Unconventional oil reservoir exploitation device based on high-energy CO2 fluid fracturing

Abstract

The invention relates to the technical field of oil and gas exploitation, in particular to an unconventional oil reservoir exploitation device based on high-energy CO2 fluid fracturing, which comprises a flow stabilizing pipe and a flow limiting assembly arranged on the inner side of the lower part of the flow stabilizing pipe, the flow limiting assembly comprises a taper sleeve, a piston and a fixing plate, and the annular fixing plate is fixedly mounted on the inner side of the lower part of the flow stabilizing pipe. The flow stabilizing pipe is reasonable and compact in structure, during use, the flow stabilizing pipe is inserted into an underground well to exploit oil gas containing CO2, the oil gas flows into the upper end of the flow stabilizing pipe after passing through the second overflowing hole, the first overflowing hole and the inner side of the taper sleeve, and when the oil gas pressure at the lower end of the flow stabilizing pipe is too large, the oil gas acts on the lower end of the piston to push the piston to move upwards; when the upper end of the piston is inserted into the inner side of the upper end of the taper sleeve, the outer side of the upper end of the piston is in sealing contact with the inner side of the upper end of the taper sleeve, so that the inner side of the upper end of the taper sleeve is closed, the flow area of oil gas passing through the taper sleeve can be reduced, the oil gas flowing through the taper sleeve can be limited, and oil gas extraction operation is more stable.

Description

Technical Field

[0001] This invention relates to the field of oil and gas extraction technology, and is an unconventional reservoir extraction device based on high-energy CO2 fluid fracturing. Background Technology

[0002] Oil and natural gas are stored in underground rock formations. During extraction, rock fracturing equipment is needed to open up the rock formations so that oil and gas can be released. The main force transmission medium of rock fracturing equipment is fracturing fluid. Specifically, high-pressure fracturing fluid is injected into the oil and gas well. The fracturing fluid enters the rock formation through the openings on the well wall and then opens up the rock formation with hydraulic pressure.

[0003] Currently, CO2 fracturing technology, as an unconventional oil and gas extraction technology, has been widely applied in oil and gas extraction operations. Its principle differs from traditional hydraulic fracturing technology. Traditional hydraulic fracturing technology uses high-pressure water to forcefully inject into the wellhead, cracking the rock and forming fractures to release natural gas. CO2 fracturing technology, on the other hand, injects high-pressure (exceeding saturation pressure) carbon dioxide into the rock, causing it to reach above the critical point, forming a dense fluid, thereby generating slow osmotic pressure, which eventually causes the rock to crack. Since different strata have different rock qualities, the hydraulic pressure required to crack the rock strata also varies. Excessive pressure will put strong pressure on the pipeline. Traditional pipelines are at risk of fracturing due to the high gas pressure, thus affecting the extraction and use effect. Summary of the Invention

[0004] This invention provides an unconventional reservoir development device based on high-energy CO2 fluid fracturing, which overcomes the shortcomings of the prior art and can effectively solve the problem of pipeline fracturing caused by the large flow pressure in the connecting pipe and stabilizing pipe of the existing development device.

[0005] The technical solution of the present invention is achieved through the following measures: an unconventional reservoir development device based on high-energy CO2 fluid fracturing, comprising a flow stabilizing pipe and a flow limiting component located on the inner side of the lower part of the flow stabilizing pipe. The flow limiting component includes a conical sleeve, a piston, and a fixed plate. A circular fixed plate is fixedly installed on the inner side of the lower part of the flow stabilizing pipe. A conical sleeve is fixedly installed above the fixed plate, with its lower outer end fixedly attached to the inner side of the flow stabilizing pipe. The conical sleeve is tapered, with a smaller upper end and a larger lower end. Several first flow holes with internal and external communication are distributed at intervals on the outer side of the conical sleeve. A guide sleeve is fixedly installed on the inner side of the fixed plate. A piston is fitted inside the guide sleeve, which can make sealed contact with the inner side of the upper end of the conical sleeve after its upper outer end moves upward. Several first elastic reset members are distributed at intervals along the circumference between the lower end of the piston and the lower end of the fixed plate. Several second flow holes with vertical penetration are distributed at intervals along the circumference at the upper end of the fixed plate corresponding to the position of the outer side of the guide sleeve.

