Method for grouting and water plugging of sandstone aquifer

Abstract

The present application relates to the technical field of coal mining, and provides a sandstone aquifer grouting water plugging method, which comprises the following steps: drilling at least two grouting channels by a drilling machine; wherein one end of the grouting channel is located at the bottom plate of a direct water filling aquifer; configuring slurry by a grouting device, and injecting the slurry into the sandstone formation through the grouting channel; and driving the slurry to diffuse and flow by a grouting electric device. In the embodiment of the present application, the slurry diffusion flow is determined by the grouting electric device, so that the diffusion range of the slurry is increased.

Description

Technical Field

[0001] This invention relates to the field of coal mining technology, and in particular to a grouting and water-blocking method for sandstone aquifers. Background Technology

[0002] With the continuous changes in production and daily life, people's demand for coal resources is gradually increasing, leading to the need for mining surface coal resources. In some areas, sandstone fissures and aquifers are widely developed in the overlying strata of the main coal seams, and the water volume is relatively abundant. During mechanized mining, this may cause water inrush or gushing from the coal seam roof, resulting in water seepage accidents at the mining face. Sandstone grouting is one of the important technologies for preventing water from entering the coal seam roof. Currently, the main sandstone grouting methods have the significant drawback of a small grout diffusion range. To achieve the desired water-blocking effect, a large amount of engineering work is required, leading to increased engineering costs. Summary of the Invention

[0003] This invention provides a grouting and water plugging method for sandstone aquifers, which solves the defect of small grout diffusion range in the prior art and achieves the technical effect of increasing the diffusion range of grout.

[0004] This invention provides a grouting and water plugging method for sandstone aquifers, comprising:

[0005] At least two grouting channels are drilled using a drilling rig; one end of each grouting channel is located at the bottom plate of the directly filled aquifer.

[0006] The prepared grout is injected into the sandstone stratum through the grouting channel using grouting equipment;

[0007] The grout is diffused and flowed by an electric grouting device.

[0008] According to the present invention, a grouting and water plugging method for sandstone aquifers is provided, wherein the grout comprises CaCl2 solution or Na2SiO3 solution.

[0009] According to the present invention, a grouting and water plugging method for sandstone aquifers is provided, wherein the concentration of the CaCl2 solution or the Na2SiO3 solution is 25% to 40%.

[0010] According to the present invention, a grouting and water plugging method for sandstone aquifers is provided. The grouting electric device includes a DC power supply, a conductor, and positive and negative electrodes. The positive and negative electrodes are connected to the DC power supply through the conductor, and the positive and negative electrodes are respectively inserted into two adjacent grouting channels.

[0011] According to the present invention, a grouting and water plugging method for sandstone aquifers is provided, wherein the voltage range of the DC power supply is 200V to 600V, and the conductor is copper wire.

[0012] According to the present invention, a grouting and water plugging method for a sandstone aquifer is provided, wherein the grouting channel has a three-section structure, wherein the first section of the three-section structure is opened to the bedrock, the second section of the three-section structure is opened to the upper layer of the grouting section, and the third section of the three-section structure is the grouting section, which is opened to the bottom plate of the directly filled aquifer.

[0013] According to the present invention, a grouting and water plugging method for sandstone aquifers is provided, wherein the grouting section includes bare holes or perforated pipes.

[0014] According to the present invention, a grouting and water plugging method for sandstone aquifers is provided, wherein drilling at least two grouting channels by a drilling rig includes:

[0015] The borehole spacing is determined based on the diffusion range of the grout, and at least two grouting channels are drilled according to the borehole spacing.

[0016] According to the present invention, a grouting and water plugging method for a sandstone aquifer includes injecting a prepared grout into the sandstone formation through the grouting channel using a grouting device, comprising:

[0017] During the process of injecting the grout into the sandstone sub-base, the grout pressure and / or grout concentration are adjusted by the injection volume of the grout.

[0018] According to the present invention, a grouting and water plugging method for sandstone aquifers is provided, wherein the diameter of the grouting channel ranges from 98 mm to 445 mm.

