A directional carbon dioxide fracturing device

Abstract

The application discloses a directional carbon dioxide fracturing device, which comprises a plurality of fracturing unit, the plurality of fracturing units can be connected in sequence, two adjacent fracturing units are connected through a connecting charging wire group, the connecting charging wire group comprises a first connecting head and a second connecting head; the center of the end charging wire head, the first connecting head and the second connecting head is provided with a charging wire channel, a positive electrode tube and a negative electrode tube are arranged in the charging wire channel, and the center channel of the positive electrode tube is a liquid charging channel; the fracturing unit comprises two liquid storage tubes and an energy release head, a liquid storage cavity is arranged in each liquid storage tube, an excitation tube is arranged in the liquid storage cavity, the two excitation tubes are electrically connected through a first connecting wire and a second connecting wire, the first connecting wire and the second connecting wire pass through the energy release head, the two ends of the energy release head are provided with bursting discs, and two energy release air inlet channels and an energy release air outlet channel are arranged in the energy release head. The application has simple circuit and is not easy to be damaged.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of carbon dioxide fracturing device, in particular to a directional carbon dioxide fracturing device. BACKGROUND

[0002] At present, the carbon dioxide fracturing device has some problems such as high cost and inconvenient operation in application, but as a beneficial supplement of explosives, it has unique advantages in underground coal seam gas extraction, precious stone processing, geological exploration, dredging and silt removal, and blasting operation that cannot use explosives, and with the continuous improvement and optimization of equipment and the progress of new materials and new technology, the carbon dioxide fracturing device will play an important role.

[0003] In the process of open-pit limestone mining and underground coal mining, special operations such as permeability improvement, tunneling, coal roof pressure relief, city building demolition, high-gas mine gas control and rock burst control are often required, and these special operations have directional requirements, but the existing directional carbon dioxide fracturing device cannot meet the needs of field construction.

[0004] However, in the existing carbon dioxide fracturing device, the line connection is complex when the fracturing pipe is connected in series, and in the complex environment on site, the line connection may be broken, causing the hole blasting to fail, and in addition, the liquid filling hole is also separately arranged, and the structure is complex.

[0005] Therefore, there is an urgent need in the art for a new directional carbon dioxide fracturing device to solve the above problems. SUMMARY

[0006] The purpose of the present application is to provide a directional carbon dioxide fracturing device to solve the problems existing in the prior art, combine the line with the liquid filling hole, simplify the line connection, and the line is not easy to be damaged.

[0007] To achieve the above purpose, the present application provides the following scheme:

[0008] The present application discloses a directional carbon dioxide fracturing device, comprising a plurality of fracturing device units, when the number of fracturing device units is two or more, the plurality of fracturing device units can be connected in sequence, and the adjacent two fracturing device units are connected through a connecting charging connection group, the connecting charging connection group comprises a first connecting head and a second connecting head, the first connecting head and the second connecting head are respectively installed on the adjacent surfaces of the adjacent two fracturing device units, and the first connecting head and the second connecting head can be detachably connected; when the number of fracturing device units is one, one end of the fracturing device unit is provided with an end charging connection head, and the other end of the fracturing device unit is provided with a first connecting head.

[0009] The end filling connector, the first connector, and the second connector are all provided with a filling connection channel at their center. A positive electrode and a negative electrode are provided in the filling connection channel. The positive electrode is located inside the negative electrode. An insulating layer is provided between the positive electrode and the negative electrode. The central channel of the positive electrode is a liquid filling channel.

[0010] The fracturing unit includes two liquid storage tubes and a venting head. The two liquid storage tubes are respectively connected to the two ends of the venting head. Each liquid storage tube has a liquid storage chamber, and an excitation tube is provided in the liquid storage chamber. The two excitation tubes are electrically connected by a first connecting wire and a second connecting wire. The first connecting wire and the second connecting wire pass through the venting head. The positive electrode and the negative electrode are both electrically connected to the excitation tube. Both ends of the venting head are provided with rupture discs. The venting head also has two venting air inlet channels and one venting air outlet channel. The two venting air inlet channels are connected to the venting air outlet channel.

