Experimental device and method for simulating water curtain water seal effect under different engineering geological conditions

Abstract

The invention discloses an experimental device and method for simulating water curtain water sealing effects under different engineering geological conditions. The device comprises a geological layer model, a water supply device and a data acquisition device. The geological layer model comprises a water tank, a cavern and a groundwater simulation device are arranged at the bottom of the water tank, the water tank is filled with simulated geological layer materials, and the geological layer materials and the simulation object materials meet similar conditions. The groundwater simulation device comprises a water curtain pipeline, and the water curtain pipeline is arranged around the cavern; a water-permeable hole is arranged on the water curtain pipeline, the water inlet of the water curtain pipeline is connected to the water supply device, and a valve is arranged between the water supply device and the inlet of the water curtain pipeline; a waterproof layer and a drainage structure are arranged at the bottom of the cavern, a flow meter is arranged at the outlet of the drainage structure, and a distributed optical fiber sensor, a stress strain sensor and the flow meter are all connected to a data acquisition center. The device and method of the invention can provide approximately real simulated data for analyzing the water curtain water sealing effects under different engineering geological conditions, thereby providing a design reference for the project.

Description

Technical Field

[0001] The invention belongs to the technical field of underground cavern oil storage, and in particular relates to an experimental device and method for simulating water curtain water sealing effects under different engineering geological conditions. Background Art

[0002] As an important strategic resource of a country, oil holds the lifeline of the national economy. Oil reserves have an important impact on a country's security and policy formulation. Underground water-sealed oil depot technology is favored by various countries due to its large capacity, high safety, good concealment and many other advantages. In the process of underground cavern oil storage, in order to ensure that the oil does not leak and ensure its safe operation, high requirements are placed on its water sealing properties. In the oil storage cavern projects currently under construction or already in operation in my country, the research on the water sealing properties of underground water-sealed oil depots is mostly based on numerical simulation software. Whether a set of experimental equipment for evaluating the water sealing effect of water curtains can be designed and the traditional water curtain layout can be optimized has become a hot issue that needs to be solved urgently.

[0003] Some research institutions or production units may have conducted relevant field tests, but no institution or individual has proposed an experimental device for evaluating and optimizing the water curtain water seal effect under different engineering geological conditions. The invention has important theoretical and practical significance for the optimization design of the water curtain of the underground water seal oil depot. Summary of the invention

[0004] In order to solve the deficiencies in the prior art, the present invention provides an experimental device and method for simulating the water curtain water seal effect under different engineering geological conditions, simulating the relative position relationship of underground water seal oil depots, restoring the engineering geology and hydrogeology environment of underground caverns, and better simulating whether the water curtain can meet the required water seal conditions during the operation of underground oil storage caverns, so as to provide guidance for further optimizing the water curtain arrangement and improving the water seal effect.

[0005] To achieve the above-mentioned purpose, the present invention adopts the following technical scheme: an experimental device for simulating the water curtain water seal effect under different engineering geological conditions, comprising a geological layer model, a water supply device and a data acquisition device, the geological layer model comprising a water tank, a cavern and a groundwater simulation device are arranged at the bottom of the water tank, the water tank is filled with simulated geological layer materials, and the geological layer materials and the materials of the simulation object meet similar conditions, the groundwater simulation device comprises a water curtain pipe, and the water curtain pipe is arranged around the cavern; a water-permeable hole is opened on the water curtain pipe, the water inlet of the water curtain pipe is connected to the water supply device, and a valve is arranged between the water supply device and the inlet of the water curtain pipe; the data acquisition device comprises a distributed optical fiber sensor, a stress strain sensor and a flow meter, a waterproof layer and a drainage structure are arranged at the bottom of the cavern, a flow meter is arranged at the outlet of the drainage structure, the distributed optical fiber sensor, the stress strain sensor and the flow meter are all connected to the data acquisition center, the distributed optical fiber sensor and the stress strain sensor are buried in the geological layer material, and a group of faucets are arranged on the water tank in the vertical direction.

[0006] At least three faucets are provided, and the faucets are arranged on the same vertical line.

[0007] A drainage ditch is arranged at the bottom of the cavern, the drainage ditch is connected to a drainage pipe, and a flow meter is arranged on the drainage pipe; a slope is arranged on the bottom surface of the cavern, and the connection between the drainage ditch and the drainage pipe is the lowest point of the slope.

[0008] The water supply device comprises a water collecting box and a water pipe. A plurality of water outlets are arranged at the bottom of the water collecting box. One end of the water pipe is connected to the water outlets, and the other end is connected to the water inlet of the water curtain pipe. A valve is arranged on the water pipe.

