Drilling, sealing and pressing integrated hydraulic fracturing device for directional drilling machine

Abstract

The invention relates to the technical field of hydraulic fracturing, in particular to a drilling, sealing and fracturing integrated hydraulic fracturing device for a directional drilling machine. The high-low pressure switching mechanism in the device can achieve the functions of low-pressure passing and high-pressure sealing, and a good guarantee foundation is provided for hydraulic fracturing operation. When the device is used, under the condition of low-pressure water, the piston core cannot completely compress the first spring, at the moment, the high-pressure and low-pressure switching mechanism in the device is in an access state, and the low-pressure water is introduced to the position of a drill bit to assist drilling. When hole sealing and fracturing operation is carried out, high-pressure water is introduced into the hollow drill rod, the piston core is gradually pressed by the high-pressure water, the first channel and the second channel are disconnected from each other, and the high-low pressure switching mechanism is in a closed state; high-pressure water is introduced into the hole sealing and fracturing mechanism and is sprayed out of the fracturing hole in a high-pressure state, so that the hydraulic fracturing effect is achieved; in other words, the device can achieve integrated operation of drilling, sealing and pressing, and the construction efficiency is greatly improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of hydraulic fracturing, in particular to a drilling, sealing and pressurizing integrated hydraulic fracturing device for a directional drilling machine. BACKGROUND

[0002] In the process of safe mining of coal, the exposed coal seam roof inside the goaf needs to be cut and pressure released, so as to reduce the loose degree and deformation of the goaf roof by sinking of the coal seam roof, and to reduce the stress concentration area on the goaf roof, so as to realize safe and effective control of the coal seam roof.

[0003] In the prior art, hydraulic fracturing technology is increasingly used for cutting and pressure releasing operation, coal seam permeability improvement operation, etc. In the process of hydraulic fracturing operation, a drilling machine is usually used to drill a hole to the position where hydraulic fracturing is needed, then the drill rod and drill bit are withdrawn from the hole, the drill bit is removed from the drill rod, the hydraulic fracturing device is installed on the drill rod and reinserted into the hole for hydraulic fracturing operation. Such operation process is very cumbersome, the construction efficiency is very low, and it seriously affects the progress of safe production.

[0004] Therefore, it is necessary to provide an improved technical solution for the above-mentioned deficiencies of the prior art. SUMMARY

[0005] The purpose of the present application is to provide a drilling, sealing and pressurizing integrated hydraulic fracturing device for a directional drilling machine to solve or alleviate the problems existing in the prior art.

[0006] In order to achieve the above-mentioned purpose, the present application provides the following technical solution: A drilling, sealing and pressurizing integrated hydraulic fracturing device for a directional drilling machine, the device comprising a high-low pressure switching mechanism and a hole sealing and fracturing mechanism, the high-low pressure switching mechanism being located in the front part of the hole sealing and fracturing mechanism, the high-low pressure switching mechanism being used to maintain a pass-through state when low-pressure water enters the liquid inlet, and being switched to a blocking state when high-pressure water enters the liquid inlet, and the high-pressure water being introduced into the hole sealing and fracturing mechanism; The high-low pressure switching mechanism comprises: A front rod body, the front end of the front rod body being a liquid outlet for connecting with a drill bit, and a flow passage being further provided in the center of the front rod body; A fixed core and a piston core, the fixed core and the piston core being located in the flow passage of the front rod body, and the piston core being located behind the fixed core, and a first spring being provided between the fixed core and the piston core; A first passage is provided in the fixed core, the cross-sectional dimension of the first passage along the axial direction being consistent; a second passage is provided in the piston core, the cross-sectional dimension of the inlet of the second passage being smaller than that of the outlet; and the first passage and the second passage are arranged in axial direction with each other. When low pressure water enters the piston core, the piston core remains stationary, at this time, there is a gap between the piston core and the fixed core, the first channel and the second channel remain in communication; When high pressure water enters the piston core, the piston core compresses the first spring and moves towards the fixed core, at this time, the front end face of the piston core is pressed on the rear end face of the fixed core, the first channel and the second channel are disconnected with each other.

