A hydraulic fracturing ground stress test device with a pressure relief control switch

Abstract

The present invention discloses a hydraulic fracturing ground stress test device with a pressurization and pressure relief control switch, comprising a piston assembly, a valve body, and a rubber plug. The valve body has two fluid pipelines, which are used to pressurize and relieve the pressure of the rubber plug and pressurize the fracturing section respectively. The two fluid pipelines are separated by four sealing ring grooves in the valve body. The piston connected to the clamping reducer stays at different positions of the valve body, and the two fluid channels can be pressurized and relieved respectively, so as to realize the functions of first filling the rubber plug with liquid and pressurizing it, stopping the liquid and maintaining the pressure; then pressurizing the fracturing section; and finally relieving the pressure of the rubber plug.

Description

Technical Field

[0001] The present invention belongs to the field of hydraulic fracturing geostress measurement, and specifically relates to a hydraulic fracturing geostress test device with a pressurization and pressure relief control switch. The hydraulic fracturing geostress test in a dry borehole is realized by the device, especially solving the pressure conversion and pressurization and pressure relief problems in the measurement process. Background Art

[0002] Geostress is a natural stress existing in the strata. It is the fundamental force that causes deformation and destruction of underground powerhouses and other underground projects. Therefore, the magnitude and direction of geostress directly affect the stability of the surrounding rock of underground projects. Measuring the initial stress of underground projects and studying the stress distribution characteristics of surrounding rocks are necessary prerequisites for conducting stability analysis of surrounding rocks of underground projects and realizing scientific excavation design of underground projects. Hydraulic fracturing is the most widely used and common method for measuring geostress.

[0003] There are two liquid pressurization methods for measuring geostress by hydraulic fracturing: single-channel and double-channel. The single-channel method has simple equipment and is easy to install and disassemble. In single-channel testing, the pressurization equipment is set at the wellhead surface. In the rock borehole, when the equipment is lowered to the predetermined test depth, the rubber isolation plug is first pressurized through the drill pipe, and the upper and lower rubber plugs expand at the same time. The borehole rock body isolated by these two expanded rubber plugs is the test section; the piston system is lowered, the fluid channel is switched to the test section, and liquid is pumped into the test section to pressurize (at this time, the upper and lower rubber isolation plugs are still in the expansion and pressure-maintaining state) until the borehole rock body of the isolation section is broken, and the pressure change curve of the liquid pumped in during the test is recorded, and the geostress size is calculated according to the characteristic value, which completes a test; then the drill pipe and control valve are lifted to remove the pressure in the isolation plug, so that it can return to its original state under its own elastic state, and the next test is carried out.

[0004] like Figure 1As shown, it is a conventional hydraulic fracturing method ground stress test device, including a piston assembly, a valve body, and a rubber plug. The piston assembly includes a stopper 12 and a piston 14 connected to a drill pipe in sequence. A hollow cavity is provided on the valve body 15. An expansion water delivery channel 15-5, a fracturing water delivery channel 15-4, a pressure relief hole 15-2 and a sealing ring groove 15-1 are provided in the valve body 15 from top to bottom. A limiting sleeve 13 is connected to the top of the valve body 15, and has a through space therein, which can limit the up and down movement of the stopper 12, the piston 4 and the drill pipe. The stopper 12 is connected to the drill pipe at the top and to the active ring at the bottom. The piston 4 is connected with the stopper 14, and the stopper is provided with a water passage; a water delivery channel 14-1 connected with the upper stopper 12 is provided in the piston 4, and water delivery holes 14-2 evenly arranged and connected to the water delivery channel 14-1 are provided below the water delivery channel 14-1. The piston 14 is inserted into the valve body 15 and can stay at different positions in the valve body 15. Different positions of the piston correspond to different valve body fluid channels 15-4, 15-5 and pressure relief holes 15-2. Four sealing ring grooves 15-1 are provided on the valve body 15. Sealing rings and polytetrafluoroethylene pads are installed in the grooves to seal and separate various fluid channels together with the piston 14. The piston 14 is located at the upper position, the first and second sealing rings play a sealing role, the piston water delivery hole 14-2 corresponds to the expansion water delivery channel 15-5 in the valve body, and the fluid enters the inner cavity of the rubber isolation plug 17 below the valve body through the expansion water delivery channel 15-5; the piston is pulled up from the bottom to the middle position, the second and third sealing rings play a sealing role, the piston water delivery hole 14-5 is connected to the pressure relief hole 15-5 on the valve body, and the fluid in the drill pipe is discharged through the pressure relief hole 15-5; the piston is located at the lower position, the third and fourth sealing rings play a sealing role, the piston water delivery hole 14-2 is connected to the fracturing water delivery channel 15-4 in the valve body, the fluid enters the fracturing steel pipe 18 through the fracturing water delivery channel 15-4, and enters the test section between the upper and lower rubber isolation plugs 7 through the fracturing hole to fractur the rock mass in the borehole. The lower end of the valve body 15 is provided with an exhaust hole 15-6, which is connected to the outside world to eliminate the reaction force generated by gas compression when the piston moves in the valve body.

