A salt cavern gas storage small interval pair well cavity test device

Abstract

This invention provides a small-spacing well-to-well cavity creation test device for salt cavern gas storage, comprising: a frame, a sliding specimen support, a main column, a pair of outer sleeves, a pair of inner sleeves, a salt rock specimen, a peristaltic pump, and a double-cylinder water tank. The sliding specimen support is installed at the bottom of the frame, and the salt rock specimen is installed on the sliding specimen support. The main column and the peristaltic pump are both installed at the top of the frame. The pair of outer sleeves are fitted one-to-one with the pair of inner sleeves. The pair of outer sleeves and the pair of inner sleeves are both installed in the main column. The bottom ends of the pair of outer sleeves and the pair of inner sleeves penetrate the frame and are inserted into the salt rock specimen. The double-cylinder water tank is installed in the frame. The peristaltic pump is connected to one inner sleeve of the pair of inner sleeves and the double-cylinder water tank.

Description

Technical Field

[0001] This invention relates to the field of cavity-making experimental equipment technology, and in particular to a cavity-making experimental device for small-spacing wells in a salt cavern gas storage facility. Background Technology

[0002] The single-well cavity creation method is currently the main method used for constructing salt cavern gas storage facilities. However, layered salt rock differs from salt dome geological conditions, characterized by thin salt layers and numerous interlayers. The single-well cavity creation method suffers from disadvantages in engineering applications, including long dissolution time, low cavity creation efficiency, high construction costs, and low salt layer utilization. In contrast, the small-spacing dual-well cavity creation method is a new approach, offering advantages such as shorter cavity creation cycles, lower costs, improved gas injection and production efficiency, and increased cavity volume. Its main process involves drilling two closely spaced vertical wells into the target salt layer, then connecting the bottoms of the two wells using horizontal drilling technology, and utilizing the two wells for convection dissolution cavity creation.

[0003] As a novel cavity-creating method, small-interval well cavity-creating technology has only a few engineering applications and is still in the research stage. The cavity-creating rules and parameter settings of this technology have not been fully studied, and extensive experimental research is needed. Currently, there is a lack of a well cavity-creating test setup to complete similar model tests. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a small-spacing well cavity creation test device for salt cavern gas storage, which addresses the shortcomings of the prior art.

[0005] The technical solution of the present invention to solve the above-mentioned technical problems is as follows: A small-spacing well-to-well cavity creation test device for salt cavern gas storage includes: a frame, a sliding specimen support, a main column, a pair of outer sleeves, a pair of inner sleeves, a salt rock specimen, a peristaltic pump, and a double-cylinder water tank. The sliding specimen support is installed at the bottom of the frame, the salt rock specimen is installed on the sliding specimen support, the main column and the peristaltic pump are both installed at the top of the frame, the pair of outer sleeves are correspondingly sleeved on the outside of the pair of inner sleeves, the pair of outer sleeves and the pair of inner sleeves are both installed in the main column, the bottom ends of the pair of outer sleeves and the pair of inner sleeves penetrate the frame and are inserted into the salt rock specimen, the double-cylinder water tank is installed in the frame, and the peristaltic pump is connected to one inner sleeve of the pair of inner sleeves and the double-cylinder water tank respectively.

[0006] The beneficial effects of adopting the technical solution of this invention are as follows: Two sets of tubing can simulate two sets of brine injection and drainage tubing in a well cavity construction project. A peristaltic pump can inject fresh water into the cavity model through the inner casing. When the cavity is filled with brine, brine pressure will be formed, and the brine will be discharged along the other set of tubing. Model tests are conducted based on the well cavity construction project of a salt cavern gas storage facility to guide engineering operations, and indoor similar model tests are carried out to guide the setting of engineering parameters. Setting different cavity construction parameters for similar model tests allows for the inversion and correction of cavity construction parameters based on the test results. This provides more direct guidance for setting cavity construction parameters in well cavity construction projects, improving the construction quality of salt cavern gas storage facilities. It can be used to explore the characteristics of cavity morphology development and brine concentration distribution during the cavity construction process, forming a method for controlling cavity shape expansion by different cavity construction parameters. Furthermore, different similar models can be built according to the engineering site conditions, and cavity construction parameters referencing the site construction conditions can be applied to predict cavity morphology changes, guiding the construction of small-spacing well cavity construction projects in salt cavern gas storage facilities.