[0011] Preferably, the insulating layer is made of plastic.

[0012] Preferably, a switch bolt is threaded onto each of the end filling connector, the first connector, and the second connector, and the switch bolt can block the liquid filling channel.

[0013] Preferably, the end filling connector, the first connector, and the second connector are all electrically connected to the excitation tube via a spring assembly, and the first connector and the second connector are also electrically connected via the spring assembly.

[0014] The spring assembly includes an outer torsion spring and an inner torsion spring. One end of the outer torsion spring is connected to the excitation tube, and the other end of the outer torsion spring is sleeved on the outside of the negative electrode tube. One end of the inner torsion spring is connected to the excitation tube, and the other end of the inner torsion spring is inserted into the central channel of the positive electrode tube.

[0015] The positive electrode of the first connector and the positive electrode of the second connector are connected by the inner torsion spring, and the negative electrode of the first connector and the negative electrode of the second connector are connected by the outer torsion spring.

[0016] Preferably, the diameter of the liquid filling channel and the inner diameter of the positive electrode are both 3 mm, and the outer diameter of the negative electrode and the inner diameter of the filling wiring channel are both 4 mm.

[0017] Preferably, the outer side of the excitation tube is provided with a positioning ring, and the positioning ring is provided with a plurality of liquid passage holes in the circumferential direction.

[0018] Preferably, the corner between the energy-dissipating air intake channel and the energy-dissipating air outlet channel is set as a rounded corner.

[0019] Preferably, the liquid storage tube is provided with two annular wire receiving grooves on the side near the energy release head.

[0020] Preferably, each end of the energy release head is provided with a mounting groove, a shear protection pad is installed at the bottom of the mounting groove, and the rupture disc is placed on the side of the shear protection pad away from the bottom of the mounting groove.

[0021] Preferably, the outer ring of the rupture disc is provided with an insulating washer.

[0022] The present invention achieves the following technical effects compared to the prior art:

[0023] This invention combines the filling hole with the wiring hole, which simplifies the specific structure of the end filling connector, the first connector and the second connector, enhances its durability and improves its impact resistance.

[0024] Furthermore, this invention designs a novel energy release head that improves the smoothness of phase change gas flow, reduces energy loss during gas flow, and minimizes impact damage to the energy release head. Simultaneously, by combining two liquid storage pipes into a single system, one energy release head and its connecting devices are eliminated, improving the utilization efficiency of the device.

[0025] Furthermore, this invention designs a new fracturing tube connection device. Because it uses a flexible torsion spring connection, compared with the traditional pin connection, it eliminates the risk of pin breakage during handling, filling, and connection, reduces the probability of accidents when installing fracturing tubes, and greatly improves the connection and installation efficiency.

[0026] Furthermore, the connection between the rupture disc and the energy release head was improved, and a shear protection gasket was added to the energy release head to reduce the damage to the energy release head caused by the phase change gas flow during the blasting process. This solved the problem that the original right-angled sidewalls of the shear rupture disc of the original energy release head were often worn down after repeated use, which prevented the rupture disc from quickly completing shearing failure during blasting and caused the blasting to fail. Attached Figure Description

[0027] To more clearly illustrate the technical solutions in the embodiments of the present invention 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 the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0028] Figure 1A schematic diagram of the structure of a directional carbon dioxide fracturing device according to an embodiment of the present invention;

[0029] Figure 2 A schematic diagram of the end-filling connector in a directional carbon dioxide fracturing device according to an embodiment of the present invention;

[0030] Figure 3 A side view of the end-filled connector in a carbon dioxide fracturing device oriented according to an embodiment of the present invention;

[0031] Figure 4 A front sectional view of the end filling connector in a carbon dioxide fracturing device oriented according to an embodiment of the present invention;

[0032] Figure 5 A schematic diagram of the liquid storage pipe in a directional carbon dioxide fracturing device according to an embodiment of the present invention;