[0007] The drilling, sealing and pressurizing integrated hydraulic fracturing device for the directional drilling machine, preferably, the inner cavity of the through-flow channel in the front rod body is a conical frustum, and the outer peripheral surface of the fixed core and the outer peripheral surface of the piston core are both conical frustums.

[0008] The drilling, sealing and pressurizing integrated hydraulic fracturing device for the directional drilling machine, preferably, the front end face of the piston core and / or the rear end face of the fixed core is provided with a clearance slot, and the first spring is located in the clearance slot between the piston core and the fixed core.

[0009] The drilling, sealing and pressurizing integrated hydraulic fracturing device for the directional drilling machine, preferably, the sealing and pressurizing mechanism comprises a rear rod body, the rear end of the rear rod body is a liquid inlet for being connected with a hollow drill rod, and the center of the rear rod body is provided with a hollow channel.

[0010] The drilling, sealing and pressurizing integrated hydraulic fracturing device for the directional drilling machine, preferably, the front end of the rear rod body is provided with an external threaded shaft, and the rear end of the front rod body is provided with an internal threaded hole, so that the external threaded shaft of the rear rod body is threadedly connected in the internal threaded hole of the front rod body.

[0011] The drilling, sealing and pressurizing integrated hydraulic fracturing device for the directional drilling machine, preferably, the front end of the rear rod body is provided with a piston cavity, the front end of the piston core is guided to move in the piston cavity, and the peripheral surface of the front end of the piston core is in sealing contact with the inner peripheral surface of the piston cavity. The front end of the rear rod body is further provided with a plurality of radial holes, and the inner side of each radial hole is in communication with the piston cavity. When low pressure water is introduced into the device, the front end face of the piston core is located at the rear side of the radial hole; when high pressure water is introduced into the device, the front end face of the piston core is located at the front side of the radial hole.

[0012] The drilling, sealing and pressurizing integrated hydraulic fracturing device for the directional drilling machine, preferably, a plurality of axial main holes are further arranged in the rear rod body, the axial line of the axial main hole is parallel to the axial direction of the device, and each radial hole is in communication with an axial main hole.

[0013] The drilling, sealing and fracturing integrated hydraulic fracturing device for the directional drilling machine has the following preferred technical solutions. The front sealing sleeve and the rear sealing sleeve are in communication with the axial main hole.

[0014] The drilling, sealing and fracturing integrated hydraulic fracturing device for the directional drilling machine has the following preferred technical solutions. The rear end surface of the rear rod body is uniformly provided with a plurality of connecting holes, each of which is connected between an axial main hole and an axial auxiliary hole. The rear rod body is also uniformly provided with a plurality of fracturing holes, which are perpendicular to the axial direction of the device and located between the front sealing sleeve and the rear sealing sleeve. The front end of the axial auxiliary hole extends between the front sealing sleeve and the rear sealing sleeve, one end of the fracturing hole is in communication with the front end of the axial auxiliary hole, and the other end penetrates through the outer peripheral surface of the rear rod body; and a second spring and a push plate are arranged at the front end of the axial auxiliary hole, the push plate moves in the axial auxiliary hole in a guided manner, and the second spring is connected between the push plate and the bottom of the front end hole of the axial auxiliary hole.

[0015] The drilling, sealing and fracturing integrated hydraulic fracturing device for the directional drilling machine has the following preferred technical solutions.

[0016] Compared with the closest prior art, the technical scheme of the embodiment of the present application has the following beneficial effects: The high-low pressure switching mechanism in the device can realize low-pressure passing and high-pressure sealing, thereby providing a better guarantee for hydraulic fracturing operation.

