Shale formation crack fracturing simulation experiment device and experiment method

Abstract

The invention belongs to the technical field of fracturing simulation experiments, and discloses a shale formation fracture fracturing simulation experiment device and an experiment method. The shale formation crack fracturing simulation experiment device comprises a bottom plate, clamping assemblies, a working plate and a driving assembly, a chuck is arranged on the bottom plate, and the multiple sets of clamping assemblies are arranged on multiple clamping jaws of the chuck correspondingly; the working plate is arranged above the bottom plate, a supporting seat is arranged on the working plate and used for placing a rock sample, a plurality of radial sliding grooves are formed in the working plate around the supporting seat, and clamping guide rods of the plurality of clamping assemblies respectively penetrate through the plurality of radial sliding grooves and can slide along the radial sliding grooves to clamp or release the rock sample; the driving assembly is configured to drive the ultrasonic probe to move in the height direction of the rock sample. According to the invention, rock samples with irregular shapes and sizes are fixed, each ultrasonic probe can move along the height direction of the rock samples to realize multi-position detection, the cost is low, and the detection efficiency is high.

Description

Technical Field

[0001] The present invention relates to the technical field of fracturing simulation experiments, and in particular to a shale formation fracture fracturing simulation experiment device and an experiment method. Background Art

[0002] In the field of oil extraction, fracturing refers to the use of hydraulic pressure to create cracks in oil and gas layers during oil or gas production. Fracturing artificially creates cracks in the formation to improve the flow of oil underground, thereby increasing well production. It plays a vital role in improving bottomhole flow conditions, mitigating interlayer friction, and improving reservoir production.

[0003] The fracturing simulation experimental device can not only flexibly control the opening position of the fracturing hole, but also monitor the occurrence and development of fracturing cracks in real time, thus providing a basis for the actual fracturing process design on site.

[0004] Current fracturing simulation experimental devices typically require a large number of ultrasonic probes to monitor the fracturing process. Each ultrasonic probe can only detect a fixed location, resulting in a limited detection range and high detection costs. Furthermore, existing fracturing simulation experimental devices can generally only hold rock samples of a fixed size, requiring pre-processing of the rock samples. However, grinding and cutting rock samples is cumbersome, affecting experimental efficiency. Therefore, a device is needed that can hold rock samples of different sizes, thereby reducing grinding and cutting operations and, in turn, reducing worker workload. Summary of the Invention

[0005] The purpose of the present invention is to provide a shale formation fracture fracturing simulation experimental device and experimental method to solve the problem that each ultrasonic probe in the existing experimental device can only detect a fixed position and can only fix a rock sample of a fixed size.

[0006] To achieve this object, the present invention adopts the following technical solutions:

[0007] The present invention first provides a shale formation fracture fracturing simulation experimental device, comprising:

[0008] a bottom plate, wherein a chuck is provided on the bottom plate;

[0009] A clamping assembly, wherein the clamping assembly is provided in multiple groups, and the multiple groups of clamping assemblies are respectively provided on multiple claws of the chuck, and each group of the clamping assemblies includes a clamping guide rod;

[0010] A working plate, the working plate is arranged above the bottom plate, the working plate is provided with a support seat for placing the rock sample, the working plate is provided with a plurality of radial slots around the support seat, the plurality of radial slots are arranged in a one-to-one correspondence with the plurality of clamping assemblies, the plurality of clamping guide rods of the plurality of clamping assemblies respectively pass through the plurality of radial slots from bottom to top and can slide along the radial slots to clamp or release the rock sample;

[0011] A driving assembly is provided on the working plate. An ultrasonic probe is provided on the driving assembly. The driving assembly is configured to drive the ultrasonic probe to move along the height direction of the rock sample.

[0012] Optionally, the clamping assembly includes:

[0013] A linkage column connected to the claw;

[0014] An extension bar, fixed to the linkage column and extending along the extension and retraction direction of the claw;

[0015] A linkage rod, one end of which is fixed to the extension bar, and the other end of which is connected to the clamping guide rod.

[0016] Optionally, the clamping assembly further comprises:

[0017] A support and limit plate, the two ends of which are fixedly connected to the base plate and the working plate respectively;

[0018] A spring rod, one end of which is connected to the extension bar and coaxially arranged with the extension bar, and the other end of which passes through the support and limiting plate;

[0019] A spring is sleeved on the spring rod, and the spring is located between the other end of the spring rod and the support limit plate. When the extension bar drives the spring rod to move to clamp the rock sample, the other end of the spring rod can compress the spring; when the rock sample is released, the extension bar can be reset under the elastic force of the spring.

