Brine well wall anti-collapse structure and construction method and application thereof

Abstract

The invention discloses a brine well wall anti-collapse structure and a construction method and application thereof. The brine well wall anti-collapse structure comprises a supporting disc cavity, a grouting blocking device and a supporting disc pouring body. The grouting blocker is a soft bag and is filled with a first grouting material so as to expand and block the opening of the cavity of the supporting disc; and the branch plate pouring body is formed by injecting second grouting material into the branch plate cavity, and is used for filling the branch plate cavity and plugging a gap between the grouting barrier device and the branch plate cavity. According to the invention, a composite grouting process system of branch plate grouting and high-pressure jet grouting is innovatively developed; a supporting disc structure is formed in a sand layer through expansion and extrusion, then an anti-seepage grouting material is injected through a grouting blocking device to form a sand prevention supporting layer, then a gap between a supporting disc and the grouting blocking device is recharged and solidified through a high-pressure rotary jet grouting technology, and finally a well wall overall reinforcing body formed by mutually meshing and connecting the grouting blocking device and the supporting disc structure is constructed. The problems that an existing brine well faces fine sand silting wells, soft soil layer frameworks are dissolved and collapsed and the like are solved.

Description

Technical Field

[0001] This invention relates to the field of resource extraction technology, and in particular to a brine well wall anti-collapse structure, its construction method, and its application. Background Technology

[0002] After 20 years of intensive mining, the shallow brine in the Qaidam Basin is nearly exhausted. Therefore, pressurized brine with a depth of more than 10 meters and a volume of hundreds of billions of cubic meters has become the core of development. It is rich in elements such as potassium, lithium, and magnesium, and its resource volume is several times that of the shallow brine. Therefore, it has become a key strategic resource to ensure national food and energy security.

[0003] However, pressurized brine is buried at great depths and has relatively dense salt layers, making its development dependent on well extraction technology. For a long time, brine extraction wells have faced four major technical challenges: overall wellhead collapse, well wall cavity collapse, well wall salt deposition, and sudden sand inrush in the wellbore, severely restricting the large-scale extraction of pressurized brine. Of the more than 300 gravel-filled single-casing brine extraction wells constructed by various salt lake companies before 2020, 70% collapsed and were abandoned within a year of operation, with a brine extraction rate of only 40-80 cubic meters per second. 3 The efficiency is low, mainly because the soft soil layer of the salt lake has fluid plasticity, the brine has a complex composition and high mineralization, and the mineral types are diverse. Under the strong hydrodynamic conditions of artificial brine extraction, it faces technical challenges such as fine sand silting up wells and dissolution and collapse of the soft soil layer skeleton.

[0004] Hydration and compression of the clastic layer framework and dissolution by readily soluble salts in well-mining areas are the main causes of formation instability and collapse. In contrast, the instability and collapse of the soft soil layer in salt lake well-mining areas is the result of a synergistic effect of multiple mechanisms including hydration, dissolution, scouring, and mechanical degradation. Specifically, this manifests as: intense hydration and expansion of clay minerals in high-salinity brine environments, leading to a significant decrease in cementation strength; simultaneous rapid dissolution of readily soluble salts (such as NaCl) forming a dissolution pore network; and under strong brine extraction dynamic conditions (e.g., at depths of 120-240m), further deterioration occurs. 3 Under the scouring of / h), the soft soil layer undergoes narrowing and plastic flow, and fine particles are continuously lost.

[0005] Operational practice has proven that isolating and preventing seepage, and reducing water immersion and erosion are key aspects of new technologies for treating soft soil layers. Currently, publicly available methods for treating soft soil layers in salt lake areas include rockfill displacement, dynamic compaction replacement, replacement filling, gravel piles, and curtain grouting. For example, Chinese invention patents ZL202223033295.1 and CN117468894A employ the rockfill displacement method, which involves filling the soft soil layer with gravel to improve soil support and integrity, preventing cavities in the well wall. Other Chinese invention patents, including ZL202223033295.1, CN111287703A, CN112459752A, and CN111287704A, all focus on the wellhead edge. The method involves continuous bottom-up drilling and grouting, using a grouting pump to inject cementitious materials composed of magnesium oxide, magnesium chloride, brine, and saline soil in different proportions into the strata to form a continuous and closed curtain wall; the Chinese invention with patent number ZL202323362516.4 uses multiple steel cage-wrapped piles and multiple mesh bag-wrapped piles at the wellhead to place crushed stone in high-strength geotextile bags, restricting the lateral movement of the crushed stone material, improving the shear strength and vertical bearing capacity of the pile, improving the water resistance of the soft soil layer, and preventing the well from collapsing.