[0006] The following are further optimizations and / or improvements to the above-mentioned technical solution: A pressure-reducing component may be provided above the aforementioned flow-limiting component. The pressure-reducing component includes a flow divider plate, a movable plate, a sealing rod, and a second elastic reset component. A flow divider plate is fixedly installed on the inner side of the upper part of the flow stabilizing pipe corresponding to the position above the cone sleeve. A tapered flow divider cone with a larger upper part and a smaller lower part is fixedly installed at the center of the lower end of the flow divider plate. Several third flow holes that pass through the flow divider plate are evenly distributed along the circumference at the upper end of the flow divider plate corresponding to the outer position of the flow divider cone. A movable plate fitted inside the flow stabilizing pipe is provided below the flow divider cone. A fourth flow hole that passes through the flow divider plate is provided at the center of the movable plate. Several second elastic reset components are evenly distributed along the circumference between the upper end of the movable plate and the lower end of the flow divider plate. At least one sealing rod corresponding to the third flow hole is fixedly installed on the upper end of the flow divider plate. After the outer side of the upper end of the at least one sealing rod moves upward, it can make sealing contact with the inner side of the corresponding third flow hole.

[0007] The upper part of the aforementioned movable plate may have several vertically penetrating limiting holes distributed at intervals along the circumference. Each limiting hole is coaxially fitted with a guide rod whose upper end is fixedly installed at the corresponding position on the lower outer side of the diverter cone.

[0008] A connecting pipe can be fixedly installed on the upper end of the aforementioned flow stabilizing pipe. An upper connecting plate is fixedly installed on the outer side of the upper part of the connecting pipe. Several vertically penetrating mounting holes are evenly distributed along the circumference of the upper end of the upper connecting plate. A lower connecting plate is fixedly installed on the outer side of the upper part of the flow stabilizing pipe. The lower end of the lower connecting plate corresponding to each upper mounting hole position is provided with an upward-opening threaded hole. A connecting screw with a connecting nut is screwed into each threaded hole.

[0009] The lower end of the aforementioned lower connecting plate can be fixedly installed with a protective tube that is coaxially fitted on the outside of the flow stabilizer tube and whose lower end is located below the fixing plate. The lower part of the protective tube is tapered, wider at the top and narrower at the bottom. A locking nut is screwed onto the outer side of the lower part of the protective tube. Several expansion grooves that connect the inside and outside are evenly distributed along the circumference at the lower end of the protective tube.

[0010] A base plate can be fixedly installed on the inner side of the lower end of the above-mentioned flow stabilizer tube. The center of the base plate has a liquid inlet hole that runs vertically through it. A filter screen is fixedly installed on the inner side of the lower part of the flow stabilizer tube at the position between the lower end of the base plate and the fixed plate. Several fifth flow holes that are connected internally and externally are distributed circumferentially on the outer side of the lower part of the flow stabilizer tube at the position between the filter screen and the base plate.

[0011] A sealing sleeve can be fixed to the inner side of the upper end of the aforementioned cone sleeve, and the inner side of the sealing sleeve matches the upper end face of the piston.

[0012] The lower end of the piston can be fixed with a guide plate coaxially fitted inside the guide sleeve. Several support blocks are evenly distributed along the circumference on the inner side of the lower end of the fixed plate. The lower end of the first elastic reset member is fixedly installed together with the upper side of the support block, and the upper end of the first elastic reset member is fixedly installed together with the corresponding position of the lower end of the guide plate.