[0033] Figure 6 A front cross-sectional view of the liquid storage tube in a carbon dioxide fracturing device oriented according to an embodiment of the present invention;

[0034] Figure 7 A schematic diagram of the energy release head in the directional carbon dioxide fracturing device according to an embodiment of the present invention;

[0035] Figure 8 A front cross-sectional view of the energy release head in a directional carbon dioxide fracturing device according to an embodiment of the present invention;

[0036] Figure 9 A schematic diagram illustrating the installation of the shear protection gasket in the directional carbon dioxide fracturing device according to an embodiment of the present invention;

[0037] Figure 10 A schematic diagram of the structure of the filling wiring assembly in the carbon dioxide fracturing device oriented according to an embodiment of the present invention;

[0038] Figure 11 A schematic diagram showing the disassembled filling wiring assembly in a carbon dioxide fracturing device oriented according to an embodiment of the present invention;

[0039] Figure 12 A front sectional view of the filling wiring assembly in a carbon dioxide fracturing apparatus oriented according to an embodiment of the present invention;

[0040] In the diagram: 1-End filling connector; 101-Liquid filling channel; 102-Positive electrode; 103-Negative electrode; 104-Insulating layer; 105-Switch bolt; 2-Storage tube; 201-Excitation tube; 202-Positioning ring; 203-Storage chamber; 3-Energy release head; 301-Energy release inlet channel; 302-Energy release outlet channel; 303-Shear protection gasket; 304-Positioning arm; 305-Positioning hole; 4-Connecting filling connector assembly; 401-First connector; 402-Second connector; 403-Outer torsion spring; 404-Inner torsion spring; 5-First connecting wire; 6-Second connecting wire. Detailed Implementation

[0041] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0042] The purpose of this invention is to provide a directional carbon dioxide fracturing device to solve the problems existing in the prior art, which combines the circuit with the filling hole, simplifies the circuit connection, and makes the circuit less prone to damage.

[0043] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0044] like Figures 1-12 As shown, this embodiment provides a directional carbon dioxide fracturing device, including several fracturing units. One, two, or more fracturing units can be provided as needed. When there are two or more fracturing units, they can be connected end-to-end, and adjacent fracturing units are connected via a connecting filling wiring assembly 4. The connecting filling wiring assembly 4 includes a first connector 401 and a second connector 402. The first connector 401 and the second connector 402 are respectively threaded onto the adjacent surfaces of two adjacent fracturing units. The first connector 401 and the second connector 402 are detachably connected via threads. The ends of the fracturing units located at both ends, away from the adjacent fracturing unit, are respectively connected to an end filling wiring head 1 and a first connector 401. When there is only one fracturing unit, one end of the fracturing unit is provided with an end filling wiring head 1, and the other end of the fracturing unit is provided with a first connector 401.

[0045] The end filling connector 1, the first connector 401, and the second connector 402 all have a filling connection channel at their center, and these channels are coaxially arranged. A positive electrode 102 and a negative electrode 103 are located within each filling connection channel. Both the positive and negative electrodes 102 and 103 are conductive steel or iron pipes, with the positive electrode 102 coaxially positioned inside the negative electrode 103. An insulating layer 104 separates the positive and negative electrodes 102 and 103. The central channel of the positive electrode 102 is a liquid filling channel 101, through which liquid carbon dioxide is supplied to the storage tube 2.