[0009] The water supply device also includes a bracket and a bracket base. The bracket is arranged on the bracket base. A sliding block is arranged on the bracket. The water collecting tank is connected to the sliding block.

[0010] The side of the sink adopts a double-layer design, with the inner layer being a water-permeable structure and the outer layer being a waterproof structure.

[0011] The water curtain pipe is arranged as a horizontal water curtain pipe, a vertical water curtain pipe, an inclined water curtain pipe or a combination of two thereof.

[0012] The water curtain pipes are evenly arranged around the cavern.

[0013] An experimental method for evaluating the water curtain water seal effect under different engineering geological conditions includes the following steps:

[0014] Step 1: configure geological layer materials that meet similar conditions based on the actual physical and mechanical parameters of the surrounding rock of the cavern;

[0015] Step 2, arranging a cavern and a water curtain pipe in the formation model, connecting the water curtain pipe to a water supply device, spreading the geological layer material configured in step 1 in layers, and forming a geological layer model through manual compaction and vibration, and at the same time, burying an optical fiber sensor around the cavern and connecting a flow meter to obtain a formation model;

[0016] Step 3, supplying water to the formation model obtained in step 2 to collect data on seepage pressure, water inflow, flow rate, and stress-strain;

[0017] Step 4, changing the height of the water supply device, repeating step 3, and obtaining the seepage pressure, water inflow, flow rate and stress-strain data at different water head heights;

[0018] Step 5, control the opening / closing of the valve between the water supply device and the water curtain pipe, change the spacing of the water curtain distribution holes, change the different water curtain hole combinations, repeat step 3, and obtain the seepage pressure, water inflow, flow rate and stress-strain data under different water curtain pipe distributions;

[0019] Step 6: Compare and analyze the seepage pressure, water inflow, flow rate and stress-strain collected in step 4 and step 5 to compare the water sealing effects under different water curtain schemes.

[0020] Changing the opening of the faucet changes the state of groundwater in the formation model, so that the formation model can obtain the seepage pressure, water inflow, flow rate and stress-strain data under different groundwater height conditions.

[0021] Compared with the prior art, the present invention has the following beneficial effects: the device of the present invention can be used to simulate the water seal effect in different formation models, and can collect the seepage pressure, water inflow, flow rate and stress-strain data according to different simulation conditions, and the data can be used to analyze and compare the water seal effect under different water curtain schemes, the interaction between the actual groundwater cavern, water curtain, groundwater and surrounding rock environment, and help to more comprehensively consider the role of groundwater and water curtain system in the normal operation of underground water seal oil depot. The device conforms to the similarity theory with the actual project, is representative for the actual project, has strong pertinence and can be close to the actual situation; controlling the opening / closing of the valve between the water supply device and the water curtain pipeline can directly change the water curtain pipeline. The spatial distribution of the channels reduces the tedious procedures of disassembly and production, and can artificially and more flexibly control the spatial layout of the water curtain pipeline; the data acquisition device on the periphery of the cavern model can dynamically simulate the change law of the cavern seepage field and the stress and strain of the cavern surrounding rock in real time, and the various water curtain models can truly reflect the contribution rate of different water curtain schemes to the water sealing effect of the underground cavern, so as to further optimize the water curtain design; the present invention simulates different geological conditions, different groundwater conditions and different water curtain spatial distribution conditions. The present invention only needs to change the ratio of similar materials in the formation model, change the water level of the groundwater simulation device, and change the control switch of the water conduit in the water supply device of the water curtain hole model to simulate a variety of different working conditions, and has good operability and repeatability.

[0022] Furthermore, at least three faucets are provided, and the faucets are arranged on the same vertical line. Firstly, it is easy to process, and multiple faucets discharge water step by step, which can better control the speed of discharging water and changing the water level.

[0023] Furthermore, a drainage ditch is arranged at the bottom of the cavern, the drainage ditch is connected to a drainage pipe, and a flow meter is arranged on the drainage pipe; a slope is arranged on the bottom surface of the cavern, and the connection between the drainage ditch and the drainage pipe is the lowest point of the slope. Only one water outlet is arranged at the bottom of the cavern, and a flow meter is arranged at the water outlet to facilitate recording of the drainage flow.

[0024] Furthermore, the water supply device includes a water collecting tank and a water pipe. A plurality of water outlets are opened at the bottom of the water collecting tank. One end of the water pipe is connected to the water outlet, and the other end is connected to the water inlet of the water curtain pipe. A valve is arranged on the water pipe. The water pipe is connected to the water curtain pipe one by one, so that water can be passed to different areas and the water flow rate can be changed, which is conducive to changes according to actual needs.

