Device and method for simulating deep water pressure wave generation and water-rock interface propagation effect

Abstract

The application discloses a device and method for simulating deep water pressure wave generation and water-rock interface propagation effect, wherein the device comprises: a gas source device for providing different pressure gases; a stress pulse excitation device for exciting multi-wave dynamic stress waves; a water pressure wave excitation and fluid-solid coupling device for exciting and transmitting water pressure waves, realizing water pressure wave propagation and effect under high stress of a water-rock interface; an initial water pressure loading device for storing fluid media and providing initial pressure for the water pressure wave excitation and fluid-solid coupling device; and a monitoring device for monitoring parameter states in the process of water pressure wave generation and water-rock interface propagation effect. The application can simulate different water pressure waves in a deep rock propagation environment, and can study water pressure wave energy transmission, effect and attenuation characteristics under fluid-solid coupling.

Description

Device and Method for Simulating the Generation and Propagation of Deep Hydrodynamic Pressure Waves at the Water-Rock Interface Technical Field

[0001] This invention relates to the field of deep rock mechanics and multi-field coupling testing technology, and in particular to a device and method for simulating the generation of deep dynamic water pressure waves and the propagation of water-rock interfaces. Background Technology

[0002] As mining operations extend deeper, rock masses under high stress contain substantial elastic deformation energy. These masses are highly susceptible to rock bursts and rockbursts under the influence of blasting and other disturbances, severely impacting operational safety in rock engineering. Therefore, there is an urgent need to explore non-blasting rock-breaking methods that overcome the drawbacks of traditional drill-and-blast methods. Hydraulic technology, as a non-blasting rock-breaking method, has been widely used in the oil and gas sector and is increasingly being applied in deep hard rock mining and other areas.

[0003] In recent years, researchers in rock mechanics, mining engineering, and related fields have conducted extensive research on hydraulic fracturing technology in deep hard rock mines. The technology has gradually evolved from static hydraulic fracturing to dynamic hydraulic fracturing, and has been tested in various applications, including circulating hydraulic fracturing, pulsed hydraulic fracturing, and blasting hydraulic fracturing. However, research on the mechanisms of how dynamic water pressure propagates along water channels in deep, high-stress rock masses, the interaction between water and rock, and energy attenuation still lags behind practical application.

[0004] Currently, there is a lack of testing devices for the generation of deep hydrodynamic pressure waves and the propagation of water-rock interfaces. For example: (1) Most pulse hydraulic fracturing devices can only achieve small pulse pressures and have simple pulse waveforms. Patent application CN111980879A discloses a high-pressure pulse fluid output device and a rock hydraulic fracturing method, but the device structure is still difficult to meet the output conditions of transient ultra-high water pressure of over 100MPa in the microsecond to millisecond range, such as hydraulic blasting; (2) Existing devices are mostly focused on testing and researching the effects of output parameters such as pumping pressure frequency, rate and flow rate, and it is still difficult to reproduce the complete process of hydrodynamic pressure wave excitation, propagation and fluid-structure interaction at the water-rock interface; (3) For testing the propagation effect of hydrodynamic pressure waves, existing impact loading devices can only simulate fluid-structure interaction conditions and it is still difficult to realize waveform analysis of the propagation process of hydrodynamic pressure waves and real-time monitoring of the effects in multiphase media.

[0005] Therefore, research is urgently needed on the mechanism of transient water pressure propagation along the water passage, water-rock interface interaction, and energy attenuation during dynamic hydraulic fracturing of deep high-stress rock masses in the microsecond to millisecond range. This requires the development of devices and methods for generating dynamic water pressure waves and understanding the water-rock interface interaction. Summary of the Invention

[0006] To address the shortcomings of the existing technology, this invention provides a device and method for simulating the generation of deep hydrodynamic pressure waves and the propagation of water-rock interfaces. This device and method can simulate the high-stress, high-water-pressure fluid-structure interaction environment of deep rock masses, enabling the study of the propagation of transient hydrodynamic pressure waves along water passages, the effects of water-rock interfaces, and energy attenuation characteristics.

[0007] Firstly, a device is provided to simulate the generation of deep hydrodynamic pressure waves and the propagation effect at the water-rock interface, comprising:

[0008] Gas supply device, used to provide gas at different pressures;

[0009] A stress pulse excitation device, one end of which is connected to the gas source device, is used to excite dynamic stress waves;

[0010] A device for exciting and fluid-structure interaction of dynamic water pressure waves is coaxially disposed at the other end of the stress pulse excitation device. It is used to excite and transmit dynamic water pressure waves to realize the propagation and action of dynamic water pressure waves under high stress at the water-rock interface.