[0046] The fracturing unit includes two liquid storage pipes 2 and one energy release head 3. The two liquid storage pipes 2 are respectively connected to the two ends of the energy release head 3. Each liquid storage pipe 2 has a liquid storage chamber 203, which is used to contain liquid carbon dioxide. An excitation tube 201 (i.e., a heating tube) is installed in the liquid storage chamber 203. The positive and negative terminals of the two excitation tubes 201 are electrically connected through a first connecting wire 5 and a second connecting wire 6. The first connecting wire 5 and the second connecting wire 6 pass through the energy release head 3, such as... Figure 8 As shown, the energy release head 3 has corresponding through holes for the first connecting wire 5 and the second connecting wire 6 to pass through. Furthermore, the positive electrode 102 and negative electrode 103 in the end filling connector 1, the first connector 401, and the second connector 402 are all electrically connected to the positive and negative electrodes in the excitation tube 201. Both ends of the energy release head 3 are equipped with rupture discs, which are clamped between the energy release head 3 and the liquid storage tube 2. The energy release head 3 also has two energy release inlet channels 301 and one energy release outlet channel 302. The two energy release inlet channels 301 are located on both sides of the energy release outlet channel 302, and both are connected to the energy release outlet channel 302. One end of the energy release outlet channel 302 extends to the surface of the energy release head 3, serving as the outlet (also called the energy release port).

[0047] In practical use, the fracturing unit is first assembled. The activation tube 201 is electrically connected to the positive and negative electrodes 102 and 103 in the end filling connector 1. The liquid storage tube 2 is rotatably connected to the end filling connector 1 via their threads. Simultaneously, another activation tube 201 is threaded to the first connector 401, and this activation tube 201 is also electrically connected to the positive and negative electrodes 102 and 103 in the first connector 401. Finally, the two liquid storage tubes 2 are rotatably connected to a single energy release head 3 via their threads. This completes the assembly of one fracturing unit. Then, liquid carbon dioxide is filled through the liquid filling channel 101 of the end filling connector 1, and the unit is assembled in series near the borehole, inserted into the borehole, and the borehole is sealed. Finally, detonation occurs. The activation tube 201 heats the liquid carbon dioxide, causing it to vaporize. The vaporized carbon dioxide ruptures the rupture discs and enters the borehole through the energy release inlet channel 301 and the energy release outlet channel 302, completing the detonation.

[0048] In this embodiment, the insulating layer 104 can be made of plastic to isolate the positive electrode 102 from the negative electrode 103.

[0049] In this embodiment, a switch bolt 105 is threaded onto the end filling connector 1, the first connector 401, and the second connector 402. The switch bolt 105 is perpendicular to the filling connection channel and can block the liquid filling channel 101. The operator can control the flow of liquid in each liquid filling channel 101 by turning the switch bolt 105.

[0050] In this embodiment, the end filling connector 1, the first connector 401, and the second connector 402 are all electrically connected to the positive and negative terminals of the excitation tube 201 via a spring assembly. Furthermore, the first connector 401 and the second connector 402 are also electrically connected to each other via a spring assembly.

[0051] The spring assembly comprises an outer torsion spring 403 and an inner torsion spring 404, with the inner torsion spring 404 positioned inside the outer torsion spring 403. When the end-filled connector 1, the first connector 401, and the second connector 402 are connected to the positive and negative terminals of the excitation tube 201 via the spring assembly, one end of the outer torsion spring 403 is connected to the negative terminal of the excitation tube 201, and the other end is sleeved on the outside of the negative electrode tube 103, thus achieving an electrical connection between the negative terminal of the excitation tube 201 and the negative electrode tube 103. One end of the inner torsion spring 404 is connected to the positive terminal of the excitation tube 201, and the other end is inserted into the central channel of the positive electrode tube 102, thereby achieving an electrical connection between the positive terminal of the excitation tube 201 and the positive electrode tube 102.

[0052] The first connector 401 and the second connector 402 are fixed together by a threaded connection. In order to achieve the electrical connection between the first connector 401 and the second connector 402, the positive electrode 102 of the first connector 401 and the positive electrode 102 of the second connector 402 are connected by an inner torsion spring 404, and the negative electrode 103 of the first connector 401 and the negative electrode 103 of the second connector 402 are connected by an outer torsion spring 403. The positive and negative connections between the first connector 401 and the second connector 402 are achieved by the inner torsion spring 404 and the outer torsion spring 403.

[0053] Because it uses a flexible spring for connection, compared with the traditional pin connection, it eliminates the risk of pin breakage during handling, filling, and connection, reduces the probability of accidents when installing cracked tubes, and greatly improves the connection and installation efficiency.