[0013] This invention has a reasonable and compact structure. In use, the flow stabilizing pipe is inserted into the underground well to extract CO2-containing oil and gas. The oil and gas flow into the upper end of the flow stabilizing pipe after passing through the second flow hole, the first flow hole, and the inner side of the cone sleeve. When the oil and gas pressure at the lower end of the flow stabilizing pipe is too high, the oil and gas acts on the lower end of the piston, pushing the piston upward. When the upper end of the piston is inserted into the inner side of the upper end of the cone sleeve, the outer side of the upper end of the piston and the inner side of the upper end of the cone sleeve are in sealing contact, thereby closing the inner side of the upper end of the cone sleeve. This reduces the flow area of ​​oil and gas through the cone sleeve and can limit the flow of oil and gas through the cone sleeve, making the oil and gas extraction operation more stable. When the oil and gas pressure decreases, the piston moves downward and resets under the action of the first elastic reset member. In this way, the inner side of the upper part of the cone sleeve is opened, restoring the flow area of ​​oil and gas through the cone sleeve, and oil and gas extraction can continue smoothly. Attached Figure Description

[0014] Appendix Figure 1 These are schematic diagrams of the main cross-sectional structure of embodiments one to eight of the present invention.

[0015] Appendix Figure 2 These are three-dimensional structural diagrams of embodiments one through eight of the present invention.

[0016] Appendix Figure 3 This is a three-dimensional structural diagram of the current-stabilizing tube in Embodiments 1 to 8 of the present invention.

[0017] Appendix Figure 4 This is a three-dimensional structural diagram of the current limiting component in Embodiments 1 to 8 of the present invention.

[0018] Appendix Figure 5 This is a cross-sectional view of the current limiting components in Embodiments 1 to 8 of the present invention.

[0019] Appendix Figure 6 This is a cross-sectional structural diagram of the pressure-reducing components in Embodiments 2 to 8 of the present invention.

[0020] Appendix Figure 7 This is a partial cross-sectional view of the flow stabilizing tube in Embodiments 1 to 8 of the present invention.

[0021] The codes in the attached diagram are as follows: 1 is the flow stabilizer, 2 is the cone sleeve, 3 is the piston, 4 is the fixed plate, 5 is the guide sleeve, 6 is the first flow passage hole, 7 is the first elastic reset element, 8 is the second flow passage hole, 9 is the flow divider plate, 10 is the flow divider cone, 11 is the movable plate, 12 is the sealing rod, 13 is the second elastic reset element, 14 is the third flow passage hole, 15 is the fourth flow passage hole, 16 is the limiting hole, 17 is the guide rod, 18 is the connecting pipe, 19 is the upper connecting plate, 20 is the lower connecting plate, 21 is the connecting screw, 22 is the connecting nut, 23 is the protective pipe, 24 is the locking nut, 25 is the telescopic groove, 26 is the bottom plate, 27 is the liquid inlet hole, 28 is the filter screen, 29 is the fifth flow passage hole, 30 is the sealing sleeve, 31 is the guide plate, and 32 is the support block. Detailed Implementation

[0022] The present invention is not limited to the following embodiments, and the specific implementation can be determined according to the technical solution of the present invention and the actual situation.

[0023] In this invention, for ease of description, the description of the relative positions of the components is based on the appendix to the specification. Figure 1 The layout is described using a diagrammatic method, such as the positional relationships of front, back, top, bottom, left, and right, which are based on the instructions attached. Figure 1 The orientation of the layout is determined by the direction of the map.