[0011] An initial water pressure loading device is connected to the dynamic water pressure wave excitation and fluid-structure interaction device, and is used to store fluid medium and provide initial pressure for the dynamic water pressure wave excitation and fluid-structure interaction device;

[0012] The monitoring device is connected to the device for excitation of dynamic water pressure waves and fluid-structure interaction, and is used to monitor the parameter status of the dynamic water pressure wave generation and water-rock interface propagation process.

[0013] Furthermore, the gas source device includes a high-pressure nitrogen cylinder, a pressure reducing valve, a pneumatic booster station, a pneumatic control valve, and an output control unit connected in sequence.

[0014] Furthermore, the stress pulse excitation device includes a high-pressure gas storage chamber, a transmitting tube, a punch, and a speed measuring device;

[0015] The high-pressure gas storage chamber is equipped with a high-pressure gas chamber and a pneumatic control opening and closing device; the launching tube is cylindrical, and its rear end is coaxially connected to the high-pressure gas chamber. The pneumatic control opening and closing device controls the communication state between the launching tube and the high-pressure gas chamber; the punch is coaxially arranged inside the launching tube, and the speed measuring device is arranged at the front end of the launching tube.

[0016] Furthermore, stress waves of different waveforms can be generated by using punches with different head profile shapes.

[0017] Furthermore, the device for excitation of dynamic water pressure waves and fluid-structure interaction includes an incident end reaction seat, a cylindrical reaction pad, a cylindrical incident rod, a cylindrical high-pressure water cylinder, a cylindrical rock core rod, a cylindrical transmission rod, a hydraulic loading cylinder, a cylinder reaction seat, and a reaction connecting rod. The cylindrical reaction pad, cylindrical incident rod, cylindrical high-pressure water cylinder, cylindrical rock core rod, cylindrical transmission rod, and hydraulic loading cylinder are sequentially and coaxially connected. The cylindrical reaction pad is embedded in the incident hole at the center of the incident end reaction seat, and the rear end of the hydraulic loading cylinder is embedded in the mounting groove at the center of the cylinder reaction seat. Reaction rod holes are provided on both sides of the incident end reaction seat and the cylinder reaction seat, and they are connected by the reaction connecting rod.

[0018] The effective length of the cylindrical high-pressure water cylinder is not less than twice the dominant wavelength of the dynamic water pressure wave. The effective length of the cylindrical incident rod and the length of the cylindrical core rod are both not less than twice the dominant wavelength of the stress wave. The inner diameter of the cylindrical high-pressure water cylinder is the same as the diameter of the cylindrical incident rod and the cylindrical core rod. The side wall of the cylindrical high-pressure water cylinder is equally divided into at least three sets of pressure sensors along the axial direction. The side wall of the cylindrical high-pressure water cylinder is also provided with an injection hole and an exhaust hole. The pressure sensors, the injection hole, and the exhaust hole are all connected to the inner cavity of the cylindrical high-pressure water cylinder. A high-pressure shut-off valve is also connected to the outside of the injection hole and the exhaust hole.

[0019] A force sensor is installed at the front end of the hydraulic loading cylinder, and the hydraulic loading cylinder is connected to a servo hydraulic station.

[0020] Furthermore, the cylindrical incident rod is coaxially inserted into one end of the cylindrical high-pressure water cylinder, and a sealing ring is provided at the connection; the cylindrical rock core rod is coaxially inserted into the other end of the cylindrical high-pressure water cylinder, and a sealing ring is provided at the connection.

[0021] Furthermore, the dynamic water pressure wave excitation and fluid-structure interaction device and the stress pulse excitation device are coaxially mounted on the support platform, and the cylindrical reaction pad of the dynamic water pressure wave excitation and fluid-structure interaction device is close to the emitting end of the stress pulse excitation device.

[0022] Furthermore, the initial water pressure loading device includes a water tank, a high-pressure horizontal flow pump, and a liquid shut-off valve. The water tank, the high-pressure horizontal flow pump, the liquid shut-off valve, and the high-pressure shut-off valve connected to the injection hole are connected in sequence through a high-pressure pipeline.