[0017] When the device is in use, under low-pressure water condition, the piston core cannot completely compress the first spring, at this time, the high-low pressure switching mechanism in the device is in a pass-through state, and low-pressure water is introduced into the drill bit position to assist drilling. When the hole sealing and fracturing operation is performed, high-pressure water is introduced into the hollow drill rod, the high-pressure water gradually compresses the piston core, the first channel and the second channel are disconnected from each other, and the high-low pressure switching mechanism is in a closed state; the high-pressure water is introduced into the hole sealing and fracturing mechanism, and the high-pressure water is sprayed from the fracturing hole in a high-pressure state to achieve the effect of hydraulic fracturing; that is, the device can realize drilling, sealing and fracturing integrated operation, thereby greatly improving the construction efficiency. BRIEF DESCRIPTION OF DRAWINGS

[0018] The accompanying drawings, which are incorporated in and constitute a part of this specification, are included to provide a further understanding of the application, and are incorporated in and constitute a part of this specification, illustrate embodiments of the application and together with the description serve to explain the application. In the drawings: Figure 1 State diagram for passing low pressure water in a device according to some embodiments of the application; Figure 2 State diagram for passing high pressure water in a device according to some embodiments of the application; Figure 3 A-A sectional view in Figure 2 A-A sectional view in Figure 4 B-B sectional view in Figure 2 B-B sectional view in Figure 5 Cross sectional schematic view of a piston core according to some embodiments of the application; Figure 6 Cross sectional schematic view of a fixed core according to some embodiments of the application.

[0019] BRIEF DESCRIPTION OF DRAWINGS 1. Front rod body; 11. Fixed core; 12. First spring; 13. Piston core; 14. First passage; 15. Second passage; 2. Back rod body; 21. Piston cavity; 22. Radial hole; 23. Axial main hole; 24. Front sealing hole sleeve; 25. Back sealing hole sleeve; 26. Axial auxiliary hole; 27. Fracturing hole; 28. Push plate; 29. Second spring; 210. Plug; 211. Connection hole. DETAILED DESCRIPTION

[0020] The application will be described in relation to the enclosed drawings and embodiments. Each example is provided by way of explanation of the application and is not meant as a limitation of the application. In fact, many variations and modifications of the application can be made that fall within the scope of the application. For instance, features developed for one embodiment can be used in another embodiment to produce yet another embodiment. It is therefore intended that this application encompass all such modifications and variations as fall within the scope of the appended claims and their equivalents. It is to be understood that the singular forms "a", "an", and "the" include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to "a component" includes a plurality of such components.

[0021] In the following description, the terms "first", "second", "third", are used only to distinguish similar objects, and do not represent a specific order or sequence of the objects, and it is understood that the "first", "second", "third" can be interchanged with a specific order or sequence as allowed, so that the embodiments of the application described herein can be implemented in an order other than that illustrated or described herein.

[0022] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. The terminology used in the description herein is for describing particular embodiments only and is not intended to be limiting of the disclosure.

[0023] In the description of the present application, the orientation or positional relationship indicated by the terms "longitudinal", "transverse", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present application and does not require the present application to be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation of the present application. The terms "connected", "connected", "provided" used in the present application should be understood broadly, for example, it can be fixedly connected or detachably connected; it can be directly connected or indirectly connected through intermediate components; it can be wired electrical connection, wireless electrical connection or wireless communication signal connection, and the specific meaning of the above terms can be understood by those skilled in the art according to the specific circumstances.

[0024] The present application will be described in detail below with reference to the drawings and in combination with the embodiments. It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other without conflict.

[0025] According to a specific embodiment of the present application, as shown in Figures 1-6 The present application provides a drilling, sealing and pressurizing integrated hydraulic fracturing device for a directional drilling machine, the device comprising a high-low pressure switching mechanism and a hole sealing and fracturing mechanism, the high-low pressure switching mechanism being located in the front part of the hole sealing and fracturing mechanism, the high-low pressure switching mechanism being used to maintain a pass-through state when low-pressure water enters the liquid inlet; and being switched to a plugging state when high-pressure water enters the liquid inlet, and introducing high-pressure water into the hole sealing and fracturing mechanism; in the present embodiment, the high-low pressure switching mechanism is located in the downstream direction of the hole sealing and fracturing mechanism, that is, the downstream direction is the front of the axial direction of the device, and the upstream direction is the rear of the axial direction of the device.

