True triaxial salt rock block gas storage cavity forming and injection-production whole process indoor simulation system

Abstract

The application discloses a true triaxial salt rock block gas storage cavity forming and whole process simulation system, which comprises a salt rock main component, a true triaxial pressurizing component, a cavity forming component and a production and injection component. The salt rock main component comprises a base, a salt rock block and a joint casing pipe, and the true triaxial pressurizing component is used for applying three-way stress to the salt rock block. The cavity forming component is used for injecting fresh water into the salt rock block and discharging brine, and collecting the brine discharged by the salt rock block. The production and injection component is used for injecting gas into the salt rock block to discharge the brine, and periodically injecting and producing gas into the salt rock block. According to the true triaxial salt rock block gas storage cavity forming and whole process simulation system, the whole process of "ground stress loading-water solution cavity forming-gas injection and brine discharge-cyclic injection and production-gas injection and brine discharge" can be simulated integrally and continuously, and the engineering safety of the salt rock block gas storage can be evaluated more accurately.

Description

Technical Field

[0001] This invention relates to the field of underground storage engineering technology, and in particular to an indoor simulation system for the entire process of cavity construction and gas production and injection in a true triaxial salt rock block gas storage facility. Background Technology

[0002] Among related technologies, salt rock blocks are widely recognized as an ideal medium for storing energy sources such as natural gas and hydrogen due to their extremely low permeability and excellent self-healing ability. The construction of salt rock block gas storage facilities typically includes four core stages: water-soluble cavity construction, gas injection and brine discharge, production and injection operation, and brine injection and venting.

[0003] However, existing indoor simulation testing technologies have the following significant limitations: Distortion in stress environment simulation: Existing cavity-building simulation devices for salt rock blocks mostly use conventional triaxial or even simple containers without confining pressure, which cannot reproduce the true triaxial stress state (σ1>σ2>σ3) commonly found in deep strata. Differences in stress state directly affect the water dissolution rate and cavity morphology of salt rock blocks. Cavity-building experiments lacking realistic stress constraints result in cavity morphologies that deviate significantly from actual engineering practices.

[0004] The fragmentation of the entire life cycle simulation: Current experimental devices are functionally limited and exhibit a "fragmented" characteristic. One type of device focuses only on mechanical properties, such as a true triaxial fracturing test machine, which cannot perform water-soluble cavity creation; another type of device focuses only on fluid erosion and cannot apply high ground stress or perform high-pressure injection-production gas circulation. This fragmentation of the process makes it difficult for researchers to observe the "real cavity morphology" and study the impact on "injection-production stability". Summary of the Invention

[0005] This invention aims to at least solve one of the technical problems existing in the prior art. To this end, this invention proposes an indoor simulation system for the entire process of cavity construction and production / injection in a true triaxial salt rock block gas storage facility. This indoor simulation system can realize integrated continuous simulation of the entire process of "ground stress loading - water-soluble cavity construction - gas injection and brine discharge - cyclic injection and production - brine injection and venting", and more accurately assess the engineering safety of salt rock block gas storage facilities.

[0006] The indoor simulation system for the entire process of cavity construction and production / injection in a true triaxial salt rock block gas storage facility according to an embodiment of the present invention includes: a salt rock main body component, a true triaxial pressurization component, a cavity construction component, and a production / injection component. The main component of the salt rock assembly includes a base, a salt rock block, and a combined casing. The salt rock block is fixed above the base, and a vertical shaft opening is provided above the salt rock block. The lower end of the combined casing extends into the vertical shaft opening. The combined casing includes an inner tube and an outer tube arranged coaxially. The outer tube is sleeved outside the inner tube, and the outer wall of the outer tube is provided with an annular sealing isolation element, which mates with the wall of the vertical shaft opening. The true triaxial pressurization assembly is used to apply independent triaxial stress to the surfaces of the salt rock block other than the bottom surface to simulate the three-dimensional stress state of the real formation. The cavity-forming assembly is connected to the inner tube and the outer tube respectively, and is used to inject fresh water into the salt rock block and discharge brine for water-soluble cavity-forming, as well as to collect the brine discharged from the salt rock block. The production-injection assembly is connected to the inner tube and the outer tube respectively, and is used to inject gas into the salt rock block to discharge brine, as well as to periodically inject and produce gas into the salt rock block.

[0007] The true triaxial indoor simulation system for the entire process of cavity construction and gas production and injection in a salt rock block gas storage facility according to an embodiment of the present invention, by setting up a salt rock main body component, a true triaxial pressurization component, a cavity construction component, and a production and injection component, wherein the true triaxial pressurization component is used to apply independent triaxial stress to the surfaces of the salt rock block other than the bottom surface, the cavity construction component is used to inject fresh water into the salt rock block and discharge brine for water-soluble cavity construction, and to collect the brine discharged from the salt rock block, and the production and injection component is used to inject gas into the salt rock block and discharge brine, and to periodically inject and extract gas into the salt rock block, is a device that integrates a true triaxial geostress loading system with a fluid dissolution and gas injection and production system, realizing integrated continuous simulation of the entire process of "geostress loading - water-soluble cavity construction - gas injection and brine discharge - cyclic injection and production - brine injection and exhaust", so as to more accurately assess the engineering safety of the salt rock block gas storage facility.

[0008] In addition, the true triaxial salt rock block gas storage cavity construction and production-injection full-process indoor simulation system according to this application may also have the following additional technical features: In some embodiments of the present invention, the true triaxial pressurization assembly includes: a friction-reducing layer, a steel plate force transmission unit, a hydraulic jack, a reaction force device unit, and a hydraulic control unit. The friction-reducing layer is laid on each stress-bearing surface of the salt rock block to reduce boundary friction effects. The steel plate force transmission unit is composed of multiple layers of steel plates with gradually varying sizes stacked together and is closely attached to the outside of the friction-reducing layer to uniformly transmit hydraulic loads to the surface of the salt rock block. The hydraulic jack acts on the outermost layer of the steel plate force transmission unit. The reaction force device unit provides stable support for the hydraulic jack and includes cement mortar and a force transmission column. The two ends of the force transmission column are connected to the hydraulic jack and the cement mortar, respectively. The hydraulic control unit is connected to the hydraulic jack and controls the hydraulic jack to apply force toward the steel plate force transmission unit.

[0009] In some embodiments of the present invention, each force-bearing surface of the salt rock block is provided with a plurality of hydraulic jacks, and the hydraulic jacks on two opposite force-bearing surfaces of the salt rock block are arranged opposite or symmetrically; and / or, there are a plurality of hydraulic jacks and a plurality of hydraulic control units, each of which is simultaneously connected to a plurality of hydraulic jacks; and / or, the hydraulic control unit includes an oil pump, a hydraulic controller, a liquid pressure gauge, a hydraulic pipe and a hydraulic pipe connector, the oil pump is used to pump oil toward the hydraulic jack, the hydraulic pipe connector is fixed on the hydraulic jack, the oil pump and the hydraulic pipe connector are connected through the hydraulic pipe, the hydraulic controller and the liquid pressure gauge are connected in series between the oil pump and the hydraulic pipe connector, the hydraulic controller is used to control the pumping volume of the oil pump, and the liquid pressure gauge is used to measure the oil pressure in the hydraulic pipe; and / or, the center of the steel plate force transmission unit on the top surface is provided with a clearance hole penetrating the steel plate force transmission unit on the top surface.