[0023] Furthermore, the monitoring device includes an ultra-dynamic signal acquisition instrument and an industrial control computer. At least three sets of strain gauges are evenly distributed along the axial direction on the surface of the cylindrical rock core rod, and one set of strain gauges is arranged along the axial direction on the surface of the cylindrical incident rod. Each set of strain gauges is electrically connected to the ultra-dynamic signal acquisition instrument, which is also electrically connected to the pressure sensor and the force sensor. The industrial control computer is electrically connected to the ultra-dynamic strain gauge.

[0024] Secondly, a method for simulating the generation of deep hydrodynamic pressure waves and the propagation of water-rock interfaces is provided, including the following steps:

[0025] Assemble the device for simulating the generation of deep hydrodynamic pressure waves and the propagation of water-rock interfaces as described above.

[0026] The initial water pressure loading device is used to provide initial pressure for the dynamic water pressure wave excitation and fluid-structure interaction device, thereby realizing the initial water pressure loading at the water-rock interface;

[0027] A device for excitation of dynamic water pressure waves and fluid-structure interaction was used to apply high static stress and hydrostatic pressure loading to the water-rock interface.

[0028] The dynamic stress wave is excited by the gas source device and the stress pulse excitation device and then applied to the dynamic water pressure wave excitation and fluid-structure interaction device, thereby exciting and transmitting the dynamic water pressure wave and realizing the propagation and action of the dynamic water pressure wave under high stress at the water-rock interface.

[0029] The monitoring device monitors the parameter status of the generation of dynamic water pressure waves and the propagation process of the water-rock interface.

[0030] This invention proposes a device and method for simulating the generation of deep hydrodynamic pressure waves and the propagation effect at the water-rock interface, which has the following advantages compared with the prior art:

[0031] 1. High pulse pressure, high pulse frequency, and simplified structure: It overcomes the shortcomings of existing fluid pulse generators, such as complex structure, high cost, limited high-frequency and high-pressure output capability, and slow response speed due to reliance on complex pump and valve systems. It utilizes a stress pulse excitation device and a gas source device to convert the internal energy of high-pressure gas into the kinetic energy of the punch. The transient high-peak stress wave generated by the transient impact of the punch on the cylindrical incident rod is transmitted to the liquid, directly converting the stress pulse in the solid into a dynamic water pressure wave in the liquid. Under the hydrostatic pressure and reaction force constraint provided by the initial water pressure loading device, the stress wave can excite high-pressure, high-frequency dynamic water pressure waves in the liquid, which can realize the dynamic water pressure output of microseconds to milliseconds and peak values ​​exceeding 100 MPa during dynamic hydraulic fracturing.

[0032] 2. Simulation of stress wave propagation and action at the water-rock fluid-structure interaction interface: This method overcomes the shortcomings of existing impact loading devices, which can only simulate fluid-structure interaction conditions and cannot detect the clear propagation process of dynamic hydraulic waves in the rock medium due to the superposition of dynamic hydraulic waves in the sample. The device for excitation of dynamic water pressure waves and fluid-structure interaction can simulate the physical scene of fluid propagation and action at the water-rock interface during pulsed hydraulic fracturing. By monitoring the parameter states of the generation of dynamic water pressure waves, their propagation at the water-rock interface, and their action on the distant rock mass, the mechanical action mechanism of dynamic water pressure waves at the water-rock interface can be analyzed, thus providing a theoretical basis for dynamic hydraulic fracturing.

[0033] 3. Controllable pulse waveform: It overcomes the shortcomings of existing fluid pulse generators in accurately controlling microsecond-level transient dynamic hydraulic waves of different waveforms. By adjusting the contour shape of the punch head of the stress pulse excitation device, the directional modulation of the stress wave waveform can be achieved. Attached Figure Description

[0034] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art 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.

[0035] Figure 1 is a schematic diagram of the device for simulating the generation of deep dynamic water pressure waves and the propagation of water-rock interface provided in an embodiment of the present invention.

[0036] Figure 2 is a front view of the device for simulating the generation of deep dynamic water pressure waves and the propagation of water-rock interface provided in an embodiment of the present invention.

[0037] Figure 3 is a top view of the device for simulating the generation of deep dynamic water pressure waves and the propagation of water-rock interface provided in an embodiment of the present invention.