[0026] The high-low pressure switching mechanism comprises: A front rod body 1, the front end of the front rod body 1 being a liquid outlet for connecting with a drill bit; the center of the front rod body 1 further being provided with a flow passage.

[0027] A fixed core 11 and a piston core 13, both the fixed core 11 and the piston core 13 being located in the flow passage of the front rod body 1, and the piston core 13 being located behind the fixed core 11; and a first spring 12 being arranged between the fixed core 11 and the piston core 13.

[0028] The first channel 14 is arranged in the fixed core 11 and has a uniform cross-sectional dimension in the axial direction; the second channel 15 is arranged in the piston core 13 and has a cross-sectional dimension at the inlet smaller than that at the outlet; and the first channel 14 and the second channel 15 are arranged in the axial direction and staggered with each other.

[0029] When the low-pressure water enters the piston core 13, the piston core 13 remains stationary, and at this time, a gap exists between the piston core 13 and the fixed core 11, and the first channel 14 and the second channel 15 are kept in communication.

[0030] When the high-pressure water enters the piston core 13, the piston core 13 compresses the first spring 12 and moves towards the fixed core 11, and at this time, the front end surface of the piston core 13 is pressed against the rear end surface of the fixed core 11, and the first channel 14 and the second channel 15 are disconnected from each other.

[0031] In the device, when the low-pressure water enters the high-low pressure switching mechanism, the pressure of the water acting on the piston core 13 is smaller than the elastic force of the first spring 12, and at this time, a gap exists between the piston core 13 and the fixed core 11, and the first channel 14 and the second channel 15 are kept in communication, and the high-low pressure switching mechanism remains in the open state, and the low-pressure water can flow from the high-low pressure switching mechanism to the drill bit to assist the drill bit in drilling.

[0032] When the high-pressure water enters the high-low pressure switching mechanism, due to the fact that the cross-sectional dimension at the inlet of the second channel 15 in the piston core 13 is smaller than that at the outlet, the pressure at the inlet of the piston core 13 gradually increases, and when the pressure at the inlet of the piston core 13 is greater than the elastic force of the first spring 12, the piston core 13 starts to move forward and gradually compresses the first spring 12 until the front end surface of the piston core 13 is pressed against the rear end surface of the fixed core 11, and at this time, the high-pressure water completely presses the piston core 13, disconnects the first channel 14 and the second channel 15 from each other, and the high-low pressure switching mechanism is in the closed state, and the high-pressure water cannot pass through the high-low pressure switching mechanism. That is, the high-low pressure switching mechanism in the device can realize the functions of low-pressure passing and high-pressure closing, and provides a better guarantee for the hydraulic fracturing operation.

[0033] The inner cavity of the flow passage in the front rod body 1 is in the shape of a truncated cone, and the outer periphery of the fixed core 11 and the outer periphery of the piston core 13 are both in the shape of a truncated cone.

[0034] In the embodiment, the size of the flow passage in the shape of a truncated cone gradually decreases from the rear to the front, the size of the fixed core 11 in the shape of a truncated cone gradually decreases from the rear to the front, and the size of the piston core 13 in the shape of a truncated cone gradually decreases from the rear to the front. When the high-pressure water presses the piston core 13 against the fixed core 11, the outer periphery of the piston core 13 in the shape of a truncated cone also fits the inner periphery of the flow passage in the shape of a truncated cone, and the truncated cone structure can withstand a larger pressure, thereby ensuring that the high-low pressure switching mechanism has better structural stability.

[0035] In the embodiment, the inner cavity of the flow passage in the front rod body 1 is a circular truncated cone, and the outer circumferential surface of the fixed core 11 and the outer circumferential surface of the piston core 13 are both circular truncated cones.