[0010] In some embodiments of the present invention, the cavity-forming assembly includes a first cavity-forming unit and a second cavity-forming unit, the first cavity-forming unit being connected to the inner tube, the second cavity-forming unit being connected to the outer tube, one of the first cavity-forming unit and the second cavity-forming unit being used to inject fresh water into the salt rock block, and the other of the first cavity-forming unit and the second cavity-forming unit being used to collect the brine discharged from the salt rock block.

[0011] In some embodiments of the present invention, the first cavity-forming unit is connected to the inner tube via a water supply pipe and includes: a first bidirectional pump, a first inlet valve, a first outlet valve, a first clear water tank, a first brine tank, a high-precision mass meter, and a liquid level sensor. The first brine tank is used to store brine, and the first clear water tank is used to store clear water. The first brine tank and the first clear water tank are connected to the inner tube via the water supply pipe. The first inlet valve is used to control the connection between the first clear water tank and the inner tube. The first outlet valve is used to control the connection between the first brine tank and the inner tube. The first bidirectional pump is used to drive the flow of clear water or brine in the water supply pipe. The high-precision mass meter is used to measure the liquid mass in the first brine tank and the first clear water tank, respectively. The liquid level sensor is used to measure the liquid mass in the first brine tank and the first clear water tank, respectively. Body fluid level; and / or, the second cavity-forming unit is connected to the outer pipe via a water supply pipe and includes: a second bidirectional pump, a second inlet valve, a second outlet valve, a second clear water tank, a second brine tank, a high-precision mass meter, and a liquid level sensor. The second brine tank is used to store brine, and the second clear water tank is used to store clear water. The second brine tank and the second clear water tank are connected to the outer pipe via the water supply pipe. The second inlet valve is used to control the connection between the second clear water tank and the outer pipe. The second outlet valve is used to control the connection between the second brine tank and the outer pipe. The second bidirectional pump is used to drive the flow of clear water or brine in the water supply pipe. The high-precision mass meter is used to measure the liquid mass in the second brine tank and the second clear water tank respectively. The liquid level sensor is used to measure the liquid level in the second brine tank and the second clear water tank respectively.

[0012] In some embodiments of the present invention, the gas injection and extraction assembly includes: a high-pressure gas injection unit and a gas extraction and collection unit. The high-pressure gas injection unit is connected to the outer pipe and is used to inject gas into the salt rock block. The gas extraction and collection unit is connected to the inner pipe or the outer pipe and is used to extract and collect gas from the salt rock block.

[0013] In some embodiments of the present invention, the high-pressure gas injection unit includes: a high-pressure gas source, a booster pump, a first pressure gauge, and an intake control valve. The high-pressure gas source stores high-pressure gas and is connected to the outer pipe via a gas delivery pipe. The booster pump, the first pressure gauge, and the intake control valve are connected in series between the high-pressure gas source and the outer pipe. The booster pump drives the gas to flow from the high-pressure gas source to the outer pipe. The first pressure gauge monitors the injection pressure. The intake control valve controls the connection and disconnection between the high-pressure gas source and the outer pipe; and / or, The gas collection unit includes a gas collection container, a pump, a second pressure gauge, and an outlet control valve. The gas collection container is used to store the gas extracted from the salt rock block and is connected to the inner pipe through a gas delivery pipe. The pump, the second pressure gauge, and the outlet control valve are connected in series between the gas collection container and the inner pipe. The pump drives the gas to flow from the inner pipe to the gas collection container. The second pressure gauge monitors the gas extraction pressure. The outlet control valve controls the connection between the gas collection container and the inner pipe.

[0014] In some embodiments of the present invention, the indoor simulation system for the entire process of cavity construction and brine extraction in a true triaxial salt rock block gas storage facility includes a water-soluble cavity construction stage, a gas injection and brine discharge stage, a extraction and injection stage, and a brine injection and venting stage. In the water-soluble cavity construction stage, the first cavity construction unit injects fresh water into the salt rock block through the inner pipe, and the second cavity construction unit collects the brine discharged from the salt rock block through the outer pipe; or the second cavity construction unit injects fresh water into the salt rock block through the outer pipe, and the first cavity construction unit collects the brine discharged from the salt rock block through the inner pipe. In the gas injection and venting stage… During the brine extraction stage, the high-pressure gas injection unit injects gas into the salt rock block through the outer pipe, and the first cavity-forming unit collects the brine discharged from the salt rock block through the inner pipe; during the extraction and injection stage, the high-pressure gas injection unit injects gas into the salt rock block through the outer pipe, and the gas extraction and collection unit extracts and collects the gas from the salt rock block through the inner pipe; during the brine extraction and degassing stage, the first cavity-forming unit injects fresh water into the salt rock block through the inner pipe, and the gas extraction and collection unit extracts and collects the gas from the salt rock block through the outer pipe.

[0015] In some embodiments of the present invention, displacement sensors are connected to the surfaces of the salt rock block other than the bottom and top surfaces to monitor the displacement of the salt rock block.

[0016] In some embodiments of the present invention, a cementing layer is provided between the outer pipe and the inner wall of the vertical shaft hole. The cementing layer is located at one end near the open end of the vertical shaft hole, and the cementing layer is an expansive cement component or a modified concrete component.

[0017] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0018] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which: Figure 1 This is a schematic diagram of the main salt rock component of the indoor simulation system for the entire process of cavity construction and production and injection of a true triaxial salt rock block gas storage tank according to an embodiment of the present invention; Figure 2 This is a schematic diagram of the main salt rock component and the true triaxial pressurization component of the indoor simulation system for the cavity construction and full process of production and injection of a true triaxial salt rock block gas storage tank according to an embodiment of the present invention. Figure 3 This is a schematic diagram of the cavity-building stage of the indoor simulation system for the entire process of cavity building and production and injection in a true triaxial salt rock block gas storage tank according to an embodiment of the present invention. Figure 4 This is a schematic diagram of the indoor simulation system for the entire process of cavity construction and production and injection of a true triaxial salt rock block gas storage tank according to an embodiment of the present invention, during the gas injection and brine discharge stage. Figure 5 This is a schematic diagram of the indoor simulation system for the entire process of cavity construction and production and injection of a true triaxial salt rock block gas storage tank according to an embodiment of the present invention during the production and injection stage; Figure 6 This is a schematic diagram of the brine injection and exhaust stage of the indoor simulation system for the entire process of cavity construction and gas production and injection in a true triaxial salt rock block gas storage tank according to an embodiment of the present invention.

