zone to be constructed and the center point of the inclined well. Thus, at the opening and closing positions of the vertical borehole on the ground, the hydraulic connection between different aquifers can be effectively separated, the seepage point can be accurately treated, the construction efficiency and water interception effect can be improved, and the safety and durability of the inclined well can be ensured.

[0051] (II) The method of the present invention obtains the spatial distribution of the reinforcing bars around the leakage point and the gap position between the longitudinal and transverse reinforcing bars, thereby determining the opening position of the micro grouting hole in the inclined shaft and completing the opening. Since the distribution, position and spacing of the longitudinal reinforcing bars, annular reinforcing bars and stirrups of the inclined shaft wall at the leakage point are accurately identified and delineated, it can effectively guide the micro grouting hole in the inclined shaft to avoid the reinforcing bars in the shaft, avoid damage to the structure of the inclined shaft, and protect the safety and structural integrity of the inclined shaft.

[0052] (III) The method of the present invention combines two wellbore leakage point treatment methods, namely "upward extraction and downward injection" and "downward drainage and upward injection". By drilling water through vertical boreholes on the ground, a good grout diffusion environment is created for grouting of the well wall, so that the grout preferentially forms a thin shell-shaped grouting anti-seepage body in the annular space around the wellbore, reducing the amount of water seepage in the wellbore and protecting the wellbore from groundwater erosion.

[0053] (IV) Based on the formation of a closed grouting anti-seepage zone, this invention connects the micro-grouting holes of the inclined well shaft with the loosened ring of the surrounding rock by setting an extended screen pipe. Drainage is carried out through the micro-grouting holes of the inclined well shaft, creating a good grout diffusion environment for grouting in the loosened ring of the vertical borehole on the ground. This allows the grout to form a grouting anti-seepage body in the loosened ring of the surrounding rock, thereby strengthening the closed grouting anti-seepage zone on the outside of the well shaft and ensuring the safe operation of the inclined well shaft in all aspects. Attached Figure Description

[0054] Figure 1 This is a schematic diagram of the spatial relationship between the inclined shaft, the annular void around the inclined shaft, and the surrounding rock of the present invention;

[0055] Figure 2 This is a front view of the inclined shaft to be treated in Example 1;

[0056] Figure 3 This is a top view of the inclined shaft to be treated in Example 1;

[0057] Figure 4 This is a schematic diagram of the water storage space around the inclined shaft.

[0058] Figure 5 This is a schematic diagram showing the distribution of reinforcing steel bars in the inclined shaft and the shape of seepage points;

[0059] Figure 6 This is a schematic diagram of the reinforcement gap distribution in the inclined shaft.

[0060] Figure 7 This is a cross-sectional view along line A-A' of Example 1;

[0061] Figure 8 This is a schematic diagram of the "upward pumping and downward injection" treatment for water leakage in the inclined well shaft in Example 1;

[0062] Figure 9 This is a schematic diagram of the "bottom discharge and top injection" treatment for water leakage in the inclined well shaft in Example 1;

[0063] Figure 10 This is a schematic diagram illustrating the effect of water leakage treatment in the inclined well shaft in Example 1;

[0064] Figure 11 This is a simulated cloud map of the loosened zone of the surrounding rock in the inclined shaft in Example 1;

[0065] Figure 12 This refers to the change in seepage during the treatment process of the inclined well shaft in Example 1.

[0066] The meaning of each label in the diagram:

[0067] 1. Inclined shaft; 1-1. Longitudinal reinforcement; 1-2. Circumferential reinforcement; 1-3. Stirrups; 1-4. Construction joint; 1-5. Crack; 1-6. Centralized water collection pipe; 2. Gap between the inclined shaft and the inner boundary of the loosened zone surrounding rock; 3. Loosened zone; 4. Plastic zone; 5. Loose aquifer; 6. Weathered bedrock aquifer; 7. Sandstone aquifer; 8. Water-rich body; 9. Micro-grouting holes in the shaft; 10. Vertical boreholes on the ground; 11. Closed grouting anti-seepage zone; 12. Grouting external seepage reinforcement zone; 13. Extended screen pipe.