[0036] The front end surface of the piston core 13 and / or the rear end surface of the fixed core 11 is provided with a clearance slot, and the first spring 12 is located in the clearance slot between the piston core 13 and the fixed core 11.

[0037] In the embodiment, one end of the first spring 12 is fixedly connected to the front end surface of the piston core 13, and the other end of the first spring 12 is fixedly connected to the rear end surface of the fixed core 11. The front end surface of the piston core 13 is provided with a clearance slot, and the rear end surface of the fixed core 11 is also provided with a clearance slot. When the piston core 13 is pressed against the fixed core 11, the clearance slot in the front end surface of the piston core 13 and the clearance slot in the rear end surface of the fixed core 11 are mutually opposed, and the first spring 12 is located between the clearance slot in the front end surface of the piston core 13 and the clearance slot in the rear end surface of the fixed core 11.

[0038] In other embodiments, the front end surface of the piston core 13 can be provided with a clearance slot only, or the rear end surface of the fixed core 11 can be provided with a clearance slot only. When the piston core 13 is pressed against the fixed core 11, the first spring 12 is completely located in the clearance slot in the front end surface of the piston core 13, or the first spring 12 is completely located in the clearance slot in the rear end surface of the fixed core 11.

[0039] In the embodiment, only one large first spring 12 can be provided, and at this time, the large first spring 12 is sleeved in the clearance slot between the piston core 13 and the fixed core 11. Alternatively, a plurality of small first springs 12 can be provided and evenly distributed in the clearance slot between the piston core 13 and the fixed core 11.

[0040] The hole sealing and fracturing mechanism comprises a rear rod body 2, the rear end of the rear rod body 2 is a liquid inlet for being connected with a hollow drill rod, and the center of the rear rod body 2 is provided with a hollow passage.

[0041] In the embodiment, one end of the hollow drill rod is connected to the rear rod body 2 of the device, and the other end is connected to a drilling machine, so that the device can realize the normal drilling operation process of the drilling machine. Low-pressure water is introduced through the hollow drill rod, and the low-pressure water can flow normally in the device, thereby assisting the drilling operation.

[0042] The front end of the rear rod body 2 is provided with an external threaded shaft, and the rear end of the front rod body 1 is provided with an internal threaded hole, so that the external threaded shaft of the rear rod body 2 is threadedly connected in the internal threaded hole of the front rod body 1. In the embodiment, the front rod body 1 and the rear rod body 2 are threadedly connected, which can facilitate the disassembly and maintenance operation of the device.

[0043] The front end of the rear rod body 2 is provided with a piston cavity 21, the front end of the piston core 13 is guided to move in the piston cavity 21, and the front end peripheral surface of the piston core 13 is in sealing contact with the inner peripheral surface of the piston cavity 21; the front end of the rear rod body 2 is also arranged with a plurality of radial holes 22, the inner side of each radial hole 22 is in communication with the piston cavity 21; when low-pressure water is introduced into the device, the front end surface of the piston core 13 is located at the rear side of the radial hole 22; when high-pressure water is introduced into the device, the front end surface of the piston core 13 is located at the front side of the radial hole 22.

[0044] In the embodiment, a plurality of sealing rings can be arranged on the front end peripheral surface of the piston core 13, so as to always ensure that the front end peripheral surface of the piston core 13 is in sealing contact with the inner peripheral surface of the piston cavity 21, and good sealing performance is ensured between the piston core 13 and the piston cavity 21.