[0006] However, the above-mentioned technical solutions all have problems such as insufficient structural reinforcement strength and weak anti-seepage ability, and in practical applications they still cannot meet the well wall anti-collapse requirements under the dynamic conditions of strong brine extraction. Summary of the Invention

[0007] To address the shortcomings of existing technologies, the present invention aims to provide a brine well wall anti-collapse structure, its construction method, and its application.

[0008] To achieve the aforementioned objectives, the technical solution adopted by this invention includes:

[0009] In a first aspect, the present invention provides a brine well wall anti-collapse structure, which includes a support plate cavity, a grouting barrier and a support plate injection body;

[0010] The opening of the support plate cavity is located on the well wall, and the cavity extends radially along the brine well; the grouting barrier is a soft bag filled with a first grouting material to expand and seal the opening of the support plate cavity; the support plate injection body is formed by injecting a second grouting material into the support plate cavity, filling the support plate cavity and sealing the gap between the grouting barrier and the support plate cavity.

[0011] Secondly, the present invention also provides a method for constructing an anti-collapse structure for brine well walls, comprising:

[0012] An expansion drill bit is used to expand the well wall, forming a support cavity;

[0013] Insert the grouting barrier into the vicinity of the support plate cavity, and inject the first grouting material into the grouting barrier to cause the grouting barrier to expand and seal the opening of the support plate cavity;

[0014] A second grout is injected near the cavity of the support plate using a high-pressure rotary jet method, so that the second grout is injected into the cavity of the support plate and seals the gap between the grouting barrier and the cavity of the support plate, forming a support plate grouting body.

[0015] Thirdly, the present invention also provides a brine well, the brine well having the above-mentioned brine well wall anti-collapse structure and auxiliary structures, the auxiliary structures including a brine pump and a brine conveying pipeline disposed in the brine well, the brine conveying pipeline extending from the brine pump to the outside of the well.

[0016] Based on the above technical solution, compared with the prior art, the beneficial effects of the present invention include at least the following:

[0017] The technical solution proposed in this invention addresses the technical challenge of wellbore cavitation and collapse during brine extraction in single or multiple layers of soft soil (usually 1-4 layers) in saline-bearing reservoirs of salt lakes. It innovatively develops a composite grouting process system of "support plate injection + high-pressure jet grouting." This technical solution first uses expansion to form a support plate structure in the sand layer. Then, it injects anti-seepage grouting material through a precisely positioned grouting barrier to form a sand-control support layer. Subsequently, high-pressure jet grouting technology is used to backfill and consolidate the gap between the support plate and the grouting barrier. Finally, it constructs an integrally reinforced wellbore structure with the grouting barrier and support plate structure interlocking, achieving the effects of sand fixation and seepage prevention, and wellbore reinforcement. This solves the problems faced by existing brine wells, such as fine sand siltation and soft soil layer dissolution and collapse.

[0018] This invention is based on an original design of a support plate grouting well structure, which constructs a multi-point radial support system to significantly improve well wall stability. When constructing the above structure, a high-pressure jet grouting and debris solidification process is adopted to actively consolidate the soft soil layer of the well wall, effectively preventing the collapse of the well wall cavity under strong hydrodynamic conditions. The grouting material is made of a material with a compressive strength of more than 40MPa, which can significantly improve the ability to resist water erosion.

[0019] Ultimately, the structure provided by this invention enables millimeter-level precision deformation control of the reinforcing layer, successfully solving the technical problem of wellbore cavity collapse under strong brine extraction dynamic conditions.

