Rock stratum in-situ permeability coefficient testing device
By designing a rock formation in situ permeability coefficient testing device including pressure channels, water pressure sensors, liquid conduit pipelines, pressure-controlled expansion plugs and guide wheels, the problem that the rock formation permeability coefficient measurement results are lower than the actual value in the field in the prior art, and accurate and reliable permeability coefficient testing is achieved in situ of the rock formation.
Patent Information
- Application Number
- CN202421690834.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-07-17
- Publication Date
- 2025-06-17
- Estimated Expiration
- 2034-07-17
AI Technical Summary
The existing rock formation permeability coefficient measurement technology has the problem that indoor test results are lower than the actual value on site, and it is difficult to achieve accurate and reliable testing on site in-situ testing equipment.
A rock formation in-situ permeability coefficient testing device is designed, including pressure channels, water pressure sensors, liquid conduit pipelines, pressure-controlled expansion rubber plugs and guide wheels. Through the reasonable configuration of these components, the in-situ permeability coefficient testing is achieved in-situ in-situ in-situ, avoiding disturbance and damage during sample collection, transportation and processing.
The device can accurately measure the permeability coefficient under the in-situ conditions of the rock formation, avoid stress release and disturbance damage, improve the reliability and representativeness of the test results, and the device can be reused and operated with simple operation.
Smart Images
Figure CN222994270U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of geotechnical engineering testing, in particular to a device for testing the in-situ permeability coefficient of rock strata. Background Art
[0002] The permeability coefficient of rock strata is an important physical property index required for the development of underground rock and mineral resources. Existing permeability coefficient measurement technologies can be divided into two methods according to the test conditions: laboratory measurement and in-situ measurement on site. The laboratory measurement method requires obtaining rock or core samples through technical means such as drilling first, processing them into specimens of a certain size by devices such as cutters and grinders, and then measuring them using indoor test equipment. However, since the test specimens in the laboratory mostly come from intact and dense rock or core samples, their measurement results are often several orders of magnitude lower than the actual in-situ permeability coefficient of the site. Therefore, the indoor test measurement method still has limitations in practical applications. Compared with the laboratory method, the in-situ test method on site does not require collecting rocks or cores, and the test is directly carried out in the in-situ rock strata, avoiding the disturbance and damage of the samples during transportation and processing, and the representativeness of the test data is better.
[0003] Therefore, we propose a device for testing the in-situ permeability coefficient of rock strata. Content of the Utility Model
[0004] The utility model mainly solves the above technical problems and provides a device for testing the in-situ permeability coefficient of rock strata.
[0005] To achieve the above object, the utility model adopts the following technical scheme. A device for testing the in-situ permeability coefficient of rock strata includes: a pressure channel Ⅰ, the upper end of which is connected to an external pressure source, the lower end of which is connected to the top of the test device and passes through the test device to communicate with the upper space a of the core;
[0006] A lifting ring, fixed to the top of the test device for hoisting and transportation work;
[0007] A water pressure sensor, installed inside the test device, communicates with test points at different heights through a liquid guide pipeline, and can monitor the water pressure at each point in real time;
[0008] A liquid guide pipeline, used to connect the water pressure sensor and each test point to transmit liquid pressure;
[0009] A pressure-controlled expansion rubber plug Ⅰ, fixed at equal intervals in the lower annular space of the test device, connected to an external pressure source through a pressure channel Ⅱ, and used to divide the gap between the instrument barrel wall and the core into multiple independent regions;
[0010] A pressure channel Ⅱ, connecting the pressure-controlled expansion rubber plug Ⅰ, the pressure-controlled expansion rubber plug Ⅱ and an external pressure source, and used to inject pressure fluid to expand the rubber plugs;
[0011] The guide wheels, with spring telescopic devices at the tails, are symmetrically installed on the outer shell of the testing device and are used to ensure the centering of the device.
[0012] The second pressure-controlled expansion rubber plug is used to balance the pressure of the first pressure-controlled expansion rubber plug on the barrel wall of the instrument and prevent the deformation of the barrel wall of the instrument.