[0007] Furthermore, a top control box is provided at the top of the main column, and a control panel and a digital display screen are provided between the main column and the frame. The control panel, the digital display screen and the peristaltic pump are all connected to the top control box.

[0008] The beneficial effects of adopting the above-mentioned further technical solutions are: it facilitates the control and operation of the small-pitch well cavity creation test device for salt cavern gas storage, facilitates intuitive observation of the operating status of the small-pitch well cavity creation test device for salt cavern gas storage, and improves automation.

[0009] Furthermore, the main column is equipped with a stepper motor for controlling the lifting and lowering of a pair of outer sleeves and a pair of inner sleeves. The pair of outer sleeves and the pair of inner sleeves are slidably installed in the main column. The stepper motor is connected to the pair of outer sleeves and to the top control box.

[0010] The beneficial effects of adopting the above-mentioned further technical solution are: using a stepper motor to realize the lifting and lowering of the inner and outer tubes, and recording the height of the inner and outer tubes through the PLC control center and outputting it to the digital display panel.

[0011] Furthermore, LED light tubes are provided on the inner wall of the top of the frame, and the side walls of the frame are transparent acrylic sheets.

[0012] The beneficial effects of adopting the above-mentioned further technical solutions are: the built-in LED tube can provide illumination for the specimen, which is more conducive to the monitoring of cavity morphology, and can complete the monitoring of solvent depth, brine flow rate, and brine concentration in the salt cavity. The cavity morphology can be recorded by a camera system through a transparent acrylic sheet.

[0013] Furthermore, a concentration meter is connected to each of the two inner tubes, and the peristaltic pump is connected to the double-cylinder water tank through a water tank valve.

[0014] The beneficial effects of adopting the above-mentioned further technical solution are: the concentration meter is installed in the inlet and outlet brine pipelines, the concentration meter reading is observed by a camera, and it is connected to a computer to read the brine concentration in real time.

[0015] Furthermore, it also includes a laser imaging device, which is adjacent to the sliding specimen support. The bottom of the sliding specimen support is provided with multiple pulleys, and the bottom inner wall of the frame is provided with a support pulley locking device.

[0016] The beneficial effects of adopting the above-mentioned further technical solution are: the addition of a laser imaging device allows for scanning and three-dimensional imaging of the cavity's morphology; and the sliding support facilitates the internal and external transportation of the specimen.

[0017] Furthermore, a cabinet door is provided on one side of the frame, and a storage slot for placing the cabinet door is provided at the bottom of the frame.

[0018] The beneficial effect of adopting the above-mentioned further technical solution is that the cabinet door can be slid into the bottom of the device after being opened, which facilitates continuous observation during the experiment.

[0019] Furthermore, the main column has a sliding groove on its side wall, and a pair of outer sleeves have lifting handles, which are slidably installed in the sliding grooves.

[0020] The beneficial effects of adopting the above-mentioned further technical solution are: the main column has grooves (slide grooves) on both sides to accommodate the lifting handles of the inner and outer tubes (outer sleeve and inner sleeve), which can manually lift the inner and outer tubes without computer control.

[0021] Furthermore, a secondary support column is fitted around the main column, the bottom of the secondary support column is connected to the top of the frame, and there is a gap between the secondary support column and the main column.

[0022] The beneficial effects of adopting the above-mentioned further technical solution are: the secondary support is a hollow structure to allow internal and external water supply hoses and data cables to pass through, so that the pipelines are not exposed and the risk of aging and leakage is reduced.

[0023] Furthermore, each of the pair of outer sleeves is provided with a protective fluid, each of the pair of inner sleeves is provided with an inner tube adapter, and each of the pair of outer sleeves is provided with an outer tube adapter.