[0025] Furthermore, the water supply device also includes a bracket and a bracket base, the bracket is arranged on the bracket base, a slider is arranged on the bracket, the water collecting tank is connected to the slider, and the height of the water collecting tank can be changed by raising or lowering the slider, thereby further changing the water head height of the water collecting tank.

[0026] Furthermore, the water curtain pipe is arranged as a horizontal water curtain pipe, a vertical water curtain pipe, an inclined water curtain pipe or a combination of two thereof. Different water curtain pipe arrangement directions can simulate underground water flow conditions in different water flow directions, thereby improving the practicality of the device.

[0027] The method of the present invention first configures geological layer materials according to similar conditions, then arranges the cavern, water curtain pipe, water supply device, optical fiber sensor and flow meter according to the device of the present invention, turns on the water supply device, and then observes and collects seepage pressure, water inflow, flow rate and stress-strain data, and then changes the test conditions and parameter monitoring parameters according to the geological characteristics of the simulated geological layer, and finally obtains data about the simulated geological layer, providing data that is closer to the actual situation for analyzing the water curtain water seal effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 This is the main view of the model of the present invention;

[0029] Figure 2 A top view of the water curtain hole model arrangement of the present invention;

[0030] Figure 3 This is a front view of the water curtain hole model arrangement of the present invention;

[0031] Figure 4 This is a schematic diagram of a water supply device for a water curtain hole model of the present invention;

[0032] Figure 5 It is a schematic diagram of the connection between the bottom of the water supply device of the water curtain hole model of the present invention and the water pipe;

[0033] Figure 6 for Figure 1 The partially enlarged schematic diagram I in the middle is a schematic diagram of the water conduit of the present invention;

[0034] Figure 7 It is a schematic diagram of the groundwater simulation device of the present invention;

[0035] Figure 8 for Figure 1 The partially enlarged schematic diagram II in the middle is a schematic diagram of the water curtain pipeline of the present invention;

[0036] Fig. 9 It is a schematic diagram of the water collection hole inside the cave model of the present invention;

[0037] Fig.10 This is the front view of the cave model of the present invention;

[0038] In the figure, 1- bracket, 2- knob, 3- bracket base, 4- water flow, 5- water collecting box, 6- water guide pipe, 7- water curtain pipe, 8- faucet, 9- distributed optical fiber sensor, 10- cave model, 11- drain pipe, 12- flow meter, 13- water inlet, 14- water outlet, 15- rubber plug, 16- sink, 17- water-permeable glass, 18- water-permeable hole, 19- water collecting ditch, 20- valve, 21- thread. DETAILED DESCRIPTION

[0039] The present invention is described in detail below with reference to specific embodiments and accompanying drawings.

[0040] refer to Figure 1 to Figure 10 , an experimental device for simulating the water curtain water seal effect of different engineering geological conditions, including a geological layer model, a water supply device and a data acquisition device, the geological layer model includes a water tank 16, a cave model 10 and a groundwater simulation device are arranged at the bottom of the water tank 16, the water tank 16 is filled with simulated geological layer materials, and the geological layer materials and the materials of the simulation object meet similar conditions, the groundwater simulation device includes a water curtain pipe 7, and the water curtain pipe 7 is arranged around the cave model 10; a water permeable hole 18 is opened on the water curtain pipe 7, the water inlet of the water curtain pipe 7 is connected to the water supply device, and a valve is arranged between the water supply device and the water curtain pipe inlet; the data acquisition device includes a distributed optical fiber sensor 9, a stress strain sensor and a flow meter, a waterproof layer and a drainage structure are arranged at the bottom of the cave model 10, a flow meter 12 is arranged at the outlet of the drainage structure, the distributed optical fiber sensor 9, the stress strain sensor and the flow meter 12 are all connected to the data acquisition center, the distributed optical fiber sensor 9 and the stress strain sensor are buried in the geological layer material, and a group of faucets 8 are arranged on the water tank 16 in the vertical direction.

[0041] At least three faucets 8 are provided, and the faucets 8 are arranged on the same vertical line.

[0042] A drainage ditch 19 is arranged at the bottom of the cave model 10, and the drainage ditch 19 is connected to the drainage pipe 11, and a flow meter 12 is arranged on the drainage pipe 11; a slope is arranged on the bottom surface of the cave model 10, and the connection between the drainage ditch 19 and the drainage pipe 11 is the lowest point of the slope.

[0043] The water supply device includes a water collecting box 5 and a water pipe 6. A plurality of water outlets are provided at the bottom of the water collecting box 5. One end of the water pipe 6 is connected to the water outlets, and the other end is connected to the water inlet of the water curtain pipe 7. A valve is provided on the water pipe 6.

