CN110879188B - Mobile fast coal and rock permeability measuring instrument - Google Patents

Abstract

The invention provides a mobile rapid coal and rock permeability measuring instrument, and belongs to the technical field of coal and rock permeability measurement. The movable rapid coal and rock permeability measuring instrument comprises a support sleeve, a left main packer, a right main packer, a left secondary packer, a right secondary packer, a first high-pressure gas cylinder, a second high-pressure gas cylinder, a data recorder and the like. The invention has the beneficial effects that: the material can be repeatedly used, and the service life is long; the measurement operation is simple, multipoint and rapid measurement can be implemented in one drill hole, the measurement time is generally 10-30 minutes, the measurement time is short, the switching of the measurement points can be realized only by deflating each packer through an exhaust valve, the switching speed of the measurement points is high, the air tightness between the packers and the inner wall of the drill hole is detected in real time in the measurement process, the accuracy of measurement data is ensured, and the intensive, rapid and accurate measurement of the coal bed air permeability coefficient is realized.

Description

Mobile fast coal and rock permeability measuring instrument

technical field

The invention relates to the technical field of coal and rock permeability measurement, in particular to a mobile fast coal and rock permeability measuring instrument.

Background technique

Coal seam permeability coefficient is a numerical index reflecting the difficulty of gas flow in the coal seam. It is an important parameter for gas drainage design, gas flow simulation analysis, and measuring the risk of coal and gas outburst. It is also the most direct technology for evaluating the effect of permeability enhancement. index. There are laboratory and in situ (field) measurements for coal seam permeability. Due to the influence of fracture distribution, stress, moisture, temperature, and sampling, processing and analysis processes in the coal body, the permeability coefficient of coal samples obtained in the laboratory has a poor correlation with the permeability coefficient of the original coal seam, so the results measured in the laboratory are usually As a substitute for field measurements, it is used for model validation, etc., while the results of in-situ measurements are used as the actual coal seam permeability coefficient.

With the diversification of the application of coal seam permeability in gas disaster prediction and prevention and coalbed methane development, there is an increasing demand for rapid and accurate determination of coal seam permeability coefficient. In the past, the permeability coefficient of a point was used to represent a region or a For the permeability of coal seams, the precise evaluation of the effects of drainage, outburst elimination, and displacement requires measuring the permeability distribution. Obviously, the traditional measurement methods can no longer meet such requirements, mainly in: (1) The measurement efficiency is low, a Drilling holes can only measure one point; (2) the measurement time is long, generally more than three weeks; (3) there is a lack of rapid measurement methods and theoretical support.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide a mobile fast coal and rock permeability measuring instrument, which can realize intensive, rapid and accurate measurement of the coal seam permeability coefficient of coal and rock.

The invention provides a mobile fast coal and rock permeability measuring instrument, comprising a support casing, a left main packer, a right main packer, a left secondary packer, a right secondary packer, a first high-pressure gas cylinder, Second high pressure gas cylinder and data recorder;

The left main packer and the right main packer are arranged on the support casing. The left main packer and the right main packer are arranged around the support casing, and there is a space between the left main packer and the right main packer. spacing;

The left secondary packer is arranged on the outer side of the left main packer on the support casing, and the right secondary packer is arranged on the outer side of the right main packer on the support casing. Arranged around the support casing, leaving a space between the left secondary packer and the left main packer, and leaving a space between the right secondary packer and the right main packer;

The first high-pressure gas cylinder is respectively connected to the left secondary packer, the left main packer, the right main packer and the right secondary packer through the gas injection pipeline. A first pressure gauge is arranged on the outside of a valve, an exhaust pipeline is connected to the inner side of the first valve on the gas injection pipeline, and an exhaust valve is arranged on the exhaust pipeline;

The second high-pressure gas cylinder is connected to one end of the measurement pipeline, the other end of the measurement pipeline is located between the left main packer and the right main packer, and the measurement pipeline is provided with a second pressure gauge and a second valve;

A first pressure sensor is arranged on the gas injection pipeline and inside the first valve, a second pressure sensor is arranged between the left secondary packer and the left main packer, and between the right secondary packer and the right main packer A third pressure sensor is arranged, a fourth pressure sensor is arranged between the left main packer and the right main packer, and the data recorder is respectively connected to the first pressure sensor, the second pressure sensor, the third pressure sensor and the fourth pressure sensor. Pressure Sensor.