[0024] The present invention will be further described below with reference to embodiments and accompanying drawings: Example 1: As shown in the attached document Figure 1 , 4 As shown in Figure 5, the unconventional reservoir development device based on high-energy CO2 fluid fracturing includes a flow stabilizing pipe 1 and a flow limiting component located on the lower inner side of the flow stabilizing pipe 1. The flow limiting component includes a conical sleeve 2, a piston 3, and a fixing plate 4. A circular fixing plate 4 is fixedly installed on the lower inner side of the flow stabilizing pipe 1. A conical sleeve 2 is fixedly installed on the upper outer side of the fixing plate 4 and is fixedly installed on the inner side of the flow stabilizing pipe 1. The conical sleeve 2 is conical in shape, with a smaller upper end and a larger lower end. Several first flow holes 6 with internal and external communication are distributed at intervals on the outer side of the conical sleeve 2. A guide sleeve 5 is fixedly installed on the inner side of the fixing plate 4. A piston 3 is installed inside the guide sleeve 5, which can make a sealing contact with the upper inner side of the conical sleeve 2 after the upper outer side moves upward. Several first elastic reset members 7 are distributed at intervals along the circumference between the lower end of the piston 3 and the lower end of the fixing plate 4. Several second flow holes 8 with vertical penetration are distributed at intervals along the circumference at the upper end of the fixing plate 4 corresponding to the position of the outer side of the guide sleeve 5.

[0025] According to requirements, piston 3 has a cylindrical structure. In use, the flow stabilizing pipe 1 is inserted into the underground well to extract CO2-containing oil and gas. The oil and gas flow into the upper end of the flow stabilizing pipe 1 after passing through the second flow hole 8, the first flow hole 6, and the inner side of the upper conical sleeve 2. When the oil and gas pressure at the lower end of the flow stabilizing pipe 1 is too high, the oil and gas exert force on the lower end of piston 3, pushing piston 3 upwards. When the upper end of piston 3 is inserted into the inner side of the upper end of conical sleeve 2, the outer side of the upper end of piston 3 seals against the inner side of the upper end of conical sleeve 2, thus closing the inner side of the upper end of conical sleeve 2. This reduces the flow area of ​​oil and gas through conical sleeve 2, limiting the flow of oil and gas through conical sleeve 2 and making the oil and gas extraction operation more stable. When the oil and gas pressure decreases, piston 3 moves downwards and resets under the action of the first elastic reset member 7. This opens the inner side of the upper part of conical sleeve 2, restoring the flow area of ​​oil and gas through conical sleeve 2, allowing for continued smooth extraction of oil and gas.

[0026] The above-mentioned unconventional reservoir development equipment based on high-energy CO2 fluid fracturing can be further optimized and / or improved according to actual needs: Example 2: As an optimization of the above examples, as shown in the appendix. Figure 1 , 6 As shown, a pressure-reducing component is provided above the flow-limiting component. The pressure-reducing component includes a flow-diverting plate 9, a movable plate 11, a sealing rod 12, and a second elastic reset component 13. A flow-diverting plate 9 is fixedly installed on the inner side of the upper part of the flow-stabilizing pipe 1, which is located above the cone sleeve 2. A tapered flow-diverting cone 10, which is larger at the top and smaller at the bottom, is fixed at the center of the lower end of the flow-diverting plate 9. A number of third flow holes 14, which are vertically connected, are evenly distributed around the upper end of the flow-diverting plate 9, which is located on the outer side of the flow-diverting cone 10. A movable plate 11, which is fitted inside the flow-stabilizing pipe 1, is provided below the flow-diverting cone 10. A fourth flow hole 15, which is vertically connected, is provided at the center of the movable plate 11. A number of second elastic reset components 13 are evenly distributed around the upper end of the movable plate 11 and the lower end of the flow-diverting plate 9, which are circumferentially connected. At least one sealing rod 12, which corresponds to the third flow hole 14, is fixedly installed on the upper end of the flow-diverting plate 9. After the outer side of the upper end of the at least one sealing rod 12 moves upward, it can make sealing contact with the inner side of the corresponding third flow hole 14.