[0044] The water supply device further comprises a bracket 1 and a bracket base 3. The bracket 1 is arranged on the bracket base 3. A slider is arranged on the bracket 1. The water collecting tank 5 is connected to the slider.

[0045] The side of the water tank 16 adopts a double-layer design, the inner layer is a water-permeable structure, and the outer layer is a waterproof structure.

[0046] The water curtain pipe is arranged as a horizontal water curtain pipe, a vertical water curtain pipe, an inclined water curtain pipe or a combination of two thereof.

[0047] The water curtain pipes 7 are evenly arranged around the cave model 10 .

[0048] An experimental method for evaluating the water curtain water seal effect under different engineering geological conditions includes the following steps:

[0049] Step 1: configure geological layer materials that meet similar conditions based on the actual physical and mechanical parameters of the surrounding rock of the cavern;

[0050] Step 2, arranging a cave model 10 and a water curtain pipe 7 in the formation model, the water curtain pipe 7 is connected to a water supply device, the geological layer material configured in step 1 is spread in layers, and the geological layer model is formed by manual compaction and vibration. At the same time, an optical fiber sensor is buried around the cave, connected to a flow meter 12, and a formation model is obtained;

[0051] Step 3, supplying water to the formation model obtained in step 2 to collect data on seepage pressure, water inflow, flow rate, and stress-strain;

[0052] Step 4, changing the height of the water supply device, repeating step 3, and obtaining the seepage pressure, water inflow, flow rate and stress-strain data at different water head heights;

[0053] Step 5, control the opening / closing of the valve between the water supply device and the water curtain pipe 7, change the spacing of the water curtain distribution holes, change the different water curtain hole combinations, repeat step 3, and obtain the seepage pressure, water inflow, flow rate and stress-strain data under different water curtain pipe distributions;

[0054] Step 6: Compare and analyze the seepage pressure, water inflow, flow rate and stress-strain collected in step 4 and step 5 to compare the water sealing effects under different water curtain schemes.

[0055] Changing the opening of the faucet 8 changes the state of groundwater in the formation model, so that the formation model can obtain the seepage pressure, water inflow, flow rate and stress-strain data under different groundwater height conditions.

[0056] An experimental device for judging and optimizing the water curtain water seal effect under different engineering geological conditions comprises a stratum model, a cavern, a water supply device, a groundwater simulation device and a data acquisition device; the stratum model is provided with similar materials that meet the requirements of the simulated stratum, and the physical and mechanical parameters and geometric dimensions of the similar materials should meet the requirements of the similarity theory.

[0057] like Figure 1 , Fig. 9 and Fig.10As shown, the cave model 10 is made of permeable material, the bottom surface of the cave model 10 is provided with a slope, the slope is inclined toward the water collection ditch, the ground of the cave model 10 is provided with a water collection ditch 19, the water collection ditch 19 is connected to the drainage pipe 11, the drainage pipe 11 is provided with a flow meter 12, the connection between the water collection ditch 19 and the drainage pipe 11 is the lowest point of the bottom surface of the cave model 10, the cave model is made of permeable material, the cave model should reflect the real distribution characteristics of the underground space, the permeable material needs to meet the surrounding water body in time to discharge into the cave cavity, and the cave itself does not deform; the bottom of the cave model is made of impermeable material and has a sloped water collection ditch 19, which is convenient for the collection of seepage water, and the outside of the cave model 10 is provided with a drainage pipe 11, the drainage pipe 11 discharges the seepage water and collects and records the seepage water in real time; the flow meter 12 is connected to the input end of the data acquisition center.

[0058] A water curtain model is arranged around the cave model 10. The water curtain model includes a plurality of water curtain pipes 7. Water curtain pipes 7 are provided with water permeable holes 18. The water curtain pipes 7 are made of copper tubes. The water curtain model is symmetrically distributed around the cave. The outer diameter of the water curtain pipes 7 is 6 mm, the inner diameter is 3 mm, the diameter of the water permeable holes is 3 mm, and the axial spacing and circumferential spacing are both 1.5 mm. Internal threads are arranged at both ends of the water curtain pipes 7, and the internal threads are used to connect the external water curtain water supply device.

[0059] The water curtain model is arranged according to the relative position relationship between the water curtain and the cavern in the actual project. It can be set as a horizontal water curtain, a vertical water curtain or an inclined water curtain. Different water curtain types can also be combined to compare the water sealing effects of different water curtain setting schemes.

[0060] The water curtain water supply device mainly includes a water collecting box 5, a bracket 1, and a water pipe 6. The water collecting box 5 is arranged on the bracket 1, and the height of the water collecting box 5 can be changed along the direction of the bracket 1; a water outlet hole is arranged at the bottom of the water collecting box 5, and a plurality of water outlet holes are arranged, and the water outlet holes are connected to the water pipe 6. A rubber plug 15 is arranged at one end of the water pipe 6, and an external threaded joint is arranged at the other end. A valve 20 is also arranged on the water pipe 6, and the valve 20 is arranged at a position close to the water collecting box 5.