Further, each packer is configured as an air bag, the air bag includes an inner air bag and an outer air bag that are stacked from the inside to the outside, the inner air bag is arranged around the support sleeve, and the outer air bag is arranged around the inner air bag.

Further, the inner airbag is made of material A, the outer airbag is made of material B, and the hardness of material A is greater than that of material B.

Further, both the gas injection pipeline and the measurement pipeline are located inside the support sleeve.

Further, the gas injection pipelines are respectively connected with a first gas injection branch pipeline, a second gas injection branch pipeline, a third gas injection branch pipeline and a fourth gas injection branch pipeline, and each gas injection branch pipeline is located inside the support sleeve. , the supporting casing is provided with gas injection holes at the positions surrounding each packer, and the end of the gas injection branch pipeline is connected to the gas injection holes; the supporting casing is provided at the position between the left main packer and the right main packer. There is a measuring hole, and the other end of the measuring pipeline is connected to the measuring hole.

Further, the data recorder is respectively connected to the first pressure sensor, the second pressure sensor, the third pressure sensor and the fourth pressure sensor through the signal cable, and the signal cable connecting the second pressure sensor, the third pressure sensor and the fourth pressure sensor is located in the the inside of the support sleeve.

Further, the position of the support casing between the left secondary packer and the left main packer, the position between the right secondary packer and the right main packer, and the left main packer and the right main packer There are sensor detection holes in the positions between them, the second pressure sensor, the third pressure sensor and the fourth pressure sensor are assembled in the sensor detection holes, and the detection parts of the second pressure sensor, the third pressure sensor and the fourth pressure sensor are located in the place. the outside of the support sleeve.

Further, the mobile rapid gas permeability measuring instrument further includes a guide rod, and the guide rod is connected to the support sleeve.

Further, the data recorder is a computer.

Further, the high-pressure gas filled in the first high-pressure gas cylinder and the second high-pressure gas cylinder is nitrogen.

Compared with the prior art, the mobile fast coal and rock permeability measuring instrument of the present invention has the following characteristics and advantages:

The mobile fast coal and rock permeability measuring instrument of the invention can be used repeatedly and has a long service life; the measurement operation is simple, and multi-point and rapid measurement can be carried out in one borehole, and the measurement time is generally 10 to 30 minutes. Short time, only need to deflate each packer through the exhaust valve to realize the switching of measurement points, the switching speed of measurement points is fast, and the measurement process can detect the air tightness between the packer and the inner wall of the borehole in real time to ensure the measurement The data is accurate, and the dense, fast and accurate measurement of the coal seam permeability coefficient is realized.

The features and advantages of the present invention will become more apparent after reading the detailed description of the present invention in conjunction with the accompanying drawings.

Description of drawings

In order to illustrate the embodiments of the present invention or the technical solutions in the prior art more clearly, the following briefly introduces the accompanying drawings that need to be used in the description of the embodiments or the prior art. Obviously, the drawings in the following description are For some embodiments of the present invention, for those of ordinary skill in the art, other drawings can also be obtained according to these drawings without creative efforts.

Fig. 1 is the structural representation of the mobile fast coal and rock permeability measuring instrument of the embodiment;

Fig. 2 is C-C sectional view in Fig. 1;

Fig. 3 is the structural schematic diagram of the packer in the mobile fast coal and rock permeability measuring instrument of the embodiment;

Figure 4 is a graph of measuring pressure-time in an enclosed space.

Detailed ways

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, but not all of the embodiments.

In order to make the above objects, features and advantages of the present invention more obvious and easy to understand, the mobile fast coal and rock permeability measuring instrument of the present invention will be described in detail below with preferred embodiments and the accompanying drawings.

In the description of the present invention, it should be noted that the orientations or positional relationships indicated by the terms "upper", "lower", "vertical", "horizontal", "inner", "outer", etc. are based on those shown in the accompanying drawings. The orientation or positional relationship is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the indicated device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention .

As shown in FIG. 1 to FIG. 3 , this embodiment provides a mobile fast coal and rock permeability measuring instrument, including a support casing 1 , a left main packer 21 , a right main packer 22 , and a left secondary packer 23. The right secondary packer 24, the first high-pressure gas cylinder 31, the second high-pressure gas cylinder 32, the data recorder 4, the guide rod and other components.