[0045] In the embodiment, the front end of the rear rod body 2 can be uniformly arranged with a plurality of radial holes 22, and the number of the radial holes 22 can be selected as required, which is five in this case, or can be other numbers, which is not limited herein. When low-pressure water is introduced into the device, the front end surface of the piston core 13 is located at the rear side of the radial hole 22, at this time, the low-pressure water directly flows from the hole sealing and fracturing mechanism to the high-low pressure switching mechanism, that is, the low-pressure water directly flows through the device; when high-pressure water is introduced into the device, the front end surface of the piston core 13 is located at the front side of the radial hole 22, at this time, the high-low pressure switching mechanism is closed, and the high-pressure water cannot flow through the high-low pressure switching mechanism, and due to the forward movement of the piston, the radial hole 22 at the front end of the rear rod body 2 is exposed, so that the high-pressure water is introduced into the radial hole 22 of the rear rod body 2, so that the high-pressure water enters the hole sealing and fracturing mechanism.

[0046] A plurality of axial main holes 23 are also arranged in the rear rod body 2, the axis of the axial main hole 23 is parallel to the axial direction of the device, and each radial hole 22 is in communication with an axial main hole 23. In the embodiment, the high-pressure water introduced into the radial hole 22 is introduced into the axial main hole 23 of the rear rod body 2.

[0047] The outer periphery of the rear rod body 2 is also sleeved with a front hole sealing sleeve 24 and a rear hole sealing sleeve 25, the front hole sealing sleeve 24 is sleeved at the front part of the rear rod body 2, and the rear hole sealing sleeve 25 is sleeved at the rear part of the rear rod body 2; and the front hole sealing sleeve 24 and the rear hole sealing sleeve 25 are in communication with the axial main hole 23.

[0048] In the embodiment, the front hole sealing sleeve 24 and the rear hole sealing sleeve 25 are made of elastic material, which can be made of rubber material in this case.

[0049] When the high pressure water is introduced into the axial main hole 23 of the rear rod body 2, the high pressure water gradually enters into the front sealing hole sleeve 24 and the rear sealing hole sleeve 25, and the front sealing hole sleeve 24 and the rear sealing hole sleeve 25 are radially expanded by the filling of the high pressure water, so that the front sealing hole sleeve 24 and the rear sealing hole sleeve 25 can completely seal the drill hole, and the device realizes the hole sealing function to provide the operation condition for the hydraulic fracturing.

[0050] The rear rod body 2 is also uniformly provided with a plurality of axial auxiliary holes 26, and the axial lines of the axial auxiliary holes 26 are parallel to the axial direction of the device.

[0051] The rear end surface of the rear rod body 2 is uniformly provided with a plurality of connecting holes 211, and each connecting hole 211 is connected between an axial main hole 23 and an axial auxiliary hole 26.

[0052] The rear rod body 2 is also uniformly provided with a plurality of fracturing holes 27, and the fracturing holes 27 are perpendicular to the axial direction of the device, and the fracturing holes 27 are located between the front sealing hole sleeve 24 and the rear sealing hole sleeve 25.

[0053] The front end of the axial auxiliary hole 26 extends to between the front sealing hole sleeve 24 and the rear sealing hole sleeve 25, one end of the fracturing hole 27 is communicated with the front end of the axial auxiliary hole 26, and the other end penetrates through the outer circumferential surface of the rear rod body 2; and the second spring 29 and the push plate 28 are also arranged at the front end of the axial auxiliary hole 26, the push plate 28 is guided to move in the axial auxiliary hole 26, and the second spring 29 is connected between the push plate 28 and the bottom hole of the front end of the axial auxiliary hole 26.

[0054] In this embodiment, the high pressure water entering into the axial main hole 23 enters into the axial auxiliary hole 26 through the connecting hole 211. Before the high pressure water enters into the axial auxiliary hole 26, the push plate 28 is located at the rear side of the fracturing hole 27, and after the high pressure water enters into the axial auxiliary hole 26, the high pressure water gradually accumulates energy, and when the pressure of the high pressure water is greater than the elastic force of the second spring 29, the high pressure water pushes the push plate 28 to compress the second spring 29, and at this time, the push plate 28 is located at the front side of the fracturing hole 27, and the high pressure water is sprayed out of the fracturing hole 27 in a high pressure state to achieve the hydraulic fracturing effect.

