Visual crack propagation detection device and detection method

Abstract

The invention discloses a visual crack propagation detection device which comprises a constant-speed constant-pressure pump, the constant-speed constant-pressure pump is sequentially connected with an oil-water isolator and a visual crack detection box through a pipeline, and an acoustic emission probe is arranged on the side face of the visual crack detection box. The acoustic emission probe is sequentially connected with an acoustic emission detection amplifier, a data collector and an image processor through wires, and the image processor is connected with an illuminating lamp through a wire. A first three-way ball valve is arranged between the constant-speed constant-pressure pump and the oil-water isolator, and a second three-way ball valve is arranged between the oil-water isolator and the visual crack detection box; the system further comprises a camera device and a sand mixing pump, the camera device is connected with the image processor in a wireless connection mode, and the sand mixing pump is connected with the first three-way ball valve and the second three-way ball valve through pipelines. The invention also discloses a method for detecting crack propagation by using the device. According to the visual crack propagation detection device and the detection method, the problem that the dynamic crack propagation process cannot be observed in the prior art is solved.

Description

Technical Field

[0001] The invention belongs to the technical field of hydraulic fracture extension detection equipment for oil and gas field development, and in particular relates to a visual fracture extension detection device, and also relates to a method for detecting fracture extension by using the device. Background Art

[0002] Hydraulic fracturing fracture expansion has always been an important topic in the development and research of low-permeability and dense oil and gas reservoirs. A large number of physical and mathematical simulations have been conducted on hydraulic fracturing fracture expansion at home and abroad. Among them, indoor physical simulation experiments are an important means to observe and analyze the mechanism of hydraulic fracture initiation and fracture network formation. However, as a "black box experiment", hydraulic fracturing physical simulation experiments cannot observe the dynamic expansion process of fractures in real time.

[0003] Traditional indoor hydraulic fracturing physical simulation experiments mostly use cement rock samples, and there are few visual fracture models. Fracture monitoring methods use indirect means such as acoustic emission, optical fiber, and CT scanning to characterize rock fractures after fracturing, or observe and analyze fracture morphology by cutting the fracture surface. These methods are limited to observing and analyzing fracture morphology, which is not conducive to fully understanding the dynamic expansion process of fractures. Flat proppant migration experiments are usually displayed in the form of single fractures or branch fractures. Although they can be observed intuitively, they cannot consider the three-dimensional stress state of the formation. The fracture morphology studied is only an idealized straight fracture, and it is impossible to study the real rough fracture surface, fracture morphology and impact produced by actual hydraulic fracturing.

[0004] Therefore, it is urgent to develop a visual experimental method that can detect the dynamic process of crack initiation and expansion in real time. Summary of the invention

[0005] The purpose of the present invention is to provide a visual crack extension detection device, which solves the problem that the prior art cannot observe the dynamic crack extension process.

[0006] Another object of the present invention is to provide a method for detecting crack propagation using a visual crack propagation detection device.

[0007] The technical solution adopted by the present invention is that the visual crack extension detection device includes a constant speed and constant pressure pump, which is sequentially connected to an oil-water isolator and a visual crack detection box through a pipeline, an acoustic emission probe is arranged on the side of the visual crack detection box, and the acoustic emission probe is sequentially connected to an acoustic emission detection amplifier, a data acquisition device and an image processor through a wire, and the image processor is connected to a lighting lamp through a wire; a first three-way ball valve is arranged between the constant speed and constant pressure pump and the oil-water isolator, and a second three-way ball valve is arranged between the oil-water isolator and the visual crack detection box;

[0008] It also includes a camera device and a sand mixing pump. The camera device is connected to the image processor via a wireless connection, and the sand mixing pump is connected to the first three-way ball valve and the second three-way ball valve via pipelines.

[0009] The present invention is also characterized in that:

[0010] The camera device comprises a first high-speed camera and a second high-speed camera, and the first high-speed camera and the second high-speed camera are respectively connected to the image processor via a wireless connection.

[0011] The visual crack detection box is made of acrylic material, a blind hole is opened inside the visual crack detection box, and a prefabricated slit is opened on the inner wall of the visual crack detection box.

[0012] The lighting lamp is selected from one of a laser lighting lamp, an LED lighting lamp and an infrared lighting lamp.

