Comprehensive seepage control method for underground water-sealed cave depot based on water curtain hole seepage reduction

Abstract

The invention belongs to the technical field of underground water-sealed cave depot seepage control, and particularly discloses an underground water-sealed cave depot comprehensive seepage control method based on water curtain hole seepage reduction, which comprises the steps of problem diagnosis and data acquisition, tracer agent test, in-cave leakage point grouting, water curtain hole grouting seepage reduction, and effect verification and reinforcement. The method comprises the following steps: monitoring the water seepage amount of an oil storage cavern, screening abnormal water curtain holes and injecting a tracer agent to judge connectivity; if the tracer agent exists in the oil storage cavern, grouting and water plugging are conducted on the leakage point; if no tracer agent exists or the water injection rate is still high after grouting, grouting and seepage reduction are conducted on the water curtain holes; finally, the effect is verified through a water pressure test and water seepage amount comparison, and reinforcing grouting is carried out if the standard is not reached. The method can effectively solve the problem that the water seepage amount of the water diversion fissure zone of the underground water-sealed cavern is difficult to control, and a feasible construction method is provided for effectively plugging a concentrated water seepage channel in surrounding rock of an oil storage cavern and controlling the water seepage amount.

Description

Technical Field

[0001] The present invention relates to the technical field of underground water-sealed cavern seepage control, and in particular to a comprehensive seepage control method for underground water-sealed caverns based on water curtain hole seepage reduction. Background Art

[0002] Underground water-sealed oil storage caverns utilize hydrogeological engineering principles to achieve safe oil storage. This involves constructing an oil storage cavern within the rock formation below the stable groundwater level, replacing traditional artificial anti-seepage structures with a natural water curtain barrier formed by water in the rock mass's fissures. The core technology is embodied in two aspects: first, maintaining the stability of the water seal system through a "natural recharge" mechanism of fissure water storage; second, establishing a dynamically balanced oil-water pressure system to ensure that the static pressure of the oil storage is always lower than the surrounding groundwater pressure. This technology is based on the dynamic balance of water and oil pressure, and its core lies in achieving a sealing effect through the natural barrier formed by water in the surrounding rock fissures.

[0003] The main structure of an underground water-sealed cavern includes an oil storage chamber, a water curtain system, and a construction tunnel. The water curtain system, located approximately 25 meters above the vault of the oil storage chamber, comprises a water curtain tunnel and water curtain holes. By continuously injecting water, it keeps the surrounding rock saturated with water, creating a stable hydraulic seal. However, a key challenge in this technology lies in balancing water seepage control: maintaining a certain level of seepage to ensure water sealing while strictly controlling the total amount of leakage.

[0004] Conventional seepage control methods primarily rely on grouting to block water seepage within the tunnel. However, due to the spatial variability of geological conditions, water-conducting fissures may appear during construction, leading to dramatic increases in localized seepage. Traditional tunnel grouting is inefficient in sealing these fissures, making it difficult to effectively control seepage and easily causing problems such as abnormal drops in groundwater levels during construction. Therefore, in situations where large water injection volumes from water curtain holes are required during construction and tunnel grouting is ineffective in controlling seepage, a groundwater-sealed cavern seepage control method that can effectively block water-conducting fissures is urgently needed. Summary of the Invention

[0005] The purpose of the present invention is to provide a comprehensive seepage control method for underground water-sealed caverns based on water curtain hole seepage reduction, so as to solve the above-mentioned technical problems existing in the prior art.

[0006] To achieve the above-mentioned object, the present invention provides the following solution: a comprehensive seepage control method for underground water-sealed caverns based on water curtain hole seepage reduction, comprising the following steps:

[0007] Step S1, problem diagnosis and data collection: monitor the daily water seepage of the oil storage cavern, screen the water curtain holes with abnormal water injection volume, and record their daily water injection volume before grouting;

[0008] Step S2, tracer test: inject a tracer into the abnormal water curtain hole to determine its connectivity with the oil storage cavern; if the tracer is present in the oil storage cavern, proceed to step S3; if the tracer is not present in the oil storage cavern, proceed directly to step S4;

[0009] Step S3, grouting the leaking point in the cave: Grouting is performed to block the tracer leaking point in the oil storage cavern. If the water injection rate of the water curtain hole returns to normal, construction is continued. If the grouting effect of the oil storage cavern is not good and the water injection rate of the water curtain hole is still too high, the process proceeds to step S4.