[0024] The beneficial effect of adopting the above-mentioned further technical solution is that a protective liquid can be injected into the outer tube to limit the degree of dissolution in the cavity, so as to form a more stable cavity.

[0025] The advantages of additional aspects 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

[0026] Figure 1 This is one of the structural schematic diagrams of the small-pitch well cavity creation test device for salt cavern gas storage provided in an embodiment of the present invention.

[0027] Figure 2 This is the second schematic diagram of the structure of the salt cavern gas storage small-pitch well cavity creation test device provided in the embodiment of the present invention.

[0028] Explanation of reference numerals: 1. Skeleton; 2. Sliding specimen platform; 3. Secondary support column; 4. Top control box; 5. Main column; 6. Control panel; 7. Digital display screen; 8. Outer sleeve; 9. Inner sleeve; 10. Salt rock specimen; 11. Inner pipe adapter; 12. Outer pipe adapter; 13. Peristaltic pump; 14. LED lamp tube; 15. Concentration meter; 16. Water tank valve; 17. Double-cylinder water tank; 18. Platform pulley locking device. Detailed Implementation

[0029] The principles and features of the present invention are described below with reference to the accompanying drawings. The examples given are only for explaining the present invention and are not intended to limit the scope of the present invention.

[0030] like Figure 1 and Figure 2 As shown, this embodiment of the invention provides a small-spacing well-to-well cavity construction test device for a salt cavern gas storage facility, comprising: a frame 1, a sliding specimen support 2, a main column 5, a pair of outer sleeves 8, a pair of inner sleeves 9, a salt rock specimen 10, a peristaltic pump 13, and a double-cylinder water tank 17. The sliding specimen support 2 is installed at the bottom of the frame 1, and the salt rock specimen 10 is installed on the sliding specimen support 2. The main column 5 and the peristaltic pump 13 are both installed at the top of the frame 1. The pair of outer sleeves 8 are correspondingly sleeved on the outside of the pair of inner sleeves 9. The pair of outer sleeves 8 and the pair of inner sleeves 9 are both installed in the main column 5. The bottom ends of the pair of outer sleeves 8 and the pair of inner sleeves 9 penetrate the frame 1 and are inserted into the salt rock specimen 10. The double-cylinder water tank 17 is installed in the frame 1. The peristaltic pump 13 is connected to one inner sleeve 9 of the pair of inner sleeves 9 and the double-cylinder water tank 17, respectively.

[0031] The beneficial effects of adopting the technical solution of this invention are as follows: Two sets of tubing can simulate two sets of brine injection and drainage tubing in a well cavity construction project. A peristaltic pump can inject fresh water into the cavity model through the inner casing. When the cavity is filled with brine, brine pressure will be formed, and the brine will be discharged along the other set of tubing. Model tests are conducted based on the well cavity construction project of a salt cavern gas storage facility to guide engineering operations, and indoor similar model tests are carried out to guide the setting of engineering parameters. Setting different cavity construction parameters for similar model tests allows for the inversion and correction of cavity construction parameters based on the test results. This provides more direct guidance for setting cavity construction parameters in well cavity construction projects, improving the construction quality of salt cavern gas storage facilities. It can be used to explore the characteristics of cavity morphology development and brine concentration distribution during the cavity construction process, forming a method for controlling cavity shape expansion by different cavity construction parameters. Furthermore, different similar models can be built according to the engineering site conditions, and cavity construction parameters referencing the site construction conditions can be applied to predict cavity morphology changes, guiding the construction of small-spacing well cavity construction projects in salt cavern gas storage facilities.