[0068] The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments. Detailed Implementation

[0069] Following the above technical solutions, specific embodiments of the present invention are given below. It should be noted that the present invention is not limited to the following specific embodiments, and all equivalent modifications made based on the technical solutions of this application fall within the protection scope of the present invention.

[0070] The technical terms involved in this invention are explained as follows:

[0071] Annular voids around the inclined shaft: refers to the closed, annular voids formed between the outer wall of the inclined shaft and the inner boundary of the loosened surrounding rock.

[0072] Inclined shaft excavation height: The vertical distance from the bottom to the top of the shaft in the inclined shaft excavation section.

[0073] The present invention will be further described in detail below with reference to the embodiments.

[0074] Example 1

[0075] In this embodiment, the inclined shaft leakage treatment required is for the main inclined shaft of a coal mine in Inner Mongolia. The cross-section of the inclined shaft is as follows: Figure 1 As shown.

[0076] Following the above technical solution, this embodiment provides a method for targeted treatment of water leakage in inclined wells of water-rich formations, including the following steps:

[0077] Step 1: Obtain geological data and well construction data of the inclined shaft. Based on the obtained data, determine the physical characteristics of the surrounding rock and the water inflow data of the inclined shaft. Based on the obtained physical characteristics of the surrounding rock and the water inflow data of the inclined shaft, determine the area to be treated.

[0078] The physical characteristic data of the surrounding rock of the inclined shaft includes the stratification location of the surrounding rock, the cohesion and internal friction angle of each stratification of the surrounding rock, the width of the annular void around the inclined shaft and the measured radius of the loosened zone around the inclined shaft; it also includes the vertical height of the inclined shaft, the width of the inclined shaft, the initial in-situ stress of the surrounding rock, the weight of the surrounding rock around the inclined shaft, the burial depth of the inclined shaft, and the initial support reaction force of the inclined shaft.

[0079] The water inflow data of the inclined shaft includes the location of the leakage point, the number of leakage points, and the total water inflow of the inclined shaft.

[0080] like Figure 2 and Figure 3 As shown, there are 5 leakage points in the inclined shaft, with a total water inflow of 92m³. 3 / h. The slope of the inclined shaft is set at 23°.

[0081] As needed, drilling can be used to conduct supplementary exploration to obtain more data, such as aquifer thickness, burial depth, hydraulic head, permeability coefficient, water yield, porosity, aquitard thickness, burial depth, permeability coefficient, and compressive strength. The grouting material mix ratio can be adjusted based on these data during grouting.

[0082] In this embodiment, the aquifers are mainly identified as loose sand aquifers, weathered bedrock aquifers, and sandstone aquifers; wherein the burial depth of the loose sand aquifers is 0–46 meters, the burial depth of the weathered bedrock aquifers is 47.5–51 meters, and the burial depth of the sandstone aquifers is 65–73 meters. The cohesion of the sand layer is c = 0, and the internal friction angle is... The cohesion of weathered bedrock is c=0, and the internal friction angle is... Groundwater level depth H 埋 =11m, the width of the annular void around the inclined shaft is 5cm; the measured radius of the loosened zone of the surrounding rock of the inclined shaft is 6.8m.

[0083] This implementation also obtained the following through detection: Figure 11 The image shows a simulated cloud map of the loosened zone of the surrounding rock in the inclined shaft.

[0084] Step 2: Based on the data obtained in Step 1, the theoretical radius of the loosened zone of the surrounding rock of the inclined shaft is calculated using theoretical calculation methods;

[0085] like Figure 4 As shown, the center of the loosened surrounding rock zone is the geometric center of the wellbore, and the outer side of the loosened surrounding rock zone is the plastic zone.

[0086] As a preferred embodiment, this embodiment uses the existing method for calculating the radius of the loosened zone based on the Mohr-Coulomb criterion to determine the theoretical radius of the loosened zone of the surrounding rock in the deviated well:

[0087] In this embodiment, since the inclined shaft is as follows Figure 1 As shown in the horseshoe shape, the equivalent radius of the inclined shaft needs to be calculated based on the width and vertical height of the inclined shaft. The width of the inclined shaft refers to the horizontal distance between the two side walls at the opening end of the U-shaped shaft.