[0020] Optionally, the driving assembly includes:

[0021] A mounting ring, wherein the working plate is provided with an annular groove, and the mounting ring is arranged in the annular groove; an outer circumferential surface of the mounting ring is provided with an outer gear ring, and an inner circumferential surface of the mounting ring is provided with an inner gear ring;

[0022] a first gear, the first gear being rotatably connected to the working plate and meshingly connected to the outer gear ring;

[0023] a second gear, the second gear being rotatably connected to the working plate and meshingly connected to the inner gear ring; a plurality of second gears being provided, and the plurality of second gears being arranged in a one-to-one correspondence with the plurality of radial slide grooves;

[0024] a driving member, the driving member being disposed on the working plate, wherein an output end of the driving member is connected to the first gear to drive the first gear to rotate;

[0025] a screw rod, wherein a plurality of the screw rods are provided, and the plurality of the screw rods are arranged in a one-to-one correspondence with the plurality of the clamping guide rods; the bottom end of the screw rod is fixedly connected to the second gear and can rotate synchronously with the second gear;

[0026] A linkage mechanism is connected between the screw and the corresponding clamping guide rod, the ultrasonic probe is arranged on the linkage mechanism, and the screw drives the ultrasonic probe to move through the linkage mechanism.

[0027] Optionally, the linkage mechanism includes:

[0028] A threaded sleeve, the threaded sleeve is threadedly connected to the screw, and the threaded sleeve is provided with a first linkage plate;

[0029] A sliding sleeve, the sliding sleeve is sleeved on the clamping guide rod and is slidably connected to the clamping guide rod, the sliding sleeve is provided with a second linkage plate, and the ultrasonic probe is provided on the sliding sleeve or the second linkage plate;

[0030] A linkage guide rod is provided between the first linkage plate and the second linkage plate. One of the second linkage plate and the first linkage plate is fixedly connected to the linkage guide rod, and the other is slidably connected to the linkage guide rod, and the sliding direction is along the axial direction of the linkage guide rod.

[0031] Optionally, the shale formation fracture fracturing simulation experimental device also includes a reinforcement mechanism, which is arranged above the working plate and fixedly connected to the working plate through a support rod, the top end of each screw is rotatably connected to the reinforcement mechanism, and the top end of each clamping guide rod is slidably connected to the reinforcement mechanism.

[0032] Optionally, the reinforcement mechanism includes a reinforcement ring having an inner hole, and the side wall of the inner hole is provided with multiple reinforcement sliders. The multiple reinforcement sliders can telescopically move along the radial direction of the inner hole, and the top end of the clamping guide rod is connected to the reinforcement slider.

[0033] Optionally, the reinforcement mechanism also includes a reinforcement slide rod, and a plurality of radial through holes are provided on the hole wall of the inner hole. One end of the reinforcement slide rod is inserted into the radial through hole and can slide in the radial through hole, and the other end of the reinforcement slide rod is connected to the reinforcement slider.

[0034] Optionally, the clamping guide rod is provided with a plurality of arc-shaped plates, which are spaced apart along the axial direction of the clamping guide rod, and the plurality of arc-shaped plates can abut against the rock sample when the clamping guide rod clamps the rock sample.

[0035] The present invention also provides a shale formation fracture fracturing simulation experimental method. According to the shale formation fracture fracturing simulation experimental device provided by the present invention, the shale formation fracture fracturing simulation experimental method comprises the following steps:

[0036] S1, clamping and fixing the rock sample on the working plate through the clamping guide rods of the three sets of clamping assemblies;

[0037] S2, adding a fracturing fluid into the top fracturing hole of the rock sample, thereby performing a fracturing simulation experiment on the rock sample;

[0038] S3, the driving component drives the ultrasonic probe to move along the height direction of the rock sample to detect crack changes in the rock sample during the fracturing process.

[0039] Beneficial effects of the present invention:

[0040] The shale formation fracture fracturing simulation experimental device of the present invention utilizes multiple clamping assemblies provided on a chuck, each equipped with a clamping guide rod, to facilitate circumferential clamping and height limiting of rock samples, thereby enabling the securement of rock samples of irregular shapes and sizes with greater flexibility and reliability. Furthermore, the present invention utilizes a drive assembly provided on a work plate that drives an ultrasonic probe to move along the height of the rock sample. By controlling the movement of the ultrasonic probe for detection, each ultrasonic probe performs multi-position detection of the rock sample. Compared to existing technologies, this utilizes fewer ultrasonic probes, resulting in lower detection costs, an optimized structure, and higher detection efficiency.

[0041] The shale formation fracture fracturing simulation experimental method of the present invention clamps and fixes rock samples through clamping guide rods of multiple groups of clamping assemblies, which can fix rock samples of different shapes and sizes, simplifying the processing and pretreatment process of the rock samples, and helping to improve the experimental efficiency; during the experiment, the driving assembly drives the ultrasonic probe to move along the height direction of the rock sample, and through the movement control of the ultrasonic probe, multi-position detection of crack changes in the rock sample during the fracturing process is achieved, and the dynamic detection of the rock sample has a wider and more comprehensive detection range, which greatly improves the experimental detection efficiency and experimental detection reliability, and greatly reduces the experimental cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 This is a schematic diagram of the overall structure of a shale formation fracture fracturing simulation experimental device provided by an embodiment of the present invention;

[0043] Figure 2 This is a schematic structural diagram of a chuck and a clamping assembly from a first angle in a shale formation fracture fracturing simulation experimental device provided by an embodiment of the present invention;

