A grouting water plugging device for treating water inrush of a wellbore working face

Abstract

This utility model relates to a grouting and water-blocking device for treating water inrush at a well working face. It includes a water-blocking structure and construction tools. The water-blocking structure is positioned above the water-rushing working face and below the static water level. The structure comprises, from bottom to top, an isolation filter layer, a pressure cushion layer, and a single-liquid grout stop layer. The construction tools include a grouting pipe and a high-pressure grouting pump. The upper end of the grouting pipe is connected to the high-pressure grouting pump, which is located outside the well. The grouting pipe consists of a seamless steel pipe body with several outwardly extending grout nozzles in the upper middle part. A limiting device is located below the grout nozzles on the seamless steel pipe, allowing grout to flow only from the nozzles when activated. This utility model employs a three-layer combined grouting and water-blocking structure consisting of an isolation filter layer, a pressure cushion layer, and a single-liquid grout stop layer. The grout stop layer structure formed by underwater integrated casting is more robust, enabling rapid and efficient sealing of water inrush at the working face and reducing project costs.

Description

Technical Field

[0001] This utility model relates to the field of grouting structure technology for water prevention and control in underground mining engineering shafts, and is particularly aimed at the problem of water inrush at the working face of deep buried vertical shafts in heterogeneous strata such as karst. Background Technology

[0002] Mineral resources are an important pillar of national economic development. With the increasing depletion of shallow, easily mined mineral resources, most mines are gradually shifting to deep mining. Shaft excavation and lining are key links in extending mining depth, but due to the complex hydrogeological conditions at depth, sudden water inrush accidents are prone to occur, seriously threatening the safety of personnel and equipment, while also restricting project progress and increasing economic costs.

[0003] Grout stoppers are a key structure for water control during shaft construction, playing an irreplaceable role in shaft excavation and emergency rescue operations involving sudden water inrushes at the working face. However, traditional grout stopper construction methods suffer from drawbacks such as numerous pre-embedded pipes, limited grout diffusion radius, insufficient compressive strength, poor sealing, and susceptibility to grout leakage. These methods struggle to quickly form a grouting and water-stopping structure layer that meets the required thickness, compressive strength, and water-stopping capacity. Consequently, they fail to achieve ideal grouting and water-stopping effects in deep mines with high pressure, high flow rates, and strong permeability (water-rich fractured zones, heterogeneous aquifers). Summary of the Invention

[0004] The specific solution of this utility model is: a grouting and water-blocking device for dealing with water inrush at the working face of a well, comprising a water-blocking structure and construction tools. The water-blocking structure is set above the water inrush working face and below the static water level. The water-blocking structure includes an isolation filter layer, a pressure pad layer, and a single-liquid grout stop pad layer arranged sequentially from bottom to top. The construction tools include a grouting pipe and a high-pressure grouting pump. The upper end of the grouting pipe is connected to the high-pressure grouting pump, which is located outside the well. The grouting pipe includes a seamless steel pipe body. Several outwardly extending grouting nozzles are provided in the middle and upper part of the seamless steel pipe. A limiting device is provided below the grouting nozzles on the seamless steel pipe. When the limiting device is activated, the grout can only flow out from the grouting nozzles.

[0005] Furthermore, the grouting pipe includes a seamless steel pipe body, with three outwardly extending grouting nozzles in the upper part of the seamless steel pipe. The three grouting nozzles are at a 120° angle to each other. A limiting device is provided below the grouting nozzles on the seamless steel pipe. When the limiting device is activated, the grout can only flow out from the grouting nozzles. During construction, the grouting nozzles are located above the pressure pad layer.

[0006] Furthermore, the limiting device includes a retaining ring and a plug ball. The retaining ring is fixedly connected to the inner wall of the grouting pipe, and the diameter of the plug ball is larger than the diameter of the retaining ring but smaller than the inner diameter of the grouting pipe. The limiting device is activated by inserting the plug ball into the grouting pipe.

[0007] Furthermore, the bottom of the grouting pipe is provided with a grouting head, and multiple perforated holes are evenly distributed on the side of the grouting head, with each perforated hole communicating with the grouting pipe.

[0008] Furthermore, the filling material for the isolation filter layer is selected from stones with a particle size of 10~30mm; the filling material for the pressure pad layer is selected from red bricks, large-diameter pebbles, or large rocks.

[0009] Compared with the prior art, this utility model has the following advantages: 1. This utility model adopts a layered design, integrating isolation and filtration, pressure equalization, and efficient water plugging functions; the isolation and filtration layer can effectively block mud and sand at the bottom of the well, reduce uplift pressure, and significantly improve the safety of underwater operations; the pressure cushion layer, through its thickness advantage, evenly disperses water and soil pressure and grouting reaction force, greatly enhancing the overall stability and compressive strength of the grout-stopping cushion layer. At the same time, this layer forms a basic grouting skeleton structure, which can improve grout adhesion, reduce usage, and shorten the filling path and solidification time; the grout-stopping cushion layer composed of single-liquid grout provides rigid water stoppage, achieving efficient sealing of water inrush at the working face.