[0032] This invention provides a small-spacing cavity-building test device for salt cavern gas storage, which can serve as a similar model test platform for small-spacing cavity building. It guides engineering operations by conducting model tests based on the cavity building process of salt cavern gas storage wells. The cavity morphology formed by the small-spacing cavity building method is affected by various engineering parameters, including well spacing, water injection flow rate, and tubing and protective fluid height. Currently, there are few applicable engineering cases to draw upon. Furthermore, cavity building in salt cavern gas storage is achieved through a water-soluble method, which is irreparable. The cavity morphology can only be obtained through sonar cavity measurement technology, which is costly, and water-soluble cavity building is essentially an opaque process. Therefore, conducting indoor similar model tests is an effective and readily available method to guide the setting of engineering parameters. By setting different cavity-building parameters and conducting similar model tests, the cavity-building parameters can be inverted and corrected based on the test results. If this test device can be applied, it can more directly guide the setting of cavity-building parameters in well cavity building projects, improving the construction quality of salt cavern gas storage projects.

[0033] The small-pitch well-pitch cavity-building similar model test device of the present invention (small-pitch well-pitch cavity-building test device for salt cavern gas storage) can be used to explore the characteristics such as the development law of cavity morphology and brine concentration distribution during the cavity-building process, and to form a method for controlling the expansion of cavity shape by different cavity-building parameters. In addition, different similar models can be built according to the engineering site conditions, and cavity-building parameters referencing the site construction conditions can be applied to predict cavity morphology changes and guide the construction of small-pitch well-pitch cavity-building projects in salt cavern gas storage.

[0034] like Figure 1 and Figure 2As shown, the top of the main column 5 is provided with a top control box 4, and a control panel 6 and a digital display screen 7 are provided between the main column 5 and the frame 1. The control panel 6, the digital display screen 7 and the peristaltic pump 13 are all connected to the top control box 4.

[0035] The beneficial effects of adopting the above-mentioned further technical solutions are: it facilitates the control and operation of the small-pitch well cavity creation test device for salt cavern gas storage, facilitates intuitive observation of the operating status of the small-pitch well cavity creation test device for salt cavern gas storage, and improves automation.

[0036] Furthermore, the main column 5 is equipped with a stepper motor for controlling the lifting and lowering of a pair of outer sleeves 8 and a pair of inner sleeves 9. The pair of outer sleeves 8 and the pair of inner sleeves 9 are slidably installed in the main column 5. The stepper motor is connected to the pair of outer sleeves 8 and the stepper motor is connected to the top control box 4.

[0037] The beneficial effects of adopting the above-mentioned further technical solution are: using a stepper motor to realize the lifting and lowering of the inner and outer tubes, and recording the height of the inner and outer tubes through the PLC control center and outputting it to the digital display panel.

[0038] like Figure 1 and Figure 2 As shown, the top inner wall of the frame 1 is provided with an LED light tube 14, and the side wall of the frame 1 is a transparent acrylic sheet.

[0039] The beneficial effects of adopting the above-mentioned further technical solutions are: the built-in LED tube can provide illumination for the specimen, which is more conducive to the monitoring of cavity morphology, and can complete the monitoring of solvent depth, brine flow rate, and brine concentration in the salt cavity. The cavity morphology can be recorded by a camera system through a transparent acrylic sheet.

[0040] like Figure 1 and Figure 2 As shown, further, a pair of inner sleeves 9 are respectively connected to a concentration meter 15, and the peristaltic pump 13 is connected to the double-cylinder water tank 17 through a water tank valve 16.

[0041] The beneficial effects of adopting the above-mentioned further technical solution are: the concentration meter is installed in the inlet and outlet brine pipelines, the concentration meter reading is observed by a camera, and it is connected to a computer to read the brine concentration in real time.

[0042] Furthermore, it also includes a laser imaging device, which is adjacent to the slidable specimen support 2. The bottom of the slidable specimen support 2 is provided with multiple pulleys, and the bottom inner wall of the frame 1 is provided with a support pulley locking device 18.

[0043] The beneficial effects of adopting the above-mentioned further technical solution are: the addition of a laser imaging device allows for scanning and three-dimensional imaging of the cavity's morphology; and the sliding support facilitates the internal and external transportation of the specimen.

[0044] Furthermore, a cabinet door is provided on one side of the frame 1, and a storage slot for placing the cabinet door is provided at the bottom of the frame 1.