[0020] The above description is merely an overview of the technical solution of the present invention. In order to enable those skilled in the art to better understand the technical means of this application and to implement it in accordance with the contents of the specification, the preferred embodiments of the present invention are described below in conjunction with detailed drawings. Attached Figure Description

[0021] Figure 1This is a schematic diagram of the structure of a brine well provided in a typical embodiment of the present invention;

[0022] Figure 2 This is an example diagram showing the actual application scenario and settlement monitoring results of the anti-collapse structure provided in a typical embodiment of the present invention;

[0023] Figure 3 This is a real-life photograph of the collapsed state of a brine well provided in a typical comparative case of the present invention;

[0024] Figure 4 This is a real-time photograph of a brine well in operation, provided in a typical embodiment of the present invention.

[0025] Explanation of reference numerals in the attached figures:

[0026] 1. Clay layer; 2. Soft soil layer; 3. Halite layer; 4. Grouting barrier; 5. Support plate cavity; 6. Brine conveying pipeline; 7. Filter pipe section; 8. Solid wall pipe section; 9. Sand settling pipe section; 10. Well wall; 11. Silt barrier layer; 12. Gravel layer; 501. Support plate grouting body; 601. Brine pump. Detailed Implementation

[0027] In view of the shortcomings of the prior art, the inventors of this invention, through long-term research and extensive practice, have proposed the technical solution of this invention. The following will further explain and illustrate this technical solution, its implementation process, and its principles.

[0028] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and therefore the scope of protection of the invention is not limited to the specific embodiments disclosed below.

[0029] Moreover, relational terms such as “first” and “second” are used merely to distinguish one component or method step from another that has the same name, and do not necessarily require or imply any such actual relationship or order between these components or method steps.

[0030] Based on the research and analysis conducted by the inventors of this invention, it is believed that the instability and collapse of the soft soil layer in the salt lake well mining area is the result of the synergistic effects of multiple mechanisms, including hydration, dissolution, scouring, and mechanical degradation. In the high-salinity brine environment, the intense hydration and expansion of clay minerals (expansion rate 150-200%) leads to a significant decrease in cementation strength (cohesion c-value decreases by 40-60%). Simultaneously, readily soluble salts (such as NaCl) rapidly dissolve, forming a dissolution pore network (through-channels are formed when porosity η > 25%). Under strong brine extraction dynamic conditions (120-240m), further deterioration occurs. 3Under scouring ( / h), the soft soil layer undergoes diameter reduction (radial strain > 8%) and plastic flow (shear strain rate > 0.1% / h), with continuous loss of fine particles (15-30%). CT scans show that the piping channels expand at a rate of 0.2-0.5 mm / d. Microscopically, the clay matrix transforms from a dense, sheet-like state to a loose, flocculated state (SEM observation shows that the cementitious material degenerates from a continuous phase to an island-like distribution). The macroscopic mechanical behavior is characterized by a failure mode dominated by an inclined fracture surface caused by weakened shear strength, "pseudo-brittle" fracture propagation characteristics, and the synergistic development of annular fracture networks (width increases by 3-5 times) and plastic flow zones, ultimately leading to wellbore instability and collapse.

[0031] Therefore, regarding the above-mentioned wellbore collapse mechanism, see [link to relevant documentation]. Figure 1 As shown, this embodiment of the invention provides a brine well wall anti-collapse structure, which includes a support plate cavity 5, a grouting barrier 4, and a support plate injection body 501; the opening of the support plate cavity 5 is located on the well wall 10, and the cavity extends along the radial direction of the brine well; the grouting barrier 4 is a soft bag, which is filled with a first grouting material to expand and seal the opening of the support plate cavity 5; the support plate injection body 501 is formed by injecting a second grouting material into the support plate cavity 5, filling the support plate cavity 5 and sealing the gap between the grouting barrier 4 and the support plate cavity 5.

[0032] For details on the specific structure, please refer to [link / reference]. Figure 1 As shown, in some embodiments, the brine well involves a clay layer 11, a soft soil layer 2, and a halite layer 3 in the depth direction, and the location of the support cavity 5 corresponds to the soft soil layer 2.