[0038] Figure 4 is a main cross-sectional view of the device for simulating the generation of deep dynamic water pressure waves and the propagation of water-rock interface provided in an embodiment of the present invention. Detailed Implementation

[0039] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be described in detail below. Obviously, the described embodiments are merely some embodiments of this invention, and not all embodiments. Based on the embodiments of this invention, all other implementation methods obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0040] In the description of this invention, it should be understood that the terms "upper," "lower," "front," "rear," "left," "right," "top," "bottom," "inner," "outer," "center," "longitudinal," "lateral," "vertical," and "horizontal," etc., indicating orientation or positional relationships, are based on the orientation or positional relationships shown in the accompanying drawings and are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. When an element is referred to as being "fixed to" another element, it can be directly on the other element or there may be an intermediate element. When an element is considered to be "connected" to another element, it can be directly connected to the other element or there may be an intermediate element present. The terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or order. Furthermore, in the description of this invention, unless otherwise stated, "a plurality of" means at least two.

[0041] As shown in Figure 1, this embodiment of the invention provides a device for simulating the generation of deep hydrodynamic pressure waves and the propagation of water-rock interfaces, including a gas source device 1, a stress pulse excitation device 2, a hydrodynamic pressure wave excitation and fluid-structure interaction device 3, an initial water pressure loading device 4, a monitoring device 5, and a support platform 6.

[0042] Referring to Figures 1 and 2, the gas source device 1 includes a high-pressure nitrogen cylinder 101, a pressure reducing valve 102, a pneumatic booster station 103, a pneumatic control valve 104, and an output control unit 105 connected in sequence. The pressure reducing valve 102 and the pneumatic booster station 103 are connected by a high-pressure gas pipe 106. The gas source device is used to provide gases of different pressures. The working process is as follows: the high-pressure nitrogen cylinder 101 delivers nitrogen to the pneumatic booster station 103 via the pressure reducing valve 102 and the high-pressure gas pipe 106. The pneumatic booster station 103 pressurizes the gas to a set pressure, and the output control unit 105 controls the pneumatic control valve 104 to achieve high-pressure gas output control.

[0043] Referring to Figures 2 to 4, the stress pulse excitation device 2 includes a high-pressure gas storage chamber 201, a transmitting tube 204, a punch 205, and a velocity measuring device 206. The high-pressure gas storage chamber 201 is equipped with a high-pressure gas chamber 202 and a pneumatic control opening and closing device 203. The rear end of the transmitting tube 204 is coaxially connected to the high-pressure gas chamber 202, and the pneumatic control opening and closing device 203 controls the communication state between the transmitting tube 204 and the high-pressure gas chamber 202. The punch 205 is coaxially disposed inside the transmitting tube 204, and the velocity measuring device 206 is disposed at the front end of the transmitting tube 204. The high-pressure gas storage chamber 201 of the stress pulse excitation device 2 is connected to the gas source device 1 and is used to excite multi-waveform dynamic stress waves. The working process is as follows: Initially, the punch 205 is located in a predetermined position inside the launching tube 204 and close to one end of the high-pressure gas storage chamber 201. After the pneumatic control opening and closing device 203 controls the launching tube 204 to connect with the high-pressure gas chamber 202, the ejected high-pressure gas acts on the punch 205, causing the punch 205 to accelerate within the launching tube 204 to act on the dynamic water pressure wave excitation and fluid-structure interaction device 3, thereby exciting stress waves. The velocity measuring device 206 is used to measure the speed at which the punch 205 reaches the front end of the launching tube 204. Different waveforms of stress waves can be generated by using punches with different head contour shapes.

[0044] Referring to Figures 2 to 4, the dynamic water pressure wave excitation and fluid-structure interaction device 3 is coaxially arranged at the front end of the transmitting tube 204 of the stress pulse excitation device 2, and is used to excite and transmit dynamic water pressure waves to realize the propagation and action of dynamic water pressure waves under high stress at the water-rock interface. Specifically, the device 3 for dynamic water pressure wave excitation and fluid-structure interaction includes an incident end reaction seat 313, a cylindrical reaction pad 301, a cylindrical incident rod 302, a cylindrical high-pressure water cylinder 303, a cylindrical rock core rod 307, a cylindrical transmission rod 308, a hydraulic loading cylinder 309, a cylinder reaction seat 314, and a reaction connecting rod 315. The cylindrical reaction pad 301, cylindrical incident rod 302, cylindrical high-pressure water cylinder 303, cylindrical rock core rod 307, cylindrical transmission rod 308, and hydraulic loading cylinder 309 are sequentially coaxially connected, and the cylindrical reaction pad 301 is embedded in the incident hole in the center of the incident end reaction seat 313, and the rear end of the hydraulic loading cylinder 309 is embedded in the mounting groove in the center of the cylinder reaction seat 314. Reaction rod holes are provided on both sides of the incident end reaction seat 313 and the cylinder reaction seat 314, which are threaded together by the reaction connecting rod 315. The cylindrical incident rod 302, the cylindrical high-pressure water cylinder 303, the cylindrical rock core rod 307, the cylindrical transmission rod 308, and the hydraulic loading cylinder 309 are coaxial through a support mechanism set on the reaction force connecting rod 315.

