Equipment for observing rock mass cracks in real time in hydraulic fracturing ground stress test
By designing a device for ground stress testing of hydraulic fracturing methods, including steel pipes, directional instruments, impressions and pressure supply hoses, the problem of low efficiency of existing equipment is solved, rapid observation of multiple detection areas is achieved, and detection efficiency is improved.
Patent Information
- Application Number
- CN202421664315.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-07-15
- Publication Date
- 2025-06-17
- Estimated Expiration
- 2034-07-15
AI Technical Summary
In the ground stress test of hydraulic fracturing, the existing equipment for observing rock mass fractures is low efficiency and requires position-by-position detection, resulting in low detection efficiency.
A device including steel pipes, directional instruments, impression instruments, and pressure supply hoses is designed. Through the combination of directional instruments and impression instruments on the steel pipes, the use of pressure supply hoses is achieved to achieve rapid observation of multiple detection areas.
Through the design of this equipment, cracks can be observed in multiple detection areas quickly, which improves detection efficiency and achieves the purpose of real-time observation of rock mass fractures.
Smart Images
Figure CN222994187U_ABST
Abstract
Description
Technical Field
[0001] The utility model belongs to the technical field of a real-time observation device, and more specifically, particularly relates to a device for real-time observation of rock mass cracks in a hydraulic fracturing in-situ stress test. Background Technique
[0002] The principle of the hydraulic fracturing in-situ stress test is to use a pair of expandable rubber packers to seal a section of a borehole at a predetermined test depth, and then pump a liquid medium to apply pressure to the sealed section. According to the characteristic values of the fracturing process curve, pressure parameters such as fracture pressure, instantaneous shut-in pressure, and reopening pressure can be obtained. The in-situ stress state in the plane can be directly deduced from the direction of the fracture. When conducting crack detection, usually an impression packer and a direction finder are placed at the test depth, a certain pressure is applied to the impression packer to expand it, the closed fracture in the rock mass is reopened again, and a mark is left on the surface of the impression packer. Then it is taken out, the crack indentation on the surface of the impression packer is found, and then according to the data of the direction finder and the baseline orientation of the impression packer, the strike of the measured fracture surface can be calculated.
[0003] Based on the above, the inventor found the following problems: When conducting in-situ stress tests, detections are usually carried out at multiple different positions, and when conducting crack detections, they need to be carried out one by one, resulting in low efficiency. Therefore, in view of this, research and improvement are carried out on the existing structure and deficiencies, and a device for real-time observation of rock mass cracks in a hydraulic fracturing in-situ stress test is provided, with the expectation of achieving a more practical value. Summary of the Utility Model
[0004] In order to solve the above technical problems, the utility model provides a device for real-time observation of rock mass cracks in a hydraulic fracturing in-situ stress test to solve the problem of low efficiency of the existing device for observing rock mass cracks.
[0005] The purpose and efficacy of the device for real-time observation of rock mass cracks in a hydraulic fracturing in-situ stress test of the utility model are achieved by the following specific technical means:
[0006] A device for real-time observation of rock mass cracks in a hydraulic fracturing in-situ stress test includes a steel pipe. A direction finder is installed at the bottom of the steel pipe. A plurality of impression packers are sleeved on the surface of the steel pipe. A first pressure supply hose is installed at the top of the uppermost impression packer. A second pressure supply hose is installed at the bottom of the impression packer. The second pressure supply hose is connected to the top of the next impression packer. The bottom of the lowermost impression packer is in a sealed state.
[0007] Further, first threaded grooves are formed at both the top and the bottom of the impression packer, and threaded connectors are installed on the surfaces of the first pressure supply hose and the second pressure supply hose.
[0008] Furthermore, a fixing mechanism is mounted on the surface of the impression device.
[0009] Furthermore, the fixing mechanism includes a connecting member mounted on the surface of the impression device. A second threaded groove is formed on the surface of the connecting member, and a bolt is installed in the second threaded groove.
[0010] Furthermore, a limiting mechanism is mounted on the surface of the impression device.
[0011] Furthermore, the limiting mechanism includes a limiting groove formed on the surface of the steel pipe, and a limiting block matching the limiting groove is mounted on the surface of the impression device.