[0019] Figure label: 1. Constant temperature environment; 2. Salt rock block; 3. Combined casing; 4. Cementing layer; 5. Base; 6. Cement mortar; 7. Force transmission column; 8. Hydraulic jack; 9. Steel plate force transmission unit; 901. Inner steel plate; 902. Second transition steel plate; 903. Outer pressure-bearing steel plate; 10. Anti-friction layer; 11. Hydraulic pipe joint; 12. Hydraulic pipe; 13. Liquid pressure gauge; 14. Hydraulic controller; 15. Oil pump; 16. Displacement sensor; 17. Sealing and isolation component; 101. First cavity-forming unit; 102. Second cavity-forming unit; 103. Water delivery pipe; 104. First bidirectional pump; 105. First outlet valve; 106. First inlet valve; 107. First brine tank; 108. 109. First clear water tank; 110. First high-precision mass meter; 111. Second high-precision mass meter; 112. Third high-precision mass meter; 113. Fourth high-precision mass meter; 114. Second bidirectional pump; 115. Second inlet valve; 116. Second outlet valve; 117. Second brine tank; 118. Second clear water tank; 119. Liquid level sensor; 200. High-pressure gas injection unit; 201. Gas collection unit; 202. Gas transmission pipe; 203. First pressure gauge; 204. Second pressure gauge; 205. Booster pump; 206. Inlet control valve; 207. High-pressure gas source; 209. Air pump; 210. Outlet control valve; 211. Gas collection container; 212. Cavity pressure gauge. Detailed Implementation

[0020] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0021] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential," etc., indicating orientation or positional relationships, are based on the orientation or positional relationships shown in the accompanying drawings and are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, features defined with "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "a plurality of" means two or more. In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0022] The following is for reference. Figures 1-6 This invention describes an indoor simulation system for the entire process of cavity construction and gas production and injection in a true triaxial salt rock block gas storage facility according to an embodiment of the present invention.

[0023] like Figure 1 , Figure 2 , Figure 3 and Figure 5 As shown, the indoor simulation system for the entire process of cavity construction and production / injection in a true triaxial salt rock block gas storage tank according to an embodiment of the present invention includes a salt rock main body component, a true triaxial pressurization component, a cavity construction component, and a production / injection component.

[0024] Specifically, such as Figure 1 and Figure 2 As shown, the main component of the salt rock assembly includes a base 5, a salt rock block 2, and a combined sleeve 3. The salt rock block 2 is fixed above the base 5, and a vertical shaft hole is provided above the salt rock block 2. The lower end of the combined sleeve 3 extends into the vertical shaft hole. The combined sleeve 3 includes an inner tube and an outer tube arranged coaxially. The outer tube is sleeved outside the inner tube, and an annular sealing isolation element 17 is provided on the outer wall of the outer tube. The sealing isolation element 17 is located at a predetermined position on the outer wall of the outer tube and cooperates with the wall surface of the vertical shaft hole. The true triaxial pressure assembly is used to apply independent triaxial stress to the surfaces of the salt rock block 2 other than the bottom surface to simulate the three-dimensional stress state of the real strata. The cavity-forming assembly is connected to the inner tube and the outer tube respectively, and is used to inject fresh water into the salt rock block 2 and discharge brine for water-soluble cavity-forming, as well as to collect the brine discharged from the salt rock block 2. The gas extraction and injection components are connected to the inner and outer pipes, respectively, and are used to inject gas into the salt rock block 2 to discharge brine, as well as to periodically inject and extract gas into the salt rock block 2.

[0025] Understandably, a true triaxial salt rock block gas storage cavity construction and production-injection full-process indoor simulation system is suitable for use in... Figure 1The simulation experiment was conducted under the constant temperature environment 1 shown. The core of the salt rock main component can be a cubic salt rock block 2 with dimensions of 1000mm × 1000mm × 1000mm. The salt rock block 2 is placed on the base 5, and a friction-reducing layer 10 composed of a double layer of polytetrafluoroethylene film and petroleum jelly can be laid between the salt rock block 2 and the base 5. A simulated vertical shaft hole can be drilled at the center of the upper surface of the salt rock block 2, and the specific dimensions of the vertical shaft hole can be 150mm in diameter and 700mm in depth.

[0026] A combined casing 3, simulating the structure of the wellbore on site, is installed inside the vertical shaft borehole. The combined casing 3 includes an inner tube and an outer tube arranged coaxially, forming an annular space between them. The inner and outer tubes can be designed as a single unit. The inner tube is a suspended central tube, with its lower end extending to a predetermined position at the bottom of the vertical shaft borehole. The lower end of the outer tube extends into the salt rock block 2 to a lesser depth than the lower end of the inner tube. The inner tube is made of stainless steel with an outer diameter of 48 mm, extending through the interior of the outer tube to a point 100 mm from the bottom of the borehole (the inner tube's insertion depth into the cavity is approximately 600 mm). The outer tube can be made of seamless steel with an outer diameter of 89 mm and a wall thickness of 6 mm. The lower end of the outer tube inserts into the cavity to a depth of 400 mm. The outer wall of the outer tube is roughened by sandblasting and coated with epoxy resin.

[0027] The true triaxial pressure assembly can apply independent triaxial stress to the five surfaces of the salt rock block 2, excluding the bottom surface, while the base 5 provides reaction support on the bottom surface, thereby simulating the three-dimensional stress state of the real strata.

[0028] The cavity-forming component is connected to the inner and outer tubes respectively, and is responsible for the injection and discharge of liquid, thereby constructing a liquid circulation loop. The cavity-forming component injects fresh water into the salt rock block 2, and after brine is formed, it is discharged. The cavity-forming component collects the brine discharged from the salt rock block 2, thereby realizing water-soluble cavity-forming.

[0029] The injection and extraction components are connected to the outer and inner pipes respectively, and are responsible for the injection and recovery of gas, thereby constructing a gas circulation loop. The injection and extraction components inject gas into the salt rock block 2 to discharge brine. The cavity-making component works with the injection and extraction components to collect the brine discharged from the salt rock block 2, thereby realizing gas injection and brine discharge. Alternatively, the injection and extraction components periodically inject and extract gas into the salt rock block 2 to simulate the injection and extraction cycle.

[0030] This application introduces the water-soluble cavity-building process into a true triaxial loading system, which enables the study of the effects of stress concentration and damage on the water-soluble rate and cavity expansion morphology under triaxial unequal stress, thus making up for the lack of mechanical constraints in conventional cavity-building experiments.

[0031] Furthermore, by integrating the cavity-building component with the production-injection component, each stage of the process can operate independently or cooperate with each other. The smooth transition between stages such as water-soluble cavity building, gas injection and brine discharge, injection-production circulation, and brine injection and venting via pipeline switching realistically replicates the process switching process at the engineering site. This allows for a more accurate assessment of the engineering safety of the salt rock block 2 gas storage facility. All key processes from storage construction to operation are completed uninterruptedly within a single unit. This enables the experiment to capture the cumulative impact of irregular shapes or localized damage generated during cavity building on the creep and tightness of the surrounding rock during the injection-production period, eliminating errors introduced by previous segmented tests.