[0019] This invention provides a grouting and water plugging method for sandstone aquifers. At least two grouting channels are drilled using a drilling rig. One end of each channel is located on the bottom plate of the directly filled aquifer above the main coal seam. Grout is injected into the grouting channels using grouting equipment, thereby injecting the grout into the sandstone stratum where the grouting section is located. Electric grouting equipment then diffuses and flows the grout, increasing its diffusion radius. During diffusion, the grout reacts chemically with minerals in the groundwater, forming small-particle precipitates. This effectively blocks the channels through which groundwater flows into the mine, reducing the amount of water entering the mine via lateral recharge. This method effectively solves the problem of small grout diffusion range in sandstone aquifer grouting technology, significantly increasing the grout diffusion radius. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0021] Figure 1This is a schematic flowchart of the grouting and water plugging method for sandstone aquifers provided by the present invention. Detailed Implementation

[0022] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0023] The following is combined Figure 1 The present invention describes a grouting and water plugging method for sandstone aquifers.

[0024] Figure 1 This is a flowchart illustrating a grouting and water plugging method for a sandstone aquifer according to an exemplary embodiment, such as... Figure 1 As shown in an exemplary embodiment, the BMC Flash upgrade method includes steps 110 to 130, which are described in detail below:

[0025] Step 110: Drill at least two grouting channels using a drilling rig; wherein one end of each grouting channel is located at the bottom plate of the directly filled aquifer.

[0026] Step 120: Using grouting equipment, inject the prepared grout into the sandstone stratum through the grouting channel;

[0027] Step 130: Drive the grout to diffuse and flow using an electric grouting device.

[0028] In this embodiment of the invention, at least two grouting channels are drilled using directional drilling technology. One end of each grouting channel is located on the bottom plate of the directly water-filled aquifer above the main coal seam. A grouting pump is used to pump grout into the grouting channel, injecting the grout into the sandstone stratum where the grouting section is located. Electric grouting equipment then diffuses the grout, increasing its diffusion radius. During diffusion, the grout reacts chemically with minerals in the groundwater, forming small-particle precipitates that block the channels through which groundwater enters the mine, reducing the amount of water entering the mine via lateral recharge. This effectively solves the problems of small grout diffusion range and small grout volume in sandstone aquifer grouting technology, significantly increasing the grout diffusion radius. It also reduces the amount of engineering work required for water plugging in sandstone strata, lowers construction costs, and improves coal mine efficiency. Furthermore, it is more conducive to safe mine production, reducing the impact of mine water on coal mine safety and laying a foundation for safe coal mine production.

[0029] In an exemplary embodiment of the present invention, the slurry comprises a CaCl2 solution or a Na2SiO3 solution.

[0030] In an exemplary embodiment of the present invention, the concentration of the CaCl2 solution or the Na2SiO3 solution is 25% to 40%.

[0031] In this embodiment of the invention, the grouting material is selected from CaCl2 solution or Na2SiO3 solution, with a concentration of 25% to 40%. It is then stirred with water to prepare a grout.

[0032] In an exemplary embodiment of the present invention, the grouting electric device includes a DC power supply, electrical wires, and positive and negative electrodes. The positive and negative electrodes are connected to the DC power supply through the electrical wires, and the positive and negative electrodes are respectively inserted into two adjacent grouting channels.

[0033] In an exemplary embodiment of the present invention, the voltage range of the DC power supply is 200V to 600V, and the conductor is copper wire.

[0034] In this embodiment of the invention, the grouting electric device includes: a DC power supply, conductors, and positive and negative electrodes. The DC power supply can provide a voltage of 200V to 600V, provides a stable voltage output, and can display the output voltage and current values. The conductors are copper wires with a diameter φ of 3mm to 10mm. The positive and negative electrodes are made of copper or iron with a diameter φ of 10mm to 50mm, and are respectively connected to the positive and negative terminals of the DC power supply via conductors.

[0035] During grouting, the cathode and anode of the grouting motor are placed into two adjacent grouting channels, respectively. A DC power supply is then connected, and the voltage is adjusted to allow the grout to diffuse and flow under electric drive.

[0036] In an exemplary embodiment of the present invention, the grouting channel has a three-section structure, wherein the first section of the three-section structure extends to the bedrock, the second section of the three-section structure extends to the upper layer of the grouting section, and the third section of the three-section structure is the grouting section, extending to the bottom plate of the directly filled aquifer.