[0010] Step S4, grouting the water curtain hole to reduce seepage: After performing a water pressure test on the water curtain hole, grouting is performed to reduce the permeability of the surrounding rock mass and seal the water-conducting fissures;

[0011] Step S5, effect verification and reinforcement: Evaluate the seepage control effect through water pressure test and water seepage comparison, and perform reinforcement grouting if it does not meet the standards.

[0012] The above method aims to solve the problem that during the construction period of the water-sealed cavern, the daily water injection volume of individual water curtain holes is large and the grouting effect in the cave is poor. The method adopts the method of grouting these water curtain holes to reduce seepage, specifically reducing the permeability of the rock mass around the water curtain holes and effectively blocking the concentrated seepage channels. The method actively controls the water from the water inlet source into the water guide channel of the oil storage cavern, improves the water blocking grouting effect, reduces the water seepage of the water-sealed cavern, and thus achieves the purpose of seepage control of the oil storage cavern.

[0013] As an optional implementation, in step S1, the specific method for screening abnormal water curtain holes is: locating water curtain holes with significantly increased water injection volume according to the position of the excavated tunnel section, and recording their daily water injection volume before grouting.

[0014] This option, combined with the specific location of the excavated section and injection volume data, can quickly identify water curtain holes with abnormal seepage, avoiding blind investigations and significantly improving the efficiency of problem diagnosis. Furthermore, recording daily injection volumes before grouting provides baseline data for subsequent tracer testing and grouting effect comparisons, ensuring the targeted and scientific nature of seepage control measures and laying a data foundation for subsequent implementation.

[0015] As an optional implementation, in step S2, the tracer test is used to determine whether the water-conducting fractures and the oil storage caverns form a dominant seepage channel. If not, water curtain hole grouting is directly performed to reduce seepage.

[0016] This option, through rapid tracer testing, confirms the hydraulic connectivity between the water curtain holes and the oil storage cavern, avoiding unnecessary in-hole grouting and saving construction time and resources. For areas where connectivity is lacking, grouting the water curtain holes directly reduces seepage, optimizing the seepage control process, improving overall construction efficiency, and reducing project costs.

[0017] As an optional implementation, in step S4, the water curtain hole grouting to reduce seepage includes the following steps:

[0018] Step S41, primary hole washing: using 0.4 MPa pressure to clean the water curtain hole;

[0019] Step S42, grouting: circulate cement-based grout into the water curtain holes;

[0020] Step S43, secondary hole washing: the water curtain hole is washed twice before the slurry initially sets;

[0021] Step S44, hole maintenance: fill the water curtain holes after the secondary hole washing with 10% potassium silicate solution and retain the water.

[0022] The above-mentioned alternative solution details the specific steps for water curtain hole grouting to reduce seepage. The first hole wash involves high-pressure cleaning to remove impurities from the hole, ensuring that the grout can fully penetrate the fissures during grouting. The grouting step involves circulating cement-based grout to effectively seal water-conducting fissures. The second hole wash removes residual grout before initial setting to prevent hole blockage. Finally, hole maintenance involves the water-retention effect of a potassium silicate solution, further solidifying the rock mass fissures. These steps work synergistically to significantly enhance the sealing effect and long-term stability of the grouting.

[0023] As an optional implementation, in step S42, the grouting pressure is 0.35-0.5 MPa, the initial grouting pressure is ≥0.35 MPa, the pressure is gradually increased and maintained for 30 minutes, and the grouting is terminated after the injection volume is <3 L / min.

[0024] These options define the initial grouting pressure, pressure range, and stabilization time. By precisely controlling the grouting pressure, they ensure that the grout fully fills the cracks while avoiding the risk of further rock fractures caused by excessive pressure. Furthermore, they quantify the grouting termination criteria, preventing wasteful resources or poor results caused by excessive grouting, and improving the scientific nature and reliability of grouting operations.

[0025] As an optional implementation, in step S42, the cement-based slurry used for grouting adopts ultrafine cement with a water-cement ratio of 2:1, 1:1 or 0.5:1, mixed with a suspending agent and a water reducing agent.

[0026] The above options define the composition of the grouting slurry. By flexibly selecting a variety of water-cement ratios, the slurry can adapt to the permeability requirements of different rock mass fractures, ensuring effective filling of both fine and wide fissures. The addition of suspending agents and water-reducing agents further enhances the slurry's fluidity and stability, strengthening its crack-sealing effect and providing a strong guarantee for grouting quality.