[0005] However, the above structure has the following problems: when the fluid channel is switched to the test section, the drill rod connecting the pressurizing device and the rubber plug is full of water and in a high-pressure state. The sealing ring is prone to fatigue and damage after the high-pressure water flow ejected from the piston water hole passes through it multiple times, thereby reducing the sealing performance, reducing the pressure on the rubber plug, and causing the test section of the borehole rock to be unsealed, resulting in test failure.

[0006] When there is no water or the water level is low in the borehole, the drill pipe connecting the pressure device and the isolation plug is full of water. At this time, there is no external water pressure on the outside of the rubber plug. Especially when the test section is deep, the rubber plug cannot return to its original state due to the pressure of the water column in the drill pipe above. It is in an expanded state and sticks to the hole wall, causing drill jamming and being unable to move up and down, resulting in experiment failure. Summary of the invention

[0007] The technical problem to be solved by the present invention is to provide a hydraulic fracturing ground stress test device with a pressurization and pressure relief control switch, which relies on a single-channel method to realize the function of pressurizing and relieving pressure on the plug and the test section respectively by using a drill pipe.

[0008] In order to solve the above technical problems, the technical solution adopted by the present invention is: a hydraulic fracturing ground stress test device with a pressurized pressure relief control switch, including a piston assembly, a valve body, and a rubber plug. The piston assembly includes a positioning reducer and a piston connected in sequence. The valve body is provided with a hollow cavity, and the valve body is provided with an expansion water supply channel, a fracturing water supply channel and 4 sealing ring grooves from top to bottom. The limiting sleeve is connected to the top of the valve body and has a through space inside, which can limit the up and down movement of the positioning reducer, the piston and the drill pipe. The positioning reducer is connected to the drill pipe at the top and the piston at the bottom. The positioning reducer is provided with a water flow passage. Channel; a water delivery channel connected to the upper clamping position reducer is provided in the piston, and water delivery holes in the horizontal direction connected to the water delivery channel are arranged evenly below the water delivery channel. The piston is inserted into the valve body and can stay in different positions in the valve body. Sealing rings are installed in the 4 sealing ring grooves, which are sealed together with the piston to form an upper position where the first and second sealing rings play a sealing role, a middle position where the second and third sealing rings play a sealing role, and a lower position where the third and fourth sealing rings play a sealing role. Upper and lower water inlets are provided on the upper part of the expansion water delivery channel, and a water inlet check valve is provided on the upper water inlet, and a pressure relief check valve is provided on the lower water inlet. In the initial state, the water inlet check valve corresponds to the upper position, the pressure relief check valve corresponds to the middle position, and a bypass drain port with a drain check valve is provided at the lower part of the expansion water delivery channel; a connecting rod is provided at the bottom of the piston, and a slot is provided on one side of the connecting rod facing the expansion water delivery channel, and a switch paddle protruding horizontally from the side wall of the connecting rod that can only be flipped upward by a torsion spring is installed in the slot, and an installation slot is provided at the lower part of the valve body side opposite to the switch paddle, and springs A and spring B are installed at the top and bottom of the installation slot respectively, and a push-pull plate that can move up and down is installed between the two springs, and a push-pull plate facing the valve body cavity direction is installed. The plate is provided with two upper and lower wedge-shaped grooves, the push-pull bolt A is horizontally arranged in the upper groove, the push-pull bolt B is horizontally arranged in the lower groove, a side plate with two small holes is arranged on the installation groove, the push-pull bolt A with a spring installed and the push-pull bolt B with a spring installed respectively pass through the small holes on the side plate and cooperate with the wedge-shaped grooves, and can only move horizontally under the action of the external force of the switch paddle, when the push-pull bolt moves horizontally, the push-pull plate moves up and down under the action of the wedge-shaped groove, the tail of the lower push-pull bolt B is provided with a lever, the lever passes through the push-pull plate and extends to the drainage one-way valve in the valve body, and the drainage one-way valve can be opened or closed when the lever moves horizontally.