[0013] Preferably, the pressure channel I is used to inject the test liquid into the upper space a of the core and transfer the pressure of the test liquid to the core through the pressure channel I.
[0014] Preferably, the liquid guiding pipeline is used to connect the water pressure sensors at different heights to monitor the water pressure changes at each test point.
[0015] Preferably, the first pressure-controlled expansion rubber plug divides the gap between the barrel wall of the instrument and the core into four independent regions. The uppermost region a is communicated with the pressure channel I, and the following three regions b, c, and d are respectively connected to the water pressure sensors through the liquid guiding pipeline.
[0016] Preferably, the guide wheels are symmetrically installed on the outer shell of the testing device, and the spring telescopic device at the tail is used to ensure the centering of the testing device in the borehole.
[0017] Beneficial effects
[0018] The utility model provides a device for testing the in-situ permeability coefficient of rock formations. It has the following beneficial effects:
[0019] 1. The beneficial effects of the utility model are as follows: The permeability coefficient test is carried out under the in-situ conditions of the rock formation, avoiding stress release and disturbance damage during the processes of core collection, transportation, and processing; the testing equipment can be carried into the hole by the drill pipe and taken out of the borehole by the drill pipe after the test, and can be reused; the test equipment is equipped with a centering and guiding device, improving the success rate of the test; the test principle is simple, the operation is convenient, and the results are reliable. Description of the drawings
[0020] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the following drawings are only exemplary, and for those of ordinary skill in the art, without creative efforts, other implementation drawings can also be obtained according to the provided drawings.
[0021] The structures, proportions, sizes, etc. illustrated in this specification are only used to match the content disclosed in the specification for those familiar with this technology to understand and read, and are not used to limit the implementation conditions of the present utility model. Therefore, they do not have substantial technical significance. Any modification of the structure, change in the proportional relationship, or adjustment of the size, without affecting the efficacy and purpose that the present utility model can achieve, should still fall within the scope covered by the technical content disclosed in the present utility model.
[0022] Figure 1 is a schematic diagram of the internal structure of the front side of the present utility model;
[0023] Figure 2 is a schematic cross-sectional view of the present utility model;
[0024] In the figure: 1 Pressure channel Ⅰ; 2 Suspension ring; 3 Water pressure sensor; 4 Liquid guide pipeline; 5 Pressure-controlled expansion rubber plug Ⅰ; 6 Pressure channel Ⅱ; 7 Guide wheel; 8 Pressure-controlled expansion rubber plug Ⅱ. Specific embodiments
[0025] Next, the technical solutions in the embodiments of the present utility model will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present utility model. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all the embodiments. Based on the embodiments in the present utility model, all other embodiments obtained by those of ordinary skill in the art without making creative efforts belong to the scope of protection of the present utility model.
[0026] Embodiment: A device for testing the in-situ permeability coefficient of rock formations; as Figures 1 to 2 shown, the device for testing the in-situ permeability coefficient of rock formations includes a pressure channel Ⅰ 1, a suspension ring 2, a water pressure sensor 3, a liquid guide pipeline 4, a pressure-controlled expansion rubber plug 5 Ⅰ, a pressure channel Ⅱ 6, a guide wheel 7, and a pressure-controlled expansion rubber plug 8 Ⅱ. The upper end of the pressure channel Ⅰ 1 is connected to an external pressure source, the lower end is connected to the top of the testing device, and passes through the testing device to communicate with the upper space a of the core. The suspension ring 2 is fixed to the top of the testing device for hoisting and transportation work. The water pressure sensor 3 is installed inside the testing device and communicates with the test points at different heights through the liquid guide pipeline, and can monitor the water pressure at each point in real time. The pressure-controlled expansion rubber plugs are fixed at equal intervals in the lower annular space of the testing device and are symmetrically arranged inside and outside. They are connected to the external pressure source through the pressure channel Ⅱ 6. The tail of the guide wheel 7 has a spring telescopic device, and it is symmetrically installed on the outer shell of the testing device.