[0027] As an optional embodiment, in step S42, grouting uses galvanized steel pipes with a diameter of 25 mm as grouting pipes, each 4.5 m long, connected by threaded connecting sleeves and lowered to the bottom of the hole.

[0028] This alternative solution solves the problem of insufficient grouting tube length in deep-hole grouting, ensuring that the grout reaches the bottom of the hole, and avoiding the limitations of traditional grouting tubes in deep-hole grouting. The threaded connection simplifies the construction process, improves installation and removal efficiency, and provides technical support for the smooth implementation of deep-hole grouting.

[0029] As an optional embodiment, in step S43, 2 to 6 hours after the end of the permeability reduction and before the initial setting of the slurry, the water curtain holes are cleaned at a pressure of 0.4 MPa.

[0030] The above-mentioned optional solution specifies the timing and method for secondary hole washing. By precisely controlling the timing of washing, it avoids both premature washing that affects slurry solidification and late washing that causes hole blockage. High-pressure washing effectively removes residual slurry, ensuring smooth subsequent water injection through the water curtain holes and guaranteeing the long-term stable operation of the water curtain system.

[0031] As an optional implementation, in step S44, the time for channel maintenance is ≥ 3 days.

[0032] The above-mentioned alternative requires a maintenance period of at least three days. The water curtain holes are then filled with a 10% potassium silicate solution to retain moisture. The potassium silicate solution reacts with the rock mass to form a cement, further sealing microcracks and enhancing the long-term anti-seepage performance of the grouting. This rigid maintenance period ensures the chemical reaction is fully complete, preventing a decrease in sealing effectiveness due to inadequate maintenance and providing strong support for the durability of the water curtain holes.

[0033] As an optional implementation, in step S5, the effect is verified by comparing the water injection volume of the water curtain hole before and after grouting, the water seepage volume of the oil storage cavern and the rock permeability. If the standards are not met, step S4 is repeated.

[0034] This optional solution enables a comprehensive, multi-metric assessment, avoiding the one-sidedness of a single indicator and ensuring the scientific and comprehensive nature of seepage control. The dynamic reinforcement mechanism automatically triggers reinforcement grouting when results fall short of target, creating a closed-loop control system that ultimately ensures the achievement of seepage control objectives and provides reliable support for the long-term, stable operation of underground water-sealed caverns.

[0035] Compared with the prior art, the present invention has at least the following beneficial effects:

[0036] The present invention proposes a comprehensive seepage control method for underground water-sealed caverns based on water curtain hole seepage reduction, which incorporates water curtain hole seepage reduction into the seepage control design of underground water-sealed caverns, providing a feasible method for effectively blocking concentrated seepage channels in the surrounding rock of oil storage caverns and controlling the amount of seepage. The construction method can effectively solve the problem that the injection volume of individual water curtain holes is large and the grouting effect in the cave is poor during the construction period of underground water-sealed caverns, and provides a feasible construction method for effectively blocking concentrated seepage channels in the surrounding rock of oil storage caverns and controlling the amount of seepage. After being applied in the construction of a large underground water-sealed cavern, it can effectively reduce the seepage volume of the main cavern and achieve significant technical and economic results - the post-grouting drilling and grouting volume are saved by 10,000 meters and 180 tons respectively, and the grouting construction period is saved by 3 months, which has a broad application prospect. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0038] Figure 1 is a flow chart of the method of the present invention;

[0039] Figure 2 This is a vertical view of the water curtain hole grouting in the method of the present invention;

[0040] Figure 3 It is a plan view of the water curtain hole grouting in the method of the present invention;

[0041] Figure 4 Flowchart of the optimization scheme of the method of the present invention;

[0042] In the figure: 1. Oil storage cavern; 2. Water curtain tunnel; 3. Water curtain hole; 4. Water-conducting fissure. DETAILED DESCRIPTION

[0043] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0044] like Figure 2 and Figure 3As shown in the figure, the underground water-sealed cavern mainly consists of an oil storage cavern 1, a water curtain system, and a construction tunnel. The oil storage cavern 1 is used to store crude oil. The water curtain system includes a water curtain tunnel 2 and a water curtain hole 3, located approximately 25 meters above the vault of the oil storage cavern 1 and covering the entire oil storage cavern tank area. The underground water-sealed cavern is pressurized by injecting water through the water curtain system to ensure that the surrounding rock is saturated with water. Groundwater is used to seal the oil storage cavern 1. Continuous water replenishment through the water curtain ensures that the rock mass surrounding the oil storage cavern 1 remains saturated, creating a stable hydraulic seal. This requires both ensuring a certain seepage environment and controlling the total amount of seepage. Maintaining water sealing while controlling leakage is crucial to the success of the water-sealed cavern. Conventional seepage control measures involve grouting to block water seepage within the cavern. However, due to the spatial variability of geological conditions, water-conducting fissures 4 may appear within the project area, leading to a sharp increase in seepage in this section of the cavern.