[0044] Figure 3 This is a schematic diagram of the structure of the chuck and the clamping assembly from a second angle in the shale formation fracture fracturing simulation experimental device provided by an embodiment of the present invention;

[0045] Figure 4 This is a schematic structural diagram of a driving assembly on a working plate in a shale formation fracture fracturing simulation experimental device provided by an embodiment of the present invention;

[0046] Figure 5 Schematic diagram of the structure of the working plate in the shale formation fracture fracturing simulation experimental device provided by an embodiment of the present invention;

[0047] Figure 6 A schematic diagram of the positional relationship between the linkage mechanism, the clamping guide rod, and the screw rod in the shale formation fracture fracturing simulation experimental device provided by an embodiment of the present invention;

[0048] Figure 7 A schematic structural diagram of a linkage mechanism in a shale formation fracture fracturing simulation experimental device provided by an embodiment of the present invention;

[0049] Figure 8 A schematic structural diagram of a reinforcement mechanism in a shale formation fracture fracturing simulation experimental device provided by an embodiment of the present invention;

[0050] Figure 9 A schematic cross-sectional view of the reinforcement mechanism in a shale formation fracture fracturing simulation experimental device provided by an embodiment of the present invention.

[0051] In the picture:

[0052] 100. Rock sample; 101. Fracturing hole; 200. Ultrasonic probe;

[0053] 1. Base plate; 11. Chuck; 111. Jaw;

[0054] 2. Clamping assembly; 21. Clamping guide rod; 211. Arc plate; 22. Linkage column; 23. Extension bar; 24. Linkage rod; 241. Linkage block; 242. Clamping slider; 25. Support limit plate; 26. Spring rod; 27. Spring;

[0055] 3. Working plate; 31. Support seat; 32. Radial slide; 33. Annular slide;

[0056] 4. Drive assembly; 41. Mounting ring; 411. Outer gear ring; 412. Inner gear ring; 42. First gear; 43. Second gear; 44. Drive member; 45. Screw; 46. Linkage mechanism; 461. Threaded sleeve; 462. Sliding sleeve; 463. Linkage guide rod; 4611. First linkage plate; 4621. Second linkage plate;

[0057] 5. Reinforcement mechanism; 51. Reinforcement ring; 511. Inner hole; 512. Radial through hole; 52. Reinforcement slider; 53. Reinforcement slide bar;

[0058] 6. Support rod. DETAILED DESCRIPTION

[0059] The present invention will be further described in detail below with reference to the accompanying drawings and examples. It will be understood that the specific embodiments described herein are intended only to illustrate the present invention and are not intended to limit the present invention. It should also be noted that, for ease of description, the accompanying drawings only illustrate portions relevant to the present invention, not all structures.

[0060] In the description of the present invention, unless otherwise expressly specified or limited, the terms "connected," "connected," and "fixed" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integration; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and internal communication between two components or interaction between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention in specific circumstances.

[0061] In the present invention, unless otherwise expressly specified or limited, a first feature being "above" or "below" a second feature may include the first and second features being in direct contact, or may include the first and second features being in contact not directly but through another feature between them. Furthermore, a first feature being "above," "above," and "above" a second feature may include the first feature being directly above or obliquely above the second feature, or may simply mean that the first feature is higher in level than the second feature. A first feature being "below," "below," and "below" a second feature may include the first feature being directly below or obliquely below the second feature, or may simply mean that the first feature is lower in level than the second feature.

[0062] In the description of this embodiment, terms such as "upper," "lower," "left," and "right" are used to refer to positions or locations based on those shown in the accompanying drawings. These terms are intended solely to facilitate description and simplify operation, and are not intended to indicate or imply that the devices or components referred to must have, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on the present invention. Furthermore, the terms "first" and "second" are used solely for descriptive purposes and have no special meaning.

[0063] The embodiment of the present invention provides a shale formation fracture fracturing simulation experimental device, such as Figures 1-4 As shown, it includes a base plate 1, a clamping assembly 2, a working plate 3 and a driving assembly 4. A chuck 11 is provided on the base plate 1; the chuck 11 is provided with claws 111. In this embodiment, a three-jaw chuck is used as an example for explanation. Three claws 111 are provided on the chuck 11. The chuck 11 is fixed to the base plate 1. There are multiple groups of clamping assemblies 2, and the multiple groups of clamping assemblies 2 are respectively provided on the multiple claws 111 of the chuck 11. Each group of clamping assemblies 2 includes a clamping guide rod 21; the multiple claws 111 can drive the corresponding multiple clamping assemblies 2 to extend and retract when they are extended and retracted, thereby enabling the multiple clamping guide rods 22 to clamp the rock sample 100 in the circumference for fixation. The working plate 3 is arranged above the base plate 1, and a support seat 31 is provided on the working plate 3 for placing the rock sample 100. A plurality of radial grooves 32 are provided around the support seat 31 on the working plate 3, and the plurality of radial grooves 32 are arranged one-to-one corresponding to the plurality of clamping components 2. The plurality of clamping guide rods 21 of the plurality of clamping components 2 pass through the plurality of radial grooves 32 from bottom to top and can slide along the radial grooves 32 to clamp or release the rock sample 100; the driving component 4 is arranged on the working plate 3, and an ultrasonic probe 200 is provided on the driving component 4. The driving component 4 is configured to drive the ultrasonic probe 200 to move along the height direction of the rock sample 100.