The guide rod is connected to the support casing 1, and the support casing 1 and the packers on it are sent to the set position in the borehole through the guide rod.

The left main packer 21 and the right main packer 22 are arranged in the middle position on the support casing 1. The left main packer 21 and the right main packer 22 are arranged around the support casing 1, and the left main packer 21 and the right main packer 22 is spaced apart.

The high-pressure gas filled in the first high-pressure gas cylinder 31 and the second high-pressure gas cylinder 32 is non-toxic and harmless nitrogen gas.

The high-pressure gas in the first high-pressure gas cylinder 31 inflates and expands the left main packer 21 and the right main packer 22 through the gas injection pipeline 41, and the expanded left main packer 21 and the right main packer 22 are closely connected to the borehole. fit. The left main packer 21 , the right main packer 22 , the outer wall of the support casing 1 and the inner wall of the borehole together form a measurement closed space.

A left secondary packer 23 is arranged on the outer side of the left main packer 21 on the support casing 1, and a right secondary packer 24 is arranged on the outer side of the right main packer 22 on the supporting casing 1, and the left secondary packer 23 and the right secondary packer 24 are arranged around the support casing 1 . A space is left between the left secondary packer 23 and the left main packer 21 , and a space is left between the right sub-packer 24 and the right main packer 22 .

The high-pressure gas in the first high-pressure gas cylinder 31 inflates and expands the left secondary packer 23 through the gas injection pipeline 41, and the expanded left secondary packer 23 and the left main packer 21 closely fit the borehole. The left secondary packer 23, the left main packer 21, the outer wall of the support casing 1 and the inner wall of the borehole together form a left detection closed space.

The high-pressure gas in the first high-pressure gas cylinder 31 inflates and expands the right secondary packer 24 through the gas injection pipeline 41, and the expanded right secondary packer 24 and the right main packer 22 closely fit the borehole. The right secondary packer 24, the right main packer 22, the outer wall of the support casing 1 and the inner wall of the borehole together form a right detection closed space.

The first high pressure gas cylinder 31 is respectively connected to the left secondary packer 23 , the left main packer 21 , the right main packer 22 and the right secondary packer 24 through the gas injection pipeline 41 . The gas injection pipeline 41 is provided with a first valve 51 , and the gas injection pipeline 41 is provided with a first pressure gauge 61 outside the first valve 51 . Based on the pressure reading of the first pressure gauge 61 , the operator controls the rate of gas injection into the packer through the first valve 51 .

An exhaust pipeline 43 is connected to the gas injection pipeline 41 and inside the first valve 51 , and an exhaust valve 53 is provided on the exhaust pipeline 43 . Through the exhaust valve 53, the high-pressure gas in each packer can be released through the exhaust pipeline 43, so as to realize the switching of the measurement point.

The second high pressure gas cylinder 32 is connected to one end of the measurement pipeline 42 , the other end of the measurement pipeline 42 is located between the left main packer 21 and the right main packer 22 , and the measurement pipeline 42 is provided with a second pressure gauge 62 and the second valve 52 . The high-pressure gas in the second high-pressure gas cylinder 32 is injected into the measurement closed space through the measurement pipeline 42 . Based on the pressure reading of the second pressure gauge 62, the operator controls the rate of gas injection into the measurement enclosure through the second valve 52.

Each of the above packers (the left main packer 21, the right main packer 22, the left secondary packer 23 and the right secondary packer 24) are all configured as airbags, and the airbags include an inner airbag A1 stacked from the inside to the outside. And the outer airbag A2, the inner airbag A1 is arranged around the support sleeve 1, and the outer airbag A2 is arranged around the inner airbag A1. The inner airbag A1 is made of material A, the outer airbag A2 is made of material B, and the hardness of material A is greater than that of material B.

The packer adopts an air bag, which expands and contracts faster than the water bag, which improves the measurement efficiency. The injected gas is nitrogen, which is non-toxic and harmless, which ensures the safety of measurement and construction. The packer adopts a double-layer structure. The inner airbag A1 has a higher hardness to withstand high-pressure gas and maintain the shape set by the airbag. The outer airbag A2 has a smaller hardness. The deformation occurs to wrap the coal and rock particles, so that the outer airbag A2 is closely attached to the inner wall of the borehole, and the air tightness between the airbag and the inner wall of the borehole is improved.