[0013] Another technical solution adopted by the present invention is a method for detecting crack extension, comprising the following steps:

[0014] Step 1: prepare a visual crack detection box and load the fracturing fluid into an oil-water separator;

[0015] Step 2, open the first three-way ball valve and the second three-way ball valve to connect with the oil-water separator, start the constant speed and constant pressure pump, and pump the fracturing fluid in the oil-water separator into the visual crack detection box;

[0016] Step 3: Turn on the first high-speed camera, the second high-speed camera, the data collector and the image processor, and collect data using the data collector and the image processor;

[0017] Step 4, close the constant speed and constant pressure pump, open the first three-way ball valve and the second three-way ball valve to connect with the sand mixing pump, start the constant speed and constant pressure pump, pump the sand and gravel of different particle sizes in the sand mixing pump into the visual crack detection box, and use the data acquisition device and the image processor to collect data;

[0018] Another technical solution of the present invention is also characterized in that:

[0019] The specific process of preparing a visual crack detection box is as follows: acrylic material is selected to prepare a complete sealed cavity, and visual test pieces with natural cracks of different angles, cracks of different spacings, and different spacing segments are formed through drilling, cutting, and glue injection processes.

[0020] The beneficial effects of the present invention are:

[0021] The present invention provides a real-time detection device and method for visualizing the expansion of artificial fractures, which can intuitively display the dynamic process of the initiation, expansion and migration of artificial fractures. By using transparent brittle materials and at least one visualization window in the experimental system, the entire experimental process is visualized, and a high-speed camera is used to collect video image data. The stress loading of the experimental material is based on the actual research basin reservoir conditions, while taking into account the performance indicators of the experimental device, ensuring that the expansion of fractures during the experiment can effectively guide the optimization design of hydraulic fracturing. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a structural schematic diagram of a visual real-time detection device and method for artificial crack extension according to the present invention.

[0023] In the figure, 1. constant speed and constant pressure pump, 2. first three-way ball valve, 3. oil-water isolator, 4. second three-way ball valve, 5. acoustic emission probe, 6. acoustic emission detection amplifier, 7. visual crack detection box, 8. blind hole, 9. prefabricated slit, 10. first high-speed camera, 11. second high-speed camera, 12. lighting, 13. data collector, 14. image processor, 15. sand mixing pump. DETAILED DESCRIPTION

[0024] The present invention is described in detail below with reference to the accompanying drawings and specific embodiments.

[0025] The present invention provides a visual crack extension detection device, such as Figure 1 As shown, it includes a constant speed and constant pressure pump 1, which is sequentially connected to an oil-water separator 3 and a visual crack detection box 7 through pipelines. An acoustic emission probe 5 is provided on the side of the visual crack detection box 7. The acoustic emission probe 5 is used to detect the extended signal of the visual crack detection box 7. The acoustic emission probe 5 is sequentially connected to an acoustic emission detection amplifier 6, a data collector 13 and an image processor 14 through wires. The image processor 14 is connected to a lighting lamp 12 through wires. The acoustic emission detection amplifier 6 can enhance and amplify the extended signal. The data collector 13 and the image processor 14 convert the signal into a curve of acoustic emission energy changing with time. The lighting lamp 12 is used to illuminate the migration state of the liquid or proppant in the visual crack detection box 7. A first three-way ball valve 2 is provided between the constant speed and constant pressure pump 1 and the oil-water separator 3, and a second three-way ball valve 4 is provided between the oil-water separator 3 and the visual crack detection box 7.

[0026] It also includes a first high-speed camera 10, a second high-speed camera 11 and a sand mixing pump 15. The sand mixing pump 15 is connected to the first three-way ball valve 2 and the second three-way ball valve 4 through pipelines, and the connection between the sand mixing pump 15 and the constant speed and pressure pump 1 or the oil-water isolator 3 can be switched through the first three-way ball valve 2 and the second three-way ball valve 4. The first high-speed camera 10 and the second high-speed camera 11 are respectively connected to the image processor 14 through wireless connection. The first high-speed camera 10 and the second high-speed camera 11 shoot the dynamic change process of crack initiation, expansion and migration of the visualization crack detection box 7 from two directions.

[0027] The visual crack detection box 7 is a transparent closed structure. The material of the visual crack detection box 7 is acrylic material, and its fracture toughness is close to that of rock. The purpose is to simulate the rock crack state while ensuring visibility. A blind hole 8 is opened inside the visual crack detection box 7, and a prefabricated slit 9 is opened on the inner wall of the visual crack detection box 7.