[0032] This application overcomes the shortcomings of the existing technology in true triaxial compressive stress and phase separation of the entire process of cavity construction and injection in the salt rock block 2. It realizes integrated and continuous simulation of the entire life cycle from cavity construction to injection under in-situ stress level, and provides a reliable test device and method for the safety assessment and optimization design of the salt rock block 2 gas storage facility.

[0033] The true triaxial indoor simulation system for the entire process of cavity construction and gas production and injection in a salt rock block gas storage facility according to an embodiment of the present invention, by setting up a salt rock main body component, a true triaxial pressurization component, a cavity construction component, and a production and injection component, wherein the true triaxial pressurization component is used to apply independent triaxial stress to the surfaces of the salt rock block 2 except for the bottom surface, the cavity construction component is used to inject fresh water into the salt rock block 2 and discharge brine for water-soluble cavity construction, and to collect the brine discharged from the salt rock block 2, and the production and injection component is used to inject gas into the salt rock block 2 and discharge brine, and to periodically inject and extract gas into the salt rock block 2, is a device that integrates a true triaxial geostress loading system with a fluid dissolution and gas injection and production system, realizing integrated continuous simulation of the entire process of "geostress loading - water-soluble cavity construction - gas injection and brine discharge - cyclic injection and production - brine injection and exhaust", so as to more accurately assess the engineering safety of the salt rock block 2 gas storage facility.

[0034] In some embodiments of the present invention, such as Figure 1 and Figure 2 As shown, the true triaxial pressure assembly includes: a friction-reducing layer 10, a steel plate force transmission unit 9, a hydraulic jack 8, a reaction force device unit, and a hydraulic control unit. The friction-reducing layer 10 is laid on each stress-bearing surface of the salt rock block 2 to reduce boundary friction effects. The steel plate force transmission unit 9 is composed of multiple layers of steel plates with gradually varying sizes, stacked tightly against the outside of the friction-reducing layer 10, used to uniformly transfer hydraulic loads to the surface of the salt rock block 2. The hydraulic jack 8 acts on the outermost layer of the steel plate force transmission unit 9. The reaction force device unit provides stable support for the hydraulic jack 8 and includes cement mortar 6 and a force transmission column 7. The two ends of the force transmission column 7 are connected to the hydraulic jack 8 and the cement mortar 6, respectively. The hydraulic control unit is connected to the hydraulic jack 8 and is used to control the hydraulic jack 8 to apply force towards the steel plate force transmission unit 9.

[0035] The friction-reducing layer 10 is wrapped around the outer periphery of the salt rock block 2 to reduce the friction between the base 5 and the steel plate force transmission unit 9 on the salt rock block 2. Specifically, the friction-reducing layer 10 can be composed of a double layer of polytetrafluoroethylene film and petroleum jelly. The true triaxial pressure assembly applies pressure to the salt rock block 2 using a five-sided active loading and bottom passive reaction method. The friction-reducing layer 10 and the steel plate force transmission unit 9 are laid on the front, back, left, right and top surfaces of the salt rock block 2.

[0036] The steel plate force transmission unit 9 is composed of multiple layers of steel plates with gradually varying sizes stacked together. The steel plate force transmission unit 9 adopts a "pagoda-shaped" stacking design to accommodate 1m... 2 Large-area loading and uniform force transmission. Specifically, such as... Figure 1 As shown, the steel plate force transmission unit 9 consists of an inner steel plate 901, a second transition steel plate 902, and an outer pressure-bearing steel plate 903. The inner steel plate 901 is in close contact with the salt rock block 2 and has dimensions of 980mm×980mm×80mm. The second transition steel plate 902 is located on the side of the inner steel plate 901 away from the salt rock block 2 and has dimensions of 700mm×700mm×100mm. The outer pressure-bearing steel plate 903 is located on the side of the second transition steel plate 902 away from the inner steel plate 901 and is connected to the hydraulic jack 8. The outer pressure-bearing steel plate 903 is specifically composed of two steel plates with dimensions of 300mm×300mm×100mm arranged side by side.

[0037] Preferably, the top steel plate force transmission unit 9 has a hole in the center for the combined sleeve 3 to pass through.

[0038] In some embodiments of the present invention, such as Figure 1 and Figure 2 As shown, each load-bearing surface of the salt rock block 2 is equipped with multiple hydraulic jacks 8, and the hydraulic jacks 8 on two opposite load-bearing surfaces of the salt rock block 2 are arranged oppositely or symmetrically. It can be understood that the hydraulic jacks 8 are arranged in pairs or in an array on each loading surface of the salt rock block 2, which facilitates uniform loading.

[0039] In some embodiments of the present invention, such as Figure 1 and Figure 2 As shown, there are multiple hydraulic jacks 8 and multiple hydraulic control units. Each hydraulic control unit is connected to multiple hydraulic jacks 8 at the same time. Multiple hydraulic jacks 8 are controlled synchronously by the hydraulic controller 14 to facilitate uniform loading.

[0040] Specifically, each active loading surface of the salt rock block 2 is equipped with two 1000-ton hydraulic jacks 8, which are independently controlled by the hydraulic control unit, and can achieve a true triaxial stress state of σ1≠σ2≠σ3.

[0041] In some embodiments of the present invention, such as Figure 2As shown, the hydraulic control unit includes an oil pump 15, a hydraulic controller 14, a hydraulic pressure gauge 13, a hydraulic pipe 12, and a hydraulic pipe connector 11. The oil pump 15 pumps oil towards the hydraulic jack 8. The hydraulic pipe connector 11 is fixed to the hydraulic jack 8. The oil pump 15 and the hydraulic pipe connector 11 are connected through the hydraulic pipe 12. The hydraulic controller 14 and the hydraulic pressure gauge 13 are connected in series between the oil pump 15 and the hydraulic pipe connector 11. The hydraulic controller 14 controls the amount of oil pumped by the oil pump 15, and the hydraulic pressure gauge 13 measures the oil pressure in the hydraulic pipe 12. A stable connection between the oil pump 15 and the hydraulic jack 8 can be achieved through the hydraulic pipe 12 and the hydraulic pipe connector 11. Through the cooperation of the oil pump 15, the hydraulic controller 14, and the hydraulic pressure gauge 13, the loading of the hydraulic jack 8 onto the salt rock block 2 can be controlled more stably and reliably.

[0042] In some embodiments of the present invention, such as Figure 1 and Figure 2 As shown, the center of the top steel plate force transmission unit 9 is provided with a clearance hole that penetrates the steel plate force transmission unit 9. The clearance hole is used to avoid components such as the combined sleeve 3, so that the combined sleeve 3 can be inserted into the salt rock block 2 through the clearance hole, thereby stably realizing the simulation of each stage of the process.

[0043] In some embodiments of the present invention, such as Figures 1-6 As shown, displacement sensors 16 are connected to the surfaces of the salt rock block 2, except for the bottom and top surfaces, to monitor the displacement of the salt rock block 2, thereby enabling better detection of the internal condition of the salt rock block 2.