[0012] Furthermore, the orientation instrument is mounted on the steel pipe in a detachable manner.
[0013] Compared with the prior art, the utility model has the following beneficial effects:
[0014] By the combined use of the steel pipe, the orientation instrument, the impression device, the first pressure supply hose and the second pressure supply hose, first, the orientation instrument and an appropriate number of impression devices are mounted on the steel pipe. According to the detected position, the position of the impression device is adjusted. Then, the first pressure supply hose and the second pressure supply hose are mounted on the impression device, and they are placed into the drill hole. Then, on the ground, through the pressurization system, the impression device is inflated through the first pressure supply hose, and then other impression devices are inflated through the second pressure supply hose. In order to obtain clear crack traces, sufficient high pressure needs to be applied to cause the existing cracks in the hole wall to reopen so that the rubber can be squeezed in and maintained for a corresponding time. The surface of the impression device is printed with raised imprints corresponding to the cracks. After the pressure holding time ends, the pressure of the impression device is removed and it is taken out of the drill hole. According to the orientation instrument data and the baseline orientation of the impression device, the trend of the measured fracture surface (that is, the direction of the maximum horizontal principal compressive stress) and the dip and inclination angle of the fracture surface can be calculated. At the same time, the impression device is surrounded by a transparent plastic film, and the raised imprints and baseline marks on the surface of the impression device are drawn. Through the above design, cracks in multiple detection areas can be observed quickly, improving the efficiency. BRIEF DESCRIPTION OF THE DRAWINGS
[0015] Figure 1 is an overall schematic diagram of a device for real-time observation of rock mass cracks in the hydraulic fracturing method for in-situ stress test of the utility model.
[0016] Figure 2 is a bottom view schematic diagram of the impression device of a device for real-time observation of rock mass cracks in the hydraulic fracturing method for in-situ stress test of the utility model.
[0017] Figure 3 is an assembly schematic diagram of the first pressure supply hose of a device for real-time observation of rock mass cracks in the hydraulic fracturing method for in-situ stress test of the utility model.
[0018] Figure 4 It is a schematic diagram of bolt assembly of a device for real-time observation of rock mass cracks in the in-situ stress test by hydraulic fracturing method of the present utility model.
[0019] In the figure, the corresponding relationship between the component names and the drawing reference numbers is as follows:
[0020] 1. Steel pipe; 2. Direction finder; 3. Impression device; 4. First pressure supply hose; 5. Second pressure supply hose; 6. First thread groove; 7. Threaded connector; 8. Connector; 9. Second thread groove; 10. Bolt; 11. Limit groove; 12. Limit block. Specific embodiments
[0021] The following further describes in detail the embodiments of the present utility model in conjunction with the drawings and examples. The following examples are used to illustrate the present utility model, but cannot be used to limit the scope of the present utility model.
[0022] In the description of the present utility model, unless otherwise specified, "a plurality of" means two or more; the terms "upper", "lower", "left", "right", "inner", "outer", "front end", "rear end", "head", "tail", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be construed as a limitation of the present utility model. In addition, the terms "first", "second", "third", etc. are only used for descriptive purposes and cannot be construed as indicating or implying relative importance.
[0023] In the description of the present utility model, it should be noted that unless otherwise clearly specified and defined, the terms "connected" and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood according to specific circumstances. Embodiment
[0024] As shown in the attached Figure 1 to the attached Figure 4 figures:
[0025] The utility model provides a device for real-time observation of rock mass cracks in hydraulic fracturing in-situ stress tests, including a steel pipe 1. A direction finder 2 is installed at the bottom of the steel pipe 1. A plurality of impression devices 3 are sleeved on the surface of the steel pipe 1. A first pressure supply hose 4 is installed at the top of the uppermost impression device 3. A second pressure supply hose 5 is installed at the bottom of the impression device 3. The second pressure supply hose 5 is connected to the top of the next impression device 3. The bottom of the lowermost impression device 3 is in a sealed state.