[0054] In this embodiment, the diameter of the liquid filling channel 101 is the same as the inner diameter of the positive electrode 102, both being 3mm, and the outer diameter of the negative electrode 103 is the same as the inner diameter of the filling wiring channel, both being 4mm. Figure 4 As shown, a 6mm groove is provided on the left side of the end filling connector 1 to facilitate its connection with related equipment. Of course, those skilled in the art can adjust the specific dimensions of each channel according to actual needs, and are not limited to this one method.

[0055] In this embodiment, as Figure 6 As shown, a positioning ring 202 is provided on the outer side of the excitation tube 201. The positioning ring 202 is a component that is included in the production process of the excitation tube 201. The positioning ring 202 has multiple liquid passage holes in the circumferential direction to facilitate the passage of the filling liquid.

[0056] In this embodiment, the energy release head 3 is the site for the expansion and release of carbon dioxide gas after phase change, and also serves as a device for controlling the direction of energy release and rock breaking. A key feature of this energy release head 3 is that the expansion and release of carbon dioxide gas from the two liquid storage pipes 2 after phase change shares a single outlet, thus improving rock breaking efficiency.

[0057] like Figure 8 As shown, the corner between the energy release inlet channel 301 and the energy release outlet channel 302 is set as a rounded corner, which is not a traditional right-angle corner. This improves the smoothness of the phase change gas flow, reduces energy damage during gas flow, and also reduces the impact damage to the energy release head 3.

[0058] In this embodiment, the liquid storage tube 2 is provided with two annular wire receiving grooves on the side near the energy release head 3. The first connecting wire 5 passes through the outer wire receiving groove, and the second connecting wire 6 passes through the inner wire receiving groove. This arrangement is because when the threaded connection between the liquid storage tube 2 and the energy release head 3 is made, the first connecting wire 5 and the second connecting wire 6 will also rotate. The wire receiving grooves provide room for the first connecting wire 5 and the second connecting wire 6 to move, preventing them from getting tangled and affecting the threaded connection between the liquid storage tube 2 and the energy release head 3.

[0059] In this embodiment, as Figure 9 As shown, each end of the energy release head 3 has a mounting groove, and a shear protection pad 303 is installed at the bottom of the groove. A positioning arm 304 is provided on each side of the shear protection pad 303, and the mounting groove has a corresponding groove for the positioning arm 304. A positioning hole 305 is provided on each side of the shear protection pad 303, and a positioning protrusion is provided on each side of the mounting groove. The positioning protrusion is inserted into the positioning hole 305 to fix the shear protection pad 303. A rupture disc is placed on the side of the shear protection pad 303 away from the bottom of the groove. The rupture disc is used to ensure the pressure inside the liquid storage pipe 2 by bursting carbon dioxide, and is the target of phase change gas shearing. A central through hole is provided in the center of the shear protection pad 303, and the diameter of the rupture disc is larger than the diameter of the central through hole of the shear protection pad 303. The shear protection shim 303 is used during the blasting process when the phase-change gas impacts the rupture disc to reduce wear on the energy release head 3 when the rupture disc undergoes shear failure (in actual engineering, the energy release head 3 often fails to provide shear protection due to wear caused by the rupture disc undergoing shear failure, leading to blasting failure). The shear protection shim 303 is an economically advantageous component as it is easily replaceable.

[0060] In this embodiment, the outer ring of the rupture disc is provided with an insulating washer made of rubber to provide insulation, thereby isolating the rupture disc from the energy release head 3. Simultaneously, the outer wall of the insulating washer abuts against the inner wall of the end groove of the energy release head 3, thus achieving center alignment of the rupture disc.

[0061] Specific examples have been used to illustrate the principles and implementation methods of this invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of this invention. Furthermore, those skilled in the art will recognize that, based on the ideas of this invention, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of this invention.