[0037] In this embodiment of the invention, drilling begins at the ground level, and the resulting grouting channels have a three-section structure. In one embodiment, the borehole diameter of the first section can be set to 219 mm, with one end penetrating 10 m into the bedrock. Drilling continues after the surface casing of the first section is cemented. The borehole diameter of the second section can be set to 168 mm, with a 127 mm diameter casing installed to a depth of 480 m, at a level 10 m above the grouting section. Drilling continues after the surface casing of the second section is cemented. The borehole diameter of the third section can be set to 110 mm, which is a bare borehole with a final depth of 600 m, at the level of the Luohe Formation sandstone aquifer, the main water-bearing aquifer in the coal seam being mined. The borehole spacing between adjacent grouting channels is 30 m.

[0038] In this embodiment of the invention, the area above the grouting section is completely sealed with steel pipes, and the outside of the steel pipes is cemented with cement.

[0039] In an exemplary embodiment of the present invention, the grouting section includes a bare hole or a perforated pipe.

[0040] In this embodiment of the invention, the screw holes are obtained through direct drilling without any other pipes. The grout directly fills and permeates into the formation in the grouting section. The perforated pipe is a thin-walled steel pipe with small holes drilled at varying intervals in its wall. During grouting, by controlling the grouting volume and pressure, the grout is evenly injected into the formation from the perforated steel pipe. The grout fills the voids in the formation through filling, permeation, splitting, and compaction, cementing the originally loose soil particles or fissures into a whole, forming a solidified body with a new structure, high strength, and good integrity, thereby achieving the purpose of reinforcing the formation and reducing soil disturbance.

[0041] In an exemplary embodiment of the present invention, step 110, which involves drilling at least two grouting channels using a drilling rig, includes the following steps, detailed below:

[0042] The borehole spacing is determined based on the diffusion range of the grout, and at least two grouting channels are drilled according to the borehole spacing.

[0043] In this embodiment of the invention, the drilling spacing is determined according to the diffusion range of the slurry. The diffusion range is proportional to the drilling spacing, that is, the larger the diffusion range, the larger the drilling spacing. Thus, when the slurry is driven to diffuse and flow by the grouting electric equipment, the slurry can be better diffused, so that the final diffusion range reaches a larger area.

[0044] In an exemplary embodiment of the present invention, step 120, which involves injecting the prepared grout into the sandstone formation through the grouting channel using a grouting device, includes the following steps, detailed below:

[0045] During the process of injecting the grout into the sandstone sub-base, the grout pressure and / or grout concentration are adjusted by the injection volume of the grout.

[0046] In this embodiment of the invention, during the process of injecting grout into the sandstone bottom layer, the grout pressure and / or grout concentration are adjusted by the grout injection volume. The grout injection volume is inversely proportional to the grout pressure and grout concentration; the larger the grout injection volume, the smaller the corresponding grout pressure and grout concentration.

[0047] In an exemplary embodiment of the present invention, the aperture of the grouting channel ranges from 98 mm to 445 mm.

[0048] In this embodiment of the invention, when the grouting channel has a multi-section structure, its aperture gradually decreases as it goes deeper underground. As mentioned above, when the grouting channel has a three-section structure, the aperture of the grouting section is the smallest, and the aperture of the single-section well is the largest.

[0049] In an exemplary embodiment of the present invention, the grouting and water plugging method for sandstone aquifers includes the steps of drilling, assembling grouting electric equipment, preparing grout, and grouting. The details of each step are as follows:

[0050] During the drilling process, workers drilled holes on the surface to obtain grouting channels. The borehole was a three-section structure. The diameter of the first section was set at 219mm, with one end penetrating 10m into the bedrock. After cementing the surface casing of the first section, drilling continued. The diameter of the second section was set at 168mm, with a 127mm diameter casing installed to a depth of 480m, 10m above the grouting section. After cementing the surface casing of the second section, drilling continued. The diameter of the third section was set at 110mm, and it was a bare borehole with a final depth of 600m. The final borehole was located in the Luohe Formation sandstone aquifer, the main water-bearing aquifer of the coal seam being mined. The distance between adjacent grouting channels was 30m.

[0051] In the assembly process of the grouting electric equipment, the DC power supply voltage of the grouting electric equipment is 400V, the conductor is copper wire with a diameter of 3mm, and the positive and negative electrodes are made of iron with a wire diameter of 10mm, and are connected to the positive and negative terminals of the DC power supply respectively.