[0061] As an optional embodiment, the bracket 1 adopts a screw rod, a knob 2 is provided on the bracket 1, a slider is provided above the knob 2, the slider is connected to the water collecting box 5, the height of the water collecting box 5 is controlled by the knob 2 on the axis of the bracket 1, the water inlet and outlet of the water collecting box 5 can control the water level in the water collecting box to remain unchanged, the bottom of the water collecting box 5 is connected to a water pipe 6, one end of the water pipe 6 is provided with a rubber plug 15, and the other end of the water pipe 6 is connected to the water curtain model through an external threaded joint, and the device can provide a stable water head height for the water curtain; a valve is provided on the water pipe 6 to adjust the closure of a single water curtain hole in the water curtain model;

[0062] like Figure 1 , Figure 4 and Figure 7 As shown, the groundwater simulation device uses a 1 cm thick organic glass plate to make a water tank 16, the width of the water tank 16 is 5 cm, the inner layer of the water tank 16 is a water-permeable glass 17, and the outer layer of the water tank 16 is an impermeable glass. The water supply device on the top of the water tank 16 replenishes water to the water tank 16 at a set rate to simulate the actual stable natural groundwater level; faucets 8 are installed at three different heights of the water tank 16 to control different groundwater replenishment heads, and can also simulate seasonal changes in groundwater levels or changes in water heads caused by artificial extraction of groundwater;

[0063] The data acquisition device, including distributed optical fiber sensors 9, stress and strain sensors and flow meters, collects and records the seepage pressure at different parts of the cave, the amount of water seepage on the inner surface of the cave, the flow rate and the stress and strain of the surrounding rock of the cave. Generally, during the safe operation of the cave, the stress field is mainly concentrated within the range of three times the length of the cave, so the stress and strain sensors can be arranged within the range of three times the length of the cave. The seepage field is mainly concerned with the inrush flow and water sealing effect of the cave, so the flow and velocity sensors can be arranged on the side walls of the cave, or the flow meter 12 can be used to count the inrush flow of the entire cave, and the water pressure sensor can be arranged on the vault of the cave to measure the seepage pressure of the model, so as to analyze its water sealing effect and facilitate the collection and analysis of the original data.

[0064] An experimental device for judging and optimizing the water curtain water seal effect under different engineering geological conditions. For complex geological environments such as island environments and regional fault structures, this can be achieved by adding island environments or structural models to the device's stratum model; specifically: a structural model with similar material properties to the fault zone is set, and a thin layer is added to the corresponding stratum model to simulate the fault zone. The thin layer position can be reduced according to the similarity ratio based on the spatial occurrence, distribution and other information of the structural development in reality, and the fracture model should reflect the characteristics of the actual structural development or the dominant water-conducting effect; for the island environment, the seawater environment is simulated outside the groundwater simulation device, or salt is added to the groundwater simulation device to simulate the seawater intrusion problem, thereby realizing the simulation of the seawater environment.

[0065] In the evaluation of the model water seal effect, it is generally believed that if there is no "drainage zone" on the top of the cavern, it can ensure that oil and gas in the cavern will not leak, indicating that the water seal effect is good. In this model test, whether the water seal effect meets the requirements is mainly judged by whether the water seal pressure is "0".

[0066] The experimental method of the present invention for judging and optimizing the water curtain water seal effect under different engineering geological conditions comprises the following steps:

[0067] Step 1: configure the formation materials that meet similar conditions based on the actual physical and mechanical parameters of the surrounding rock of the cavern;

[0068] Step 2, arranging a cave model 10 and a water curtain pipe 7 in the stratum model, connecting the water curtain pipe 7 to a water supply device, spreading the model material in layers, and manually compacting and vibrating to form a geological layer model, while burying an optical fiber sensor around the cave and connecting it to a flow meter 12;

[0069] Step 3, supplying water to the formation model to collect seepage pressure, water inflow, flow rate and stress-strain data;

[0070] Step 4, changing the height of the water supply device, repeating step 3, and obtaining the seepage pressure, water inflow, flow rate and stress-strain data at different water head heights;

[0071] Step 5, control the opening / closing of the valve between the water supply device and the water curtain pipe 7, change the spacing of the water curtain distribution holes, change the different water curtain hole combinations, repeat step 3, and obtain the seepage pressure, water inflow, flow rate and stress-strain data under different water curtain pipe distributions;

[0072] Step 6: Compare and analyze the seepage pressure, water inflow, flow rate, stress and strain collected in step 4 and step 5 to compare the water sealing effects under different water curtain schemes.