[0045] More specifically, the effective length of the cylindrical high-pressure water cylinder 303 is not less than twice the dominant wavelength of the dynamic water pressure wave, the effective length of the cylindrical incident rod 302 is not less than twice the dominant wavelength of the stress wave, and the length of the cylindrical core rod 307 is not less than twice the dominant wavelength of the stress wave, to ensure that the dynamic water pressure wave and stress wave maintain a one-dimensional propagation state within their respective media during the effective loading time and to avoid end reflection interference; the inner diameter of the cylindrical high-pressure water cylinder 303 is the same as the diameter of the cylindrical incident rod 302, and the inner diameter of the cylindrical high-pressure water cylinder 303 is also the same as the diameter of the cylindrical core rod 307; the sidewall of the cylindrical high-pressure water cylinder 303 is equally divided along the axial direction with no less than three sets of pressure sensors. Device 306, the side wall of the cylindrical high-pressure water cylinder 303 is also provided with a liquid injection hole 304 and a vent hole 305, the pressure sensor 306, the liquid injection hole 304 and the vent hole 305 are all connected to the inner cavity of the cylindrical high-pressure water cylinder 303; a high-pressure shut-off valve 316 is also connected to the outside of the liquid injection hole 304 and the vent hole 305; the cylindrical injection rod 302 is coaxially inserted into one end of the cylindrical high-pressure water cylinder 303, and a sealing ring 312 is provided at the connection; the cylindrical rock core rod 307 is coaxially inserted into the other end of the cylindrical high-pressure water cylinder 303, and a sealing ring 312 is provided at the connection; a force sensor 310 is provided at the front end of the hydraulic loading cylinder 309, and the hydraulic loading cylinder 309 is connected to a servo hydraulic station 311.

[0046] Referring to Figures 1 and 4, the dynamic water pressure wave excitation and fluid-structure interaction device 3 and the stress pulse excitation device 2 are coaxially mounted on the support platform 6. The cylindrical reaction pad 301 of the dynamic water pressure wave excitation and fluid-structure interaction device 3 is close to the front end of the emission tube 204 of the stress pulse excitation device 2.

[0047] The initial water pressure loading device 4, connected to the dynamic water pressure wave excitation and fluid-structure interaction device 3, is used to store the fluid medium and provide initial pressure for the dynamic water pressure wave excitation and fluid-structure interaction device 3. Specifically, referring to Figures 1 and 2, the initial water pressure loading device 4 includes a water tank 402, a high-pressure horizontal flow pump 401, and a liquid shut-off valve 403. The water tank 402, the high-pressure horizontal flow pump 401, the liquid shut-off valve 403, and the high-pressure shut-off valve 316 connected to the injection hole 304 are connected in sequence through a high-pressure pipeline 404.

[0048] The monitoring device 5 is connected to the hydrodynamic pressure wave excitation and fluid-structure interaction device 3, and is used to monitor the parameter status of the hydrodynamic pressure wave generation and water-rock interface propagation process. Specifically, referring to Figures 1 and 2, the monitoring device 5 includes a hyperdynamic signal acquisition instrument 501 and an industrial control computer 502. At least three sets of strain gauges 503 are evenly distributed along the axial direction on the surface of the cylindrical rock core rod 307, and one set of strain gauges 503 is arranged along the axial direction on the surface of the cylindrical incident rod 302. The hyperdynamic signal acquisition instrument 501 is electrically connected to each set of strain gauges 503, and is also electrically connected to the pressure sensor 306 and the force sensor 310. The industrial control computer 502 is electrically connected to the hyperdynamic signal acquisition instrument 501.