[0045] The beneficial effect of adopting the above-mentioned further technical solution is that the cabinet door can be slid into the bottom of the device after being opened, which facilitates continuous observation during the experiment.

[0046] Furthermore, the main column 5 has a sliding groove on its side wall, and a pair of outer sleeves 8 are provided with lifting handles, which are slidably installed in the sliding groove.

[0047] The beneficial effects of adopting the above-mentioned further technical solution are: the main column has grooves (slide grooves) on both sides to accommodate the lifting handles of the inner and outer tubes (outer sleeve and inner sleeve), which can manually lift the inner and outer tubes without computer control.

[0048] like Figure 1 and Figure 2 As shown, further, a secondary support column 3 is fitted on the outside of the main column 5, the bottom of the secondary support column 3 is connected to the top of the frame 1, and there is a gap between the secondary support column 3 and the main column 5.

[0049] The beneficial effects of adopting the above-mentioned further technical solution are: the secondary support is a hollow structure to allow internal and external water supply hoses and data cables to pass through, so that the pipelines are not exposed and the risk of aging and leakage is reduced.

[0050] like Figure 1 and Figure 2 As shown, further, each of the pair of outer sleeves 8 is provided with a protective fluid, each of the pair of inner sleeves 9 is provided with an inner tube adapter 11, and each of the pair of outer sleeves 8 is provided with an outer tube adapter 12.

[0051] The beneficial effect of adopting the above-mentioned further technical solution is that a protective liquid can be injected into the outer tube to limit the degree of dissolution in the cavity, so as to form a more stable cavity.

[0052] The specific functions are as follows:

[0053] Two sets of tubing (one set consisting of an outer casing and an inner casing) can simulate two sets of brine injection and discharge tubing in well cavity construction. Fresh water can be injected into the cavity model through the inner casing 9 by the peristaltic pump 13. When the cavity is full of brine, brine pressure will be formed, and the brine will be discharged along the other set of tubing.

[0054] A protective liquid can be injected into the outer tube 8 to limit the degree of dissolution in the cavity, so as to form a more stable cavity.

[0055] Stepper motors can be used to raise and lower the inner and outer tubes (outer tube and inner tube), and the height of the inner and outer tubes can be recorded by the PLC control center and output to the digital display panel (digital display screen).

[0056] The sliding support platform (sliding specimen support platform) can facilitate the internal and external transportation of specimens (salt rock specimens).

[0057] The secondary support column (secondary pillar) is hollow to allow internal and external water supply hoses and data cables to pass through, preventing the pipelines from being exposed and reducing the risk of aging and leakage.

[0058] Built-in LED tubes can provide illumination for the specimen, which is more conducive to monitoring the cavity morphology and completing tasks such as monitoring the depth of the solvent barrier in the salt cavity, monitoring the brine flow rate, and monitoring the brine concentration. The cavity morphology can be recorded by a camera system through a transparent acrylic sheet.

[0059] The concentration meter can be a Baumé concentration meter, which is installed in the inlet and outlet brine pipelines. The meter reading is observed through a camera and connected to a computer, allowing for real-time reading of the brine concentration.

[0060] The main column has slots on both sides to accommodate the lifting handles for the inner and outer tubes, allowing for manual lifting of the inner and outer tubes (outer sleeve and inner sleeve) without computer control.

[0061] The cabinet door can be slid into the bottom of the device after opening, facilitating continuous observation during the experiment.

[0062] A laser imaging device has been added, which can scan the shape of the cavity and create a three-dimensional image.

[0063] The water pump (peristaltic pump) and water tank (double-cylinder water tank) are all built-in, improving portability and aesthetics.

[0064] This invention provides an experimental apparatus for model experiments of small-interval well cavity creation under different cavity creation parameters. Firstly, it allows for the investigation of cavity expansion patterns under different cavity creation parameters (well spacing, water injection flow rate, and alternating water injection and brine discharge methods). By recording the cavity morphology and calculating its size using a camera system, the influence of different cavity creation parameters on cavity expansion can be obtained, providing a reference for the formulation of cavity creation engineering schemes. Furthermore, by verifying reasonable and mature mathematical control equations and cavity creation models based on physical models, it is possible to more accurately optimize different cavity creation parameters, formulate cavity creation schemes for pilot projects of small-interval well cavity creation in salt cavern gas storage, and guide the construction of small-interval well cavity creation projects in salt cavern gas storage.