[0026] The combined use of the steel pipe 1, the direction finder 2, the impression devices 3, the first pressure supply hose 4 and the second pressure supply hose 5 is as follows: First, install the direction finder 2 and an appropriate number of impression devices 3 on the steel pipe 1. Adjust the positions of the impression devices 3 according to the detected positions. Then install the first pressure supply hose 4 and the second pressure supply hose 5 on the impression devices 3 and place them into the borehole. Then, on the ground, use a pressurization system to expand the impression devices 3 through the first pressure supply hose 4, and then expand other impression devices 3 through the second pressure supply hose 5. In order to obtain clear crack traces, sufficient high pressure needs to be applied to cause the existing cracks in the borehole wall to reopen so that the rubber can be squeezed in and maintained for a corresponding time. The surface of the impression device 3 is printed with raised imprints corresponding to the cracks. After the pressure holding time ends, release the pressure of the impression device 3 and lift it out of the borehole. According to the data of the direction finder 2 and the baseline orientation of the impression device 3, the strike of the measured fracture surface (i.e., the direction of the maximum horizontal principal compressive stress), the dip and dip angle of the fracture surface can be calculated. At the same time, surround the impression device 3 with a transparent plastic film and draw down the raised imprints and baseline marks on the surface of the impression device 3. Through the above design, cracks in multiple detection areas can be observed quickly, improving the efficiency.
[0027] Wherein, first threaded grooves 6 are opened at both the top and bottom of the impression device 3. Threaded connectors 7 are installed on the surfaces of the first pressure supply hose 4 and the second pressure supply hose 5.
[0028] Through the use of the first threaded grooves 6 and the threaded connectors 7, the installation and disassembly of the first pressure supply hose 4 and the second pressure supply hose 5 can be facilitated.
[0029] Wherein, a fixing mechanism is installed on the surface of the impression device 3.
[0030] Wherein, the fixing mechanism includes a connector 8 installed on the surface of the impression device 3. A second threaded groove 9 is opened on the surface of the connector 8. A bolt 10 is installed in the second threaded groove 9.
[0031] Through the combined use of the connector 8, the second threaded groove 9 and the bolt 10, when the position of the impression device 3 needs to be adjusted, just loosen the bolt 10, then the position of the impression device 3 can be adjusted, and then tighten the bolt 10 to fix it.
[0032] Among them, a limiting mechanism is installed on the surface of the impressioner 3.
[0033] Among them, the limiting mechanism includes a limiting groove 11 opened on the surface of the steel pipe 1, and a limiting block 12 matching the limiting groove 11 is installed on the surface of the impressioner 3.
[0034] By using the limiting groove 11 and the limiting block 12, the impressioner 3 can be positioned so that the orientations of multiple impressioners 3 and the orientation instrument 2 are the same.
[0035] Among them, the orientation instrument 2 is installed on the steel pipe 1 in a detachable manner.
[0036] Specific usage method and function of this embodiment:
[0037] When the utility model is in use, first, a drill hole with a smooth hole wall and a consistent hole diameter is opened at the depth position where the intact core is located on the ground, and then a pair of expandable rubber packers are placed at the depth position to be measured by a drill pipe.
[0038] Through the pressurization system on the ground, the two packers are pressurized simultaneously to make them expand and closely contact the hole wall, so that the fracturing section can be isolated to form a closed space.