[0073] Embodiment 1:

[0074] In order to make the technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail with reference to the accompanying drawings. It should be noted that the following disclosure is only a preferred embodiment of the present invention. Of course, this cannot be used to limit the scope of the rights of the present invention. Without departing from the principle of the present invention, those skilled in the art can also make some improvements and modifications, which should also be regarded as the protection scope of the present invention.

[0075] To simplify the explanation, a vertical water curtain is arranged around the cavern in this example. The experimental device used to evaluate and optimize the water curtain water seal effect under different engineering geological conditions includes a stratum model simulating actual engineering geology and a water curtain hole model according to Figure 2 The water curtain pipes 7 shown are evenly arranged around the cave model 10. The water curtain water supply device mainly includes a water collecting box 5, a bracket 1, and a water pipe 6. The water collecting box 5 is arranged on the bracket 1, and the height of the water collecting box 5 can be changed along the direction of the bracket 1; a water outlet hole is opened at the bottom of the water collecting box 5, and a plurality of water outlet holes are arranged. The water outlet holes are connected to the water pipe 6, and a rubber plug 15 is arranged at one end of the water pipe 6, and an external threaded joint is arranged at the other end. A valve 20 is also arranged on the water pipe 6, and the valve 20 is arranged at a position close to the water collecting box 5. The water pipe 6 connects the water curtain model with the water curtain hole model water supply device, and the upper and lower parts are connected accordingly; the groundwater simulation device mainly includes a faucet 8, a water tank 16 and a water-permeable glass 17; the opening of the faucet 8 in the groundwater simulation device is changed by changing the opening of the valve 20, and different combinations simulate different situations.

[0076] In the water curtain hole model water supply device, the bracket 1 and the bracket base 3 keep the water collecting box 5 stable, and the knob 2 is rotated to adjust the up and down movement of the water collecting box 5 to change the water head applied to the water curtain pipe 7; the water collecting box 5 adopts an open water collecting box.

[0077] The water collecting tank 5 has a water inlet 13 and a water outlet 14, and the water level is kept at a height equal to the water outlet 14 and will not change;

[0078] The faucet 8 of the groundwater simulation device controls different groundwater heights, and the permeable glass 17 allows water to freely enter the internal cave model 10; drainage pipes 11 are connected to both sides of the cave model 10 for water discharge, and there is a drainage ditch 19 inside the cave model 10 to collect water and discharge it from the drainage pipe 11; the bottom of the cave model 10 is made of impermeable material, and the bottom has a gentle inclination angle of 1°, which is convenient for collecting seepage water.

[0079] The data acquisition device includes an optical fiber sensor 9, a drainage pipe 11 and a flow meter 12. Distributed optical fiber sensors are used to measure the strain and seepage pressure on the top of the cavern. The flow meter 12 is used to measure the drainage volume and flow rate. In addition, stress strain sensors and other devices are arranged on the arch as needed. The water-permeable holes 18 of the water curtain hole model 7 are evenly arranged in a plum blossom pile shape to provide water curtain hole pressure to the outer periphery of the cavern.

[0080] Open all the water curtain pipes for data collection; control the outer water curtain pipe to close and the inner water curtain pipe to open to change the distance between the water curtain pipe and the cavern; open the water curtain pipe switch every other time to change the spacing of the water curtain pipes; and vice versa; rotate knob 2 to change the water head pressure and repeat the measurement.

[0081] Figure 1 This is the main view of the main model of the present invention. The model uses formation-similar materials as the formation model. The groundwater simulation device simulates different groundwater heads to judge whether water curtain holes are needed. The porous copper tubes are used as water curtain holes. The top water curtain hole model water supply device provides a stable water head for the water curtain holes to simulate the replenishment effect of the water curtain on the cavern in actual engineering. The data acquisition device is used to collect data.

[0082] Figure 2 and Figure 3 The front view and top view of the water curtain hole model of the present invention are arranged; the water curtain holes are symmetrically arranged around the cavern, the water curtain hole spacing is 11cm, the outer diameter of the hole is 6mm, the inner diameter is 3mm, the water curtain hole model is 58cm long, the bottom of the water curtain hole model is 12cm away from the outermost side of the water curtain hole, the distance between the water tanks of the underground water device is 5cm, the underground cavern is a prefabricated horseshoe shape, the cavern width is 10cm, the height is 15cm, and the length is the shortest distance between the two caverns is 5cm, which meets the similar geometric conditions; the bottom of the water curtain hole is at the same elevation as the cavern floor, the total height of the model is 80cm, reference Figure 2 and Figure 3 The drainage pipe extends out of the cave to drain the internal seepage. The diameter of the drainage pipe is 10mm and is connected to the external data measuring device.