In this embodiment, the gas injection pipeline 41 and the measurement pipeline 42 are both located inside the support sleeve 1 to avoid damage to the gas injection pipeline 41 and the measurement pipeline 42 during the measurement construction process. The gas injection pipeline 41 is respectively connected with a first gas injection branch pipeline 411 , a second gas injection branch pipeline 412 , a third gas injection branch pipeline 413 and a fourth gas injection branch pipeline 414 . Each gas injection branch pipe (the first gas injection branch pipe 411, the second gas injection branch pipe 412, the third gas injection branch pipe 413 and the fourth gas injection branch pipe 414) is located inside the support sleeve 1 to avoid the The gas branch line was damaged during the measurement construction. The support casing 1 is provided with gas injection holes at the positions surrounding each packer (the left main packer 21, the right main packer 22, the left secondary packer 23 and the right secondary packer 24). The end of the road is connected to the air injection hole. Specifically, the end of the first gas injection branch pipe 411 is connected to the gas injection hole at the position of the left main packer 21 , the end of the second gas injection branch pipe 412 is connected to the right main packer 22 , and the third gas injection branch pipe 413 The end is connected to the left secondary packer 23 , and the end of the fourth gas injection branch line 414 is connected to the right secondary packer 24 . The support casing 1 is provided with a measurement hole at a position between the left main packer 21 and the right main packer 22 , and the other end of the measurement pipeline 42 is connected to the measurement hole.

A first pressure sensor 71 is arranged on the gas injection pipeline 41 and inside the first valve 51 , a second pressure sensor 72 is arranged between the left secondary packer 23 and the left main packer 21 , and the right secondary packer 24 A third pressure sensor 73 is arranged between the left main packer 21 and the right main packer 22 , and a fourth pressure sensor 74 is arranged between the left main packer 21 and the right main packer 22 .

The position of the support casing 1 between the left secondary packer 23 and the left main packer 21, the position between the right secondary packer 24 and the right main packer 22, and the position between the left main packer 21 and the right main packer The positions between the packers 22 are all provided with sensor detection holes. The second pressure sensor 72 , the third pressure sensor 73 and the fourth pressure sensor 74 are fitted in the sensor detection holes, and the detection portions of the second pressure sensor 72 , the third pressure sensor 73 and the fourth pressure sensor 74 are located outside the support sleeve 1 .

The first function of the first pressure sensor 71 is to determine when gas is charged to each packer (left main packer 21, right main packer 22, left secondary packer 23 and right secondary packer 24). Whether the pressure in each packer has reached the set pressure value, so that each packer is closely fitted with the borehole to ensure tightness, and it will not cause the packer to burst due to excessive inflation pressure; the second The function is to detect the stability (drop) of the pressure in the packer during the measurement and construction process after the inflation of each packer is completed, and determine whether the contact surface between the packer and the borehole is leaking, so as to analyze the packing Whether the tightness of the device and the drill hole meets the requirements. In addition, if a packer ruptures, the pressure reading of the first pressure sensor 71 will drop rapidly, and the measurement will fail.

Even if the packer is filled with high-pressure gas to achieve sufficient pressure, due to the uneven local position of the inner wall of the borehole, it cannot be ensured that the contact surfaces between the left main packer 21, the right main packer 22 and the borehole will not leak. . The second pressure sensor 72 detects the pressure change in the left detection closed space, and the third pressure sensor 73 detects the pressure change in the right detection closed space. The tightness of the closed space is detected and measured by the second pressure sensor 72 and the third pressure sensor 73 . For example, when air leakage occurs at the contact surface between the left main packer 21 and the borehole, and gas continues to be injected into the measurement closed space, the pressure in the left detection closed space will increase; when the right main packer 22 and the borehole are connected Air leakage occurs at the contact surface between them, and the pressure of the right detection closed space will increase when the gas is continuously injected into the measurement closed space. In addition, when gas is initially injected into the measurement closed space, if there is a little leakage in the contact surfaces between the left main packer 21, the right main packer 22 and the borehole (does not affect the measurement). At this time, the left secondary packer 23 and the right secondary packer 24 achieve secondary sealing, reducing gas leakage in the measurement closed space.