[0039] Using a high-pressure pump to pressurize the fracturing test section through a drill pipe or a high-pressure pipe. During the pressurization process, since a pressure sensor is installed in the high-pressure pipeline, the pressure value on the recording instrument will rapidly increase as the high-pressure liquid is pumped in. Due to the stress concentration around the drill hole, the rock in the fracturing section will crack at the position of the minimum tangential stress under the action of sufficient hydraulic pressure, that is, crack in the direction perpendicular to the minimum horizontal principal stress. The critical pressure value Pb recorded at this time is the fracture pressure of the rock. Once the rock generates cracks, the pressure will drop sharply. If the displacement is continuously maintained for pressurization, the cracks will remain open and extend longitudinally;
[0040] After the rock cracks, the high-pressure pump is closed to stop injecting pressure into the test section. At the moment of closing the pump, the pressure will drop sharply; then, as the liquid infiltrates into the formation, the pressure will drop slowly. Under the action of the rock mass stress, the cracks tend to close. The pressure recorded when the cracks are in the critical closing state is the closing pressure;
[0041] When the pressure in the fracturing section tends to be stable or no longer drops significantly, the pressure in this packer section can be relieved to connect to the atmosphere, and the already opened cracks will close;
[0042] Then, install the orientation instrument 2 and an appropriate number of impression makers 3 on the steel pipe 1. Adjust the position of the impression maker 3 according to the detected position, and then tighten the bolt 10 for fixation. Then, install the first pressure supply hose 4 and the second pressure supply hose 5 on the impression maker 3 through the threaded connector 7, and place it into the drill hole. Then, on the ground, expand the impression maker 3 through the first pressure supply hose 4 by the pressurization system, and then expand the other impression makers 3 through the second pressure supply hose 5. In order to obtain clear crack traces, sufficient high pressure needs to be applied to prompt the existing cracks in the hole wall to reopen so that the rubber can be squeezed in, and maintain the corresponding time. The surface of the impression maker 3 is printed with raised imprints corresponding to the cracks. After the pressure holding time ends, release the pressure of the impression maker 3 and lift it out of the drill hole. According to the data of the orientation instrument 2 and the baseline orientation of the impression maker 3, the trend of the measured fracture surface (i.e., the direction of the maximum horizontal principal compressive stress) and the dip and dip angle of the fracture surface can be calculated. At the same time, surround the impression maker 3 with a transparent plastic film, draw the raised imprints and baseline marks on the surface of the impression maker 3. Through the above design, the cracks in multiple detection areas can be observed quickly, improving the efficiency.
[0043] The embodiments of the present invention are given for purposes of illustration and description, and are not exhaustive or limit the present invention to the disclosed form. Many modifications and variations are obvious to those of ordinary skill in the art. The embodiments are chosen and described in order to better explain the principles of the present invention and its practical applications, and to enable those of ordinary skill in the art to understand the present invention and design various embodiments with various modifications suitable for specific purposes.
Claims
1. A device for real-time observation of rock mass cracks in a hydraulic fracturing ground stress test, comprising a steel pipe (1), characterized in that: An orienting instrument (2) is installed at the bottom of the steel pipe (1), and a plurality of molds (3) are sleeved on the surface of the steel pipe (1). A first pressure supply hose (4) is installed at the top of the topmost mold (3), and a second pressure supply hose (5) is installed at the bottom of the mold (3). The second pressure supply hose (5) is connected to the top of the next mold (3), and the bottom of the bottommost mold (3) is in a sealed state.
2. A device for real-time observation of rock mass cracks in a hydraulic fracturing ground stress test according to claim 1, characterized in that: The top and bottom of the impression device (3) are both provided with first thread grooves (6), and the surfaces of the first pressure supply hose (4) and the second pressure supply hose (5) are provided with threaded connectors (7).
3. A device for real-time observation of rock mass cracks in a hydraulic fracturing ground stress test according to claim 2, characterized in that: A fixing mechanism is installed on the surface of the impression device (3).
4. A device for real-time observation of rock mass cracks in a hydraulic fracturing ground stress test according to claim 3, characterized in that: The fixing mechanism comprises a connecting piece (8) mounted on the surface of the impression device (3), a second thread groove (9) being formed on the surface of the connecting piece (8), and a bolt (10) being mounted in the second thread groove (9).
5. A device for real-time observation of rock mass cracks in a hydraulic fracturing ground stress test according to claim 4, characterized in that: A limiting mechanism is installed on the surface of the impression device (3).
6. A device for real-time observation of rock mass cracks in a hydraulic fracturing ground stress test according to claim 5, characterized in that: The limiting mechanism comprises a limiting groove (11) formed on the surface of the steel pipe (1), and a limiting block (12) matching the limiting groove (11) is installed on the surface of the impression device (3).
7. A device for real-time observation of rock mass cracks in a hydraulic fracturing ground stress test according to claim 6, characterized in that: The orientation instrument (2) is detachably mounted on the steel pipe (1).