[0033] By employing the above technical solution, this invention constructs a multi-point radial support system through a combination of expansion and compression bearings and grouting consolidation. By actively consolidating the soft soil layer 2 of the well wall 10, it effectively prevents the collapse of the cavity in the well wall 10 under strong hydrodynamic conditions during brine extraction. This technical solution successfully solves key technical problems such as sand inrush and collapse in brine wells in soft soil strata, overcoming the limitations of traditional anti-collapse technologies. The practical application results are significant: the service life of brine wells has been extended from less than one year to more than three years, and the single-well production capacity has increased by more than 50%. It has achieved long-term stable and efficient operation of brine wells under complex geological conditions in salt lakes. The successful development of this technical system provides important technical support and guarantee for the safe and efficient development of potassium resources in my country's salt lakes.

[0034] In some embodiments, a hollow vertical pipe is also included in the brine well, the outer periphery of the vertical pipe having a gap with the well wall 10, and the grouting barrier 4 is fixed to the pipe body of the vertical pipe.

[0035] In some embodiments, the gap between the vertical pipe and the well wall 10 is filled with gravel to form a gravel layer 12.

[0036] In some embodiments, the riser includes a water filter section 7, a solid wall section 8, and a sedimentation section 9; the water filter section 7 allows liquid to pass through the pipe wall and is provided corresponding to the halite layer 3; the solid wall section 8 blocks liquid from passing through the pipe wall and is provided corresponding to the clay layer 11 and the soft soil layer 2; the sedimentation section 9 is provided at the bottom of the riser and is used to settle sediment.

[0037] In some embodiments, a silt barrier layer 11 is also provided at the bottom of the brine well to fix the vertical pipe and prevent the bottom silt from surging up.

[0038] To form the aforementioned anti-collapse structure of the brine well wall 10, this embodiment of the invention also provides a method for constructing the anti-collapse structure of the brine well wall 10, which includes the following steps:

[0039] The well wall 10 is expanded using an expansion drill bit to form a support cavity 5;

[0040] Insert the grouting barrier 4 into the vicinity of the support plate cavity 5, and inject the first grouting material into the grouting barrier 4 to cause the grouting barrier 4 to expand and seal the opening of the support plate cavity 5.

[0041] A second grout is injected near the cavity 5 of the support plate using a high-pressure rotary jet method, so that the second grout is injected into the cavity 5 of the support plate and seals the gap between the grouting barrier 4 and the cavity 5 of the support plate, forming a support plate grouting body 501.

[0042] High-pressure jet grouting is developed based on hydrostatic grouting and incorporates hydraulic coal mining technology. It utilizes jet propulsion to cut and mix the strata, altering their structure and composition. A high-pressure rotating nozzle injects reinforcing material into the strata, mixing it with the soil to form a curtain, thereby reinforcing the foundation and preventing water seepage. The biggest advantages of high-pressure jet grouting compared to ordinary grouting are: it effectively solves the problem of uncontrollable slurry flow in ordinary grouting, the shape of the solidified body is controllable, and the reinforcement effect is excellent. By drilling jet grouting boreholes on the outer side of the wellbore (10) for high-pressure jet grouting consolidation of the soft soil layer (2), the integrity and strength of the wellbore (wall) are improved, ensuring that no collapse or cavity forms during brine extraction, and reducing the maintenance costs of gravel filling and cavity repair.

[0043] In some implementations, the construction method specifically includes the following steps:

[0044] The grouting barrier 4 is fixed at a selected position on the vertical pipe, the outer diameter of which is smaller than the inner diameter of the brine well.

[0045] The vertical pipe is placed into the brine well;

[0046] The first grouting material is injected into the grouting barrier 4 to cause the grouting barrier 4 to expand;

[0047] A high-pressure jet grouting drill bit is inserted into the gap between the vertical pipe and the well wall 10 to the vicinity of the selected position, and high-pressure jet grouting is performed using a second grouting material;

[0048] The selected location is determined based on the position of the support cavity 5 in the brine well.

[0049] In addition, in some embodiments, the construction method may also include the following steps: inserting a high-pressure jet grouting drill bit into the gap between the vertical pipe and the well wall 10 to near the bottom of the brine well, and using a third grouting material for high-pressure jet grouting to form a silt barrier layer 11 at the bottom of the brine well.