[0027] According to the requirements, the second elastic reset component 13 is a known prior art, such as a compression spring. To facilitate the installation of the compression spring, a limiting step surface is provided on the inner side of the flow stabilizing pipe 1 at the lower end of the movable plate 11. The lower end of the movable plate 11 sits on the limiting step surface. Six vertically penetrating third flow holes 14 are evenly distributed along the circumference of the upper end of the diverter plate 9. Two sealing rods 12 are fixedly installed on the upper end of the diverter plate 9. The two sealing rods 12 are symmetrically arranged. To facilitate the installation of the second elastic reset component 13, the lower end of the diverter plate 9 and the upper end of the movable plate 11 are connected. The upper and lower mounting sleeves are fixed at the ends. The upper and lower ends of the second elastic reset member 13 are respectively installed in the upper and lower mounting sleeves. In order to protect the second elastic reset member 13, a telescopic sleeve is fitted on the outside of the second elastic reset member 13. The upper and lower ends of the telescopic sleeve are fixed together with the outer side of the upper mounting sleeve and the corresponding lower mounting sleeve by clamps. In order to allow the sealing rod 12 to be smoothly inserted into the third flow hole 14, the lower end of the third flow hole 14 and the upper end of the sealing rod 12 can be provided with chamfers.

[0028] In use, the flow stabilizer 1 is inserted into the underground well to extract CO2-containing oil and gas. The oil and gas flow into the upper end of the flow stabilizer 1 after passing through the second flow hole 8, the first flow hole 6 and the inner side of the cone sleeve 2. When the oil and gas pressure at the lower end of the flow stabilizer 1 is too high, the oil and gas acts on the lower end of the piston 3, pushing the piston 3 to move upward. When the upper end of the piston 3 is inserted into the inner side of the upper end of the cone sleeve 2, the outer side of the upper end of the piston 3 is in sealing contact with the inner side of the upper end of the cone sleeve 2, thereby closing the inner side of the upper part of the cone sleeve 2. This can reduce the flow area of ​​oil and gas through the cone sleeve 2 and can limit the flow of oil and gas through the cone sleeve 2, making the oil and gas extraction operation more stable.

[0029] When the oil and gas pressure continues to rise, the oil and gas flowing through the first flow hole 6 acts on the lower end face of the movable plate 11, causing the lower end of the movable plate 11 to press against the second elastic reset member 13 and move upward. When the upper end of the sealing rod 12 is inserted into the corresponding position of the third flow hole 14, the flow area of ​​the oil and gas can be reduced. The oil and gas can only flow upward into the inner side of the upper end of the flow stabilizing pipe 1 from the fourth flow hole 15 and the remaining third flow hole 14, which can further limit the flow and reduce the pressure of the oil and gas.

[0030] When the oil and gas pressure decreases, the piston 3 moves downward and resets under the action of the first elastic reset member 7, which opens the upper inner side of the cone sleeve 2. At the same time, the sealing rod 12 moves downward and resets under the action of the second elastic reset member 13 and the movable plate 11, which opens the third flow hole 14 and restores the flow area of ​​oil and gas through the cone sleeve 2.

[0031] Example 3: As an optimization of the above examples, as shown in the appendix. Figure 1 , 6 As shown, the upper end of the movable plate 11 has several vertically penetrating limiting holes 16 distributed along the circumference. Each limiting hole 16 is coaxially fitted with a guide rod 17 whose upper end is fixedly installed at the corresponding position on the lower outer side of the diverter cone 10.

[0032] During use, by setting the guide rod 17, the movable plate 11 can ensure that the upper end of the sealing rod 12 is finally inserted into the corresponding third flow hole 14 during the upward movement, so that the sealing rod 12 can smoothly close the corresponding third flow hole 14.

[0033] Example 4: As an optimization of the above examples, as shown in the appendix. Figure 1 , 2 As shown, a connecting pipe 18 is fixedly installed on the upper end of the flow stabilizing pipe 1, and an upper connecting plate 19 is fixedly installed on the outer side of the upper part of the connecting pipe 18. Several vertically penetrating mounting holes are evenly distributed along the circumference of the upper end of the upper connecting plate 19. A lower connecting plate 20 is fixedly installed on the outer side of the upper part of the flow stabilizing pipe 1. The lower end of the lower connecting plate 20 corresponding to each upper mounting hole position is provided with an upward-opening threaded hole. A connecting screw 21 with a connecting nut 22 screwed into each threaded hole is screwed in.