[0009] The distance from the upper end of the piston to the lower end of the drill pipe is equal to the sum of the thickness of the upper end of the limiting sleeve and the height difference from the water inlet check valve to the water inlet of the fracturing water delivery channel.

[0010] The distance from the lower end of the piston to the upper end of the push-pull bolt A is greater than the height difference from the water inlet check valve to the water inlet of the fracturing water delivery channel.

[0011] The distance from the lower end of the connecting rod to the lower end of the hollow cavity is greater than the height difference from the water inlet check valve to the water inlet of the fracturing water delivery channel.

[0012] The center distance between the push-pull bolt A and the push-pull bolt B is smaller than the height difference between the water inlet check valve and the water inlet of the fracturing water delivery channel.

[0013] The beneficial effects of the present invention are: it overcomes the technical defects of the existing equipment, realizes the pressurization and depressurization of the rubber plug and the test section by relying on the lifting and falling of the device itself. The equipment is simple to operate and easy to control, the sealing ring is well preserved, and the success rate of the test is significantly improved; the test can also be stably carried out in dry holes or low-water-level boreholes. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 The present invention is a schematic diagram of the connection structure of a hydraulic fracturing ground stress test device in the prior art.

[0015] Figure 2 It is a schematic diagram of the connection structure of the hydraulic fracturing ground stress test device with a pressurization and pressure relief control switch of the present invention.

[0016] Figure 3 Schematic diagram of the switch paddle connection.

[0017] Figure 4 Schematic diagram of the push-pull switch structure.

[0018] Figure 5 Figure 1 is a diagram of a first process used for the test apparatus of the present invention.

[0019] Figure 6 A second process diagram for use with the test apparatus of the present invention.

[0020] In the figure, 0-1 ground, 0-2 borehole wall, 1-1 drill pipe, 1-2 clamping reducer, 1-3 water pipeline, 1-4 water hole, 1-5 piston, 1-6 connecting rod, 1-7 switch paddle, 1-8 torsion spring, 2-1 limit sleeve, 2-2 sealing ring, 2-3 valve body, 2-4 exhaust hole, 3-1 water inlet check valve, 3-2 pressure relief check valve, 3-3 drainage check valve, 3-4 expansion water check valve, 3-5 fracturing water channel, 3-6 drain port, 3-7 rubber plug connecting channel, 4-1 spring A, 4-2 spring B, 4-3 push-pull plug A, 4-4 push-pull plug B, 4-5 push-pull plate, 5-1 upper rubber plug, 5-2 lower rubber plug, 5-3 fracturing steel pipe, 5-4 fracturing hole, 5-5 plugger. DETAILED DESCRIPTION

[0021] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention; it is obvious that the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments, and all other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making creative work are within the scope of protection of the present invention.

[0022] In the description of the present invention, it should be noted that the terms "upper", "lower", "inner", "outer", "top / bottom" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific position, be constructed and operated in a specific position, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance.

[0023] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "provided with", "mounted / connected", "connected", etc. should be understood in a broad sense. For example, "connected" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0024] One-way valves are set at the upper and middle positions of the valve body and connected to the expansion water channel. By reducing the water pressure in the water channel, the low-pressure water ejected during the up and down movement of the piston can reduce the abnormal pressure relief caused by the damage of the sealing ring. A one-way valve is set in the expansion water channel, and a corresponding push-pull plate device is designed to control the opening and closing function of the one-way valve, thereby completing the water retention and drainage work of the expansion water channel.