[0050] The function of the silt barrier layer 11 is twofold: firstly, to prevent silt from rising with the pressurized brine and entering the well, causing problems such as pump burial; secondly, to fix the vertical pipe and prevent the well pipe from being squeezed and deformed by the water hammer effect during the brine pumping process.

[0051] In the above structural scheme and construction method, although the grouting materials are described as first grouting material, second grouting material, and third grouting material, this does not mean that the three are necessarily different materials. In practical applications, the three can be completely identical, or the composition and proportion can be adjusted appropriately according to the specific application location.

[0052] Furthermore, this invention does not impose specific limitations on the specific components, proportions, and sources of the three grouting materials, but preferably requires that their compressive strength after solidification be above 40 MPa; otherwise, they will not easily resist long-term water erosion. For example, the three grouting materials can be commercially available high-strength special grouting materials for drilling and underground engineering, or they can be corresponding high-strength grouting materials formulated by the engineering application itself. Any material that can be used in conjunction with the appropriate process to achieve solidification and anti-seepage effects is acceptable.

[0053] Based on the above structure, a third aspect of the present invention also provides a brine well, the brine well having the brine well wall 10 anti-collapse structure and auxiliary structure provided in any of the above embodiments, the auxiliary structure including a brine pump 601 and a brine conveying pipe 6 disposed in the brine well, the brine conveying pipe 6 extending from the brine pump 601 to the outside of the well.

[0054] The technical solution of the present invention will be further described in detail below through several embodiments and in conjunction with the accompanying drawings. However, the selected embodiments are only used to illustrate the present invention and do not limit the scope of the present invention. It should also be noted that although the typical embodiments of the present invention are presented using salt lake brine wells as an example, it does not mean that the technical solution provided by the present invention can only be used in salt lakes. Similar brine wells in other regions can also use the structure and method proposed by the present invention to achieve well wall anti-collapse.

[0055] Example 1

[0056] This embodiment illustrates the well-forming process of a brine well, and the operation flow includes:

[0057] The first step is to drill a brine well with a diameter of 1.3 meters using a drilling rig.

[0058] The second step involves using a support drill bit to radially expand and squeeze the soft soil layer in the brine well, forming a support cavity to compact the easily collapsible soft soil layer.

[0059] The third step is to lower a 900mm diameter hollow vertical pipe into the well, keeping the vertical pipe basically coaxial with the well, and to tie and fix an empty grouting barrier at a selected height position on the vertical pipe (the position is calculated in advance and tied to the corresponding depth of the soft soil layer), and to accurately embed it into the cavity of the support plate along with the filter pipe.

[0060] The fourth step involves injecting grout into the grouting barrier on the ground through its own pressure pipe. This causes the barrier to expand, forming a vertical waterproof scour wall that essentially shields the opening of the support plate cavity.

[0061] The fifth step involves using a drill rod with a high-pressure rotary nozzle to penetrate deep into the support plate from the gap between the well wall (1.3 meters) and the vertical pipe (900 millimeters). High-pressure rotary grouting is then performed to inject grouting material into the cavity of the support plate, ensuring that the gaps and cracks between the support plate and the barrier are tightly filled (to prevent the support plate from being hollowed out by water flow during later brine extraction). This allows the support plate and the barrier to form a tight whole, improving the overall resistance to water erosion.

[0062] The sixth step is to fill the gaps in the well wall with gravel to form a gravel-filled layer, thus completing the well construction of the brine well.

[0063] To verify the solidification effect, a grouting test of the new anti-seepage material barrier was conducted on the surface before installation inside the brine well. The uniaxial compressive strength of the grouting product was 68.19 MPa. This process achieves breakthroughs through several technological innovations: first, it pioneered the design of a support plate grouting well body structure, establishing a multi-point radial support system; second, it developed a high-pressure jet grouting debris solidification process to actively consolidate the soft soil layer.

[0064] Operational practice in brine wells has demonstrated that this composite process effectively resists strong hydrodynamic scouring, prevents hydration deformation of soft soil layers, and significantly improves well stability, providing a reliable technical solution to the problem of well wall instability in salt lake brine production. This technology extends the service life of brine wells from less than one year to over three years, increases single-well production capacity by more than 50%, and controls the deformation of the reinforced layer with millimeter-level precision, providing crucial technical support for the safe and efficient development of potassium resources in salt lakes.