[0088] In some embodiments, if the inclined shaft is cylindrical, the equivalent radius of the inclined shaft is the same as the radius of the inclined shaft, and then the theoretical radius of the loosened zone of the surrounding rock of the inclined shaft can be directly substituted into the following formula to calculate the theoretical radius.

[0089]

[0090] In the formula:

[0091] R b理 This represents the theoretical radius of the loosened zone of the surrounding rock in the inclined shaft, in meters (m).

[0092] R0 is the equivalent radius of the inclined shaft, and R0 = (h + b) / 4, in meters.

[0093] h represents the excavation height of the inclined shaft, in meters (m).

[0094] b is the width of the inclined shaft, in meters (m).

[0095] P is the initial in-situ stress of the surrounding rock of the inclined shaft, and P = γH 埋 The unit is MPa;

[0096] γ is the density of the rock mass surrounding the inclined shaft, in N / m³. 3 ;

[0097] H 埋 The depth of the inclined shaft is expressed in meters (m).

[0098] P1 is the initial support reaction force of the inclined shaft, in MPa;

[0099] c represents the cohesion of the surrounding rock of the inclined shaft, in MPa;

[0100] The internal friction angle of the surrounding rock of the inclined shaft is expressed in degrees (°).

[0101] Substituting the relevant parameters of the surrounding rock strata for each inclined shaft into the above formula, four theoretical radius values ​​are obtained. For example, the parameters of the loose sand aquifer are: h = 6m, b = 8.4m, resulting in R0 = (h + b) / 4 = 3.6m, p1 = 0.10 MPa, and c = 0 MPa. 22°, P=γH 埋 γ=18N / m3, H 埋 = 46 meters, the final calculated R b理The value is 8.8 meters; the parameters of the weathered bedrock aquifer are: h = 6 m, b = 8.4 m, R0 = (h + b) / 4 = 3.6 m, p1 is 0.10 MPa, and c is 0 MPa. 26°, P=γH 埋 γ=18N / m 3 H 埋 =51m, the final calculated R b理 The value was 5.16 meters. Finally, the maximum value of 8.8 meters was selected from the two theoretical radii obtained from the calculation as the theoretical radius of the loosened zone of the surrounding rock of the inclined shaft.

[0102] Step 3: Based on the data obtained in Step 1, a numerical simulation model of the coal mine inclined shaft and surrounding rock structure is constructed. Then, the simulated radius of the loosened zone of the surrounding rock in the inclined shaft is calculated. The simulated radius of the loosened zone of the surrounding rock in the inclined shaft can be calculated using FLAC. 3D Numerical simulation software such as ANSYS and UDEC;

[0103] The calculated simulated radius of the loosened zone is 6.6 meters.

[0104] Step 4: Take the maximum value among the measured radius obtained in Step 1, the theoretical radius obtained in Step 2, and the simulated radius obtained in Step 3 as the radius of the loosened zone of the surrounding rock in the inclined shaft, and determine the boundary of the loosened zone of the surrounding rock.

[0105] Step 5: Determine the radial distance from the outer boundary of the annular void around the inclined shaft to the outer boundary of the loosened zone of the surrounding rock;

[0106] As a preferred embodiment, the radial distance from the outer boundary of the annular void surrounding the inclined shaft to the boundary of the loosened surrounding rock is determined by the following formula:

[0107] D 外 =R b -R0-D 内 ;

[0108] In the formula:

[0109] D 外 The radial distance, in meters, is from the outer boundary of the annular void around the inclined shaft to the outer boundary of the loosened zone of the surrounding rock.

[0110] R b The radius of the loosened zone of the surrounding rock of the inclined shaft is in meters.

[0111] R0 is the equivalent radius of the inclined shaft, in meters (m).

[0112] D 内 The width of the annular void around the inclined shaft is in meters (m), and the measured value in this study is 0.06 m.