[0049] Based on the device for simulating the generation of deep hydrodynamic pressure waves and the propagation of water-rock interfaces provided in the above embodiments, this invention also provides a method for simulating the generation of deep hydrodynamic pressure waves and the propagation of water-rock interfaces, comprising the following steps:

[0050] Step 1: Processing of columnar rock core rod 307. The deep rock sample is cut into a columnar rock core rod with a diameter of 50mm. The two ends of the columnar rock core rod are ground until the end face is parallel. At least three sets of strain gauges 503 are evenly spaced along the axial direction on the surface of the columnar rock core rod 307.

[0051] Step 2: Design and fabrication of cylindrical high-pressure water cylinder 303. The cylindrical high-pressure water cylinder 303 is designed with a length of 2000mm and an inner diameter of 50mm. It is a seamless cylindrical water cylinder made of 40Cr material and has a water pressure withstand limit of 300MPa. At least three sets of pressure sensors 306 can be installed at equal intervals along the axial direction on the side wall of the cylindrical high-pressure water cylinder 303. The side wall is also provided with a liquid injection hole 304 and a vent hole 305.

[0052] Step 3: Equipment pre-loading. Connect the cylindrical reaction pad 301, cylindrical incident rod 302, cylindrical high-pressure water cylinder 303, cylindrical rock core rod 307, cylindrical transmission rod 308, and hydraulic loading cylinder 309 in sequence. Insert the cylindrical incident rod 302 into the sealing ring 312 at one end of the cylindrical high-pressure water cylinder 303, and insert the cylindrical rock core rod 307 into the sealing ring 312 at the other end of the cylindrical high-pressure water cylinder 303. The cylindrical incident rod 302 is 2000mm long, has the same diameter as the cylindrical high-pressure water cylinder 303, and is cast from high-strength alloy steel. A set of strain gauges 503 are attached to the surface of the cylindrical incident rod 302 along the axial direction.

[0053] Step 4: Initial water pressure loading, water is injected into water tank 402 to the set value and then the injection stops; the injection hole 304 and vent hole 305 on the cylindrical high-pressure water cylinder 303 are opened, the high-pressure horizontal flow pump 401 is started, and after the gas in the cylindrical high-pressure water cylinder 303 is vented, the high-pressure shut-off valve 316 connected to the vent hole 305 is closed, and the high-pressure horizontal flow pump 401 continues to pressurize the liquid pressure in the cylinder to the initial pressure, and the liquid shut-off valve 403 connected to the injection hole is closed;

[0054] Step 5: High static stress and hydrostatic pressure loading, turn on the monitoring device ultra-dynamic signal acquisition instrument 501 and industrial control computer 502, and turn on the servo hydraulic station 311. Use the hydraulic loading cylinder 309 to support the cylindrical transmission rod 308 and the cylindrical rock core rod 307, so that the reading of the force sensor 310 reaches the specified force value, and the liquid in the cylindrical high pressure water cylinder 303 simultaneously reaches the specified pressure.

[0055] Step 6: Dynamic water pressure wave excitation and monitoring. Continue to keep the monitoring device running. Place the punch 205 at the designated position at the bottom of the transmitting tube 204. Different head contours of the punch can be used to achieve directional modulation of the stress wave waveform. For example, a double-cone punch striking a cylindrical incident rod 302 produces a sine wave; a flat-end cylindrical punch striking a cylindrical incident rod 302 produces a square wave; and a single-cone punch striking a cylindrical incident rod 302 produces a triangular wave. Start the air source device and use the pneumatic control valve 104 to regulate the pneumatic booster station 103 to fill the high-pressure chamber 202 of the high-pressure storage chamber 201 to the rated pressure. The filling pressure range can be 0.2~4MPa. Wait for the air pressure to reach the specified level. After stabilization, the high-pressure gas in the high-pressure chamber 202 is transiently driven by the pneumatic control opening and closing device 203 to accelerate the punch 205 to a specified speed. The punch 205 impacts the cylindrical reaction pad 301 and the cylindrical incident rod 302, generating stress waves with a period of microseconds to milliseconds and a peak pressure exceeding 100 MPa. The speed of the punch 205 is measured by the speed measuring device 206, with a speed measuring range of 0.1 m / s to 100 m / s and a speed measuring accuracy of 0.01 m / s. The stress wave further generates a transient hydrodynamic pressure wave exceeding 100 MPa in the cylindrical high-pressure water cylinder 303. The hydrodynamic pressure wave further propagates and acts on the cylindrical rock core rod 307, propagating along the cylindrical rock core rod. At the same time, the ultra-dynamic signal acquisition instrument 501 collects the pressure, strain, and force signals during the test process.