[0044] Optionally, the center of the steel plate force transmission unit 9 at the other force-bearing surfaces of the salt rock block 2, excluding the top and ground surfaces, is provided with a clearance hole to avoid the displacement sensor 16.

[0045] In some embodiments of the present invention, such as Figure 1 and Figure 2 As shown, a cementing layer 4 is provided between the outer pipe and the inner wall of the vertical shaft hole. The cementing layer 4 is located at one end near the opening of the vertical shaft hole. The cementing layer 4 is an expansive cement component or a modified concrete component. The cementing layer 4 is used to ensure the airtightness of the inside of the salt rock block 2.

[0046] Preferably, a sealing isolation element 17 is provided at a predetermined height on the outer wall of the combined casing 3. The sealing isolation element 17 is located below the cementing layer 4. The sealing isolation element 17 is interference-fitted with the inner wall of the vertical shaft hole to support and intercept the cementing layer 4 injected above, ensuring that the preset open hole cavity section is retained below. The outer wall of the outer casing is provided with a surface friction-increasing structure or coating to enhance the strength of the cementing interface.

[0047] Specifically, the minimum distance between the sealing isolation element 17 located on the outer wall of the combined casing 3 and the open end of the vertical shaft hole is 300mm, and the material is a rubber / silicone sealing ring. The space between the outer wall of the combined casing 3 and the inner wall of the vertical shaft hole is filled with high-strength expansive concrete of grade C60 and mixed with 8% UEA expansive agent to form a well-sealed cementing layer 4.

[0048] In some embodiments of the present invention, such as Figure 1 , Figure 2 and Figure 6 As shown, the cavity-forming assembly includes a first cavity-forming unit 101 and a second cavity-forming unit 102. The first cavity-forming unit 101 is connected to the inner pipe, and the second cavity-forming unit 102 is connected to the outer pipe. One of the first cavity-forming unit 101 and the second cavity-forming unit 102 is used to inject fresh water into the salt rock block 2, and the other of the first cavity-forming unit 101 and the second cavity-forming unit 102 is used to collect the brine discharged from the salt rock block 2. Through the cooperation of the first cavity-forming unit 101 and the second cavity-forming unit 102, water-soluble cavity-forming in both forward and reverse circulation can be realized, improving the effect and efficiency of water-soluble cavity-forming. For example, the first cavity-forming unit 101 can be used for water injection during forward circulation and brine discharge during reverse circulation, while the second cavity-forming unit 102 can be used for brine discharge during forward circulation or water injection during reverse circulation.

[0049] In some embodiments of the present invention, such as Figure 3 , Figure 4 and Figure 6 As shown, the first cavity-forming unit 101 is connected to the inner pipe via a water supply pipe 103 and includes: a first bidirectional pump 104, a first inlet valve 106, a first outlet valve 105, a first clear water tank 108, a first brine tank 107, a high-precision mass meter, and a level sensor 118. The first brine tank 107 is used to store brine, and the first clear water tank 108 is used to store clear water. The first brine tank 107 and the first clear water tank 108 are connected to the inner pipe via a water supply pipe 103. The first inlet valve... Valve 106 controls the connection between the first clear water tank 108 and the inner pipe; the first outlet valve 105 controls the connection between the first brine tank 107 and the inner pipe; the first bidirectional pump 104 drives the flow of clear water or brine in the water supply pipe 103; a high-precision mass meter measures the liquid mass in the first brine tank 107 and the first clear water tank 108 respectively; and a level sensor 118 measures the liquid level in the first brine tank 107 and the first clear water tank 108 respectively. By controlling the start, stop, and flow direction of the first bidirectional pump 104, the water-soluble process can be precisely controlled. Through the cooperation between the components in the first cavity-forming unit 101, the injection of fresh water into the salt rock block 2 and the discharge of brine for water-soluble cavity-forming can be precisely and stably controlled, as well as the collection of brine discharged from the salt rock block 2, thereby improving the water-soluble cavity-forming effect and efficiency.

[0050] The high-precision mass meter includes a first high-precision mass meter 109 and a second high-precision mass meter 110. The first high-precision mass meter 109 is connected to the first brine tank 107 and is used to measure the mass of the brine in the first brine tank 107. The second high-precision mass meter 110 is connected to the first clear water tank 108 and is used to measure the mass of the clear water in the first clear water tank 108.

[0051] The specific control method of the first cavity-making unit 101 in the simulation of cavity-making and gas injection and brine discharge in the true triaxial salt rock block 2 gas storage tank is described below.

[0052] In some embodiments of the present invention, such as Figure 3 As shown, the second cavity-forming unit 102 is connected to the outer pipe through a water supply pipe 103 and includes: a second bidirectional pump 111, a second inlet valve 112, a second outlet valve 113, a second clear water tank 115, a second brine tank 114, a high-precision mass meter, and a liquid level sensor 118. The second brine tank 114 is used to store brine, and the second clear water tank 115 is used to store clear water. The second brine tank 114 and the second clear water tank 115 are connected to the outer pipe through the water supply pipe 103. The second inlet valve 112 is used to control the connection and disconnection between the second clear water tank 115 and the outer pipe, and the second outlet valve 113 is used to control the connection and disconnection between the second brine tank 114 and the outer pipe. The second bidirectional pump 111 is used to drive the flow of clear water or brine in the water supply pipe 103. The high-precision mass meter is used to measure the liquid mass in the second brine tank 114 and the second clear water tank 115 respectively. The liquid level sensor 118 is used to measure the liquid level in the second brine tank 114 and the second clear water tank 115 respectively. By controlling the start, stop, and flow direction of the second bidirectional pump 111, the water-soluble process can be precisely controlled. Through the cooperation between the components within the second cavity-forming unit 102, the second cavity-forming unit 102 can be precisely and stably controlled to inject fresh water into the salt rock block 2 and discharge brine for water-soluble cavity forming, as well as to collect the brine discharged from the salt rock block 2, thereby improving the water-soluble cavity-forming effect and efficiency.

[0053] The high-precision mass measuring instrument includes a third high-precision mass measuring instrument 116 and a fourth high-precision mass measuring instrument 117. The third high-precision mass measuring instrument 116 is connected to the second brine tank 114 and is used to measure the mass of the brine in the second brine tank 114. The fourth high-precision mass measuring instrument 117 is connected to the second clear water tank 115 and is used to measure the mass of the clear water in the second clear water tank 115.

[0054] The specific control method of the second cavity-making unit 102 during the cavity-making simulation of the true triaxial salt rock block 2 gas storage tank is described below.