[0064] The shale formation fracture fracturing simulation experimental device of the present invention comprises multiple clamping assemblies 2 disposed on a chuck 11, each of which is provided with a clamping guide rod 21, which facilitates circumferential clamping and fixing of a rock sample 100. Furthermore, since the clamping guide rod 21 is highly extended, it can limit and clamp the rock sample 100 in the height direction, providing more stable fixation, thereby achieving a more flexible and reliable fixation of rock samples 100 of irregular shapes and sizes. The present invention comprises a drive assembly 4 disposed on a working plate 3, securing an ultrasonic probe 200 to the drive assembly 4. The drive assembly 4 drives the ultrasonic probe 200 to move along the height direction of the rock sample 100, thereby controlling the movement of the ultrasonic probe 200 to achieve multi-position detection of the rock sample 100. Compared with the prior art ultrasonic probe 200 that can only perform fixed-position detection, the present invention employs a smaller number of ultrasonic probes 200, and each ultrasonic probe 200 can achieve multi-position detection of the rock sample 100 through lifting or moving motion, resulting in low detection cost and high detection efficiency.

[0065] Optionally, the clamping assembly 2 includes a linkage column 22, an extension bar 23 and a linkage rod 24, the linkage column 22 is connected to the claw 111; the extension bar 23 is fixed on the linkage column 22 and extends along the telescopic direction of the claw 111; one end of the linkage rod 24 is fixed on the extension bar 23, and the other end of the linkage rod 24 is connected to the clamping guide rod 21.

[0066] like Figure 1-Figure 3 In this embodiment, the chuck 11 is provided with three jaws 111, which can be moved closer or further apart to achieve contraction and release. A linkage column 22 abuts against the outer side of each jaw 111 along the direction of movement. When the jaws 111 move closer and contract, they push the linkage column 22 to move, causing the multiple linkage columns 22 to drive the multiple extension bars 23 to move closer and contract. A linkage rod 24 is fixed to the extension bar 23, and the three linkage rods 24 then drive the three clamping guide rods 21 to move relative to each other and contract to clamp the rock sample 100. Among them, the bottom end of the linkage rod 24 is fixed to the top of the extension bar 23 through the linkage block 241, and the linkage rod 24 is extended along the height direction of the rock sample 100. The top of the linkage rod 24 is provided with a clamping slider 242, and the clamping slider 242 is slidably connected in the radial slide groove 32. The bottom end of the clamping guide rod 21 is fixedly connected to the clamping slider 242, so that the clamping guide rod 21 slides along the radial slide groove 32 with the clamping slider 242, so that the three clamping guide rods 21 clamp the rock sample 100 with three claws.

[0067] Optionally, the clamping assembly 2 further includes a support and limit plate 25, a spring rod 26, and a spring 27. The two ends of the support and limit plate 25 are respectively fixedly connected to the base plate 1 and the working plate 3, thereby fixing the relative positions of the base plate 1 and the working plate 3 and providing guidance and support for the radial movement of the extension bar 23. One end of the spring rod 26 is connected to the extension bar 23 and is coaxially arranged with the extension bar 23. The other end of the spring rod 26 passes through the support and limit plate 25. The spring 27 is sleeved on the spring rod 26 and is located between the other end of the spring rod 26 and the support and limit plate 25. When the extension bar 23 drives the spring rod 26 to move to clamp the rock sample 100, the other end of the spring rod 26 can compress the spring 27. When the rock sample 100 is released, the extension bar 23 can be reset under the elastic force of the spring 27.

[0068] like Figure 1-Figure 3 As shown, the spring rod 26 is connected to the end of the extension bar 23 away from the linkage column 22 through the linkage block 241. In some embodiments, the spring rod 26 and the extension bar 23 can be composed of a single rod. The spring rod 26 passes through the support limit plate 25 and can slide relative to the support limit plate 25. The end of the spring rod 26 away from the extension bar 23 has a limit protrusion. The two ends of the spring 27 can respectively stop between the limit protrusion and the support limit plate 25. When the extension bar 23 drives the spring rod 26 to retract, the limit protrusion moves toward the direction of the compression spring 27, causing the spring 27 to store energy. When the clamping claw 111 releases, the spring rod 26 retracts and resets under the elastic force of the spring 27, thereby driving the extension bar 23 to move radially, so that the clamping guide rod 21 can release the rock sample 100. It can be understood that by providing the spring 27, the connection between the linkage column 22 and the clamping claw 111 is simplified. The contraction and release movements can be achieved by only abutting, which is simple in structure and easy to control.