[0010] 2. In this utility model, a grouting nozzle is welded to the grout outlet of the grouting pipe, which effectively prevents the grouting pipe from becoming blocked and enables the grout to diffuse in a directional and uniform manner in the pressure pad layer and the isolation filter layer. The three grouting nozzles are controlled by a limiting device to increase the grout diffusion radius of the single-liquid grout stop pad layer and improve the efficiency of grouting work.

[0011] 3. This utility model adopts high-pressure jet grouting technology, which has the advantages of good grout fluidity and high uniformity of grout output compared with concrete grouting method, thereby effectively improving the structural strength of the grouting plug and reducing the overall cost. Attached Figure Description

[0012] Figure 1 This is a construction diagram of this utility model;

[0013] Figure 2 This is a schematic diagram of the grouting pipe of this utility model;

[0014] Figure 3 yes Figure 2 Enlarged view of point V;

[0015] In the diagram: 1. Well shaft; 2. Static water level; 3. Limiting device; 31. Retaining ring; 32. Plug ball; 4. Isolation filter layer; 5. Pressure pad layer; 6. Single-liquid grout stop pad layer; 7. Grouting pipe; 8. Grouting head; 9. Hole; 10. Grouting nozzle; 11. Water inrush working face; 12. High-pressure grouting pump; 13. Drainage pump; 14. Drainage pipe. Detailed Implementation

[0016] like Figure 1-3As shown, this embodiment provides a grouting and water-blocking device for treating water inrush at the wellhead working face. The specific construction process includes the following steps:

[0017] This embodiment uses a pre-fabricated grouting pipe 7, which includes a seamless steel pipe body. Three outwardly extending grouting nozzles 10 are located in the upper part of the seamless steel pipe, with each nozzle 10 forming a 120° angle with the others. A limiting device 3 is located below the nozzles 10 on the seamless steel pipe. When the limiting device 3 is activated, the grout can only flow out from the nozzles 10. A grouting head 8 is located at the bottom of the grouting pipe 7, and multiple perforated holes 9 are evenly distributed on the side of the grouting head 8. Each perforated hole 9 communicates with the grouting pipe 7. The limiting device 3 includes a retaining ring 31 and a plug ball 32. The retaining ring 31 is fixedly connected to the inner wall of the grouting pipe 7. The diameter of the plug ball 32 is larger than the diameter of the retaining ring 31 but smaller than the inner diameter of the grouting pipe 7. The limiting device 3 is activated by inserting the plug ball 32 into the grouting pipe 7. Step 1: Static water level 2 observation: Before construction, the water inflow and static water level 2 of the well shaft 1 should be observed over a long period. Based on the obtained monitoring data, the thickness of the three construction layers in this grouting and water-blocking structure is calculated. After the wellbore 1 rises to the static water level 2, the change range of the water accumulation elevation in the wellbore 1 is observed for 12 hours to determine whether the process implementation conditions are met. The thickness A of the isolation filter layer 4, the thickness B of the pressure cushion layer 5, and the thickness C of the single-liquid grout stop cushion layer 6 are calculated as follows: A = Q1 / (πβr) + 0.25; B = xA (x is 3~5); C = Pr / σ + 0.3r; where Q1 is the water inflow in the wellbore 1 within 15 minutes, β is the porosity of the filter layer filler, r is the excavation radius of the wellbore 1, P is the maximum grouting pressure, and σ is the allowable compressive strength of the concrete. In this embodiment, taking a certain construction site as an example, the thickness A of the isolation filter layer 4, the thickness B of the pressure cushion layer 5, and the thickness C of the single-liquid grout stop cushion layer 6 are calculated according to the above formulas as 1m, 3m, and 5m respectively. Step 2: Construction of the Isolation Filter Layer 4: Before construction of this layer, use a long rope or steel wire to suspend a heavy object and measure in detail the water depth inside the well barrel 1 and the thickness of the silt at the bottom of the well. Lower the hoisting platform to a suitable position and place about 1m thick gravel with a particle size of 10-20mm into the well bottom to isolate the silt at the bottom of the well. Step 3: Lowering the Grouting Pipe 7: Use a winch, bucket, steel wire rope, etc. to vertically lower the grouting pipe 7 into the well barrel 1 until the grouting head 8 contacts the upper surface of the isolation filter layer 4 at the bottom of the well. Step 4: Construction of the Pressure Cushion Layer 5: After the grouting pipe 7 is lowered into place, lower the bucket above the water surface in the well barrel 1 and evenly throw red bricks into the area of ​​the well barrel 1. The thickness of the red brick layer is about 3m. Step 5: Bottom Grouting: Using the 3SNS high-pressure grouting pump 12, inject a single-liquid ordinary silicate cement grout with a water-cement ratio of 0.75:1, modified with 0.05% triethanolamine and 0.5% industrial salt into the grouting pipe 7 in the well shaft 1. Stop grouting once the grout has filled the isolation filter layer 4 and the pressure cushion layer 5 skeleton. Before grouting, estimate the grouting volume of the isolation filter layer 4 and the pressure cushion layer 5: Q2 = πr²h(1 - 1 / k); where r is the excavation radius of the well shaft 1, h is the thickness of the isolation filter layer 4 and the pressure cushion layer 5, and k is the looseness coefficient of the filling material. The approximate grouting time for the isolation filter layer 4 and the pressure cushion layer 5 can be determined based on the calculated Q2 and the parameters of the grouting pump.Step 6: Constructing the single-component grout sealing layer 6: A plugging ball 32 (approximately φ40mm cast iron ball) is placed into the grouting pipe 7. The plugging ball blocks the retaining ring 31, thus activating the limiting device 3. At this point, the limiting device 3 is positioned above the pressure cushion layer 5. After the pneumatic limiting device 3 is activated, the grout can only be evenly sprayed from the three nozzles above the grouting pipe 7. Grouting continues into the grouting pipe 7 until the sealing layer thickness reaches the calculated 5m. Then, the grouting pipe 7 is withdrawn. Step 7: Draining accumulated water and verifying the water-sealing effect: After curing and confirming that the single-component grout sealing layer 6 at the bottom of the well has sufficient strength, a drainage pump 13 connected to a drainage pipe 14 is inserted into the upper surface of the single-component grout sealing layer 6 to begin draining accumulated water. During drainage, the water level change inside the well shaft 1 is observed, and the water-sealing effect at the bottom of the well is preliminarily calculated. If the conditions are met, the accumulated water at the bottom of the well is completely drained. If the water sealing effect is poor, consider extending the curing time or injecting a 2-3m thick layer of single-component grout through another grouting pipe 7. Drainage should only proceed after the grout reaches the required strength. Step 8: Grouting Pad Reinforcement: If, after draining the water from well 1, there is still significant concentrated water discharge or large-area seepage on the surface of the single-component grouting pad, a 2m thick layer of C40, P8 anti-seepage concrete grouting pad needs to be poured on top of the existing grouting pad. The grouting and water-blocking construction method for treating sudden water inrush at the working face of well 1 described in this utility model has the core advantage of achieving a synergistic effect of water isolation and filtration, pressure equalization, and efficient water blocking through layered design. It can directly complete the integrated pouring of the water isolation and filtration layer 4, pressure pad layer 5, and single-component grouting pad layer 6 underwater, even when sudden water inrush occurs at the working face of well 1 and drainage is not required. This invention effectively overcomes the technical problems of large drainage and long grout solidification period in traditional well construction using grout sealing pads. The constructed water-blocking structure has excellent stability, high compressive strength and excellent water-blocking effect, while significantly saving construction time and economic costs.

