A test device for salt rock brine fracturing crystallization

Abstract

The utility model discloses a kind of for salt rock brine fracturing crystallization test device, belong to salt rock underground energy storage cavity technology field;The system includes feeding assembly, heating assembly, pressurizing pump and test bin;Feeding assembly includes the liquid storage bin for storing salt rock brine, and the supply pipeline of salt rock brine is communicated between liquid storage bin and test bin;Heating assembly is set in liquid storage bin;Pressurizing pump is provided on supply pipeline;Test bin inside is used to place core sample;The utility model is through the cooperation of feeding assembly, heating assembly, pressurizing pump and test bin, temperature and pressure adjustment are carried out to salt rock brine by the setting of heating assembly and pressurizing pump, to simulate the core sample fracturing and crystallization condition under different pressure and different temperature conditions in the process of no support fracturing underground reinjection of salt rock brine, to simulate the relationship of reinjection pressure and reinjection temperature encountered in the process of traditional salt rock brine reinjection, and explore brine crystallization law.

Description

Technical Field

[0001] This utility model relates to the field of underground energy storage cavity construction technology in salt rock, and in particular to a test device for fracturing and crystallizing salt rock brine. Background Technology

[0002] Unsupported fracturing in salt brine is a core technology in the construction of salt cavern gas and oil storage facilities and brine mining. It involves injecting high-pressure brine into the well to artificially create and propagate fractures within the salt rock mass. When the injection pressure exceeds the sum of the in-situ stress and tensile strength of the salt rock, fractures will form in the weakest direction, resulting in a stable fracture morphology. In short, unsupported fracturing in salt brine is a highly efficient, "green," and cavity-building technology that is highly dependent on geological conditions and rock properties. It abandons traditional proppant agents and instead utilizes the physicochemical properties of the salt rock itself to create stable seepage channels. In cavity construction, it is necessary to understand the influence of various physical quantities on the unsupported fracturing process of salt brine and design the construction method based on this understanding. Simulation experiments are conducted to simulate the entire process of unsupported fracturing in salt brine. Based on the experimental results, reasonable unsupported fracturing schemes are designed for formations with different lithologies.

[0003] To address the aforementioned problems, this invention provides a test device for fracturing and crystallizing salt brine, thus solving the technical problem that existing technologies cannot simulate unsupported fracturing operations in salt brine. Utility Model Content

[0004] This invention provides a test device for fracturing and crystallizing salt brine, in order to solve the technical problem of insufficient accuracy in simulating unsupported fracturing operations in salt brine in the prior art.

[0005] To achieve the above objectives, the technical solution adopted by this utility model is as follows: This utility model provides a test apparatus for fracturing and crystallizing salt rock brine, comprising: Feeding assembly, heating assembly, pressure pump, and test chamber; The feeding assembly includes a storage tank for storing brine, and a brine supply pipe is connected between the storage tank and the test tank. A feeding port is provided on the top of the storage tank. The heating component is installed inside the storage tank and is used to heat the brine in the storage tank. The pressurizing pump is installed on the supply pipeline, and the pressurizing pump is used to pressurize the brine in the supply pipeline. The test chamber is equipped with a liquid inlet at the top, which is connected to the supply pipeline. The test chamber is equipped with a drain outlet at the bottom, which is used to drain excess brine during the test. The interior of the test chamber is used to place core samples.

[0006] Furthermore, a first flow meter and a flow valve are also installed on the supply pipeline located between the pressurization pump and the liquid storage tank.

[0007] Furthermore, it also includes a recovery pipeline, one end of which is connected to the drain outlet of the test chamber, and the other end of which is connected to the storage tank. The recovery pipeline is used to recover excess brine from the salt rock during the test to the storage tank.

[0008] Furthermore, a valve and a second flow meter are installed on the recovery pipeline.

[0009] Furthermore, a stirring shaft is provided inside the liquid storage tank, and stirring blades are installed on the stirring shaft.