[0034] During use, this setup allows the flow stabilizer 1 and the connecting pipe 18 to be stably installed together. The connecting pipe 18 has connecting threads on its inner or outer side at the upper end, which facilitates the connection between the connecting pipe 18 and the mining equipment. To facilitate the disassembly and assembly of the connecting screw 21, the middle outer side of the connecting screw 21 has a disassembly and assembly groove with a square or regular hexagonal cross section.

[0035] Example 5: As an optimization of the above examples, as shown in the appendix. Figure 1 , 3As shown, a protective tube 23 is fixedly installed at the lower end of the lower connecting plate 20. It is coaxially fitted on the outside of the flow stabilizing tube 1 and the lower end is located below the fixing plate 4. The lower part of the protective tube 23 is tapered with a larger upper part and a smaller lower part. A locking nut 24 is screwed to the outer side of the lower part of the protective tube 23. Several expansion grooves 25 with internal and external communication are evenly distributed along the circumference at the lower end of the protective tube 23.

[0036] To facilitate the assembly and disassembly of the protective tube 23 and the lower connecting plate 20, the lower connecting plate 20 has an inwardly opening threaded groove at its lower end. The outer side of the upper end of the protective tube 23 is screwed into the threaded groove, which also facilitates subsequent maintenance. During use, when the locking nut 24 is tightened, the lower end of the protective tube 23 will retract, thereby fixing the protective tube 23 to the outer side of the flow stabilizing pipe 1. This can improve the strength of the flow stabilizing pipe 1 and prevent it from rupturing under excessive pressure during mining.

[0037] Example 6: As an optimization of the above examples, as shown in the appendix Figure 1 , 7 As shown, a base plate 26 is fixedly installed on the inner side of the lower end of the flow stabilizer 1. The center of the base plate 26 is provided with a liquid inlet hole 27 that runs vertically through the bottom. A filter screen 28 is fixedly installed on the inner side of the lower part of the flow stabilizer 1 at the position between the base plate 26 and the lower end of the fixed plate 4. Several fifth flow holes 29 that are connected internally and externally are distributed at intervals along the circumference on the outer side of the lower part of the flow stabilizer 1 at the position between the filter screen 28 and the base plate 26.

[0038] As required, all of the aforementioned fifth flow passages 29 are located below the protective pipe 23. During use, this configuration allows oil and gas to flow through the inlet hole 27 and the fourth flow passage 15 to the lower side of the filter screen 28 after the flow stabilizing pipe 1 is inserted into the well. This ensures the inlet cross-sectional area of ​​the oil and gas flowing into the flow stabilizing pipe 1. By setting up the filter screen 28, impurities in the oil and gas flowing into the lower inner side of the flow stabilizing pipe 1 can be filtered.

[0039] Example 7: As an optimization of the above examples, as shown in the appendix. Figure 1 , 4 As shown in Figure 5, a sealing sleeve 30 is fixed on the inner side of the upper end of the cone sleeve 2, and the inner side of the sealing sleeve 30 matches the upper end face of the piston 3.

[0040] During use, by setting the sealing sleeve 30, the contact area between the outer side of the upper end of the piston 3 and the inner side of the cone sleeve 2 after the piston 3 moves upward can be increased. This ensures the sealing effect of the upper end of the piston 3 on the inner side of the upper end of the cone sleeve 2 after the piston 3 moves upward. When the pressure is too high, it can ensure the flow restriction effect of oil and gas after passing through the second flow hole 8 and then through the first flow hole 6, reducing the pressure of oil and gas flowing through the flow restriction component. If needed, the sealing sleeve 30 can also be set as a cone shape with a smaller upper part and a larger lower part, and the outer side of the upper end of the piston 3 has a cone surface that matches the sealing sleeve 30.