[0055] The rear end of the rear rod body 2 is connected with a plug 210, and the plug 210 is used to seal the rear end surface of the rear rod body 2. In this embodiment, considering the easy processability of the axial main hole 23, the connecting hole 211 and the axial auxiliary hole 26 in the rear rod body 2, the connecting hole 211 is arranged on the rear end surface of the rear rod body 2, the axial main hole 23 and the axial auxiliary hole 26 can be processed from the rear end surface of the rear rod body 2, and after the processing is completed, the plug 210 is installed to seal the rear end surface of the rear rod body 2. The inner thread can be arranged at the rear end of the hollow channel of the rear rod body 2, and the outer thread is arranged on the plug 210, so that the plug 210 is screw-mounted on the rear rod body 2.

[0056] The device is used, the rear rod body 2 of the device is installed on the hollow drill rod of the directional drilling machine, and the drill bit is installed on the front rod body 1, then the directional drilling machine is started, and low-pressure water is injected into the device through the hollow drill rod, under the condition of low-pressure water, the piston core 13 cannot completely compress the first spring 12, at this time, the high-low pressure switching mechanism in the device is in the passage state, and the low-pressure water is introduced into the drill bit position to assist the drilling.

[0057] When the drill bit reaches the target position, and the hole sealing and fracturing operation is needed; high-pressure water is introduced into the hollow drill rod, because the cross-sectional size of the inlet of the second passage 15 in the piston core 13 is smaller than that of the outlet, the pressure at the inlet of the piston core 13 gradually increases, the piston core 13 starts to move forward and gradually compresses the first spring 12, until the front end face of the piston core 13 is pressed against the rear end face of the fixed core 11, at this time, the high-pressure water completely presses the piston core 13, so that the first passage 14 and the second passage 15 are disconnected with each other, and the high-low pressure switching mechanism is in the closed state; the high-pressure water is introduced into the hole sealing and fracturing mechanism, the high-pressure water first enters the front hole sealing sleeve 24 and the rear hole sealing sleeve 25, and is filled with high-pressure water, so that the front hole sealing sleeve 24 and the rear hole sealing sleeve 25 expand radially, so that the front hole sealing sleeve 24 and the rear hole sealing sleeve 25 can completely seal the drill hole, to provide operation conditions for hydraulic fracturing; then the high-pressure water enters the axial auxiliary hole 26, and the high-pressure water gradually accumulates energy, when the pressure of the high-pressure water is greater than the elastic force of the second spring 29, the high-pressure water pushes the push plate 28, so that the push plate 28 compresses the second spring 29, at this time, the push plate 28 is located on the front side of the fracturing hole 27, and the high-pressure water is sprayed from the fracturing hole 27 in a high-pressure state, to achieve the effect of hydraulic fracturing; that is, the device can realize the integrated operation of drilling, sealing and fracturing, and greatly improves the construction efficiency.

[0058] The above only describes the preferred embodiments of the present application, and is not used to limit the present application, and the present application can have various changes and variations for those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A hydraulic fracturing device integrating drilling, sealing, and pressure for directional drilling rigs, characterized in that, The device includes a high-low pressure switching mechanism and a sealing fracturing mechanism. The high-low pressure switching mechanism is located in front of the sealing fracturing mechanism and is used to maintain the passage state when low-pressure water enters the inlet. When high-pressure water enters the inlet, it switches to a plugging state and introduces the high-pressure water into the sealing fracturing mechanism; The high-low voltage switching mechanism includes: The front rod body has a liquid outlet at its front end for connecting to the drill bit; the center of the front rod body also has a flow channel. The fixed core and the piston core are both located in the flow channel of the front rod body, and the piston core is located behind the fixed core; and a first spring is provided between the fixed core and the piston core. The fixed core is provided with a first channel, and the cross-sectional dimension of the first channel remains consistent along the axial direction; the piston core is provided with a second channel, and the cross-sectional dimension at the inlet of the second channel is smaller than the cross-sectional dimension at the outlet; and the first channel and the second channel are staggered from each other along the axial direction. When low-pressure water enters the piston core, the piston core remains stationary. At this time, there is a gap between the piston core and the fixed core, and the first channel and the second channel remain connected. When high-pressure water enters the piston core, the piston core compresses the first spring and moves toward the fixed core. At this time, the front end face of the piston core presses against the rear end face of the fixed core, and the first channel and the second channel are disconnected from each other.