[0045] In order to solve the problem that the project area passes through the water-conducting fissure 4 area, resulting in a large daily water injection volume in the nearby water curtain hole 3 and poor grouting effect in the cave, an embodiment of the present invention proposes a comprehensive seepage control method for underground water-sealed caverns based on water curtain hole seepage reduction, which specifically reduces the permeability of the surrounding rock of the water curtain hole 3 and effectively blocks the concentrated seepage channel, actively controls the entry of groundwater into the water-conducting channel of the oil storage cavern 1 from the water inlet source, improves the water blocking grouting effect, reduces the seepage volume of the water-sealed cavern, and thus achieves the purpose of seepage control of the oil storage cavern 1.

[0046] like Figure 1 As shown, an embodiment of the present invention provides a comprehensive seepage control method for underground water-sealed caverns based on water curtain hole seepage reduction, comprising the following steps:

[0047] Step S1: Problem diagnosis and data collection

[0048] Monitor water seepage: After the excavation of oil storage cavern 1 is completed, record the daily water seepage of the main cavern;

[0049] Screening abnormal water curtain holes 3: According to the location of the excavated tunnel section, locate the water curtain holes 3 with significantly increased water injection volume, and record their daily water injection volume before grouting.

[0050] In some specific embodiments, step S1 specifically includes: grouting the oil storage cavern 1. After the grouting is completed, the water seepage of the cavern is recorded, the position of the water curtain hole 3 with a larger water injection volume is determined according to the position of the excavated cavern section, and the water injection volume of the water curtain hole the day before the grouting is recorded.

[0051] Step S2: Tracer test

[0052] A tracer is injected into the abnormal water curtain hole 3 to determine its hydraulic connectivity with the oil storage cavern 1. If the tracer appears in the oil storage cavern 1, it indicates that the water-conducting fissure 4 connects the water curtain hole 3 and the oil storage cavern 1. The process then proceeds to step S3 to seal the leak in the cavern. If the tracer does not appear in the oil storage cavern 1, it indicates that the water-conducting fissure 4 has not formed a dominant seepage channel. The process then proceeds directly to step S4 to grout the water curtain hole.

[0053] Step S3: Grouting the leaking point in the hole

[0054] Grouting is performed to block water at the tracer leakage point in the oil storage cavern 1;

[0055] If the water injection volume of the water curtain hole 3 returns to normal after grouting and blocking water, continue excavation;

[0056] If the water blocking effect of the oil storage cavern 1 is not good after grouting or the water injection amount of the water curtain hole 3 is still too high, the process proceeds to step S4.

[0057] Step S4: Grouting water curtain holes to reduce seepage

[0058] Before grouting, a water pressure test is first performed on the water curtain hole 3 to test the pre-grouting permeability of the rock mass. After the test is completed, grouting of the water curtain hole 3 is performed. The water curtain hole grouting seepage reduction method can effectively reduce the permeability of the rock mass around the water curtain hole 3 and seal the water-conducting fissures 4, thereby achieving the purpose of controlling the amount of water seepage in the oil storage cavern 1.

[0059] The grouting operation comprises the following steps:

[0060] S41. One-time hole washing: After removing the water injection plug of the water curtain hole 3, the water curtain hole 3 is washed with 0.4 MPa water.

[0061] S42. Grouting: Use three-parameter grouting in hole circulation (the three parameters include pressure, flow and density), 3SNS-A mud pump pumps the slurry, ZJ-400D pulping machine mixes the slurry, and special hydraulic plugs or mechanical plugs are used for plugging.

[0062] In some specific embodiments, since the length of the seepage-reducing curtain hole 3 is between 45.0m and 97.5m, it is difficult to reach the bottom of the hole using a general grouting pipe. Galvanized steel pipes with a diameter of 25mm and a wall thickness of 3.5mm are processed as grouting pipes. Each pipe is 4.5m long and connected with a threaded connecting sleeve. The connected galvanized steel pipes are lowered to the bottom of the hole.

[0063] In some specific embodiments, the slurry used for grouting is a cement-based slurry, including cement, a suspending agent and a water reducing agent. Specifically, the cement-based slurry uses ultrafine cement with a water-cement ratio of 2:1, 1:1 or 0.5:1, mixed with an appropriate amount of suspending agent and water reducing agent.