[0028] The present invention provides a visual crack extension detection device, the working principle of which is:

[0029] During the detection, a visual crack detection box 7 is prepared, the fracturing fluid is loaded into the oil-water separator 3, the first three-way ball valve 2 and the second three-way ball valve 4 are opened to communicate with the oil-water separator 3, the constant speed and constant pressure pump 1 is started, the fracturing fluid in the oil-water separator 3 is pumped into the visual crack detection box 7, the first high-speed camera 10, the second high-speed camera 11, the data collector 13 and the image processor 14 are opened, and the data collector 13 and the image processor 14 are used to collect and process data. The constant speed and constant pressure pump 1 is closed, the first three-way ball valve 2 and the second three-way ball valve 4 are opened to communicate with the sand mixing pump 15, the constant speed and constant pressure pump 1 is started, and the sand and gravel of different particle sizes in the sand mixing pump 15 are pumped into the visual crack detection box, and the data collector 13 and the image processor 14 are used to collect and process data. The acoustic emission probe 5 collects the crack expansion in the visual crack detection box 7. The first high-speed camera 10 and the second high-speed camera 11 can capture the crack expansion process from different angles and in multiple directions, and perform slow motion playback. The visual crack detection box 7 is a transparent structure, with a blind hole 8 opened inside the visual crack detection box 7, and a prefabricated slit 9 opened on the inner wall of the visual crack detection box 7. A hole is drilled by a drilling rig to simulate the blind hole shape in the fracturing process. After the hole is drilled, the test piece is arbitrarily slitted using a cutting machine. After the slit is completed, glue is injected and sealed to prepare test pieces with different crack densities such as single perforation or multiple perforations, simulate different on-site fracturing modes, and facilitate the formation of various crack shapes. Cracks of different angles are added to simulate the initiation and expansion of hydraulic fractures when natural fractures exist in the formation.

[0030] Example 1

[0031] The visual crack extension detection device proposed in this embodiment is as follows: Figure 1As shown, it includes a constant speed and constant pressure pump 1, which is sequentially connected to an oil-water isolator 3 and a visual crack detection box 7 through pipelines, and an acoustic emission probe 5 is arranged on the side of the visual crack detection box 7, and the acoustic emission probe 5 is sequentially connected to an acoustic emission detection amplifier 6, a data collector 13 and an image processor 14 through wires, and the image processor 14 is connected to a lighting lamp 12 through wires; a first three-way ball valve 2 is arranged between the constant speed and constant pressure pump 1 and the oil-water isolator 3, and a second three-way ball valve 4 is arranged between the oil-water isolator 3 and the visual crack detection box 7;

[0032] It also includes a camera device and a sand mixing pump 15. The camera device is connected to the image processor 14 by wireless connection, and the sand mixing pump 15 is connected to the first three-way ball valve 2 and the second three-way ball valve 4 by pipelines.

[0033] Example 2

[0034] The visual crack extension detection device proposed in this embodiment is as follows: Figure 1 As shown, it includes a constant speed and constant pressure pump 1, which is sequentially connected to an oil-water isolator 3 and a visual crack detection box 7 through pipelines, and an acoustic emission probe 5 is arranged on the side of the visual crack detection box 7, and the acoustic emission probe 5 is sequentially connected to an acoustic emission detection amplifier 6, a data collector 13 and an image processor 14 through wires, and the image processor 14 is connected to a lighting lamp 12 through wires; a first three-way ball valve 2 is arranged between the constant speed and constant pressure pump 1 and the oil-water isolator 3, and a second three-way ball valve 4 is arranged between the oil-water isolator 3 and the visual crack detection box 7;

[0035] It also includes a camera device and a sand mixing pump 15. The camera device is connected to the image processor 14 by wireless connection, and the sand mixing pump 15 is connected to the first three-way ball valve 2 and the second three-way ball valve 4 by pipelines.

[0036] The camera device includes a first high-speed camera 10 and a second high-speed camera 11 . The first high-speed camera 10 and the second high-speed camera 11 are respectively connected to an image processor 14 by wireless connection.

[0037] Example 3

[0038] The visual crack extension detection device proposed in this embodiment includes a constant speed and constant pressure pump 1, such as Figure 1 As shown, a constant speed and constant pressure pump 1 is sequentially connected to an oil-water separator 3 and a visual crack detection box 7 through pipelines, an acoustic emission probe 5 is provided on the side of the visual crack detection box 7, and the acoustic emission probe 5 is sequentially connected to an acoustic emission detection amplifier 6, a data collector 13 and an image processor 14 through wires, and the image processor 14 is connected to a lighting lamp 12 through wires; a first three-way ball valve 2 is provided between the constant speed and constant pressure pump 1 and the oil-water separator 3, and a second three-way ball valve 4 is provided between the oil-water separator 3 and the visual crack detection box 7;

[0039] It also includes a camera device and a sand mixing pump 15. The camera device is connected to the image processor 14 by wireless connection, and the sand mixing pump 15 is connected to the first three-way ball valve 2 and the second three-way ball valve 4 by pipelines.

[0040] The camera device includes a first high-speed camera 10 and a second high-speed camera 11 . The first high-speed camera 10 and the second high-speed camera 11 are respectively connected to an image processor 14 by wireless connection.