[0113] D 外 =R b -R0-D 内 =8.8-3.6-0.06=5.14m.

[0114] In this embodiment, since the cross-section of the inclined shaft is horseshoe-shaped, D 内 The width of the annular gap around the U-shaped wall of the inclined shaft, such as... Figure 4 As shown, D 内 The value is taken as the gap width between the U-shaped wall of the inclined shaft and the inner boundary of the loosening zone.

[0115] Step 6: Determine the range of horizontal distances between the closed grouting anti-seepage zone to be constructed and the center point of the inclined well, as well as the range of horizontal distances between the grouting external seepage reinforcement zone to be constructed and the center point of the inclined well. As a preferred embodiment, the range of horizontal distances between the closed grouting anti-seepage zone and the center point of the inclined well is determined by the following formula:

[0116] S 内 ∈(b / 2,b / 2+D 内 )

[0117] In the formula:

[0118] S 内 The range of values ​​for the horizontal distance between the closed grouting seepage barrier to be constructed and the center point of the inclined shaft is given, in meters (mD). 内 The width of the annular void surrounding the inclined shaft, in meters;

[0119] b represents the width of the inclined shaft, in meters (m).

[0120] As a preferred embodiment, the range of the horizontal distance between the grouting and seepage reinforcement zone to be constructed and the center point of the inclined well is determined by the following formula:

[0121] S 外 ∈(b / 2+D 内 ,b / 2+D 内 +D 外 )

[0122] In the formula:

[0123] S 外 The range of values ​​for the horizontal distance between the grouting and seepage reinforcement zone to be constructed and the center point of the inclined well shaft, in meters;

[0124] D 外 The radial distance, in meters, is from the outer boundary of the annular void surrounding the inclined shaft to the outer boundary of the loosened zone of the surrounding rock.

[0125] The final horizontal distance between the closed grouting anti-seepage zone and the center point of the inclined shaft ranges from 4.2 to 4.26 m, and the horizontal distance between the grouting external seepage reinforcement zone and the center point of the inclined shaft ranges from 4.26 to 9.4 m.

[0126] Step 7: Based on the determined range of horizontal distances between the closed grouting anti-seepage zone to be constructed and the center point of the inclined well, the range of horizontal distances between the grouting external seepage reinforcement zone to be constructed and the center point of the inclined well, and the location of the inclined well to be treated, determine the spatial location of the leakage point in the three-dimensional rectangular coordinate system.

[0127] like Figure 4 As shown, because the inclined shaft penetrates multiple aquifers such as the water-rich loose layer, the weathered sandstone layer, and the sandstone layer, the multiple aquifers are connected into one, resulting in the inclined shaft being surrounded by a cylindrical water-rich body 8.

[0128] Step 8: Determine the corresponding ground location of the seepage point based on its spatial location in the three-dimensional rectangular coordinate system. Use the ground location corresponding to the seepage point as the opening position for vertical drilling on the ground. Drill vertically on the ground until the outer boundary of the loosened zone of the surrounding rock of the inclined shaft is reached.

[0129] The three-dimensional rectangular coordinate system is established with the center of the inclined wellhead as the origin (O), the projection line of the well shaft's central axis onto the ground surface as the X-axis, the projection line of the cross-section passing through the origin (O) and perpendicular to the inclined well shaft along its longitudinal direction onto the ground surface as the Y-axis, and the vertical line passing through the origin (O) and perpendicular to the ground surface along its vertical direction as the Z-axis. Within this established three-dimensional rectangular coordinate system, the three-dimensional coordinates of the well shaft, surrounding rock, and ground surface can be obtained, thereby determining the ground surface location corresponding to the leakage point and guiding the layout of vertical drilling and micro-grouting holes in the well shaft. For example... Figure 5 As shown, water outside the inclined shaft can seep into or surge into the inclined shaft through seepage points such as construction joints 1-4, cracks 1-5, and centralized water collection pipes 1-6. After identifying the seepage points, it is necessary to determine the spatial location of the seepage points in a three-dimensional rectangular coordinate system, and then mark the corresponding locations of the seepage points such as construction joints 1-4, cracks 1-5, and centralized water collection pipes 1-6 on the ground surface.