[0069] Optionally, the driving assembly 4 includes a mounting ring 41, a first gear 42, a second gear 43, a driving member 44, a screw 45 and a linkage mechanism 46, and an annular sliding groove 33 is provided on the working plate 3, such as Figure 5 , the mounting ring 41 is provided in the annular groove 33; the outer circumferential surface of the mounting ring 41 is provided with an outer gear ring 411, and the inner circumferential surface of the mounting ring 41 is provided with an inner gear ring 412, such as Figure 4 The first gear 42 is rotatably connected to the working plate 3 and is in meshing transmission connection with the outer gear ring 411; the second gear 43 is rotatably connected to the working plate 3 and is in meshing transmission connection with the inner gear ring 412; a plurality of second gears 43 are provided, and the plurality of second gears 43 are arranged in one-to-one correspondence with the plurality of radial slots 32; a driving member 44 is provided on the working plate 3, such as Figure 2The driving member 44 is provided on the lower surface of the working plate 3, and the output end of the driving member 44 is connected to the first gear 42 to drive the first gear 42 to rotate; a plurality of screws 45 are provided, and the plurality of screws 45 are arranged in one-to-one correspondence with the plurality of clamping guide rods 21; the bottom end of the screw 45 is fixedly connected to the second gear 43 and can rotate synchronously with the second gear 43; the linkage mechanism 46 is connected between the screw 45 and the corresponding clamping guide rod 21, and the ultrasonic probe 200 is provided on the linkage mechanism 46, and the screw 45 drives the ultrasonic probe 200 to move up and down through the linkage mechanism 46.

[0070] like Figure 4 and Figure 5 , combined with Figure 1 In this embodiment, the driving member 44 can be a servo motor, electrically connected to an external power supply, and controlled by a control switch; the annular slide groove 33 is used to limit the rotation of the mounting ring 41 to ensure the rotation stability of the mounting ring 41. The driving member 44 is fixed to the lower surface of the working plate 3. The output end of the driving member 44 passes through the working plate 3 upward and is fixedly connected to the first gear 42 on the upper surface of the working plate 3. The driving member 44 can drive the first gear 42 to rotate on the upper surface of the working plate 3 and then drive the mounting ring 41 to rotate through the external gear ring 411 connected by the transmission. Figure 5 The annular chute 33 is coaxially arranged with the rock sample 100. The mounting ring 41 can slide within the annular chute 33 to rotate around the rock sample 100. The center of rotation is the center of the support base 31, which is also the center of the rock sample 100. Through the aforementioned drive assembly 4, the driver 44 drives the first gear 42 to rotate, which in turn drives the mounting ring 41 in rotation. The inner gear ring 412 then drives the three second gears 43, which in turn drive the three screws 45 to rotate synchronously, ensuring the normal operation of the device. This reduces the number of driver 44 components and helps lower manufacturing costs. The rotation of the screws 45 drives the linkage mechanism 46 to move up and down, which in turn drives the ultrasonic probe 200 to move up and down for mobile testing. The cracks in the fractured rock sample 100 will change the ultrasonic echo, thereby measuring the crack depth through the ultrasonic probe 200. Compared to the prior art, each ultrasonic probe 200 in the embodiment of the present invention can move up and down for testing, which increases the detection range and the number of detection locations, reducing the number of ultrasonic probes 200 required.

[0071] Optionally, the linkage mechanism 46 includes a threaded sleeve 461, a sliding sleeve 462 and a linkage guide rod 463, the threaded sleeve 461 is threadedly connected to the screw 45, and the threaded sleeve 461 is provided with a first linkage plate 4611; the sliding sleeve 462 is sleeved on the clamping guide rod 21 and is slidingly connected to the clamping guide rod 21, and the sliding sleeve 462 is provided with a second linkage plate 4621, and the ultrasonic probe 200 is arranged on the sliding sleeve 462 or the second linkage plate 4621; the linkage guide rod 463 is arranged between the first linkage plate 4611 and the second linkage plate 4621, and one of the second linkage plate 4621 and the first linkage plate 4611 is fixedly connected to the linkage guide rod 463, and the other is slidingly connected to the linkage guide rod 463, and the sliding direction is along the axial direction of the linkage guide rod 463.

[0072] like Figure 6 and Figure 7 In this embodiment, two linkage guide rods 463 are provided between the first linkage plate 4611 and the second linkage plate 4621, symmetrically arranged on either side of the threaded sleeve 461 and the sliding sleeve 462. One end of the linkage guide rod 463 is fixedly connected to the second linkage plate 4621, while the other end of the linkage guide rod 463 passes through the first linkage plate 4611 and is slidably connected to the first linkage plate 4611. The other end of the linkage guide rod 463 is provided with a stopper to prevent the linkage guide rod 463 from slipping. It will be understood that since the clamping guide rod 21 can slide within the radial slot 32 and thus move relative to the screw rod 45, the sliding arrangement of the linkage guide rod 463 and the first linkage plate 4611 facilitates the clamping and releasing movement of the clamping guide rod 21 and also provides a guiding function. When the second gear 43 drives the screw 45 to rotate, the threaded sleeve 461 moves up and down relative to the screw 45, and then drives the sliding sleeve 462 and the second linkage plate 4621 to move up and down through the linkage guide rod 463, thereby realizing the lifting and lowering displacement control of the ultrasonic probe 200 and realizing longitudinal multi-position detection of cracks on the rock sample 100.