[0025] like Figure 2As shown, the hydraulic fracturing ground stress test device with a pressurized pressure relief control switch of the present invention comprises a piston assembly, a valve body, and a rubber plug. The piston assembly comprises a stopper 1-2 and a piston 1-5 connected in sequence. The valve body 2-3 is provided with a hollow cavity. The valve body 2-3 is provided with an expansion water delivery channel 3-4, a fracturing water delivery channel 3-5 and four sealing ring grooves 2-2 from top to bottom. The limiting sleeve 2-1 is connected to the top of the valve body 2-3 and has a through space therein, which can limit the up and down movement of the stopper 1-2, the piston 1-5 and the drill rod 1-1. The stopper 1-2 is connected to the drill rod 1-1 at the top and to the piston 1-5 at the bottom. The stopper 1-2 is provided with a water passage; the piston 1-5 A water delivery channel 1-3 connected to the upper clamping position reducer is arranged inside, and water delivery holes 1-4 connected to the water delivery channel 1-3 are arranged evenly in the horizontal direction below the water delivery channel 1-3. The piston 1-5 is inserted into the valve body 2-3 and can stay at different positions in the valve body. Sealing rings are installed in the four sealing ring grooves 2-2, which are sealed together with the piston 1-5 to form an upper position where the first and second sealing rings play a sealing role, a middle position where the second and third sealing rings play a sealing role, and a lower position where the third and fourth sealing rings play a sealing role. An upper and lower water inlet is arranged on the upper part of the expansion water delivery channel 3-4. The upper water inlet is provided with a water inlet check valve 3-1, and the lower water inlet is provided with a pressure relief check valve 3-2. In the initial state, the water inlet check valve 3 -1 corresponds to the upper station, the pressure relief one-way valve 3-2 corresponds to the middle station, and a bypass drain port 3-6 with a drain one-way valve 3-3 is provided at the lower part of the expansion water supply channel 3-4; a connecting rod 1-6 is provided at the bottom of the piston 1-5, and a groove is provided on one side of the connecting rod 1-6 facing the expansion water supply channel 3-4, and a switch paddle 1-7 protruding horizontally from the side wall of the connecting rod 1-6 that can only be turned upward by a torsion spring 1-8 is installed in the groove, and an installation groove is provided at the lower part of one side of the valve body 2-3 opposite to the switch paddle 1-7, and a spring A4-1 and a spring B4-2 are installed at the top and bottom of the installation groove respectively, and a push-pull plate 4-5 that can move up and down is installed between the two springs, facing the inner cavity direction of the valve body 2-3 The push-pull plate 4-5 is provided with two upper and lower wedge-shaped grooves, the push-pull bolt A4-3 is horizontally arranged in the upper groove, the push-pull bolt B4-4 is horizontally arranged in the lower groove, and a side plate with two small holes is arranged on the installation groove. The push-pull bolt A4-3 installed with a spring and the push-pull bolt B4-4 installed with a spring respectively pass through the small holes on the side plate and cooperate with the wedge-shaped grooves. Under the action of the external force of the switch paddle 1-7, they can only move horizontally. When the push-pull bolt moves horizontally, the push-pull plate 4-5 moves up and down under the action of the wedge-shaped groove. The tail of the lower push-pull bolt B4-4 is provided with a lever, which passes through the push-pull plate 4-5 and extends to the drainage check valve 3-3 in the valve body 2-3. When the lever moves horizontally, the drainage check valve 3-3 can be opened or closed.

[0026] The distance from the upper end of the piston 1-5 to the lower end of the drill pipe 1-1 is equal to the sum of the thickness of the upper end of the limiting sleeve 2-1 and the height difference from the water inlet check valve 3-1 to the water inlet of the fracturing water delivery channel 3-5.

[0027] The distance from the lower end of the piston 1-5 to the upper end of the push-pull bolt A4-3 is greater than the height difference from the water inlet check valve 3-1 to the water inlet of the fracturing water delivery channel 3-5.

[0028] The distance from the lower end of the connecting rod 1-6 to the lower end of the hollow cavity is greater than the height difference from the water inlet check valve 3-1 to the water inlet of the fracturing water delivery channel 3-5.

[0029] The center distance between the push-pull bolt A4-3 and the push-pull bolt B4-4 is smaller than the height difference between the water inlet check valve 3-1 and the water inlet of the fracturing water delivery channel 3-5.

[0030] like Figure 5 , 6 As shown, when piston 1-5 is in the upper position ( Figure 5 -A), at this time, the high-pressure fluid pumped out by the high-pressure pump of the ground pressurizing device enters the water delivery channel of the piston 1-5 through the drill pipe 1-1 and the inner hole of the clamping reducer 1-2. The pressure on the left side of the water inlet check valve 3-1 is greater than that on the right side. The high-pressure fluid passes through the expansion water delivery channel 3-4 from the water inlet check valve 3-1 to pressurize the upper rubber plug 5-1 and the lower rubber plug 5-2. The isolation plug is pressurized and expanded, and the borehole of the rock test section is completely closed. The high-pressure pump of the ground pressurizing device stops pressurizing, the water inlet check valve 3-1 is closed, and the upper rubber plug 5-1 and the lower rubber plug 5-2 are in an expansion and pressure-maintaining state.