[0064] In a specific embodiment, the suspending agent is triethanolamine with a water content of 1.5% by weight, and the water reducing agent is polycarboxylic acid (XF-1) with a water content of 1%.

[0065] In some specific embodiments, the initial grouting pressure is controlled at ≥0.35MPa, the maximum pressure is 0.5MPa, and the implementation process should gradually increase the pressure between 0.35 and 0.5MPa. The grouting can be completed when the injection volume is less than 3L / min and the pressure is stabilized for more than 30 minutes. If the injection volume continues to fail to meet the requirements, the construction should be suspended, analyzed, the cause should be found, and measures should be taken before continuing.

[0066] S43. Secondary hole washing: 2 to 6 hours after the end of the seepage reduction and before the initial setting of the slurry, the water curtain hole 3 is cleaned at a pressure of 0.4 MPa.

[0067] S44. Hole maintenance: After the secondary hole washing is completed, fill the water curtain hole 3 with 10% potassium silicate solution and retain water for no less than 3 days.

[0068] Step S5: Effect verification and reinforcement

[0069] After the grouting of the water curtain hole is completed, the permeability of the rock mass after grouting is tested by a water pressure test. The water replenishment volume on the day after the water curtain hole grouting and the water seepage volume of the oil storage cavern 1 on the day are recorded and compared with the data before grouting. If the water injection volume of the grouting hole is reduced and restored to normal, and the water seepage volume of the main cavern meets the control requirements, it means that the water curtain hole grouting has a good effect on the seepage control of the cavern. Otherwise, it is necessary to reinforce the grouting of the water curtain hole 3 to better achieve the seepage control effect of the water-sealed cavern, and then the excavation of the oil storage cavern 1 can be carried out.

[0070] Figure 2 and Figure 3 The spatial position relationship between the water curtain hole 3 and the water-conducting fissure 4 is demonstrated, and the principle of grouting hole arrangement and fissure sealing is demonstrated.

[0071] To further optimize the solution, step S6 is added after step S5, such as Figure 4 As shown, this step specifically includes:

[0072] Step S6, water curtain hole connectivity test: The water curtain hole seepage reduction treatment only blocks the larger water conduction channels and reduces the permeability of the surrounding rock mass. After completion, a water curtain hole connectivity test must be carried out in accordance with the requirements for water seal cavern construction. After grouting to reduce seepage, the water curtain holes should still maintain good hydraulic connection with other water curtain holes to ensure the overall water seal effectiveness of the water curtain system. If the hydraulic connectivity does not meet the requirements, additional water curtain holes should be added in a timely manner.

[0073] The implementation principle and implementation effect of the method of the present invention are as follows:

[0074] Tracer testing is used to determine the hydraulic connectivity between the water curtain holes with abnormal water seepage and the oil storage caverns. Targeted seepage control measures are then implemented, including connectivity treatment, disconnection treatment, and effectiveness verification and reinforcement. Connectivity treatment involves: when connectivity is confirmed between the water curtain holes and the oil storage caverns, grouting is first performed to plug the leaks within the caverns. If the water curtain hole injection rate returns to normal after plugging and the seepage control effect meets the standards, excavation of the oil storage caverns continues. If the plugging effect is not good, grouting is used to reduce seepage in the water curtain holes. This reduces the permeability of the rock mass surrounding the water curtain holes at the source of the water inflow and seals water-conducting fractures, effectively controlling the amount of water seepage in the oil storage caverns. Disconnection treatment involves: when the water curtain holes are not connected to the oil storage caverns, grouting is directly performed to restore normal injection rate and control the amount of water seepage in the oil storage caverns. The effect verification and reinforcement include: after the grouting is completed, the seepage control effect is evaluated by comparing and analyzing the daily seepage volume of the oil storage cavern, the daily water injection volume of the water curtain hole and the permeability change; if the seepage control requirements are not met, the water curtain hole is reinforced with grouting until the seepage control standards are met.

[0075] In summary, this method innovatively proposes a comprehensive seepage control scheme based on water curtain hole seepage reduction, which provides a new technical idea and implementation path for seepage control of underground water-sealed caverns in water-conducting fractured areas.

[0076] In the description of the present invention, it should be understood that the terms "longitudinal", "transverse", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0077] The embodiments described above are merely descriptions of preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Without departing from the spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by persons skilled in the art should fall within the scope of protection defined by the claims of the present invention.