[0056] Step 7: Analyze the pressure, strain, and force signal data collected by monitoring, and calculate the dynamic water pressure wave process.

[0057] The above-described embodiment provides a device and method for simulating the generation of deep hydrodynamic pressure waves and the propagation of water-rock interfaces, which has the following advantages: high pulse pressure, high pulse frequency, and simplified structure; it overcomes the shortcomings of existing fluid pulse generators, such as complex structure, high cost, limited high-frequency and high-pressure output capability, and slow response speed due to reliance on complex pump and valve systems. It utilizes a stress pulse excitation device and a gas source device to convert the internal energy of high-pressure gas into the kinetic energy of a punch. The transient high-peak stress wave generated by the transient impact of the punch on the cylindrical incident rod is transmitted to the liquid, thereby exciting high-pressure, high-frequency hydrodynamic pressure waves. It can achieve transient water pressure output at the microsecond to millisecond level during dynamic hydraulic fracturing; it simulates the propagation and action of stress waves at the water-rock fluid-structure interaction interface; and it overcomes the limitations of existing impact loading devices that can only simulate... The fluid-structure interaction (FSI) condition, where dynamic hydraulic waves superimpose in the sample and fail to clearly detect their propagation in the rock medium, presents a limitation. The dynamic hydraulic pressure wave excitation and FSI device can simulate the physical scenario of fluid propagation and interaction at the water-rock interface during pulsed hydraulic fracturing. By monitoring the parameter states of the dynamic hydraulic pressure wave generation, its propagation at the water-rock interface, and its interaction with the distal rock mass, the mechanical mechanism of the dynamic hydraulic pressure wave at the water-rock interface can be analyzed, providing a theoretical basis for dynamic hydraulic fracturing. The pulse waveform is controllable, overcoming the limitation of existing fluid pulse generators in accurately controlling microsecond-level transient dynamic hydraulic waves of different waveforms. Directional modulation of the stress wave waveform can be achieved by adjusting the shape of the punch head of the stress pulse excitation device. It is understood that the same or similar parts in the above embodiments can be referenced interchangeably, and content not described in detail in some embodiments can be found in the same or similar content in other embodiments.

[0058] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A device for simulating the generation of deep hydrodynamic pressure waves and the propagation effect at the water-rock interface, characterized in that, include: A gas source device is used to provide gases of different pressures; a stress pulse excitation device, one end of which is connected to the gas source device, is used to excite dynamic stress waves; a dynamic water pressure wave excitation and fluid-structure interaction device is coaxially arranged at the other end of the stress pulse excitation device, used to excite and transmit dynamic water pressure waves, realizing the propagation and action of dynamic water pressure waves under high stress at the water-rock interface; an initial water pressure loading device is connected to the dynamic water pressure wave excitation and fluid-structure interaction device, used to store fluid medium and for the dynamic water pressure wave excitation and fluid-structure interaction. The action device provides initial pressure; the monitoring device, connected to the hydrodynamic pressure wave excitation and fluid-structure interaction device, is used to monitor the parameter status of the hydrodynamic pressure wave generation and water-rock interface propagation process; the hydrodynamic pressure wave excitation and fluid-structure interaction device includes an incident end reaction seat, a cylindrical reaction pad, a cylindrical incident rod, a cylindrical high-pressure water cylinder, a cylindrical rock core rod, a cylindrical transmission rod, a hydraulic loading cylinder, a cylinder reaction seat, and a reaction connecting rod; the cylindrical reaction pad, cylindrical incident rod, cylindrical high-pressure water cylinder, cylindrical rock core rod, and cylindrical... The transmission rod and the hydraulic loading cylinder are sequentially and coaxially connected. The cylindrical reaction pad is embedded in the injection hole at the center of the injection end reaction seat, and the rear end of the hydraulic loading cylinder is embedded in the mounting groove at the center of the cylinder reaction seat. Reaction rod holes are provided on both sides of the injection end reaction seat and the cylinder reaction seat, connected by the reaction connecting rod. The effective length of the cylindrical high-pressure water cylinder is not less than twice the dominant wavelength of the dynamic water pressure wave, and the effective length of the cylindrical injection rod and the length of the cylindrical core rod are both not less than twice the dominant wavelength of the stress wave. The inner diameter of the cylindrical high-pressure water cylinder is the same as the diameter of the cylindrical incident rod and the cylindrical rock core rod; the side wall of the cylindrical high-pressure water cylinder is equally divided into at least three sets of pressure sensors along the axial direction; the side wall of the cylindrical high-pressure water cylinder is also provided with a liquid injection hole and a vent hole; the pressure sensors, the liquid injection hole, and the vent hole are all connected to the inner cavity of the cylindrical high-pressure water cylinder; a high-pressure shut-off valve is also connected to the outside of the liquid injection hole and the vent hole; a force sensor is provided at the front end of the hydraulic loading cylinder; the hydraulic loading cylinder is connected to a servo hydraulic station.