[0010] Furthermore, a temperature measuring device is installed inside the storage tank to monitor the temperature of the brine in the storage tank in real time.

[0011] Furthermore, the heating assembly includes a heating resistor located inside the liquid storage tank and a control unit installed outside the liquid storage tank.

[0012] Furthermore, a first pressure gauge is installed at the liquid inlet of the test chamber.

[0013] Furthermore, a second pressure gauge is installed at the drain port of the test chamber.

[0014] Furthermore, the test chamber is equipped with an observation window.

[0015] Compared with the prior art, the technical solution disclosed in this utility model has the following beneficial effects: This invention utilizes a combination of a feeding assembly, a heating assembly, a pressurizing pump, and a test chamber. By adjusting the temperature and pressure of the brine through the heating assembly and pressurizing pump, it simulates the fracturing and crystallization of core samples under different pressures and temperatures during the unsupported fracturing underground reinjection of brine. This allows for the simulation of the relationship between reinjection pressure and reinjection temperature encountered during traditional brine reinjection and the exploration of brine crystallization patterns. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a schematic diagram of the experimental device for fracturing and crystallizing salt brine in an embodiment of the present invention; Figure 2 This is a schematic diagram of the structure of the test chamber in an embodiment of this utility model; Figure 3 for Figure 2 A schematic diagram of the main structure of the pilot test chamber.

[0018] The components include: 1. Storage tank; 2. Pressurization pump; 3. Test chamber; 31. Cover plate; 32. Base; 33. Shell; 34. Test cavity; 35. Column; 36. Inlet; 37. Outlet; 4. Supply pipe; 5. Feeding port; 6. First flow meter; 7. Flow valve; 8. Recovery pipe; 9. Valve; 10. Second flow meter; 11. Stirring shaft; 12. Heating resistor; 13. First pressure gauge; 14. Second pressure gauge; 15. Check valve; 16. Temperature measuring device; 17. Core sample. Detailed Implementation

[0019] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0020] To make the above-mentioned objectives, features and advantages of this utility model more apparent and understandable, the utility model will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0021] This invention provides a test device for fracturing and crystallization of salt brine, in order to solve the technical problem that existing technologies cannot simulate unsupported fracturing operations in salt brine.

[0022] Example 1 refer to Figures 1 to 3The present invention discloses a test device for fracturing and crystallizing brine, comprising a feeding assembly, a heating assembly, a pressurizing pump 2, and a test chamber 3. The feeding assembly includes a storage tank 1 for storing brine, a brine supply pipe 4 connecting the storage tank 1 and the test chamber 3, and a feeding port 5 at the top of the storage tank 1. The heating assembly is located inside the storage tank 1 and is used to heat the brine inside the storage tank 1. The pressurizing pump 2 is installed on the supply pipe 4 and is used to pressurize the brine inside the supply pipe 4. The test chamber 3 has an inlet 36 at the top, which is connected to the supply pipe 4, and a drain 37 at the bottom, which is used to drain excess brine during the test. The test chamber 3 is used to place core samples 17 inside.

[0023] In this embodiment, rock salt brine of a preset concentration is added to the storage tank 1 through the feeding port 5 located at the top of the storage tank 1. The temperature of the rock salt brine is controlled by the heating component. After the temperature in the storage tank 1 reaches the preset value, it is discharged from the storage tank 1. The feeding component also includes a water pump installed at the drain outlet of the storage tank 1, and the output end of the water pump is connected to the supply pipe 4. The rock salt brine flows to the test chamber 3 through the supply pipe 4 via the water pump. During the flow in the supply pipe 4, the rock salt brine is pressurized by the pressure pump 2. The test chamber 3 is used to place the core sample. After the pressurized rock salt brine enters the test chamber 3, the water pressure acts on the core sample, thereby causing micro-cracks in the core sample, thus simulating the fracturing process in the process of reinjecting brine during unsupported fracturing. After the cracks stabilize, rock salt brine continues to be supplied to the test chamber 3. The temperature and pressure of the rock salt brine entering the cracks are adjusted by the control of the heating component and the pressure pump 2, and the crystallization blockage of the rock salt brine channel in the micro-cracks of the core sample 17 is calculated accordingly.