2. The integrated hydraulic fracturing device for directional drilling rigs according to claim 1, characterized in that, The inner cavity of the flow channel in the front rod body is frustoconical, and the outer peripheral surfaces of the fixed core and the piston core are both frustoconical.

3. The integrated hydraulic fracturing device for directional drilling rigs according to claim 2, characterized in that, The piston core has a clearance groove on its front end face and / or the fixed core's rear end face, and the first spring is located in the clearance groove between the piston core and the fixed core.

4. The integrated hydraulic fracturing device for directional drilling rigs according to claim 2, characterized in that, The sealing and fracturing mechanism includes a rear rod body, the rear end of which is a liquid inlet for connecting to a hollow drill pipe; and a hollow channel is provided in the center of the rear rod body.

5. The integrated hydraulic fracturing device for directional drilling rigs according to claim 4, characterized in that, The front end of the rear rod is provided with an external threaded shaft, and the rear end of the front rod is provided with an internal threaded hole, so that the external threaded shaft of the rear rod is threadedly connected to the internal threaded hole of the front rod.

6. The integrated hydraulic fracturing device for directional drilling rigs according to claim 4, characterized in that, The front end of the rear rod is provided with a piston chamber, the front end of the piston core moves guided in the piston chamber, and the peripheral surface of the front end of the piston core is in sealed contact with the inner peripheral surface of the piston chamber. The front end of the rear rod is also provided with multiple radial holes, and the inner side of each radial hole is connected to the piston chamber. When low-pressure water is introduced into the device, the front end face of the piston core is located behind the radial hole; when high-pressure water is introduced into the device, the front end face of the piston core is located in front of the radial hole.

7. The integrated hydraulic fracturing device for directional drilling rigs according to claim 6, characterized in that, The rear rod body is also provided with multiple axial main holes, the axis of which is parallel to the axial direction of the device, and each radial hole is connected to an axial main hole.

8. The integrated hydraulic fracturing device for directional drilling rigs according to claim 7, characterized in that, The rear rod body is also fitted with a front sealing sleeve and a rear sealing sleeve. The front sealing sleeve is fitted on the front part of the rear rod body, and the rear sealing sleeve is fitted on the rear part of the rear rod body. Furthermore, both the front sealing sleeve and the rear sealing sleeve are interconnected with the axial main hole.

9. The integrated hydraulic fracturing device for directional drilling rigs according to claim 8, characterized in that, The rear rod body is also uniformly provided with a plurality of axial secondary holes, the axis of which is parallel to the axial direction of the device; Multiple connecting holes are evenly arranged on the rear end face of the rear rod, and each connecting hole is connected between an axial main hole and an axial secondary hole; The rear rod body is also evenly provided with a plurality of fracturing holes, which are perpendicular to the axial direction of the device and are located between the front sealing sleeve and the rear sealing sleeve. The front end of the axial secondary hole extends between the front sealing sleeve and the rear sealing sleeve. One end of the fracturing hole is connected to the front end of the axial secondary hole, and the other end penetrates the outer circumferential surface of the rear rod body. A second spring and a push plate are also provided at the front end of the axial secondary hole. The push plate moves in the axial secondary hole, and the second spring is connected between the push plate and the bottom of the front end of the axial secondary hole.

10. The integrated hydraulic fracturing device for directional drilling rigs according to claim 9, characterized in that, The rear end of the rear rod is connected to a plug, which is used to seal the rear end face of the rear rod.

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