[0052] In the slurry preparation step, the grouting material is selected as Na2SiO3 solution with a concentration of 25%, which is stirred with water to make slurry.

[0053] In the grouting process, the cathode and anode of the grouting electric equipment are placed in two adjacent grouting channels 30m apart. A grouting pump is used to pump the grout into the grouting pipeline, injecting the grout into the sandstone stratum where the grouting section is located. The grout pressure and concentration are adjusted appropriately according to the grouting volume. The DC power supply to the grouting electric equipment is connected, and the voltage is adjusted to allow the grout to diffuse and flow under electric drive. Grouting is stopped once the grout injected into the sandstone stratum reaches the designed grouting volume and pressure.

[0054] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "method," "specific method," or "some methods," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or method is included in at least one embodiment or method of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or method. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or methods. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or methods described in this specification, as well as the features of different embodiments or methods.

[0055] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method of grouting and water shutoff of sandstone aquifer, characterized in that, The method comprises the following steps: drilling at least two grouting channels by a drilling rig, wherein one end of the grouting channel is located at the bottom of the direct water filling aquifer; injecting the prepared slurry into the sandstone formation through the grouting channel by a grouting device; driving the slurry to diffuse and flow by a grouting electric device; the grouting channel is a three-opening structure, wherein one opening well section of the three-opening structure is opened to the bedrock, two opening well section of the three-opening structure is opened to the upper layer of the grouting section, and three opening well section of the three-opening structure is the grouting section and is opened to the bottom of the direct water filling aquifer; wherein the aperture of the one opening well section is 219mm, the one opening well section penetrates into the bedrock by 10m, the aperture of the two opening well section is 168mm, the two opening well section penetrates into the casing with an aperture of 127mm by 480m, and the layer position is 10m above the grouting section, the aperture of the three opening well section is 110mm, the three opening well section is a bare hole, the final hole depth is 600m, and the final hole layer position is the water filling aquifer of the sandstone of Luohe group of the coal mining aquifer; injecting the prepared slurry into the sandstone formation through the grouting channel by a grouting device, comprising: putting the cathode and anode of the grouting electric device into two adjacent grouting channels with a distance of 30m respectively, pumping the slurry into the grouting pipeline by a grouting pump, injecting the slurry into the sandstone formation where the grouting section is located by the grouting pump, and adjusting the slurry pressure and concentration according to the grouting amount; driving the slurry to diffuse and flow by a grouting electric device, comprising: connecting the direct current power supply of the grouting electric device and adjusting the voltage, so that the slurry diffuses and flows under the electric drive, and stopping grouting when the slurry injected into the sandstone formation reaches the designed grouting amount and grouting pressure.

2. The method of grouting and water shutoff of sandstone aquifer according to claim 1, characterized in that, The slurry comprises CaCl2 solution or Na2SiO3 solution.

3. The method of grouting and water shutoff of sandstone aquifer according to claim 2, characterized in that, The concentration of the CaCl2 solution or the Na2SiO3 solution is 25% to 40%.

4. The method of grouting and water shutoff of sandstone aquifer according to claim 1, characterized in that, The grouting electric device comprises a direct current power supply, an electric lead and cathode and anode electrodes, the cathode and anode electrodes are connected with the direct current power supply through the lead, and the cathode and anode electrodes are respectively inserted into two adjacent grouting channels.

5. The method of grouting and water shutoff of sandstone aquifer according to claim 4, characterized in that, The voltage range of the direct current power supply is 200V to 600V, and the lead is copper wire.

6. The method of grouting and water shutoff of sandstone aquifer according to claim 1, characterized in that, The grouting section comprises a bare hole or a flower tube.

7. The method of grouting and water plugging of sandstone aquifers according to any one of claims 1 to 6, characterized in that, The method of drilling at least two grouting channels by a drilling rig comprises: determining the drilling hole spacing according to the diffusion range of the slurry, and drilling at least two grouting channels according to the drilling hole spacing.

8. The method of grouting and water plugging of sandstone aquifers according to any one of claims 1 to 6, characterized in that, The aperture range of the grouting channel is 98mm to 445mm.

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