Claims

1. A comprehensive seepage control method for underground water-sealed caverns based on water curtain hole seepage reduction, characterized in that: The following steps are involved: Step S1, problem diagnosis and data collection: monitor the daily water seepage of the oil storage cavern (1), screen the water curtain holes (3) with abnormal water injection volume, and record their daily water injection volume before grouting; Step S2, tracer test: inject a tracer into the abnormal water curtain hole (3) to determine its connectivity with the oil storage cavern (1); if the tracer appears in the oil storage cavern (1), proceed to step S3; if the tracer does not appear in the oil storage cavern (1), proceed directly to step S4; Step S3, grouting the leaking point in the cave: Grouting is performed to block the leaking point of the tracer in the oil storage cavern (1); if the water injection volume of the water curtain hole (3) returns to normal, the construction is continued; if the grouting effect of the oil storage cavern (1) is not good and the water injection volume of the water curtain hole (3) is still high, the process proceeds to step S4; Step S4, grouting the water curtain hole to reduce seepage: After performing a water pressure test on the water curtain hole (3), grouting is performed to reduce the permeability of the surrounding rock mass and seal the water-conducting fissures (4); Step S5, effect verification and reinforcement: Evaluate the seepage control effect through water pressure test and water seepage comparison, and perform reinforcement grouting if it does not meet the standards.

2. The comprehensive seepage control method for underground water-sealed caverns based on water curtain hole seepage reduction according to claim 1 is characterized in that: In step S1, the specific method for screening abnormal water curtain holes (3) is: locating water curtain holes (3) with significantly increased water injection volume according to the position of the excavated tunnel section, and recording their daily water injection volume before grouting.

3. The comprehensive seepage control method for underground water-sealed caverns based on water curtain hole seepage reduction according to claim 1 is characterized in that: In step S2, the tracer test is used to determine whether the water-conducting fissure (4) and the oil storage cavern (1) form a dominant seepage channel. If not, water curtain hole grouting is directly performed to reduce seepage.

4. The comprehensive seepage control method for underground water-sealed caverns based on water curtain hole seepage reduction according to claim 1 is characterized in that: In step S4, the water curtain hole grouting and seepage reduction comprises the following steps: Step S41, primary hole washing: using 0.4 MPa pressure to clean the water curtain hole (3); Step S42, grouting: circulate cement-based grout into the water curtain hole (3); Step S43, secondary hole washing: the water curtain hole (3) is washed twice before the slurry initially sets; Step S44, hole maintenance: fill the water curtain hole (3) after the second hole washing with 10% potassium silicate solution and retain water.

5. The comprehensive seepage control method for underground water-sealed caverns based on water curtain hole seepage reduction according to claim 4 is characterized in that: In step S42, the grouting pressure is 0.35-0.5 MPa, the initial grouting pressure is ≥0.35 MPa, and the grouting is terminated after the pressure is gradually increased and maintained at a constant pressure for 30 minutes and the injection volume is less than 3 L / min.

6. The comprehensive seepage control method for underground water-sealed caverns based on water curtain hole seepage reduction according to claim 4 is characterized in that: In step S42, the cement-based slurry used for grouting is ultrafine cement with a water-cement ratio of 2:1, 1:1, or 0.5:1, mixed with a suspending agent and a water reducing agent.

7. The comprehensive seepage control method for underground water-sealed caverns based on water curtain hole seepage reduction according to claim 4 is characterized in that: In step S42, grouting uses galvanized steel pipes with a diameter of 25 mm as grouting pipes, each 4.5 m long, connected by threaded connecting sleeves and lowered to the bottom of the hole.

8. The comprehensive seepage control method for underground water-sealed caverns based on water curtain hole seepage reduction according to claim 5 is characterized in that: In the step S43, 2 to 6 hours after the end of the permeability reduction and before the initial setting of the slurry, the water curtain hole (3) is cleaned with a pressure of 0.4 MPa.

9. The comprehensive seepage control method for underground water-sealed caverns based on water curtain hole seepage reduction according to claim 5, characterized in that: In step S44, the time for channel maintenance is ≥ 3 days.

10. The comprehensive seepage control method for underground water-sealed caverns based on water curtain hole seepage reduction according to claim 1, characterized in that: In step S5, the effect is verified by comparing the water injection volume of the water curtain hole (3), the water seepage volume of the oil storage cavern (1) and the rock mass permeability before and after grouting. If the standards are not met, step S4 is repeated.

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