[0065] Monitoring data shows that the high-pressure jet grouting anti-collapse technology for wellhead salt pool plates and well wall support plates is reliable, with only 1-10mm deformation in the reinforced layer and no significant collapse. 2022 test data shows that the average annual maintenance cost of a traditional gravel-filled cavity well is 65,000-86,000 yuan (including 50-100m³). 3 (Gravel and labor costs), while brine wells using new technologies have significantly reduced the need for gravel filling due to improved wellbore stability, and the maintenance cost of gravel filling and cavitation in wellbore cavity filling is reduced by more than 50%.

[0066] Example 2

[0067] This embodiment demonstrates the application of the well-forming method provided in Embodiment 1 in a specific region, as shown below:

[0068] Qarhan Salt Lake is China's largest salt lake, a super-large comprehensive salt lake deposit mainly composed of potassium salt, with associated minerals such as magnesium, sodium, lithium, boron, and iodine. Figure 2 As shown, two monitoring magnetic rings were installed within a 0-6m range of the high-pressure jet grouting reinforcement layer of the brine well. On April 24, 2024, the initial installation positions of the magnetic rings were 2440.0mm and 3884.1mm. An automatic inspection was set every 8 hours. As of November 6, 2024, the position of the first magnetic ring at the wellhead was 2442.5mm, with a soil settlement of only 2mm; the position of the second magnetic ring was 3893.9mm, with a soil settlement of only 10mm.

[0069] In contrast, the collapse state of the control sample that did not adopt the brine well structure provided by this invention after one year of operation is as follows: Figure 3 As shown, the radius of the well wall cavity collapse is 5-8m; however, the well wall reinforcement layer formed by the brine well structure provided in this embodiment of the invention has a water flow erosion resistance of over 40MPa. Figure 4 As shown, under strong hydrodynamic conditions, the reinforced layer only underwent millimeter-level deformation after 3 years of scouring, and there was no problem of well wall cavity collapse.

[0070] Based on the above embodiments, it is clear that the innovative wellbore structure design with a support plate, pioneered in this invention, constructs a multi-point radial support system, significantly improving wellbore stability. Secondly, the invention's high-pressure jet grouting and debris solidification process actively consolidates the soft soil layer of the wellbore, effectively preventing wellbore cavity collapse under strong hydrodynamic conditions during brine extraction. Practice at the Qarhan Salt Lake project demonstrates that this technology extends the service life of brine wells from less than one year to over three years, increases single-well production capacity by more than 50%, and controls the deformation of the reinforced layer with millimeter-level precision, providing crucial technical support for the safe and efficient development of potassium resources in the salt lake.

[0071] Addressing the three major technical bottlenecks in pressurized brine development—formation instability, chemical blockage, and sand production risks—the project team constructed a 20 million m³ pressurized brine system at China's largest salt lake, the Qarhan Salt Lake. 3The industrial-scale brine extraction project verified the reliability of the technology: 1) Advanced technical and economic indicators. Single-well brine extraction volume increased from <80m³. 3 / h increased to >167m 3 / h, single-well productivity increased by 50% compared to traditional wells, and annual brine extraction per single well exceeded 1 million m³. 3 The lifespan of brine wells has been extended from one year to over three years, and the amount of wellbore structural collapse has been reduced from tens of meters to millimeters, essentially achieving zero collapse. The desalination cycle has been significantly shortened, and the consumption of freshwater resources per ton of brine has been reduced by 3-5 times. The annual maintenance cost per well has decreased from 70,000 yuan to 25,000 yuan. 2) The technology exhibits good reproducibility, high maturity, and strong market competitiveness. This technology has been experimentally applied to 22 new brine wells in the Biele Beach area of ​​the Qarhan Salt Lake, with a cumulative brine extraction of 66 million cubic meters. 3 The brine extraction volume increased by 100%, and the well structure achieved zero collapse within 3 years, with high desalination efficiency.