[0065] Small-pitch well-to-well cavity creation can significantly improve cavity creation efficiency, thereby accelerating the construction process of natural gas storage facilities. However, currently, a mature cavity creation scheme for small-pitch well-to-well cavity creation technology has not yet been developed and widely applied in engineering. Small-pitch well-to-well cavity creation technology can increase cavity creation rate, shorten cavity creation cycle, reduce energy consumption, and better control cavity shape. The experimental device provided by this invention can complete similar model tests under different cavity creation parameters, and perform corresponding parameter optimization tests for specific engineering projects, ultimately forming a complete small-pitch well-to-well cavity creation technology scheme, greatly accelerating the construction speed of salt cavern gas storage facilities.

[0066] This study explores the cavity expansion patterns under different cavity-building parameters (well spacing, water injection flow rate, and alternating water injection and brine discharge methods). By recording the cavity morphology and calculating its size using a camera system, the influence of different cavity-building parameters on cavity expansion can be obtained, providing a reference for the formulation of cavity-building engineering schemes. Verifying reasonable and mature mathematical control equations and cavity-building models based on physical models can more accurately guide the formulation of cavity-building technology schemes for salt cavern gas storage wells, and can provide specific cavity-building parameter optimization for the construction of corresponding gas storage wells.

[0067] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A test device for small-spacing well-to-well cavity creation in a salt cavern gas storage facility, characterized in that, include: The system comprises a skeleton, a sliding specimen support, a main column, a pair of outer sleeves, a pair of inner sleeves, a salt rock specimen, a peristaltic pump, and a double-cylinder water tank. The sliding specimen support is installed at the bottom of the skeleton, and the salt rock specimen is installed on the sliding specimen support. The main column and the peristaltic pump are both installed at the top of the skeleton. The pair of outer sleeves are fitted one-to-one with the pair of inner sleeves. Both the pair of outer sleeves and the pair of inner sleeves are installed in the main column. The bottom ends of the pair of outer sleeves and the pair of inner sleeves penetrate the main column. The skeleton is inserted into the salt rock specimen, and the double-cylinder water tank is installed in the skeleton. The peristaltic pump is connected to one inner sleeve of the pair of inner sleeves and the double-cylinder water tank. A top control box is provided at the top of the main column, and a control panel and a digital display screen are provided between the main column and the skeleton. The control panel, the digital display screen, and the peristaltic pump are all connected to the top control box. The main column is equipped with a stepper motor for controlling the lifting and lowering of the pair of outer sleeves and the pair of inner sleeves. All components are slidably installed in the main column. The stepper motor is connected to a pair of outer sleeves and to the top control box. LED lights are installed on the inner wall of the top of the frame, and the side walls of the frame are made of transparent acrylic sheets. A concentration meter is connected to each of the pair of inner sleeves. The peristaltic pump is connected to the double-cylinder water tank via a water tank valve. A laser imaging device is also included, located adjacent to the slidable specimen support. Multiple pulleys are provided at the bottom of the slidable specimen support, and a support pulley holder is provided on the inner wall of the bottom end of the frame. The frame is a fixed device; a cabinet door is provided on one side of the frame, and a storage groove for placing the cabinet door is provided at the bottom of the frame; a sliding groove is provided on the side wall of the main column, and a lifting handle is provided on a pair of outer sleeves, the lifting handle being slidably installed in the sliding groove; a secondary support is fitted on the outside of the main column, the bottom of the secondary support is connected to the top of the frame, and there is a gap between the secondary support and the main column; a protective fluid is provided in each pair of outer sleeves, an inner tube adapter is provided on each pair of inner sleeves, and an outer tube adapter is provided on each pair of outer sleeves.

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