[0024] As a further optimization, in this embodiment, the test chamber 3 includes a main body and a cover plate 31. The cover plate 31 is detachably installed on the top of the main body to seal the test cavity 34 inside the main body. The main body includes a base 32 at the bottom and a columnar shell 33 set on the base 32. A rectangular test cavity 34 is opened inside the shell 33. A drain port 37 is provided on the base 32, and a liquid inlet 36 is provided on the cover plate 31. The base 32 is also provided with a plurality of columns 35 for installing the cover plate 31. 1. A mounting hole for the column 35 is provided at the position corresponding to the column 35. During the test, the test chamber 34 inside the shell 33 is used to place the core sample 17. The test chamber 34 is adapted to the core sample 17. The rock salt brine entering the test chamber 3 is directly pressurized to the top of the core sample 17 until the core sample 17 produces microcracks. The microcracks penetrate the core sample 17, so that the rock salt brine can flow from the top of the core sample 17 to the bottom of the core sample 17 through the microcracks, thereby exploring the crystallization law of the brine.

[0025] In this embodiment, a first flow meter 6 and a flow valve 7 are also installed on the supply pipeline 4 between the pressurizing pump 2 and the storage tank 1. The first flow meter 6 measures the flow rate and flow value of the rock salt brine passing through the core sample 17. The flow valve 7 is used to precisely adjust the flow rate of the rock salt brine flowing through the supply pipeline 4. A check valve 15 is also installed between the pressurizing pump 2 and the test chamber 3 to prevent the rock salt brine in the test chamber 3 from flowing back during the experiment.

[0026] This embodiment also includes a recovery pipe 8, one end of which is connected to the drain port 37 of the test chamber 3, and the other end of which is connected to the storage chamber 1. The recovery pipe 8 is used to recover excess brine during the experiment to the storage chamber 1. At the same time, a valve 9 and a second flow meter 10 are installed on the recovery pipe 8. The recovery pipe 8 and the supply pipe 4 form a circulation path. During the experiment, the brine can flow back to the storage chamber 1 through the recovery pipe 8 to continue to participate in the next cycle, which meets the requirements of long-term and uninterrupted experimental simulation. The second flow meter 10 is used to measure the flow rate and flow value of the brine passing through the fractured rock core sample 17.

[0027] In this embodiment, a stirring shaft 11 is provided in the storage tank 1, and stirring blades are installed on the stirring shaft 11. When adjusting the concentration of rock salt brine, solid rock salt is added into the storage tank 1, and the rotation of the stirring blades is used to accelerate the dissolution rate of the solid rock salt and improve the uniformity of the brine concentration. Furthermore, the stirring shaft 11 can be driven by a motor or other means. For those skilled in the art, as long as the driving requirements are met, it is acceptable.

[0028] In this embodiment, a temperature measuring device 16 is also installed in the storage tank 1 to monitor the temperature of the brine in the storage tank 1 in real time. The temperature can be measured using a liquid thermometer. At the same time, the heating component includes a heating resistor 12 located in the storage tank 1 and a control unit installed outside the storage tank 1. The heating resistor 12 is installed inside the storage tank 1, and the control unit controls the heat output of the heating resistor 12. The control unit can use mature control components in the prior art.

[0029] In this embodiment, the inlet 36 of the test chamber 3 is equipped with a first pressure gauge 13, and the outlet 37 of the test chamber 3 is equipped with a second pressure gauge 14; the first pressure gauge 13 and the second pressure gauge 14 are used to measure and record the pressure of the rock salt brine before and after the core sample 17.

[0030] In this embodiment, the test chamber 3 is equipped with an observation window to facilitate the recording of changes in the core sample 17 by staff during the experiment.