Claims

1. A grouting and water-blocking device for treating water inrush at a well working face, characterized in that: The system includes a water-blocking structure and construction tools. The water-blocking structure is located above the water inrush working face and below the static water level. The water-blocking structure includes, from bottom to top, an isolation filter layer, a pressure pad layer, and a single-liquid grout stop pad layer. The construction tools include a grouting pipe and a high-pressure grouting pump. The upper end of the grouting pipe is connected to the high-pressure grouting pump, which is located outside the well shaft. The grouting pipe includes a seamless steel pipe body. Several outwardly extending grouting nozzles are provided in the upper middle part of the seamless steel pipe. A limiting device is provided below the grouting nozzles on the seamless steel pipe. When the limiting device is activated, the grout can only flow out from the grouting nozzles.

2. The grouting and water-blocking device for treating water inrush at the wellhead working face according to claim 1, characterized in that: The limiting device includes a retaining ring and a plug ball. The retaining ring is fixedly connected to the inner wall of the grouting pipe. The diameter of the plug ball is larger than the diameter of the retaining ring but smaller than the inner diameter of the grouting pipe. The limiting device is activated by inserting the plug ball into the grouting pipe.

3. A grouting and water-blocking device for treating water inrush at a well working face according to claim 1, characterized in that: The bottom of the grouting pipe is equipped with a grouting head, and multiple perforated holes are evenly distributed on the side of the grouting head, with each perforated hole connected to the grouting pipe.

4. A grouting and water-blocking device for treating water inrush at a well working face according to claim 1, characterized in that: The isolation filter layer is filled with gravel with a particle size of 10-30mm; the pressure cushion layer is filled with red bricks, large-diameter pebbles, or large rocks.

5. A grouting and water-blocking device for treating water inrush at a well working face according to claim 1, characterized in that: The construction tools also include a drainage pump and a drainage pipe. The drainage pump is located outside the well shaft, and one end of the drainage pipe is connected to the drainage pump, while the other end extends to the upper surface of the single-liquid grout stop pad.

Images