[0027] The working principle of the present utility model:
[0028] The method for testing the in-situ permeability coefficient of rock formations is as follows:
[0029] (1) Construct a test borehole in the rock formation;
[0030] (2) Bring the above in-situ permeability coefficient testing device of the rock stratum into the borehole via the drill pipe. During this process, the guide wheel 7 can ensure the centering of the device, greatly improving the success rate of the equipment in correctly aligning with the core.
[0031] (3) Inject the test liquid through the pressure channel I 1, displace all the original impurities in the test section, and fill the liquid guiding pipeline 4 with the test liquid.
[0032] (4) Inject pressure fluid into the pressure-controlled expansion rubber plug I 5 and the pressure-controlled expansion rubber plug II 8 through the pressure channel II 6 to make them expand. Among them, the pressure-controlled expansion rubber plug I 5 divides the gap between the instrument cylinder wall and the core into 4 independent regions. The uppermost region a is connected to the pressure channel I 1, and the following 3 regions b - d are respectively connected to each water pressure sensor 3 through the liquid guiding pipeline 4. The pressure-controlled expansion rubber plug II 8 is used to balance the pressure of the pressure-controlled expansion rubber plug I 5 on the instrument cylinder wall and prevent the deformation of the instrument cylinder wall.
[0033] (5) Inject the test liquid through the pressure channel I 1 and make the liquid pressure reach a certain predetermined value. Then maintain the liquid pressure constant and record the readings of the 3 water pressure sensors 3 until they are stable. At this time, record the flow rate of the injected liquid at a certain time interval. The permeability coefficient of the rock stratum can be calculated through the constant head permeability test permeability coefficient formula (1).
[0034]
[0035] Where: kT is the permeability coefficient of the specimen at water temperature T °C, cm / s; Q is the amount of permeated water within time t seconds, cm 3 ; L is the seepage path, cm, equal to the height of the specimen between the centers of the two pressure holes on both sides; A is the cross-sectional area of the specimen, cm 2 ; t is the time difference, s; H1 and H2 are the water level differences between the water pressure sensors 1 - 2 and 2 - 3, cm.
[0036] Main effects of the in-situ permeability coefficient testing device of the rock stratum
[0037] Accurately test the permeability coefficient: The combined use of the pressure-controlled expansion rubber plug I 5 and the pressure-controlled expansion rubber plug II 8; Through the pressure-controlled expansion rubber plug I 5 and the pressure-controlled expansion rubber plug II 8, this device can divide the gap between the instrument cylinder wall and the core into multiple independent regions. The pressure and seepage conditions of each region can be measured independently, ensuring the accuracy and reliability of the test data.
[0038] Real-time monitor the water pressure change; The water pressure sensor 3 and the liquid guiding pipeline 4; The water pressure sensor 3 is connected to the test points at different heights through the liquid guiding pipeline 4, and can real-time monitor the water pressure changes at each point. This configuration enables the acquisition of immediate seepage data during the test, facilitating the analysis of the seepage characteristics of the rock stratum.
[0039] Pressure balance; the combined action of the pressure-controlled expansion plug 5 and the pressure-controlled expansion plug 8; the pressure-controlled expansion plug 5 is connected to an external pressure source through the pressure channel II 6, and pressure fluid is injected to expand the plug, thereby dividing the gap between the instrument barrel wall and the core into independent regions. The pressure-controlled expansion plug 8 is used to balance the pressure of the plug 5 on the instrument barrel wall, prevent the barrel wall from deforming, and ensure the stability and accuracy of the test data.
[0040] Device centering: the guide wheel 7 and the spring telescopic device at its tail; the guide wheel 7 is symmetrically installed on the outer shell of the test device, and the spring telescopic device at the tail is used to ensure the centering of the device in the borehole. This design ensures the stability and precise positioning of the device during operation, and improves the reliability of the test.