2. The device for simulating deep hydrodynamic pressure wave generation and water-rock interface propagation according to claim 1, characterized in that, The gas source device includes a high-pressure nitrogen cylinder, a pressure reducing valve, a pneumatic booster station, a pneumatic control valve, and an output control unit connected in sequence.

3. The device for simulating deep hydrodynamic pressure wave generation and water-rock interface propagation according to claim 1, characterized in that, The stress pulse excitation device includes a high-pressure gas storage chamber, a launching tube, a punch, and a speed measuring device; the high-pressure gas storage chamber is equipped with a high-pressure gas chamber and a pneumatic control opening and closing device; the launching tube is cylindrical, and its rear end is coaxially connected to the high-pressure gas chamber, and the pneumatic control opening and closing device controls the communication state between the launching tube and the high-pressure gas chamber; the punch is coaxially disposed inside the launching tube, and the speed measuring device is disposed at the front end of the launching tube.

4. The device for simulating deep hydrodynamic pressure wave generation and water-rock interface propagation according to claim 3, characterized in that, Stress waves of different waveforms are generated by using punches with different head profile shapes.

5. The device for simulating deep hydrodynamic pressure wave generation and water-rock interface propagation according to claim 1, characterized in that, The cylindrical incident rod is coaxially inserted into one end of the cylindrical high-pressure water cylinder, and a sealing ring is provided at the connection; the cylindrical rock core rod is coaxially inserted into the other end of the cylindrical high-pressure water cylinder, and a sealing ring is provided at the connection.

6. The device for simulating deep hydrodynamic pressure wave generation and water-rock interface propagation according to claim 1, characterized in that, The dynamic water pressure wave excitation and fluid-structure interaction device and the stress pulse excitation device are coaxially mounted on the support platform, and the cylindrical reaction pad of the dynamic water pressure wave excitation and fluid-structure interaction device is close to the emitting end of the stress pulse excitation device.

7. The device for simulating deep hydrodynamic pressure wave generation and water-rock interface propagation according to claim 1, characterized in that, The initial water pressure loading device includes a water tank, a high-pressure horizontal flow pump, and a liquid shut-off valve. The water tank, the high-pressure horizontal flow pump, the liquid shut-off valve, and the high-pressure shut-off valve connected to the injection hole are connected in sequence through a high-pressure pipeline.

8. The device for simulating deep hydrodynamic pressure wave generation and water-rock interface propagation according to claim 1, characterized in that, The monitoring device includes an ultra-dynamic signal acquisition instrument and an industrial control computer. At least three sets of strain gauges are evenly distributed along the axial direction on the surface of the cylindrical rock core rod, and one set of strain gauges is arranged along the axial direction on the surface of the cylindrical incident rod. Each set of strain gauges is electrically connected to the ultra-dynamic signal acquisition instrument, which is also electrically connected to the pressure sensor and the force sensor. The industrial control computer is electrically connected to the ultra-dynamic strain gauge.

9. A method for simulating the generation of deep hydrodynamic pressure waves and the propagation effect at the water-rock interface, characterized in that, The method includes the following steps: assembling the device for simulating deep hydrodynamic pressure wave generation and water-rock interface propagation as described in any one of claims 1-8; providing initial pressure to the hydrodynamic pressure wave excitation and fluid-structure interaction device using an initial water pressure loading device to achieve initial water pressure loading at the water-rock interface; the hydrodynamic pressure wave excitation and fluid-structure interaction device applying high static stress and hydrostatic pressure loading to the water-rock interface; using a gas source device and a stress pulse excitation device to excite dynamic stress waves to act on the hydrodynamic pressure wave excitation and fluid-structure interaction device, thereby exciting and transmitting hydrodynamic pressure waves to achieve propagation and action of hydrodynamic pressure waves under high stress at the water-rock interface; and monitoring the parameter status of the hydrodynamic pressure wave generation and water-rock interface propagation process using a monitoring device.

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