[0083] Figure 4 It is a schematic diagram of a water supply device. The water head height in the water collecting tank is controlled to remain unchanged through the water inlet 13 and the water outlet 14. The position head of the water collecting tank 5 is changed through the knob 2. According to the water head height in the water collecting tank 5 = + water collecting tank position height ↑↓ = water curtain head height ↑↓, the position head is changed to adjust the water curtain hole pressure; the water collecting tank 5 is connected to the bottom water guide pipe 6, refer to Figure 5 .

[0084] Figure 5 This is a schematic diagram of the connection between the bottom of the water curtain hole model water supply device and the water pipe of the present invention. Figure 6 The schematic diagram of the water pipe of the present invention is shown in FIG. The bottom rubber plug 15 seals the open bottom circular hole to connect the water curtain hole. The other end of the water pipe 6 is screwed into the water curtain hole in the form of a thread 21. The valve 20 can control the opening and closing of the water pipe, thereby adjusting the spatial position relationship of the water curtain hole.

[0085] Figure 7 The schematic diagram of the groundwater simulation device of the present invention is shown in FIG. The width between the two side panels in the water tank is 5 cm, the inner glass panel is a water-permeable glass 17, the water storage height is controlled by a faucet 8, and three drainage faucets 8 of different heights are used to control different natural groundwater levels, h1=30 cm, h2=37 cm, and h3=60 cm. By considering whether different groundwater levels can form natural water seal conditions, the necessity of setting a water curtain is verified and the setting of the water curtain is optimized;

[0086] When h1=30cm, the water level in the trough is lower than the height of the cavern top, and a "drainage zone" will definitely be formed. At this time, the setting of a water curtain is essential; when h2=37cm, the water level in the trough is equal to the cavern height; when h3=60cm, the water level in the trough is higher than the height of the cavern top. The relationship between the water sealing performance of the cavern and the arrangement of the water curtain is studied under different groundwater level heights.

[0087] Figure 8 This is a schematic diagram of the water curtain model of the present invention. Fig. 9 Schematic diagram of water collection inside the cave model of the present invention. The water curtain pipe 7 of the present invention has water permeable holes 18 arranged along the pipe wall to provide water pressure to enter the cave surrounding rock. The small holes are evenly arranged. Figure 2 and 3 .

[0088] Fig.10The front view of the cave model of the present invention is shown in FIG. 10. The cave model 10 is prefabricated with porous materials. The cave is horseshoe-shaped. The cave is 10 cm wide, 30 cm long, and 15 cm high. The cave is strong and not easy to deform. The cave floor is provided with a waterproof layer and is impermeable. A concave water collection ditch 19 is provided at the central axis to facilitate the collection of seepage water. Fig. 9 .

[0089] Example 2

[0090] The device described in the present invention is used as an experimental device for feasibility study of oil storage on an island. Salt water is loaded into a groundwater simulation device to simulate the erosion of seawater on an underground reservoir (island oil storage). Then a salt content meter is arranged at the drainage pipe 11 to monitor its salt content. The salt content meter is connected to a data acquisition center. When similar materials are buried outside the cavern, other monitoring means can be arranged to monitor the migration path of seawater to simulate the resistance of the water curtain to seawater. In the groundwater simulation device, the water head height in the formation model is changed to simulate the influence of different seawater pressures on the cavern, the closure of the water curtain holes is adjusted, and the spatial layout of the water curtain is changed.

[0091] The present invention proposes an experimental device for judging and optimizing the water curtain water seal effect under different engineering geological conditions. The device consists of a stratum model made of similar materials, a cave model made of porous materials, a water curtain model made of porous copper tubes, a water curtain hole model water supply device, a groundwater simulation device, and a data acquisition device. The device of the present invention can evaluate the necessity of setting up water curtain holes, quantify the relationship between the spatial layout of the water curtain and the water seal effect of the cave, and provide guidance for the optimal design of the water curtain. The device of the present invention only needs to change the type and similarity ratio of similar materials according to the engineering geological conditions of different underground water seal reservoirs, and change the "on" and "off" of the device to adjust the engineering geological conditions of various underground water seal caverns and the water curtain replenishment forms, and has good repeatability.

[0092] The above content is a further detailed description of the present invention in combination with a specific preferred embodiment. It cannot be determined that the specific embodiments of the present invention are limited to this. For ordinary technicians in the technical field to which the present invention belongs, they can make several simple deductions or substitutions without departing from the concept of the present invention. These simple deductions or substitutions should be deemed to belong to the scope of patent protection of the present invention determined by the submitted claims.