[0130] Then, the location of the ground vertical borehole is taken as the location of the ground vertical borehole, ensuring that the vertical borehole is opened directly above the seepage point. In this embodiment, multiple ground vertical boreholes are opened in a ring shape outside the seepage point of the well.

[0131] like Figure 3 As shown, the inclined shaft penetrates multiple aquifers, including the gravel layer, loose aquifer, weathered bedrock aquifer, and sandstone aquifer, and these aquifers are interconnected. The inclined shaft is surrounded by a cylindrical water-rich body. Water seeps into or rushes into the shaft through seepage points such as construction joints 1-4, cracks 1-5, and centralized water collection pipes 1-6.

[0132] Step 9: Obtain the spatial distribution of the reinforcing bars around the leakage point and the location of the gaps between the longitudinal and transverse reinforcing bars, as detailed below. Figure 6 As shown, the opening position of the micro grouting hole in the inclined shaft is then determined and the opening is completed;

[0133] The spatial distribution of the reinforcing bars around the leakage point and the location of the gaps between the longitudinal and transverse reinforcing bars were obtained using a detection instrument installed on the wall of the inclined shaft.

[0134] like Figure 2 As shown, based on the detection results, multiple micro-grouting holes 9 were arranged near the leakage point. The hole diameter was 3cm. The opening position of the micro-grouting holes was the center point of the gap between the longitudinal and transverse reinforcing bars.

[0135] Step 10: Complete the treatment of water leakage in the inclined shaft, which includes the following sub-steps:

[0136] Step 10.1, as follows Figures 7 to 9 As shown, a water pump is lowered into a vertical borehole on the ground to pump water from the outside of the seepage point to the surface, forming an underground flow field near the seepage point; causing the water in the annular gap between the inclined shaft and the surrounding rock of the inclined shaft to flow towards the position of the vertical borehole 10 on the ground.

[0137] Step 10.2: Inject the first cement grout into the annular gap between the inclined shaft and the surrounding rock through the micro-grouting holes in the shaft to form a closed grouting anti-seepage zone in the annular gap between the inclined shaft and the loosened surrounding rock.

[0138] The first cement grout has a water-cement ratio of 0.8, a setting time of 21 min, a fluidity of 21 cm, and a 28-day strength of 19 MPa.

[0139] This completes the treatment of water leakage in the inclined well shaft using the "upward extraction and downward injection" method;

[0140] Step 10.3: Before the closed grouting seepage prevention zone constructed in step 10.1 sets, insert an extension screen pipe into the micro grouting hole of the inclined well shaft, extending into the surrounding rock within the loosened zone of the inclined well shaft. The extension screen pipe serves as a drainage channel for water outside the loosened zone of the inclined well shaft. Extract the water pump from the vertical borehole 10 on the ground.

[0141] Step 10.4, as follows Figure 10 As shown, water from the outside of the loosened zone of the surrounding rock in the inclined shaft is introduced into the inclined shaft by extending the screen pipe, and a second cement grout is injected into the vertical borehole on the ground to form a seepage-proof reinforcement zone outside the closed grouting seepage-proof zone.

[0142] Water from outside the loosened zone of the surrounding rock in the inclined well is introduced into the well shaft through an extended screen pipe. After collection, it is discharged to the surface, thus creating an artificial underground flow field near the leakage point. A second cement grout is then injected into a vertical borehole on the surface. The grout diffuses within this artificial underground flow field, entering the pores and fissures within the surrounding rock, forming a seepage barrier outside the closed grouting zone. Figure 10 The seepage prevention and reinforcement zone shown is constructed as an outer protective layer, which completely isolates the hydraulic connection between the wellbore 1 and the outer aquifer, and further strengthens the treatment of water leakage in the inclined wellbore by means of "bottom discharge and top injection".