[0041] Example 8: As an optimization of the above examples, as shown in the appendix Figure 1 , 5 As shown, a guide plate 31 is coaxially fitted inside the guide sleeve 5 and fixed to the lower end of the piston 3. Several support blocks 32 are evenly distributed along the circumference on the inner side of the lower end of the fixed plate 4. The lower end of the first elastic reset member 7 is fixedly installed together with the upper side of the support block 32, and the upper end of the first elastic reset member 7 is fixedly installed together with the corresponding position of the lower end of the guide plate 31.

[0042] According to the requirements, the first elastic reset component 7 is a known prior art, such as a tension spring. To facilitate the installation of the first elastic reset component 7, tubular mounting seats are fixedly installed at the lower end of the fixing plate 4 and the upper end of the support block 32. Each mounting seat is equipped with a connecting rod. The upper and lower ends of the tension spring have hooks. The two hooks of the tension spring are hooked on the outside of the connecting rod at the corresponding position. To protect the first elastic reset component 7 and the mounting seat, a telescopic sleeve is fitted on the outside of the first elastic reset component 7. The upper and lower ends of the telescopic sleeve are fixedly installed together with the outside of the mounting seat at the corresponding position. The two ends of the telescopic sleeve are fixedly installed together with the outside of the mounting seat by a known clamp. To facilitate the installation of the tension spring, in the initial state, that is, when the tension spring is in its natural state (not stretched), the inner side of the guide sleeve 5 at the lower end of the guide plate 31 has a stepped surface. This can avoid the phenomenon of the guide plate 31 tilting due to the installation error of the tension spring or the telescopic sleeve. In order to limit the piston 3 during the upward movement and to limit the guide plate 31, a limiting sleeve fitted on the outside of the piston 3 is screwed onto the inner side of the upper end of the guide sleeve.

[0043] During use, by setting up the support block 32 and the guide plate 31, it is easy to install the first elastic reset member 7 between the piston 3 and the fixed plate 4, reducing the difficulty of disassembly and assembly, and facilitating subsequent maintenance operations.

[0044] The above technical features constitute various embodiments of the present invention, which have strong adaptability and implementation effect. Unnecessary technical features can be added or removed according to actual needs to meet the needs of different situations.

Claims

1. An unconventional reservoir development device based on high-energy CO2 fluid fracturing, characterized in that... The device includes a flow stabilizing tube and a flow limiting assembly located on the lower inner side of the flow stabilizing tube. The flow limiting assembly includes a conical sleeve, a piston, and a fixed plate. A circular fixed plate is fixedly installed on the lower inner side of the flow stabilizing tube. A conical sleeve with its lower outer end fixedly installed on the upper part of the fixed plate is located above the fixed plate. The conical sleeve is tapered, with a smaller upper end and a larger lower end. Several first flow holes with internal and external communication are distributed at intervals on the outer side of the conical sleeve. A guide sleeve is fixedly installed on the inner side of the fixed plate. A piston with its upper outer end moving upward and sealingly contacting the upper inner side of the conical sleeve is installed inside the guide sleeve. Several first elastic reset members are distributed at intervals along the circumference between the lower end of the piston and the lower end of the fixed plate. Several second flow holes with vertical communication are distributed at intervals along the circumference on the upper part of the fixed plate corresponding to the position of the outer side of the guide sleeve.

2. The unconventional reservoir development device based on high-energy CO2 fluid fracturing according to claim 1, characterized in that... A pressure-reducing component is provided above the flow-limiting component. The pressure-reducing component includes a flow divider plate, a movable plate, a sealing rod, and a second elastic reset component. A flow divider plate is fixedly installed on the inner side of the upper part of the flow stabilizing pipe corresponding to the position above the cone sleeve. A tapered flow divider cone with a larger upper part and a smaller lower part is fixedly installed at the center of the lower end of the flow divider plate. Several third flow holes with vertical penetration are evenly distributed along the circumference at the upper end of the flow divider plate corresponding to the outer position of the flow divider cone. A movable plate is provided below the flow divider cone and fitted inside the flow stabilizing pipe. A fourth flow hole with vertical penetration is provided at the center of the movable plate. Several second elastic reset components are evenly distributed along the circumference between the upper end of the movable plate and the lower end of the flow divider plate. At least one sealing rod corresponding to the third flow hole is fixedly installed on the upper end of the flow divider plate. After the outer side of the upper end of the at least one sealing rod moves upward, it can make sealing contact with the inner side of the corresponding third flow hole.