[0031] When piston 1-5 moves down ( Figure 5 -B), the switch paddle 1-7 rotates counterclockwise without triggering the push-pull bolt A4-3.

[0032] Piston 1-5 continues to move down ( Figure 5 -C), the switch paddle 1-7 rotates counterclockwise without triggering the push-pull bolt B4-4.

[0033] When piston 1-5 moves down to the lower position ( Figure 5 -D), the switch paddle 1-7 returns to its natural state. At this time, the high-pressure fluid pumped out by the high-pressure pump of the ground pressurization device enters the water delivery channel of the piston 1-5 through the drill pipe 1-1 and the inner hole of the clamping reducer 1-2, and enters the fracturing steel pipe 5-3 from the water delivery hole 1-4 through the fracturing water delivery channel 3-5. The high-pressure fluid enters the rock test section through the fracturing hole 5-4, completing the high-pressure fracturing test of the test section.

[0034] After the fracturing test is completed, piston 1-5 moves up ( Figure 6-A), the switch paddle 1-7 triggers the push-pull bolt B 4-4 to move horizontally to the right, and the push-pull plate 4-5 moves upward. At the same time, the spring A 4-1 contracts, the spring B 4-2 stretches, the drainage check valve 3-3 opens, and the high-pressure water in the upper rubber plug 5-1 and the lower rubber plug 5-2 is discharged from the drainage port 3-6 through the drainage check valve 3-3.

[0035] When piston 1-5 continues to move up to the middle position ( Figure 6 -B), push-pull bolt B4-4 continues to move right, push-pull plate 4-5 moves upward to the limit height, moves downward, and the buckle of push-pull bolt B4-4 is stuck in the slot of push-pull plate 4-5, spring A4-1 and spring B4-2 return to the natural state, drainage check valve 3-3 is further opened, and the high-pressure water in the rubber plug continues to be discharged from the drainage port 3-6 through the drainage check valve 3-3, and the pressure in the rubber plug decreases accordingly. Piston 1-5 remains in the middle position for a period of time. When there is no water in the borehole or the water level is low, the pressure in the drill pipe 1-1 is greater than the pressure of the rubber plug, and the pressure difference is greater than the opening pressure of the pressure relief check valve 3-2, the pressure relief check valve 3-2 opens, and the high-pressure fluid in the drill pipe 1-1 is discharged from the pressure relief check valve 3-2 through the expansion water pipeline, and finally from the drainage port 3-6. The internal pressure of the drill pipe 1-1 continues to decrease until the difference between the internal pressure of the drill pipe 1-1 and the pressure of the rubber plug is no greater than the opening pressure of the pressure relief check valve 3-2, and the pressure relief check valve 3-2 is closed.

[0036] When the piston 1-5 continues to move upward to the switch paddle 1-7, the push-pull bolt A4-3 is triggered ( Figure 6 -C), the push-pull bolt A4-3 moves horizontally to the right, the spring A4-1 is compressed, and the spring B4-2 is stretched, until the push-pull plate 4-5 moves up to the limit height, the push-pull bolt B4-4 pops out to the left, and the drainage check valve 3-3 is closed.

[0037] When piston 1-5 moves up to the upper position ( Figure 6 -D), the push-pull bolt A4-3 pops out horizontally to the left, the push-pull plate 4-5 moves down, the spring A4-1 and the spring B4-2 return to their original state, and the entire equipment returns to its initial state.

[0038] Finally, lift up or lower the drill rod to continue testing other depth rock test sections.

[0039] The embodiments described above are only used to illustrate the technical ideas and features of the present invention, and their purpose is to enable those skilled in the art to understand the contents of the present invention and implement them accordingly. The scope of the invention cannot be limited by the embodiments alone, that is, any equivalent changes or modifications made to the spirit disclosed by the present invention still fall within the scope of the invention.