[0055] In some embodiments of the present invention, such as Figure 4 , Figure 5 and Figure 6As shown, the gas extraction and injection assembly includes a high-pressure gas injection unit 201 and a gas extraction and collection unit 202. The high-pressure gas injection unit 201 is connected to an outer pipe and is used to inject gas into the salt rock block 2. The gas extraction and collection unit 202 is connected to an inner or outer pipe and is used to extract and collect the gas inside the salt rock block 2. During the gas injection and brine discharge stage, the high-pressure gas injection unit 201 can cooperate with the first cavity-making unit 101 to ensure the gas injection and brine discharge effect. During the extraction and injection stage, the high-pressure gas injection unit 201 and the gas extraction and collection unit 202 work alternately to simulate the injection and extraction cycle, realize the simulation of the gas extraction and depressurization process and the collection of experimental gas. During the brine injection and venting stage, the gas extraction and collection unit 202 can cooperate with the first cavity-making unit 101 to ensure the brine injection and venting effect.

[0056] By integrating the cavity-making component with the injection and production components, each stage of the process can operate independently or cooperate with each other. The process of water-soluble cavity making, gas injection and brine discharge, injection and production circulation, and brine injection and venting can be smoothly transitioned through pipeline switching. This truly replicates the process switching process on the engineering site and allows for a more accurate assessment of the engineering safety of the salt rock block 2 gas storage facility.

[0057] In some embodiments of the present invention, such as Figure 4 and Figure 5 As shown, the high-pressure gas injection unit 201 includes: a high-pressure gas source 207, a booster pump 205, a first pressure gauge 204, and an intake control valve 206. The high-pressure gas source 207 stores high-pressure gas and is connected to an outer pipe through a gas delivery pipe 203. The booster pump 205, the first pressure gauge 204, and the intake control valve 206 are connected in series between the high-pressure gas source 207 and the outer pipe. The booster pump 205 is used to drive the gas from the high-pressure gas source 207 to the outer pipe. The first pressure gauge 204 is used to monitor the injection pressure. The intake control valve 206 is used to control the on / off connection between the high-pressure gas source 207 and the outer pipe.

[0058] The high-pressure gas source 207 can be a hydrogen cylinder, a nitrogen cylinder, or an air compressor. Through the coordination of the various components within the high-pressure gas injection unit 201, the injection of gas into the salt rock block 2 can be precisely and stably controlled, thereby improving the effect and efficiency of gas injection and brine discharge and injection-production cycles.

[0059] The specific control method of high-pressure gas source 207 during the gas injection and brine discharge simulation and injection-production cycle simulation of the true triaxial salt rock block 2 gas storage tank is described below.

[0060] In some embodiments of the present invention, such as Figure 5 and Figure 6As shown, the gas collection unit 202 includes a gas collection container 211, a suction pump 209, a second pressure gauge 208, and an outlet control valve 210. The gas collection container 211 stores the gas extracted from the salt rock block 2 and is connected to the inner pipe through a gas delivery pipe 203. The suction pump 209, the second pressure gauge 208, and the outlet control valve 210 are connected in series between the gas collection container 211 and the inner pipe. The suction pump 209 drives the gas to flow from the inner pipe to the gas collection container 211. The second pressure gauge 208 monitors the gas extraction pressure. The outlet control valve 210 controls the connection between the gas collection container 211 and the inner pipe. Through the cooperation of the components within the gas collection unit 202, the extraction and collection of gas from the salt rock block 2 can be precisely and stably controlled, thereby improving the effect and efficiency of the injection-production cycle.

[0061] The specific control method of the gas collection unit 202 during the injection and production cycle and brine injection and exhaust simulation in the true triaxial salt rock block 2 gas storage tank is described below.

[0062] In some embodiments of the present invention, such as Figures 3-6 As shown, the indoor simulation system for the entire process of cavity construction and production / injection in a true triaxial salt rock block gas storage facility includes the water-soluble cavity construction stage, the gas injection and brine discharge stage, the production and injection stage, and the brine injection and venting stage.

[0063] During the water-soluble cavity-forming stage, the first cavity-forming unit 101 injects fresh water into the salt rock block 2 through its inner pipe, and the second cavity-forming unit 102 collects the brine discharged from the salt rock block 2 through its outer pipe; alternatively, the second cavity-forming unit 102 injects fresh water into the salt rock block 2 through its outer pipe, and the first cavity-forming unit 101 collects the brine discharged from the salt rock block 2 through its inner pipe. This allows for both forward and reverse circulation water-soluble cavity-forming, improving the effect and efficiency of the process.

[0064] During the gas injection and brine discharge phase, the high-pressure gas injection unit 201 injects gas into the salt rock block 2 through the outer pipe, and the first cavity-forming unit 101 collects the brine discharged from the salt rock block 2 through the inner pipe. During the extraction and injection phase, the high-pressure gas injection unit 201 injects gas into the salt rock block 2 through the outer pipe, and the gas extraction and collection unit 202 extracts and collects the gas inside the salt rock block 2 through the inner pipe. During the brine injection and degassing phase, the first cavity-forming unit 101 injects fresh water into the salt rock block 2 through the inner pipe, and the gas extraction and collection unit 202 extracts and collects the gas inside the salt rock block 2 through the outer pipe.

[0065] By integrating the cavity-building component with the production-injection component, each stage of the process can operate independently or cooperate with each other. Through pipeline switching, the transitions between stages such as water-soluble cavity building, gas injection and brine discharge, injection-production circulation, and brine injection and venting are smoothly achieved, realistically replicating the process switching process at the engineering site. This allows for a more accurate assessment of the engineering safety of the salt rock block 2 gas storage facility. All key processes from facility construction to operation are completed uninterruptedly within a single unit. This enables the experiment to capture the cumulative impact of irregular shapes or localized damage generated during cavity building on the creep and tightness of the surrounding rock during the injection-production period, eliminating errors introduced by previous segmented tests.

[0066] The following is in conjunction with the appendix Figures 1-6 The indoor simulation method for the entire process of cavity construction and production / injection in a true triaxial salt rock block gas storage facility (Synthetic Gas Storage Facility 2) is described in the following steps: Step 1: True Triaxial Stress Loading: Activate the true triaxial pressurization assembly to apply preset vertical stress, maximum horizontal principal stress, and minimum horizontal principal stress to the salt rock block 2, and maintain a stable pressure state. Specifically, according to preset geological conditions, the stress is applied step by step: vertical stress 20MPa, maximum horizontal stress 18MPa, and minimum horizontal stress 15MPa. After the deformation of the salt rock block 2 stabilizes, the pressure is locked.

[0067] Step 2, Water-soluble cavity construction: After the true triaxial stress loading is completed, the displacement sensor 16 is activated, followed by the cavity construction assembly. The first inlet valve 106 and the second outlet valve 113 are opened, and the first outlet valve 105 and the second inlet valve 112 are closed. According to the design process, the bottom cavity is constructed by forward circulation first. When the level sensor 118 in the first clear water tank 108 or the second brine tank 114 issues an alarm, the process stops. The first outlet valve 105 and the second inlet valve 112 are opened, and the first inlet valve 106 and the second outlet valve 113 are closed. The cavity is expanded by reverse circulation. The concentration and flow rate of the discharged brine are monitored in real time. When the level sensor 118 in the second clear water tank 115 or the first brine tank 107 issues an alarm, the process stops. During this period, the preset cavity shape, such as a pear shape, is shaped by controlling the water flow speed and interface position until a cavity of the predetermined volume and shape is formed. The first outlet valve 105 and the second inlet valve 112 are then closed.