Claims

1. A directional carbon dioxide fracturing apparatus, characterized by: The application relates to a crack initiator unit, which comprises a plurality of crack initiator units, when the crack initiator units are two or more, the crack initiator units can be connected in sequence, adjacent two crack initiator units are connected through a connecting charging wire group, the connecting charging wire group comprises a first connecting head and a second connecting head, the first connecting head and the second connecting head are respectively arranged on the adjacent surfaces of the adjacent two crack initiator units, and the first connecting head and the second connecting head are detachably connected; when the crack initiator unit is one, one end of the crack initiator unit is provided with an end charging wire head, and the other end of the crack initiator unit is provided with a first connecting head. The center of the end charging wire head, the first connecting head and the second connecting head is provided with a charging wire channel, a positive electrode tube and a negative electrode tube are arranged in the charging wire channel, the positive electrode tube is arranged on the inner side of the negative electrode tube, an insulating layer is arranged between the positive electrode tube and the negative electrode tube, and the center channel of the positive electrode tube is a liquid charging channel. The crack initiator unit comprises two liquid storage tubes and an energy releasing head, the two liquid storage tubes are connected to the two ends of the energy releasing head respectively, a liquid storage cavity is arranged in each liquid storage tube, one excitation tube is arranged in the liquid storage cavity, the two excitation tubes are electrically connected through a first connecting lead and a second connecting lead, the first connecting lead and the second connecting lead pass through the energy releasing head, the positive electrode tube and the negative electrode tube are electrically connected with the excitation tube, the two ends of the energy releasing head are provided with bursting discs, and two energy releasing air inlet channels and one energy releasing air outlet channel are further arranged in the energy releasing head.

2. The directed carbon dioxide fracturing apparatus of claim 1, wherein: The material of the insulating layer is plastic.

3. The directed carbon dioxide fracturing apparatus of claim 1, wherein: A switch bolt is threadedly connected to the end charging wire head, the first connecting head and the second connecting head, and the switch bolt can block the liquid charging channel.

4. The directed carbon dioxide fracturing apparatus of claim 1, wherein: The end charging wire head, the first connecting head and the second connecting head are electrically connected with the excitation tube through a spring assembly, and the first connecting head and the second connecting head are also electrically connected through the spring assembly. The spring assembly comprises an outer circle torsion spring and an inner circle torsion spring, one end of the outer circle torsion spring is connected with the excitation tube, the other end of the outer circle torsion spring is arranged on the outer side of the negative electrode tube, one end of the inner circle torsion spring is connected with the excitation tube, and the other end of the inner circle torsion spring is inserted into the center channel of the positive electrode tube. The positive electrode tube of the first connecting head is connected with the positive electrode tube of the second connecting head through the inner circle torsion spring, and the negative electrode tube of the first connecting head is connected with the negative electrode tube of the second connecting head through the outer circle torsion spring.

5. The directional carbon dioxide fracturing apparatus of claim 1, wherein: The diameter of the liquid charging channel and the inner diameter of the positive electrode tube are both 3 mm, and the outer diameter of the negative electrode tube and the inner diameter of the charging wire channel are both 4 mm.

6. The directed carbon dioxide fracturing apparatus of claim 1, wherein: The outer side of the excitation tube is provided with a positioning ring, and a plurality of liquid passing holes are arranged in the circumferential direction of the positioning ring.

7. The directed carbon dioxide fracturing apparatus of claim 1, wherein: The corner between the energy releasing air inlet channel and the energy releasing air outlet channel is a circular arc corner.

8. The directed carbon dioxide fracturing apparatus of claim 1, wherein: The liquid storage pipe is provided with two annular wire containing grooves on the side close to the energy relief head.

9. The directed carbon dioxide fracturing apparatus of claim 1, wherein: The energy relief head is provided with an installation groove at each end, and a shearing protection gasket is installed on the groove bottom of the installation groove, and the blast disc is placed on the side of the shearing protection gasket away from the groove bottom of the installation groove.

10. The directed carbon dioxide fracturing apparatus of claim 1, wherein: An insulating gasket is arranged on the outer ring of the blast disc.

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