[0143] Vertical drilling and water pumping create a favorable environment for grout diffusion in the wellbore, allowing the grout to preferentially form a thin-shell-like grouting anti-seepage body in the annular space around the wellbore, reducing the amount of water seepage in the inclined wellbore and protecting it from groundwater erosion.

[0144] The second cement grout has a water-cement ratio of 1.3, a setting time of 38 minutes, a fluidity of 24 cm, and a 28-day strength of 11 MPa.

[0145] like Figure 12 As shown, after the main inclined shaft of the coal mine was treated, the water inflow decreased from 92m³. 3 / h, reduced to 3.6m 3 / h, the seepage volume was reduced by 96.08%, proving that the method of the present invention can achieve the effect of precise treatment of well leakage.

[0146] The above-described implementation process is merely an example to clearly illustrate this application and is not intended to limit the implementation methods. Those skilled in the art can make other variations or modifications based on the above description. It is neither necessary nor possible to exhaustively list all possible implementation methods here. However, obvious variations or modifications derived therefrom are still within the protection scope of this application.

Claims

1. A method for targeted treatment of water leakage in inclined wells of water-rich formations, characterized in that, Includes the following steps: Step 1: Obtain geological data and well construction data of the inclined shaft. Based on the obtained data, determine the physical characteristics of the surrounding rock and the water inflow data of the inclined shaft. Based on the obtained physical characteristics of the surrounding rock and the water inflow data of the inclined shaft, determine the area to be treated. The physical characteristic data of the surrounding rock of the inclined shaft include the stratification location of the surrounding rock of the inclined shaft, the cohesion and internal friction angle of each stratification of the surrounding rock of the inclined shaft, the width of the annular void around the inclined shaft, and the measured radius of the loosened zone of the surrounding rock of the inclined shaft. The water inflow data of the inclined shaft includes the location of the leakage point, the number of leakage points, and the total water inflow of the inclined shaft. Step 2: Based on the data obtained in Step 1, the theoretical radius of the loosened zone of the surrounding rock of the inclined shaft is calculated using theoretical calculation methods; Step 3: Based on the data obtained in Step 1, a numerical simulation method is used to construct a model of the coal mine inclined shaft and surrounding rock structure, and then the simulated radius of the loosened zone of the surrounding rock of the inclined shaft is calculated. Step 4: Take the maximum value among the measured radius obtained in Step 1, the theoretical radius obtained in Step 2, and the simulated radius obtained in Step 3 as the radius of the loosened zone of the surrounding rock in the inclined shaft, and determine the boundary of the loosened zone of the surrounding rock. Step 5: Determine the radial distance from the outer boundary of the annular void around the inclined shaft to the outer boundary of the loosened zone of the surrounding rock; Step 6: Determine the range of horizontal distances between the closed grouting anti-seepage zone to be constructed and the center point of the inclined well, as well as the range of horizontal distances between the grouting external seepage reinforcement zone to be constructed and the center point of the inclined well. Step 7: Based on the determined range of horizontal distances between the closed grouting anti-seepage zone to be constructed and the center point of the inclined well, the range of horizontal distances between the grouting external seepage reinforcement zone to be constructed and the center point of the inclined well, and the location of the inclined well to be treated, determine the spatial location of the leakage point in the three-dimensional rectangular coordinate system. Step 8: Determine the corresponding ground location of the seepage point based on its spatial location in the three-dimensional rectangular coordinate system. Use the ground location corresponding to the seepage point as the opening position for vertical drilling on the ground. Drill vertically on the ground until the outer boundary of the loosened zone of the surrounding rock of the inclined shaft is reached. Step 9: Obtain the spatial distribution of the reinforcing bars around the leakage point and the location of the gaps between the longitudinal and transverse reinforcing bars, and then determine the opening location of the micro-grouting holes in the inclined shaft and complete the opening. Step 10: Complete the treatment of water leakage in the inclined shaft; Step 10, which describes the treatment of leakage in the inclined well shaft, specifically includes the following sub-steps: Step 10.1: Lower a water pump into a vertical borehole in the ground to pump the water outside the seepage point to the surface, forming an underground flow field near the seepage point. Step 10.2: Inject the first cement grout into the annular gap between the inclined shaft and the surrounding rock through the micro-grouting holes in the shaft to form a closed grouting anti-seepage zone in the annular gap between the inner boundary of the loosened zone between the inclined shaft and the surrounding rock. Step 10.3: Before the grouting anti-seepage zone is fully set, insert an extension screen pipe into the micro grouting hole of the inclined shaft, extending into the surrounding rock within the loosened zone of the inclined shaft. The extension screen pipe serves as a drainage channel for water outside the loosened zone of the inclined shaft. Step 10.4: Water from the outside of the loosened zone of the surrounding rock of the inclined shaft is introduced into the inclined shaft through the extended screen pipe, and a second cement grout is injected into the vertical borehole on the ground to form a seepage prevention and reinforcement zone outside the closed grouting seepage prevention zone.