[0073] Optionally, the shale formation fracture fracturing simulation experimental device provided in this embodiment also includes a reinforcement mechanism 5, which is arranged above the working plate 3 and fixedly connected to the working plate 3 through a support rod 6, the top end of each screw 45 is rotatably connected to the reinforcement mechanism 5, and the top end of each clamping guide rod 21 is slidably connected to the reinforcement mechanism 5.

[0074] like Figure 1As shown, a reinforcement mechanism 5 is mounted above the work plate 3 via three support rods 6. This reinforcement mechanism 5 assists in securing the guide rod 21 and the screw 45, increasing the rotational stability of the screw 45 and the clamping force of the guide rod 21. The reinforcement mechanism 5 also serves to mount the fracturing experiment components. The fracturing fluid tank, fracturing pump, fracturing pipeline, control ball valve, and pressure gauge can be installed on the reinforcement mechanism 5. By opening the control ball valve and using the fracturing pump, the fluid in the fracturing fluid tank is pumped through the fracturing pipeline into the fracturing hole 101, thereby conducting a fracturing simulation experiment on the rock sample 15.

[0075] Optionally, the reinforcement mechanism 5 includes a reinforcement ring 51, the reinforcement ring 51 has an inner hole 511, and the side wall of the inner hole 511 is provided with multiple reinforcement sliders 52. The multiple reinforcement sliders 52 can telescopically move along the radial direction of the inner hole 511, and the top end of the clamping guide rod 21 is connected to the reinforcement slider 52.

[0076] like Figure 8 and Figure 9 As shown, the inner hole 511 is coaxially arranged with the support base 31. The size of the inner hole 511 is larger than the outer diameter of the rock sample 100 to facilitate the placement of the rock sample 100. A plurality of reinforcing sliders 52 are provided on the sidewall of the inner hole 511. The reinforcing sliders 52 are arranged in a one-to-one correspondence with the clamping guide rod 21. The reinforcing sliders 52 can move with the clamping guide rod 21. The reinforcing sliders 52 are slidably connected to the reinforcing ring 51. Therefore, the reinforcing sliders 52 have a limiting and reinforcing effect on the clamping guide rod 21, which is conducive to better clamping and fixing the rock sample 100 in the height direction.

[0077] Optionally, the reinforcement mechanism 5 also includes a reinforcement slide rod 53, and a plurality of radial through holes 512 are provided on the hole wall of the inner hole 511. One end of the reinforcement slide rod 53 is inserted into the radial through hole 512 and can slide in the radial through hole 512, and the other end of the reinforcement slide rod 53 is connected to the reinforcement slider 52.

[0078] like Figure 9 The inner wall of the inner hole 511 has three radial through holes 512 formed along the radial direction. The three radial through holes 512 are arranged in a one-to-one correspondence with the radial slide grooves 32. When the clamping guide rod 21 moves, the reinforcement slider 52 is driven to slide, which in turn drives the reinforcement slide rod 53 to slide within the radial through holes 512. It can be understood that the reinforcement slide rod 53 and the reinforcement slider 52 have a sliding limit function on the top end of the clamping guide rod 21, which helps to ensure that the bottom and top ends of the clamping guide rod 21 move in unison, thereby improving the clamping and fixing effect.

[0079] Optionally, a plurality of arc plates 211 are provided on the clamping guide rod 21 , and the plurality of arc plates 211 are spaced apart along the axial direction of the clamping guide rod 21 . The plurality of arc plates 211 can abut against the rock sample 100 when the clamping guide rod 21 clamps the rock sample 100 .

[0080] like Figure 6 As shown, arc plates 211 are fixedly provided at the upper and lower ends of the clamping guide rod 21, and the concave arc of the arc plate 211 faces the side of the rock sample 100. The arc plate 211 is conducive to increasing the contact area between the clamping guide rod 21 and the rock sample 100 to increase the stability of the rock sample 100 and ensure the smooth progress of the experiment.

[0081] The present invention also provides a shale formation fracture fracturing simulation experimental method. According to the shale formation fracture fracturing simulation experimental device provided by the present invention, the shale formation fracture fracturing simulation experimental method comprises the following steps:

[0082] S1, the rock sample 100 is clamped and fixed on the working plate 3 by the clamping guide rods 21 of the three sets of clamping assemblies 2, as shown in FIG. Figure 1 shown; specifically:

[0083] Use a crane to place the rock sample 100 on the support seat 31, start the three-jaw chuck 11, the three claws 111 drive the three linkage columns 22 to approach each other, the linkage column 22 drives the extension bar 23 to move the linkage block 241, the linkage block 241 drives the linkage rod 24 to move the clamping slider 242 along the radial slide groove 32, the clamping slider 242 drives the clamping guide rod 21 to move the clamping arc plate 211, the arc plate 211 approaches the rock sample 100 to clamp and fix the rock sample 100, and at the same time, the clamping guide rod 21 drives the reinforcement slider 52 to move the reinforcement slide rod 53 along the radial through hole 512, thereby increasing the stability of the movement of the clamping guide rod 21.