[0041] The visual crack detection box 7 is made of acrylic material, a blind hole 8 is provided inside the visual crack detection box 7 , and a prefabricated slit 9 is provided on the inner wall of the visual crack detection box 7 .

[0042] The lighting lamp 12 is selected from one of a laser lighting lamp, an LED lighting lamp or an infrared lighting lamp.

[0043] Example 4

[0044] The crack extension detection method proposed in this embodiment includes the following steps:

[0045] Step 1: prepare a visual crack detection box and load the fracturing fluid into an oil-water separator;

[0046] The specific process of preparing a visual crack detection box is as follows: acrylic material is selected to prepare a complete sealed cavity, and visual test pieces with natural cracks of different angles, cracks of different spacings, and different spacing segments are formed through drilling, cutting, and glue injection processes.

[0047] Step 2, open the first three-way ball valve and the second three-way ball valve to connect with the oil-water separator, start the constant speed and constant pressure pump, and pump the fracturing fluid in the oil-water separator into the visual crack detection box;

[0048] Step 3: Turn on the first high-speed camera, the second high-speed camera, the data collector and the image processor, and collect data using the data collector and the image processor;

[0049] Step 4: Close the constant speed and constant pressure pump, open the first three-way ball valve, the second three-way ball valve and the sand mixing pump, start the constant speed and constant pressure pump, pump the sand and gravel of different particle sizes in the sand mixing pump into the visual crack detection box, and use the data acquisition device and image processor to collect data.

Claims

1. Visual crack extension detection device, characterized in that: The invention comprises a constant speed and constant pressure pump (1), wherein the constant speed and constant pressure pump (1) is sequentially connected to an oil-water isolator (3) and a visual crack detection box (7) through a pipeline, an acoustic emission probe (5) is arranged on the outer side of the visual crack detection box (7), the acoustic emission probe (5) is sequentially connected to an acoustic emission detection amplifier (6), a data acquisition device (13) and an image processor (14) through a wire, and the image processor (14) is connected to an illuminating lamp (12) through a wire; a first three-way ball valve (2) is arranged on the pipeline between the constant speed and constant pressure pump (1) and the oil-water isolator (3), and a second three-way ball valve (4) is arranged on the pipeline between the oil-water isolator (3) and the visual crack detection box (7); and the invention also comprises a camera device and a sand mixing pump (15), wherein the camera device is connected to the image processor (14) through a wireless connection, and the sand mixing pump (15) is respectively connected to the first three-way ball valve (2) and the second three-way ball valve (4) through pipelines.

2. The visual crack extension detection device according to claim 1, characterized in that: The camera device comprises a first high-speed camera (10) and a second high-speed camera (11), and the first high-speed camera (10) and the second high-speed camera (11) are respectively connected to the image processor (14) by wireless connection.

3. The visual crack extension detection device according to claim 2, characterized in that: The visual crack detection box (7) is made of acrylic material, a blind hole (8) is provided inside the visual crack detection box (7), and a prefabricated slit (9) is provided on the inner wall of the visual crack detection box (7).

4. The visual crack extension detection device according to claim 3, characterized in that: The lighting lamp (12) is selected from one of a laser lighting lamp, an LED lighting lamp or an infrared lighting lamp.

5. A method for detecting crack extension, characterized in that: Using the visual crack extension detection device as claimed in claim 4 specifically comprises the following steps: Step 1, loading the fracturing fluid into the oil-water separator (3); Step 2, pumping the fracturing fluid in the oil-water separator (3) into the visual crack detection box (7); Step 3: Turn on the first high-speed camera (10), the second high-speed camera (11), the data collector (13) and the image processor (14), and use the data collector (13) and the image processor (14) to collect data in the visual crack detection box (7); Step 4: turn off the constant speed and constant pressure pump (1), use the sand mixing pump (15) to pump sand and gravel of different particle sizes into the visual crack detection box (7), and use the data acquisition device (13) and the image processor (14) to collect data in the visual crack detection box (7).

6. The method for detecting crack extension according to claim 5, characterized in that: The specific process of step 2 is: opening the first three-way ball valve (2), the second three-way ball valve (4) and connecting with the oil-water separator (3), starting the constant speed and constant pressure pump (1), and pumping the fracturing fluid in the oil-water separator (3) into the visual crack detection box (7).

7. The method for detecting crack extension according to claim 5, characterized in that: The specific process of step 4 is as follows: closing the constant speed and constant pressure pump (1), opening the first three-way ball valve (2), the second three-way ball valve (4) and the sand mixing pump (15) to connect, starting the constant speed and constant pressure pump (1), using the sand mixing pump (15) to pump sand and gravel of different particle sizes into the visual crack detection box (7), and using the data acquisition device (13) and the image processor (14) to collect data in the visual crack detection box (7).

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