The second high-pressure gas cylinder 32 injects high-pressure gas into the measurement closed space through the measurement pipeline 42, and the fourth pressure sensor 74 detects the pressure change in the measurement closed space.

The data recorder 8 is signal-connected to the first pressure sensor 71 , the second pressure sensor 72 , the third pressure sensor 73 and the fourth pressure sensor 74 , respectively. In this embodiment, the data recorder 8 is a computer, and the data recorder 8 is respectively connected to the first pressure sensor 71 , the second pressure sensor 72 , the third pressure sensor 73 and the fourth pressure sensor 74 via signal cables. The signal cables connecting the second pressure sensor 72 , the third pressure sensor 73 and the fourth pressure sensor 74 are located inside the support sleeve 1 to avoid damage to the signal cables during the measurement and construction process.

The data recorder 8 reads and records the pressure data of each pressure sensor in real time.

The present embodiment also provides an in-situ measurement method for coal seam permeability. Using the mobile fast coal and rock permeability measuring instrument described above in this embodiment, the airless spray coating method includes the following steps:

Step 1. Use layer-wise drilling to drill holes along the coal seam and clean the cuttings in the drilled holes;

Step 2: Send the support casing 1 and the packers on it to a set position in the borehole through the guide rod;

Step 3: Open the first valve 51, inflate each packer through the first high-pressure gas cylinder 31 through the gas injection pipeline 41 to expand, observe the pressure through the first pressure gauge 61 and the data recorder 8 to the set value, and then close the first pressure gauge. a valve 51;

Step 4: Open the second valve 52, through the second high-pressure gas cylinder 32 through the measurement pipeline 42 to the left main packer 21, the right main packer 22, the outer wall of the support casing 1 and the inner wall of the borehole to form a measurement seal. The space is filled with gas, and the second valve 52 is closed after the pressure detected by the fourth pressure sensor 74 of the data recorder 8 reaches the set value and remains stable, and the data recorder 8 continues to be detected by the fourth pressure sensor 74. The pressure drops to a stable value and stops measurement;

In the process of step 3 and step 4, the data recorder 8 detects and measures whether there is air leakage in the enclosed space through the first pressure sensor 71, the second pressure sensor 72 and the third pressure sensor 73. If there is air leakage, the measurement fails and needs to be re-measured. Measurement;

Step 5. After stopping the measurement, open the exhaust valve 53, and let the high-pressure gas in each packer vent through the exhaust pipeline 43. After the degassing is completed, close the exhaust valve 53, repeat steps 2 to 4, and measure the drill. Data required for calculation of coal seam permeability coefficient at other set positions in the hole;

为纵坐标、测量时间t为横纵坐标进行坐标变换，求坐标变换后一次函数的斜率b，则煤层透气性系数λ计算如下，

Step 6: Record and measure the pressure-time curve in the closed space by the data recorder 8, as shown in Figure 4, the pressure-time curve is calculated as

Coordinate transformation is carried out as the ordinate and the measurement time t as the abscissa and ordinate, and the slope b of the linear function after the coordinate transformation is obtained, then the coal seam permeability coefficient λ is calculated as follows:

in,

b为坐标变换后一次函数的斜率；L为钻孔长度，m；r_b为钻孔半径，m；V_t为测压区间体积，m³；P_t为时间t时的钻孔瓦斯压力，MPa；P₀为煤层原始瓦斯压力，MPa；P_s为标准状态的瓦斯压力，取0.1，Mpa。α is a constant, determined by the drill hole length and drill hole radius,

b is the slope of the primary function after coordinate transformation; L is the length of the borehole, m; r _b is the radius of the borehole, m; V _t is the volume of the pressure measuring interval, m ³ ; P _t is the borehole gas pressure at time t, MPa; P ₀ is the original coal seam gas pressure, MPa; P _s is the gas pressure in the standard state, taken as 0.1, Mpa.

The in-situ measurement method of coal seam permeability in this embodiment applies the mobile rapid coal and rock permeability measuring instrument of this embodiment, and adopts the method of "layer drilling + mobile rapid permeability measuring instrument + gas injection" to realize the detection of coal seam. The dense, rapid and accurate measurement of the air permeability coefficient has been verified, and the measurement results are basically consistent with other more complex measurement methods.