[0041] Multi-region independent testing: the equidistant arrangement of the pressure-controlled expansion plug 5; the pressure-controlled expansion plug 5 divides the gap between the instrument barrel wall and the core into multiple independent regions, allowing independent testing of each region. This design can conduct a detailed analysis of different regions of the core, improving the comprehensiveness and accuracy of the test results.
[0042] Structural stability; the balanced design of the pressure-controlled expansion plug 8 and the pressure-controlled expansion plug 5; the pressure-controlled expansion plug 8 is used to balance the pressure of the pressure-controlled expansion plug 5 on the instrument barrel wall, preventing the instrument barrel wall from deforming. This design not only ensures the structural stability of the device, but also improves the accuracy of the test results.
[0043] Multi-purpose adaptability: the configuration of the liquid guiding pipeline 4 and the water pressure sensor 3; the liquid guiding pipeline 4 is connected to the water pressure sensors 3 at different heights to monitor the water pressure changes at each test point. This design can adapt to the permeability coefficient tests under different depths and different geological conditions, with strong adaptability and a wide range of applications.
[0044] In summary, through the reasonable cooperation of each structural component, the in-situ permeability coefficient test device for rock strata achieves the main effects such as accurate testing, real-time monitoring, pressure balance, and device centering, and has significant secondary effects in terms of convenient transportation, multi-region independent testing, structural stability, and multi-purpose adaptability.
[0045] The above shows and describes the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited by the above embodiments. What is described in the above embodiments and the specification only illustrates the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention will have various changes and improvements, and these changes and improvements all fall within the scope of the present invention claimed. The scope of protection claimed by the present invention is defined by the appended claims and their equivalents.
Claims
1. A rock formation in-situ permeability test device, characterized in that: include: A pressure channel I (1), the upper end of which is connected to an external pressure source, the lower end of which is connected to the top of the test device, and passes through the test device to communicate with the upper space (a) of the core; A lifting ring (2), fixed on the top of the test device, used for lifting and transportation; A water pressure sensor (3) is installed inside the test device and communicates with test points at different heights through a liquid guide pipe (4) so as to monitor the water pressure at each point in real time; A liquid guiding pipeline (4) is used to connect the water pressure sensor (3) and each test point to transmit liquid pressure; Pressure-controlled expansion plugs 1 (5) are fixed at equal intervals in the annular space at the bottom of the test device and connected to an external pressure source through pressure channel II (6) to divide the space between the instrument barrel wall and the core into multiple independent areas; The pressure channel II (6) connects the pressure-controlled expansion rubber plug 1 (5), the pressure-controlled expansion rubber plug 2 (8) and an external pressure source, and is used to inject pressure fluid to expand the rubber plug; A guide wheel (7) has a spring retractable device at the rear and is symmetrically mounted on the test device housing to ensure the centering of the device; The second pressure-controlled expansion rubber plug (8) is used to balance the pressure of the first pressure-controlled expansion rubber plug (5) on the instrument tube wall to prevent the instrument tube wall from deforming.
2. The rock formation in-situ permeability test device according to claim 1, characterized in that: The pressure channel I (1) is used to inject test liquid into the upper space (a) of the core, and transmit the pressure of the test liquid to the core through the pressure channel I (1).
3. The rock formation in-situ permeability test device according to claim 1, characterized in that: The liquid guiding pipeline (4) is used to connect water pressure sensors (3) at different heights to monitor the water pressure changes at each test point.
4. The rock formation in-situ permeability test device according to claim 1, characterized in that: The pressure-controlled expansion plug 1 (5) divides the space between the instrument barrel wall and the rock core into four independent areas, the uppermost area (a) is connected to the pressure channel 1 (1), and the lower three areas (b, c, d) are connected to the water pressure sensors (3) through the liquid guide pipes (4).
5. The rock formation in-situ permeability test device according to claim 1, characterized in that: The guide wheel (7) is symmetrically mounted on the test device housing, and the spring expansion device at the tail is used to ensure that the test device is centered in the drill hole.