[0068] Step 3, Gas Injection and Brine Discharge: Simulating the brine discharge process in the engineering project. Maintaining constant ground stress, open the first water outlet valve 105, disconnect the second cavity-forming unit 102 from the outer pipe, and connect the outer pipe to the high-pressure gas injection unit 201 of the sampling and injection assembly; inject high-pressure gas into the outer pipe, using the gas pressure to force the brine in the cavity through the inner pipe into the water delivery pipe 103, and then to the first brine tank 107, until the main gas is detected being discharged from the inner pipe outlet. Close the first water outlet valve 105 and collect the mass of the discharged gas and the mass of the gas in the water delivery pipe 103, denoted as Q. 损The mass of brine in the first brine tank 107 and the mass of brine in the second brine tank 114 were measured by high-precision mass meters and high-precision mass meters respectively, and then added together to obtain the total mass Q of the brine. 卤水 The mass reduction of clean water in the first clean water tank 108 and the mass reduction of clean water in the second clean water tank 115 were measured by high-precision mass meters and high-precision mass meters respectively, and then added together to obtain the total mass Q of clean water. 清水 Through formula Q 盐岩块体 =Q 卤水 -Q 清水 The mass of the dissolved salt rock block 2 can then be obtained, and then the volume formula can be used. The volume of the dissolved cavity can be determined.

[0069] Step 4, Gas Injection and Extraction Operation: Disconnect the first cavity-forming unit 101 from the inner pipe, connect the inner pipe to the gas collection unit 202 of the gas injection and extraction assembly, open the inlet control valve 206, close the outlet control valve 210, install the cavity pressure gauge 212, and simulate the cavity gas injection process using the gas injection and extraction assembly. Observe the cavity pressure gauge 212. When the cavity pressure rises to a certain level, close the inlet control valve 206; open the outlet control valve 210, close the inlet control valve 206, and simulate the cavity gas extraction process using the gas injection and extraction assembly. Observe the cavity pressure gauge 212. When the cavity pressure drops to a certain level, close the outlet control valve 210. Within the set operating pressure range, cycle through high-pressure gas injection and gas extraction depressurization operations, and monitor the deformation characteristics of the salt rock block 2 and the airtightness of the cavity in real time until the destruction standard is reached or the predetermined number of cycles is reached. Record the cumulative mass Q of gas input into the cavity at this time. 输入 .

[0070] Step 5: Brine Injection and Venting. Simulate the venting process in the engineering project. Maintaining constant ground stress, disconnect the high-pressure gas injection unit 201 from the outer pipe, disconnect the gas extraction and collection unit 202 from the inner pipe, connect the inner pipe to the first cavity-forming unit 101, and connect the outer pipe to the gas extraction and collection unit 202; open the first water outlet valve 105, open the gas outlet control valve 210, close the first water inlet valve 106, and turn on the first bidirectional pump 104 to inject brine into the inner pipe from the first brine tank 107. Use water pressure to force the gas in the cavity through the outer pipe into the gas delivery pipe 203, and then transfer it to the gas collection container 211 until liquid is detected discharging from the outer pipe outlet. Close the gas outlet control valve 210 and record the mass of the gas in the gas collection container 211 and the mass of the gas in the gas delivery pipe 203, denoted as Q. 输出 ; Gas leakage amount: Q 泄漏 =Q 输入 -Q 输出 -Q 损 .

[0071] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0072] Although embodiments of the invention have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the claims and their equivalents.

Claims

1. An indoor simulation system for the entire process of cavity construction and gas production / injection in a true triaxial salt rock block gas storage facility, characterized in that, include: The main component of the salt rock includes a base (5), a salt rock block (2), and a combined sleeve (3). The salt rock block (2) is fixed above the base (5). A vertical shaft hole is provided above the salt rock block (2). The lower end of the combined sleeve (3) extends into the vertical shaft hole. The combined sleeve (3) includes an inner tube and an outer tube arranged coaxially. The outer tube is sleeved outside the inner tube. An annular sealing isolation element (17) is provided on the outer wall of the outer tube. The sealing isolation element (17) cooperates with the wall surface of the vertical shaft hole. The true triaxial pressure assembly is used to apply independent triaxial stress to the surfaces of the salt rock block (2) other than the bottom surface, in order to simulate the three-dimensional stress state of the real strata. A cavity-forming assembly, which is connected to the inner tube and the outer tube respectively, is used to inject fresh water into the salt rock block (2) and discharge brine to perform water-soluble cavity-forming, and to collect the brine discharged from the salt rock block (2); The gas injection assembly is connected to the inner pipe and the outer pipe respectively, and is used to inject gas into the salt rock block (2) to discharge brine, and to periodically inject and extract gas into the salt rock block (2).

2. The indoor simulation system for the entire process of cavity construction and production / injection in a true triaxial salt rock block gas storage tank according to claim 1, characterized in that, The true triaxial pressurization assembly includes: Friction-reducing layer (10) is laid on each stress-bearing surface of the salt rock block (2) to reduce the boundary friction effect; The steel plate force transmission unit (9) is made of multiple layers of steel plates with gradually changing dimensions, and is closely attached to the outside of the friction-reducing layer (10) to uniformly transmit hydraulic load to the surface of the salt rock block (2). Hydraulic jack (8), which acts on the outermost layer of the steel plate force transmission unit (9); The reaction device unit is used to provide stable support for the hydraulic jack (8). The reaction device unit includes cement mortar (6) and force transmission column (7). The two ends of the force transmission column (7) are respectively connected to the hydraulic jack (8) and the cement mortar (6). A hydraulic control unit is connected to the hydraulic jack (8) and is used to control the hydraulic jack (8) to apply force toward the steel plate force transmission unit (9).

3. The indoor simulation system for the entire process of cavity construction and production / injection in a true triaxial salt rock block gas storage tank according to claim 2, characterized in that, Each of the stress surfaces of the salt rock block (2) is provided with multiple hydraulic jacks (8), and the hydraulic jacks (8) on two opposite stress surfaces of the salt rock block (2) are arranged oppositely or symmetrically. And / or, there are multiple hydraulic jacks (8) and multiple hydraulic control units, each of which is connected to multiple hydraulic jacks (8) at the same time; And / or, the hydraulic control unit includes an oil pump (15), a hydraulic controller (14), a liquid pressure gauge (13), a hydraulic pipe (12), and a hydraulic pipe connector (11). The oil pump (15) is used to pump oil toward the hydraulic jack (8). The hydraulic pipe connector (11) is fixed on the hydraulic jack (8). The oil pump (15) and the hydraulic pipe connector (11) are connected through the hydraulic pipe (12). The hydraulic controller (14) and the liquid pressure gauge (13) are connected in series between the oil pump (15) and the hydraulic pipe connector (11). The hydraulic controller (14) is used to control the amount of oil pumped by the oil pump (15). The liquid pressure gauge (13) is used to measure the oil pressure in the hydraulic pipe (12). And / or, the center of the steel plate force transmission unit (9) on the top surface is provided with a clearance hole that penetrates the steel plate force transmission unit (9) on the top surface.