[0031] Example 2 A simulation test method for fracturing and crystallizing salt brine mainly includes the following steps: Step 1: Prepare the rock salt brine with the designed concentration and temperature for the experiment; Step 2: The rock salt brine for the test is transported to the test chamber 3 by the water pump and the booster pump 2; Step 3: By pressurizing the brine, confining pressure is generated on the core sample 17, and the core sample 17 is fractured. During pressurization, valve 9 on the recovery pipeline 8 is closed. Step 4: After the core sample 17 produces a through-hole microcrack, open the valve 9 on the recovery pipeline 8. Rock salt brine is injected from one end of the fractured core sample 17 and extracted from the other end. The flow rate and pressure data are recorded by the first flow meter 6, the second flow meter 10, the first pressure gauge 13 and the second pressure gauge 14. Step 5: Continue the experiment and estimate the crystallization blockage of the brine channel in the microfracture of core sample 17 by measuring changes in pressure and flow rate; Step 6: After the test, take out the core sample 17, observe the fracturing and crystallization of the core sample 17, and summarize the rules accordingly.

[0032] It should be noted that, for those skilled in the art, it is obvious that this utility model is not limited to the details of the above exemplary embodiments, and that this utility model can be implemented in other specific forms without departing from the spirit or essential characteristics of this utility model. Therefore, the embodiments should be regarded as exemplary and non-limiting in all respects, and the scope of this utility model is defined by the appended claims rather than the foregoing description. Therefore, it is intended to encompass all changes falling within the meaning and scope of equivalents of the claims within this utility model, and no reference numerals in the claims should be regarded as limiting the scope of the claims.

Claims

1. A test apparatus for fracturing and crystallizing salt brine, characterized in that, include: Feeding assembly, heating assembly, pressure pump, and test chamber; The feeding assembly includes a storage tank for storing brine, and a brine supply pipe is connected between the storage tank and the test tank. A feeding port is provided on the top of the storage tank. The heating component is installed inside the storage tank and is used to heat the brine in the storage tank. The pressurizing pump is installed on the supply pipeline, and the pressurizing pump is used to pressurize the brine in the supply pipeline. The test chamber is equipped with a liquid inlet at the top, which is connected to the supply pipeline. The test chamber is equipped with a drain outlet at the bottom, which is used to drain excess brine during the test. The interior of the test chamber is used to place core samples.

2. The experimental apparatus for fracturing and crystallizing salt brine according to claim 1, characterized in that, A first flow meter and a flow valve are also installed on the supply pipeline located between the pressurizing pump and the liquid storage tank.

3. The experimental apparatus for fracturing and crystallizing salt brine according to claim 1, characterized in that, It also includes a recovery pipeline, one end of which is connected to the drain outlet of the test chamber, and the other end of which is connected to the storage chamber. The recovery pipeline is used to recover excess brine from the salt rock during the test to the storage chamber.

4. The experimental apparatus for fracturing and crystallizing salt brine according to claim 3, characterized in that, The recovery pipeline is equipped with valves and a second flow meter.

5. The experimental apparatus for fracturing and crystallizing salt brine according to claim 1, characterized in that, The liquid storage tank is equipped with a stirring shaft, and stirring blades are mounted on the stirring shaft.

6. The experimental apparatus for fracturing and crystallizing salt brine according to claim 1, characterized in that, The storage tank is also equipped with a temperature measuring device for real-time monitoring of the temperature of the brine in the storage tank.

7. The experimental apparatus for fracturing and crystallizing salt brine according to claim 1, characterized in that, The heating assembly includes a heating resistor located inside the liquid storage tank and a control unit installed outside the liquid storage tank.

8. The experimental apparatus for fracturing and crystallizing salt brine according to claim 1, characterized in that, The test chamber is equipped with a first pressure gauge at its inlet.

9. The experimental apparatus for fracturing and crystallizing salt brine according to claim 1, characterized in that, A second pressure gauge is installed at the drain outlet of the test chamber.

10. The experimental apparatus for fracturing and crystallizing salt brine according to claim 1, characterized in that, The test chamber is equipped with an observation window.

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