Of course, the above description is not intended to limit the present invention, and the present invention is not limited to the above examples. Changes, modifications, additions or substitutions made by those skilled in the art within the essential scope of the present invention should also belong to the present invention. the scope of protection of the invention.

Claims (9)

1. a mobile fast coal and rock permeability measuring instrument is characterized in that: comprise guide rod, support casing, left main packer, right main packer, left secondary packer, right secondary packer, a first high-pressure gas cylinder, a second high-pressure gas cylinder and a data recorder; the guide rod is connected to the support sleeve; The left main packer and the right main packer are arranged on the support casing. The left main packer and the right main packer are arranged around the support casing, and there is a space between the left main packer and the right main packer. spacing; The left secondary packer is arranged on the outer side of the left main packer on the support casing, and the right secondary packer is arranged on the outer side of the right main packer on the support casing. Arranged around the support casing, leaving a space between the left secondary packer and the left main packer, and leaving a space between the right secondary packer and the right main packer; The first high-pressure gas cylinder is respectively connected to the left secondary packer, the left main packer, the right main packer and the right secondary packer through the gas injection pipeline. A first pressure gauge is arranged on the outside of a valve, an exhaust pipeline is connected to the inner side of the first valve on the gas injection pipeline, and an exhaust valve is arranged on the exhaust pipeline; The second high-pressure gas cylinder is connected to one end of the measurement pipeline, the other end of the measurement pipeline is located between the left main packer and the right main packer, and the measurement pipeline is provided with a second pressure gauge and a second valve; A first pressure sensor is arranged on the gas injection pipeline and inside the first valve, a second pressure sensor is arranged between the left secondary packer and the left main packer, and between the right secondary packer and the right main packer A third pressure sensor is arranged, a fourth pressure sensor is arranged between the left main packer and the right main packer, and the data recorder is respectively connected to the first pressure sensor, the second pressure sensor, the third pressure sensor and the fourth pressure sensor. Pressure Sensor. 2 . The mobile fast coal gas permeability measuring instrument according to claim 1 , wherein each packer is configured as an air bag, and the air bag comprises an inner air bag and an outer air bag that are stacked from the inside to the outside, and the inner air bag Arranged around the support sleeve, the outer balloon is arranged around the inner balloon. 3 . The mobile fast coal and rock permeability measuring instrument according to claim 2 , wherein the inner airbag is made of material A, the outer airbag is made of material B, and the hardness of material A is greater than that of material B. 4 . hardness. 4 . The mobile fast coal and rock permeability measuring instrument according to claim 1 , wherein the gas injection pipeline and the measurement pipeline are both located inside the support casing. 5 . 5. The mobile fast coal gas permeability measuring instrument according to claim 4, wherein the gas injection pipeline is respectively connected with the first gas injection branch pipeline, the second gas injection branch pipeline, the third gas injection branch pipeline and the The fourth gas injection branch pipeline, each gas injection branch pipeline is located inside the support casing, the support casing is provided with gas injection holes at the positions surrounded by each packer, and the end of the gas injection branch pipeline is connected to the gas injection holes; The support casing is provided with a measurement hole at a position between the left main packer and the right main packer, and the other end of the measurement pipeline is connected to the measurement hole. 6 . The mobile fast coal and rock permeability measuring instrument according to claim 1 , wherein the data recorder is connected to the first pressure sensor, the second pressure sensor, the third pressure sensor and the fourth pressure sensor respectively through a signal cable. 7 . , the signal cable connecting the second pressure sensor, the third pressure sensor and the fourth pressure sensor is located inside the support sleeve. 7. The mobile fast coal and rock gas permeability measuring instrument according to claim 6, characterized in that: the position of the support casing between the left secondary packer and the left main packer, the right secondary packer and the right The positions between the main packers and the positions between the left main packer and the right main packer are provided with sensor detection holes, and the second pressure sensor, the third pressure sensor and the fourth pressure sensor are assembled in the sensor detection holes , the detection parts of the second pressure sensor, the third pressure sensor and the fourth pressure sensor are located outside the support sleeve. 8 . The mobile fast coal and rock permeability measuring instrument according to claim 1 , wherein the data recorder is a computer. 9 . 9 . The mobile fast coal-rock permeability measuring instrument according to claim 1 , wherein the high-pressure gas filled in the first high-pressure gas cylinder and the second high-pressure gas cylinder is nitrogen. 10 .

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