[0084] S2, adding fracturing fluid into the top fracturing hole 101 of the rock sample 100, and the fracturing hole 101 is as shown in FIG. Figure 5 , thereby conducting a fracturing simulation experiment on the rock sample 100;

[0085] S3, the driving component 4 drives the ultrasonic probe 200 to move along the height direction of the rock sample 100 to detect the crack changes of the rock sample 100 during the fracturing process.

[0086] Specifically:

[0087] Start the driving member 44 to drive the first gear 42 to rotate and drive the outer gear ring 411. Through the rotation of the mounting ring 41 along the annular groove 33, the mounting ring 41 drives the inner gear ring 412 to move, so that the second transmission gear 43 rotates. The second gear 43 drives the screw 45 to rotate. Due to the limitation of the threaded sleeve 461 by the linkage guide rod 463, the screw 45 rotates to cause the threaded sleeve 461 to move along the screw 45. The threaded sleeve 461 drives the first linkage plate 4611 to move the linkage guide rod 463. The linkage guide rod 463 drives the second linkage plate 4621 to move. The second linkage plate 4621 drives the sliding sleeve 462 to move along the clamping guide rod 21. The sliding sleeve 462 drives the ultrasonic probe 200 to move, thereby increasing the detection range of the device.

[0088] The shale formation fracture fracturing simulation experimental method of the present invention clamps and fixes the rock sample 100 through the clamping guide rods 21 of the three groups of clamping assemblies 2, driven by the chuck 11, and can fix rock samples 100 of different shapes and sizes, simplifying the processing and pretreatment process of the rock sample 100, and helping to improve the experimental efficiency; during the experiment, the driving assembly 4 drives the ultrasonic probe 200 to move along the height direction of the rock sample 100, and realizes multi-position detection of the crack changes of the rock sample 100 during the fracturing process by controlling the movement of the ultrasonic probe 200, and the dynamic detection range of the rock sample 100 is wider and more comprehensive, which greatly improves the experimental detection efficiency and experimental detection reliability, and greatly reduces the experimental cost.

[0089] Obviously, the above embodiments of the present invention are merely examples for the purpose of clearly illustrating the present invention and are not intended to limit the embodiments of the present invention. A person skilled in the art would be able to make various obvious changes, readjustments, and substitutions without departing from the scope of protection of the present invention. It is not necessary and impossible to enumerate all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the claims of the present invention.

Claims

1. Shale formation fracture fracturing simulation experimental device, characterized in that: include: A base plate (1), wherein a chuck (11) is provided on the base plate (1); A clamping assembly (2), wherein the clamping assembly (2) is provided in a plurality of groups, and the plurality of groups of the clamping assemblies (2) are respectively provided on a plurality of claws (111) of the chuck (11), and each group of the clamping assemblies (2) includes a clamping guide rod (21); A working plate (3), the working plate (3) being arranged above the base plate (1), the working plate (3) being provided with a support seat (31) for placing a rock sample (100), the working plate (3) being provided with a plurality of radial slots (32) around the support seat (31), the plurality of radial slots (32) being arranged in a one-to-one correspondence with the plurality of clamping assemblies (2), the plurality of clamping guide rods (21) of the plurality of clamping assemblies (2) respectively passing through the plurality of radial slots (32) from bottom to top and being able to slide along the radial slots (32) to clamp or release the rock sample (100); A drive assembly (4) is provided on the working plate (3), an ultrasonic probe (200) is provided on the drive assembly (4), and the drive assembly (4) is configured to drive the ultrasonic probe (200) to move along the height direction of the rock sample (100).

2. The shale formation fracture fracturing simulation experimental device according to claim 1, characterized in that: The clamping assembly (2) comprises: A linkage column (22), wherein the linkage column (22) is connected to the claw (111); An extension bar (23), the extension bar (23) being fixed on the linkage column (22) and extending along the extension and retraction direction of the claw (111); A linkage rod (24), one end of which is fixed on the extension bar (23), and the other end of which is connected to the clamping guide rod (21).

3. The shale formation fracture fracturing simulation experimental device according to claim 2, characterized in that: The clamping assembly (2) further comprises: A support and limit plate (25), wherein two ends of the support and limit plate (25) are respectively fixedly connected to the base plate (1) and the working plate (3); a spring rod (26), one end of the spring rod (26) being connected to the extension bar (23) and being coaxially arranged with the extension bar (23), and the other end of the spring rod (26) being passed through the support and limiting plate (25); A spring (27), wherein the spring (27) is sleeved on the spring rod (26), and the spring (27) is located between the other end of the spring rod (26) and the support limit plate (25); when the extension bar (23) drives the spring rod (26) to move to clamp the rock sample (100), the other end of the spring rod (26) can compress the spring (27); when the rock sample (100) is released, the extension bar (23) can be reset under the elastic force of the spring (27).