2. The method for targeted treatment of leakage in inclined wellbore in water-rich formations as described in claim 1, characterized in that, The radial distance from the outer boundary of the annular void around the inclined shaft to the outer boundary of the loosened zone of the surrounding rock, as described in step 5, is determined by the following formula: D 外 =R b -R0-D 内 ; In the formula: D 外 The radial distance, in meters, is from the outer boundary of the annular void around the inclined shaft to the outer boundary of the loosened zone of the surrounding rock. R b The radius of the loosened zone of the surrounding rock of the inclined shaft is in meters. R0 is the equivalent radius of the inclined shaft, in meters (m). D 内 The width of the annular void around the inclined shaft is measured in meters (m).

3. The method for targeted treatment of leakage in inclined wellbore in water-rich formations as described in claim 1, characterized in that, The range of values ​​for the horizontal distance between the closed grouting seepage barrier to be constructed and the center point of the inclined well shaft, as described in step 6, is determined by the following formula: In the formula: S 内 The range of values ​​for the horizontal distance between the closed grouting seepage barrier to be constructed and the center point of the inclined shaft is given in meters. D 内 The width of the annular void surrounding the inclined shaft, in meters; b This refers to the width of the inclined shaft, in meters (m).

4. The method for targeted treatment of leakage in inclined wells in water-rich formations as described in claim 1, characterized in that, The range of values ​​for the horizontal distance between the grouting and seepage reinforcement zone to be constructed and the center point of the inclined well shaft, as described in step 6, is determined by the following formula: In the formula: S 外 The range of values ​​for the horizontal distance between the grouting and seepage reinforcement zone to be constructed and the center point of the inclined well shaft is given in meters. b This refers to the width of the inclined shaft, in meters (m). D 内 The width of the annular void surrounding the inclined shaft, in meters; D 外 It is the radial distance from the outer boundary of the annular void around the inclined shaft to the outer boundary of the loosened zone of the surrounding rock, in meters.

5. The method for targeted treatment of leakage in inclined wellbore in water-rich formations as described in claim 1, characterized in that, The opening position of the micro grouting hole in the inclined shaft described in step 9 is the center point of the gap between the longitudinal and transverse reinforcing bars.

6. The method for targeted treatment of leakage in inclined wellbore in water-rich formations as described in claim 1, characterized in that, The first cement slurry described in step 10.2 has a water-cement ratio of 0.8 to 1.5, a setting time of 20 to 40 minutes, a fluidity of 20 to 25 cm, and a 28-day strength of 8 to 20 MPa.

7. The method for targeted treatment of leakage in inclined wellbore in water-rich formations as described in claim 1, characterized in that, Step 10.4 The second cement slurry has a water-cement ratio of 0.9 to 1.8, a fly ash content of 30% to 90%, a setting time of 30 min to 90 min, a fluidity of 21 to 26 cm, and a 28-day strength of 4 MPa to 13 MPa.

8. The method for targeted treatment of leakage in inclined wellbore in water-rich formations as described in claim 1, characterized in that, The spatial distribution of the reinforcing bars around the leakage point and the location of the gaps between the longitudinal and transverse reinforcing bars were obtained using a detection instrument installed on the wall of the inclined shaft.

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