[0072] It is evident that the technical solution provided by this invention significantly improves brine extraction efficiency, effectively reduces operation and maintenance costs, and substantially increases recoverable resources, thus driving the transformation and upgrading of the salt lake resource extraction field towards intelligence and high efficiency. The economic and social benefits achieved by adopting the technical solution provided in the embodiments of this invention are significant: this technology has been gradually and experimentally applied to industrial brine extraction since 2022, resulting in a cumulative increase in economic benefits of 300 million yuan; it has reduced resource waste and improved the recovery rate of salt lake resources.

[0073] It should be understood that the above embodiments are merely illustrative of the technical concept and features of the present invention, and are intended to enable those skilled in the art to understand the content of the present invention and implement it accordingly. They should not be construed as limiting the scope of protection of the present invention. All equivalent changes or modifications made in accordance with the spirit and essence of the present invention should be covered within the scope of protection of the present invention.

Claims

1. A brine well wall anti-collapse structure, characterized in that, This includes setting up a support plate cavity, a grouting barrier, and a support plate injection body; The opening of the support plate cavity is located on the well wall, and the cavity extends radially along the brine well; the grouting barrier is a soft bag filled with a first grouting material to expand and seal the opening of the support plate cavity; the support plate injection body is formed by injecting a second grouting material into the support plate cavity, filling the support plate cavity and sealing the gap between the grouting barrier and the support plate cavity.

2. The brine well wall anti-collapse structure according to claim 1, characterized in that, In the depth direction, the brine well involves a clay layer, a soft soil layer, and a halite layer, and the location of the support cavity corresponds to the soft soil layer.

3. The brine well wall anti-collapse structure according to claim 2, characterized in that, It also includes a vertical pipe installed in the brine well, the outer periphery of the vertical pipe having a gap with the well wall, and the grouting barrier being fixed to the pipe body of the vertical pipe.

4. The brine well wall anti-collapse structure according to claim 3, characterized in that, The gap between the vertical pipe and the well wall is filled with gravel, forming a gravel layer.

5. The brine well wall anti-collapse structure according to claim 3, characterized in that, The vertical pipe includes a water filter section, a solid wall section, and a sedimentation section; the water filter section allows liquid to pass through the pipe wall and is set corresponding to the halite layer; the solid wall section blocks liquid from passing through the pipe wall and is set corresponding to the clay layer and soft soil layer; the sedimentation section is set at the bottom of the vertical pipe and is used to settle silt and sand.

6. The brine well wall anti-collapse structure according to claim 3, characterized in that, The bottom of the brine well is also equipped with a silt barrier layer to fix the vertical pipe and prevent the bottom silt from surging up.

7. A method for constructing an anti-collapse structure for brine well walls, characterized in that, include: An expansion drill bit is used to expand the well wall, forming a support cavity; Insert the grouting barrier into the vicinity of the support plate cavity, and inject the first grouting material into the grouting barrier to cause the grouting barrier to expand and seal the opening of the support plate cavity; A second grout is injected near the cavity of the support plate using a high-pressure rotary jet method, so that the second grout is injected into the cavity of the support plate and seals the gap between the grouting barrier and the cavity of the support plate, forming a support plate grouting body.

8. The construction method according to claim 7, characterized in that, Specifically, it includes: The grouting barrier is fixed at a selected position on the vertical pipe, wherein the outer diameter of the vertical pipe is smaller than the inner diameter of the brine well; The vertical pipe is placed into the brine well; The first grouting material is injected into the grouting barrier to cause the grouting barrier to expand; A high-pressure jet grouting drill bit is inserted into the gap between the vertical pipe and the well wall to the vicinity of the selected position, and high-pressure jet grouting is performed using a second grouting material; The selected location is determined based on the position of the support plate cavity in the brine well.

9. The construction method according to claim 8, characterized in that, Also includes: A high-pressure jet grouting drill bit is inserted through the gap between the vertical pipe and the well wall to the vicinity of the bottom of the brine well. A third grouting material is used for high-pressure jet grouting to form a silt barrier layer at the bottom of the brine well.

10. A brine well, characterized in that, The brine well has a brine well wall anti-collapse structure and ancillary structures as described in any one of claims 1-6. The ancillary structures include a brine pump and a brine conveying pipeline installed in the brine well, and the brine conveying pipeline extends from the brine pump to the outside of the well.

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