4. The indoor simulation system for the entire process of cavity construction and production / injection in a true triaxial salt rock block gas storage tank according to claim 1, characterized in that, The cavity creation assembly includes: A first cavity-forming unit (101) and a second cavity-forming unit (102) are connected. The first cavity-forming unit (101) is connected to the inner tube, and the second cavity-forming unit (102) is connected to the outer tube. One of the first cavity-forming unit (101) and the second cavity-forming unit (102) is used to inject fresh water into the salt rock block (2), and the other of the first cavity-forming unit (101) and the second cavity-forming unit (102) is used to collect the brine discharged from the salt rock block (2).

5. The indoor simulation system for the entire process of cavity construction and production / injection in a true triaxial salt rock block gas storage tank according to claim 4, characterized in that, The first cavity-forming unit (101) is connected to the inner tube via a water supply pipe (103) and includes: a first bidirectional pump (104), a first inlet valve (106), a first outlet valve (105), a first clear water tank (108), a first brine tank (107), a high-precision mass meter, and a level sensor (118). The first brine tank (107) is used to store brine, and the first clear water tank (108) is used to store clear water. The first brine tank (107) and the first clear water tank (108) are connected to the inner tube via the water supply pipe (103). The first inlet valve (104) is connected to the inner tube via a water supply pipe (103). 06) is used to control the connection between the first clear water tank (108) and the inner pipe, the first water outlet valve (105) is used to control the connection between the first brine tank (107) and the inner pipe, the first bidirectional pump (104) is used to drive the flow of clear water or brine in the water supply pipe (103), the high-precision mass meter is used to measure the liquid mass in the first brine tank (107) and the first clear water tank (108) respectively, and the liquid level sensor (118) is used to measure the liquid level in the first brine tank (107) and the first clear water tank (108) respectively; And / or, the second cavity-forming unit (102) is connected to the outer pipe via a water supply pipe (103) and includes: a second bidirectional pump (111), a second inlet valve (112), a second outlet valve (113), a second clear water tank (115), a second brine tank (114), a high-precision mass meter, and a level sensor (118). The second brine tank (114) is used to store brine, and the second clear water tank (115) is used to store clear water. The second brine tank (114) and the second clear water tank (115) are connected to the outer pipe via the water supply pipe (103). The second inlet valve... (112) is used to control the connection and disconnection between the second clear water tank (115) and the outer pipe; the second water outlet valve (113) is used to control the connection and disconnection between the second brine tank (114) and the outer pipe; the second bidirectional pump (111) is used to drive the flow of clear water or brine in the water supply pipe (103); the high-precision mass meter is used to measure the liquid mass in the second brine tank (114) and the second clear water tank (115) respectively; and the liquid level sensor (118) is used to measure the liquid level in the second brine tank (114) and the second clear water tank (115) respectively.

6. The indoor simulation system for the entire process of cavity construction and production / injection in a true triaxial salt rock block gas storage tank according to claim 4, characterized in that, The injection / collection assembly includes: High-pressure gas injection unit (201), which is connected to the outer pipe, is used to inject gas into the salt rock block (2); Gas extraction and collection unit (202), which is connected to the inner pipe or the outer pipe, is used to extract and collect gas in the salt rock block (2).

7. The indoor simulation system for the entire process of cavity construction and production / injection in a true triaxial salt rock block gas storage tank according to claim 6, characterized in that, The high-pressure gas injection unit (201) includes: a high-pressure gas source (207), a booster pump (205), a first pressure gauge (204), and an intake control valve (206). The high-pressure gas source (207) stores high-pressure gas and is connected to the outer pipe through a gas delivery pipe (203). The booster pump (205), the first pressure gauge (204), and the intake control valve (206) are connected in series between the high-pressure gas source (207) and the outer pipe. The booster pump (205) is used to drive gas from the high-pressure gas source (207) to the outer pipe. The first pressure gauge (204) is used to monitor the injection pressure. The intake control valve (206) is used to control the connection and disconnection between the high-pressure gas source (207) and the outer pipe. And / or, the gas collection unit (202) includes: a gas collection container (211), a pump (209), a second pressure gauge (208), and an outlet control valve (210). The gas collection container (211) is used to store the gas extracted from the salt rock block (2) and is connected to the inner pipe through a gas transmission pipe (203). The pump (209), the second pressure gauge (208), and the outlet control valve (210) are connected in series between the gas collection container (211) and the inner pipe. The pump (209) is used to drive the gas to flow from the inner pipe to the gas collection container (211). The second pressure gauge (208) is used to monitor the gas extraction pressure. The outlet control valve (210) is used to control the connection and disconnection between the gas collection container (211) and the inner pipe.

8. The indoor simulation system for the entire process of cavity construction and production / injection in a true triaxial salt rock block gas storage tank according to claim 6, characterized in that, The indoor simulation system for the entire process of cavity construction and brine extraction in a true triaxial salt rock block gas storage facility includes the water-soluble cavity construction stage, the gas injection and brine removal stage, the extraction and injection stage, and the brine injection and venting stage. During the water-soluble cavity-forming stage, the first cavity-forming unit (101) injects fresh water into the salt rock block (2) through the inner pipe, and the second cavity-forming unit (102) collects the brine discharged from the salt rock block (2) through the outer pipe; or the second cavity-forming unit (102) injects fresh water into the salt rock block (2) through the outer pipe, and the first cavity-forming unit (101) collects the brine discharged from the salt rock block (2) through the inner pipe. During the gas injection and brine discharge stage, the high-pressure gas injection unit (201) injects gas into the salt rock block (2) through the outer pipe, and the first cavity-making unit (101) collects the brine discharged from the salt rock block (2) through the inner pipe; During the injection and extraction phase, the high-pressure gas injection unit (201) injects gas into the salt rock block (2) through the outer pipe, and the gas extraction and collection unit (202) extracts and collects the gas in the salt rock block (2) through the inner pipe. During the brine injection and venting stage, the first cavity-forming unit (101) injects fresh water into the salt rock block (2) through the inner pipe, and the gas extraction and collection unit (202) extracts and collects the gas in the salt rock block (2) through the outer pipe.

9. The indoor simulation system for the entire process of cavity construction and production / injection in a true triaxial salt rock block gas storage tank according to claim 1, characterized in that, Displacement sensors (16) are connected to the surfaces of the salt rock block (2) other than the bottom and top surfaces to monitor the displacement of the salt rock block (2).

10. The indoor simulation system for the entire process of cavity construction and production / injection in a true triaxial salt rock block gas storage tank according to claim 1, characterized in that, A cementing layer (4) is provided between the outer pipe and the inner wall of the vertical shaft hole. The cementing layer (4) is located at one end near the opening of the vertical shaft hole. The cementing layer (4) is an expansive cement component or a modified concrete component.

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