4. The shale formation fracture fracturing simulation experimental device according to claim 1, characterized in that: The driving assembly (4) comprises: A mounting ring (41), wherein an annular sliding groove (33) is provided on the working plate (3), and the mounting ring (41) is arranged in the annular sliding groove (33); an outer peripheral surface of the mounting ring (41) is provided with an outer gear ring (411), and an inner peripheral surface of the mounting ring (41) is provided with an inner gear ring (412); a first gear (42), the first gear (42) being rotatably connected to the working plate (3) and meshingly connected to the outer gear ring (411); a second gear (43), the second gear (43) being rotatably connected to the working plate (3) and meshingly connected to the inner gear ring (412); a plurality of second gears (43) are provided, and the plurality of second gears (43) are arranged in a one-to-one correspondence with the plurality of radial slide grooves (32); A driving member (44), wherein the driving member (44) is provided on the working plate (3), and an output end of the driving member (44) is connected to the first gear (42) to drive the first gear (42) to rotate; a screw rod (45), wherein a plurality of the screw rods (45) are provided, and the plurality of the screw rods (45) are arranged in a one-to-one correspondence with the plurality of the clamping guide rods (21); the bottom end of the screw rod (45) is fixedly connected to the second gear (43) and can rotate synchronously with the second gear (43); A linkage mechanism (46) is connected between the screw rod (45) and the corresponding clamping guide rod (21), the ultrasonic probe (200) is arranged on the linkage mechanism (46), and the screw rod (45) drives the ultrasonic probe (200) to move through the linkage mechanism (46).

5. The shale formation fracture fracturing simulation experimental device according to claim 4, characterized in that: The linkage mechanism (46) comprises: a threaded sleeve (461), the threaded sleeve (461) being threadably connected to the screw rod (45), and a first linkage plate (4611) being provided on the threaded sleeve (461); a sliding sleeve (462), the sliding sleeve (462) being sleeved on the clamping guide rod (21) and being slidably connected to the clamping guide rod (21), the sliding sleeve (462) being provided with a second linkage plate (4621), and the ultrasonic probe (200) being provided on the sliding sleeve (462) or the second linkage plate (4621); A linkage guide rod (463) is provided between the first linkage plate (4611) and the second linkage plate (4621); one of the second linkage plate (4621) and the first linkage plate (4611) is fixedly connected to the linkage guide rod (463), and the other is slidably connected to the linkage guide rod (463), and the sliding direction is along the axial direction of the linkage guide rod (463).

6. The shale formation fracture fracturing simulation experimental device according to claim 4, characterized in that: It also includes a reinforcing mechanism (5), which is arranged above the working plate (3) and fixedly connected to the working plate (3) through a support rod (6), the top end of each of the screw rods (45) is rotatably connected to the reinforcing mechanism (5), and the top end of each of the clamping guide rods (21) is slidably connected to the reinforcing mechanism (5).

7. The shale formation fracture fracturing simulation experimental device according to claim 6, characterized in that: The reinforcement mechanism (5) comprises a reinforcement ring (51), the reinforcement ring (51) having an inner hole (511), a side wall of the inner hole (511) being provided with a plurality of reinforcement sliders (52), the plurality of reinforcement sliders (52) being capable of telescopic movement along the radial direction of the inner hole (511), and the top end of the clamping guide rod (21) being connected to the reinforcement slider (52).

8. The shale formation fracture fracturing simulation experimental device according to claim 7, characterized in that: The reinforcement mechanism (5) further includes a reinforcement slide bar (53), a plurality of radial through holes (512) are provided on the hole wall of the inner hole (511), one end of the reinforcement slide bar (53) is inserted into the radial through hole (512) and can slide in the radial through hole (512), and the other end of the reinforcement slide bar (53) is connected to the reinforcement slider (52).

9. The shale formation fracture fracturing simulation experimental device according to claim 1, characterized in that: The clamping guide rod (21) is provided with a plurality of arc-shaped plates (211), which are spaced apart along the axial direction of the clamping guide rod (21). The plurality of arc-shaped plates (211) can abut against the rock sample (100) when the clamping guide rod (21) clamps the rock sample (100).

10. A shale formation fracture fracturing simulation experimental method, characterized in that: According to the shale formation fracture fracturing simulation experimental device according to any one of claims 1 to 9, the shale formation fracture fracturing simulation experimental method comprises the following steps: S1, clamping and fixing the rock sample (100) on the working plate (3) through the clamping guide rods (21) of the three sets of clamping assemblies (2); S2, adding a fracturing fluid into the top fracturing hole (101) of the rock sample (100), thereby performing a fracturing simulation experiment on the rock sample (100); S3, the driving component (4) drives the ultrasonic probe (200) to move along the height direction of the rock sample (100) to detect crack changes in the rock sample (100) during the fracturing process.

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