3. The unconventional reservoir development device based on high-energy CO2 fluid fracturing according to claim 2, characterized in that... The upper part of the movable plate has several vertically penetrating limiting holes distributed at intervals along the circumference. Each limiting hole is coaxially fitted with a guide rod whose upper end is fixedly installed at the corresponding position on the lower outer side of the diverter cone.

4. The unconventional reservoir development device based on high-energy CO2 fluid fracturing according to claim 1, 2, or 3, characterized in that... A connecting pipe is fixedly installed at the upper end of the flow stabilizer tube. An upper connecting plate is fixedly installed on the outer side of the upper part of the connecting pipe. Several vertically penetrating mounting holes are evenly distributed along the circumference of the upper end of the upper connecting plate. A lower connecting plate is fixedly installed on the outer side of the upper part of the flow stabilizer tube. The lower end of the lower connecting plate corresponding to each upper mounting hole position is provided with an upward-opening threaded hole. A connecting screw with a connecting nut is screwed into each threaded hole.

5. The unconventional reservoir development device based on high-energy CO2 fluid fracturing according to claim 4, characterized in that... A protective tube is fixedly installed at the lower end of the lower connecting plate. It is coaxially fitted to the outside of the flow stabilizer tube and the lower end is located below the fixed plate. The lower part of the protective tube is tapered, wider at the top and narrower at the bottom. A locking nut is screwed onto the outer side of the lower part of the protective tube. Several expansion grooves with internal and external connections are evenly distributed around the lower end of the protective tube.

6. The unconventional reservoir development device based on high-energy CO2 fluid fracturing according to claim 5, characterized in that... A base plate is fixedly installed on the inner side of the lower end of the flow stabilizer tube. A liquid inlet hole that runs vertically through the center of the base plate is provided. A filter screen is fixedly installed on the inner side of the lower part of the flow stabilizer tube at the position between the lower end of the base plate and the fixed plate. Several fifth flow holes that are connected internally and externally are distributed circumferentially on the outer side of the lower part of the flow stabilizer tube at the position between the filter screen and the base plate.

7. The unconventional reservoir development device based on high-energy CO2 fluid fracturing according to claim 1, 2, 3, 5, or 6, characterized in that... A sealing sleeve is fixed to the inner side of the upper end of the cone sleeve, and the inner side of the sealing sleeve matches the upper end face of the piston.

8. The unconventional reservoir development device based on high-energy CO2 fluid fracturing according to claim 4, characterized in that... A sealing sleeve is fixed to the inner side of the upper end of the cone sleeve, and the inner side of the sealing sleeve matches the upper end face of the piston.

9. The unconventional reservoir development device based on high-energy CO2 fluid fracturing according to claim 1, 2, 3, 5, 6, or 8, characterized in that... A guide plate is fixed to the lower end of the piston and coaxially fitted inside the guide sleeve. Several support blocks are evenly distributed along the circumference on the inner side of the lower end of the fixed plate. The lower end of the first elastic reset member is fixedly installed together with the upper side of the support block, and the upper end of the first elastic reset member is fixedly installed together with the corresponding position of the lower end of the guide plate.

10. The unconventional reservoir development device based on high-energy CO2 fluid fracturing according to claim 4, characterized in that... A guide plate is fixed to the lower end of the piston and coaxially fitted inside the guide sleeve. Several support blocks are evenly distributed along the circumference on the inner side of the lower end of the fixed plate. The lower end of the first elastic reset member is fixedly installed together with the upper side of the support block, and the upper end of the first elastic reset member is fixedly installed together with the corresponding position of the lower end of the guide plate.

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