Claims

1. A hydraulic fracturing ground stress test device with a pressure relief control switch, comprising a piston assembly, a valve body, and a rubber plug, wherein the piston assembly comprises a stopper (1-2) and a piston (1-5) connected in sequence, a hollow cavity is provided on the valve body (2-3), an expansion water delivery channel (3-4), a fracturing water delivery channel (3-5) and four sealing ring grooves (2-2) are provided in the valve body (2-3) from top to bottom, a limit sleeve (2-1) is connected to the upper part of the valve body (2-3), and has a through space therein, which can limit the up and down movement of the stopper (1-2), the piston (1-5) and the drill pipe (1-1), and the upper part of the stopper (1-2) is connected to the drill pipe (1-1) , connected with the piston (1-5) at the bottom, the clamping reducer (1-2) is provided with a water passage; a water delivery channel (1-3) connected with the clamping reducer at the top is provided in the piston (1-5), and water delivery holes (1-4) connected with the water delivery channel (1-3) are arranged evenly in the horizontal direction below the water delivery channel (1-3); the piston (1-5) is inserted into the valve body (2-3) and can stay at different positions in the valve body; sealing rings are installed in the four sealing ring grooves (2-2) and are sealed together with the piston (1-5) to form an upper station where the first and second sealing rings play a sealing role, a middle station where the second and third sealing rings play a sealing role, and a lower station where the third and fourth sealing rings play a sealing role, characterized in that The upper part of the expansion water supply channel (3-4) is provided with two upper and lower water inlets, the upper water inlet is provided with a water inlet check valve (3-1), and the lower water inlet is provided with a pressure relief check valve (3-2). In the initial state, the water inlet check valve (3-1) corresponds to the upper working position, and the pressure relief check valve (3-2) corresponds to the middle working position. The lower part of the expansion water supply channel (3-4) is provided with a bypass drain port (3-6) with a drain check valve (3-3); the bottom of the piston (1-5) is provided with a connecting rod (1-6), and the connecting rod (1-6) facing the direction of the expansion water supply channel (3-4) is provided with a connecting rod (1-6). A slot is provided on one side of the connecting rod (1-6), and a switch paddle (1-7) is installed in the slot, which protrudes horizontally from the side wall of the connecting rod (1-6) and can only be turned upward by a torsion spring (1-8). A mounting slot is provided at the lower part of the valve body (2-3) opposite to the switch paddle (1-7), and a spring A (4-1) and a spring B (4-2) are installed at the top and bottom of the mounting slot respectively. A push-pull plate (4-5) that can move up and down is installed between the two springs, and two upper and lower wedge-shaped grooves are provided on the push-pull plate (4-5) facing the inner cavity of the valve body (2-3). The push-pull bolt A (4-3) is horizontally arranged in the upper groove, and the push-pull bolt B (4-4) is horizontally arranged in the lower groove. A side plate with two small holes is arranged on the installation groove. The push-pull bolt A (4-3) for installing the spring and the push-pull bolt B (4-4) for installing the spring respectively pass through the small holes on the side plate and cooperate with the wedge-shaped groove. Under the external force of the switch paddle (1-7), they can only move horizontally. When the push-pull bolt moves horizontally, the push-pull plate (4-5) moves up and down under the action of the wedge-shaped groove. The tail of the lower push-pull bolt B (4-4) is provided with a lever, and the lever passes through the small holes on the side plate. The water discharge one-way valve (3-3) is extended to the valve body (2-3) through the push-pull plate (4-5), and the water discharge one-way valve (3-3) can be opened or closed when the lever moves horizontally; the distance between the upper end of the piston (1-5) and the lower end of the drill pipe (1-1) is equal to the sum of the thickness of the upper end of the limit sleeve (2-1) and the height difference between the water inlet one-way valve (3-1) and the water inlet of the fracturing water delivery channel (3-5); the distance between the lower end of the piston (1-5) and the upper end of the push-pull bolt A (4-3) is greater than the height difference between the water inlet one-way valve (3-1) and the water inlet of the fracturing water delivery channel (3-5).

2. The hydraulic fracturing ground stress test device with a pressure relief control switch according to claim 1 is characterized in that: The distance between the lower end of the connecting rod (1-6) and the lower end of the hollow cavity is greater than the height difference between the water inlet check valve (3-1) and the water inlet of the fracturing water delivery channel (3-5).

3. The hydraulic fracturing ground stress test device with a pressure relief control switch according to claim 1 is characterized in that: The center distance between the push-pull bolt A (4-3) and the push-pull bolt B (4-4) is smaller than the height difference between the water inlet check valve (3-1) and the water inlet of the fracturing water delivery channel (3-5).

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