Claims

1. An experimental method for judging the water curtain water seal effect under different engineering geological conditions, characterized in that: An experimental device for simulating the water curtain water seal effect under different engineering geological conditions, the experimental device comprising a geological layer model, a water supply device and a data acquisition device, the geological layer model comprising a water tank (16), a cave model (10) and a groundwater simulation device being arranged at the bottom of the water tank (16), the water tank (16) being filled with simulated geological layer materials, the geological layer materials and the materials of the simulated object satisfying similar conditions, the groundwater simulation device comprising a water curtain pipe (7), the water curtain pipe (7) being arranged around the cave model (10); a water permeable hole (18) being opened on the water curtain pipe (7), the water inlet of the water curtain pipe (7) being connected to the water supply device, and a valve being arranged between the water supply device and the water curtain pipe inlet; the data acquisition device comprising A distributed optical fiber sensor (9), a stress strain sensor and a flow meter; a waterproof layer and a drainage structure are arranged at the bottom of the cave model (10); a flow meter (12) is arranged at the outlet of the drainage structure; the distributed optical fiber sensor (9), the stress strain sensor and the flow meter (12) are all connected to a data acquisition center; the distributed optical fiber sensor (9) and the stress strain sensor are buried in geological layer materials; a group of faucets (8) are arranged in the vertical direction on the water tank (16); at least three faucets (8) are arranged on the same vertical line; the water curtain pipeline is arranged as a horizontal water curtain pipeline, a vertical water curtain pipeline, an inclined water curtain pipeline or a combination of two thereof; and the following steps are included: Step 1: configure geological layer materials that meet similar conditions based on the actual physical and mechanical parameters of the surrounding rock of the cavern; Step 2, arranging a cave model (10) and a water curtain pipe (7) in the formation model, connecting the water curtain pipe (7) to a water supply device, spreading the geological layer material configured in step 1 in layers, and manually compacting and vibrating to form a geological layer model, and at the same time, burying an optical fiber sensor (9) around the cave, connecting it to a flow meter (12), and obtaining a formation model; Step 3, supplying water to the formation model obtained in step 2 to collect data on seepage pressure, water inflow, flow rate, and stress-strain; Step 4, changing the height of the water supply device, repeating step 3, and obtaining the seepage pressure, water inflow, flow rate and stress-strain data at different water head heights; Step 5, controlling the opening / closing of the valve between the water supply device and the water curtain pipe (7), changing the spacing of the water curtain distribution holes, changing different water curtain hole combinations, repeating step 3, and obtaining the seepage pressure, water inflow, flow rate and stress-strain data under different water curtain pipe distributions; Step 6: Compare and analyze the seepage pressure, water inflow, flow rate and stress-strain collected in step 4 and step 5 to compare the water sealing effects under different water curtain schemes.

2. The experimental method for judging the water curtain water seal effect under different engineering geological conditions according to claim 1 is characterized in that: Changing the opening of the faucet (8) changes the state of groundwater in the formation model, so that the formation model can obtain the seepage pressure, water inflow, flow rate and stress-strain data under different groundwater height conditions.

3. The experimental method for judging the water curtain water seal effect under different engineering geological conditions according to claim 1 is characterized in that: A water collecting ditch (19) is arranged at the bottom of the cave model (10), the water collecting ditch (19) is connected to the drainage pipe (11), and a flow meter (12) is arranged on the drainage pipe (11); a slope is arranged on the bottom surface of the cave model (10), and the connection point between the water collecting ditch (19) and the drainage pipe (11) is the lowest point of the slope.

4. The experimental method for judging the water curtain water seal effect under different engineering geological conditions according to claim 1 is characterized in that: The water supply device comprises a water collecting box (5) and a water guide pipe (6). A plurality of water outlets are provided at the bottom of the water collecting box (5). One end of the water guide pipe (6) is connected to the water outlets, and the other end is connected to the water inlet of the water curtain pipe (7). A valve is provided on the water guide pipe (6).

5. The experimental method for judging the water curtain water seal effect under different engineering geological conditions according to claim 1 is characterized in that: The water supply device also comprises a bracket (1) and a bracket base (3); the bracket (1) is arranged on the bracket base (3); a sliding block is arranged on the bracket (1); and the water collecting tank (5) is connected to the sliding block.

6. The experimental method for judging the water curtain water seal effect under different engineering geological conditions according to claim 1 is characterized in that: The side of the water tank (16) adopts a double-layer design, the inner layer is a water-permeable structure, and the outer layer is a waterproof structure.

7. The experimental method for judging the water curtain water seal effect under different engineering geological conditions according to claim 1 is characterized in that: The water curtain pipes (7) are evenly arranged around the cave model (10).

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