CN113818921B - Device and method for shortening coal bed gas pressure measurement observation time - Google Patents

Abstract

The embodiment of the present invention discloses a device and method for shortening the observation time of coal seam gas pressure measurement, which relates to the technical field of coal seam gas pressure measurement, mainly to solve the existing gas flow field equilibrium velocity in the existing coal seam gas pressure measurement device and method The problem of slow and long observation time, including the grouting mechanism, the capsule located in the borehole, the pressure measuring mechanism, the water delivery mechanism and the expansion fluid delivery mechanism, the surface of the capsule is wrapped with a lightweight, flexible, water-absorbing material, and the top of the capsule There are several nozzles, and the pressure measuring tube in the pressure measuring mechanism is sent into the capsule at the front end of the borehole, which can be close to the coal wall around the borehole before the pressure measuring borehole is sealed, preventing the gas from the coal seam around the borehole from flowing into the borehole. After the pressure measurement borehole is sealed, it can occupy most of the space in the pressure measurement chamber, reduce the volume of the pressure measurement chamber, reduce the amount of gas pouring into the pressure measurement chamber from the coal wall around the borehole, and speed up the development of the gas flow field. Balance speed and shorten observation time.

Description

A device and method for shortening the observation time of coal seam gas pressure measurement

technical field

The application relates to the technical field of coal seam gas pressure measurement, in particular to a device and method for shortening the observation time of coal seam gas pressure measurement.

Background technique

Coal seam gas pressure is a key indicator for mine gas disaster risk assessment (the gas pressure critical value for determining the lower boundary of the gas weathering zone is 0.1-0.15 MPa, and the gas pressure critical value for identifying the risk of coal seam outburst is 0.74 MPa), therefore, obtaining a reliable Coal seam gas pressure data is a key link in the prevention and control of mine gas disasters.

It is a commonly used method to measure coal seam gas pressure by drilling through seams, grouting and sealing holes; however, it takes about 10 hours from the completion of drilling construction to the solidification of the slurry and the start of pressure measurement on the table; during this period, The gas in the coal seam around the borehole is in a state of natural discharge, and the released gas is more, which directly leads to a longer time for the gas flow field to balance in the later stage; "Direct Measurement Method of Gas Pressure in Coal Seam Underground Coal Mine" (AQ/T 1047-2007) stipulates that Passive pressure measurement requires observation for 20-30 days.

In order to shorten the observation time of coal seam gas pressure measurement, the most effective method at present is active gas supplementation, that is, filling gas into the borehole to make up for the loss of gas emission before the slurry solidifies. "Direct Measurement Method of Coal Seam Gas Pressure in Underground Coal Mine" (AQ/T 1047-2007) stipulates that when the coal seam gas pressure is less than 4MPa, the active pressure measurement needs to be observed for 5-10 days. engineering), the observation time of 5-10 days is still relatively long.

Therefore, it is particularly urgent to explore new measures to speed up the equilibrium speed of gas flow field, shorten the observation time of coal seam gas pressure measurement, and relieve the constraints of long gas pressure measurement cycle on project progress and production connection.

Contents of the invention

The purpose of the embodiments of the present application is to provide a device and method for shortening the measurement and observation time of coal seam gas pressure, so as to solve the problems raised in the above-mentioned background technology.

In order to achieve the above object, the application provides the following technical solutions:

A device for shortening the observation time of coal seam gas pressure measurement, including a grouting mechanism, characterized in that it also includes:

A capsule located in the borehole, the surface of the capsule is wrapped with lightweight, flexible, water-absorbing material, and the top of the capsule is provided with several spray heads; and

A pressure measuring mechanism, the pressure measuring mechanism is provided with a pressure measuring tube for pushing the capsule to move in the borehole; and

A water delivery mechanism, the water delivery mechanism is provided with a water injection pipe, the water outlet end of the water injection pipe is connected to the lower end of the capsule, and is used to drive the nozzle to spray water to light, flexible, water-absorbing materials; and

Expansion fluid delivery mechanism, the expansion fluid delivery mechanism is equipped with a liquid injection pipe, the liquid outlet end of the liquid injection pipe is connected to the lower end of the capsule, used to deliver the expansion liquid to the capsule, and used to drive the capsule to expand and fit the coal wall, thereby hindering the coal seam Gas flow inside.

As a further solution of the present application: the contours of the several spray heads are all designed in the shape of an "umbrella" and are evenly distributed on the top of the capsule, so as to reduce the diameter of the water sprayed by the spray heads.

As a further solution of the application: the grouting mechanism includes:

a grouting pipe, the grouting port at one end of the grouting pipe is located in the borehole; and

A grouting pump, the grouting port at the other end of the grouting pipe communicates with the grouting pump for delivering grout into the borehole.

As a further solution of the present application: the pressure measuring mechanism is also provided with a pressure gauge, the pressure measuring tube is connected to the pressure gauge, and the front end and the lower end of the pressure measuring tube are respectively provided with a number of liquid inlet holes and liquid outlet holes , the slurry in the borehole enters the piezometric tube through several liquid inlet holes, and flows out through the liquid outlet holes.

As a further solution of the present application: the water delivery mechanism is further provided with a first pressure test pump, and the water inlet end of the water injection pipe is connected to the first pressure test pump.

As a further solution of the present application: the expansion liquid delivery mechanism is also provided with a second pressure test pump, and the liquid inlet end of the liquid injection pipe is connected to the second pressure test pump.

As a further solution of the present application: a baffle is also provided in the grouting mechanism, and the baffle is installed at the opening of the drilled hole to prevent the grout from flowing backward from the opening. The grouting pipe, The water injection pipe, the pressure measuring pipe and the liquid injection pipe are all plugged and connected to the baffle plate.

A method for shortening the observation time of coal seam gas pressure measurement, including a device for shortening the observation time of coal seam gas pressure measurement described in any of the above schemes, including the following steps:

S1. The pressure measuring tube pushes the capsule in the borehole to the designated position;

S2. Start the water delivery mechanism, water enters the top of the capsule through the water injection pipe, and overflows through the nozzle, wets the light and flexible material wrapped on the side of the capsule, and closes the water delivery mechanism;

S3. Start the expansion liquid delivery mechanism, the expansion liquid enters the capsule through the liquid injection pipe, and forces the capsule to expand, and the flexible material on the side of the capsule is close to the coal wall, preventing the gas in the coal seam from flowing toward the drilling hole;

S4. Start the grouting mechanism to enter the grout into the borehole. When the grout rises to the front end of the pressure measuring tube in the pressure measuring mechanism, the grout entering from the front end of the piezometric tube flows out from the lower end under the action of gravity, and close the grouting mechanism. Stop grouting and wait for the grout to solidify;

S5. Release part of the expansion fluid by adjusting the expansion fluid delivery mechanism, appropriately reduce the diameter of the capsule, separate the flexible material on the side of the capsule from the coal wall, read the pressure value through the pressure measurement mechanism, and wait for the balance of the gas flow field.

Compared with prior art, the beneficial effect of the present application is:

The capsule sent into the front end of the borehole can not only stick to the coal wall around the borehole before the pressure measurement borehole is sealed, and prevent the gas from the coal seam around the borehole from gushing into the borehole, but also occupy the space after the pressure measurement borehole is sealed. Most of the space in the pressure measuring chamber reduces the volume of the pressure measuring chamber, reduces the amount of gas pouring into the pressure measuring chamber from the coal wall around the drilling hole, speeds up the balance of the gas flow field, shortens the observation time, and solves the problem of existing coal seams. The gas pressure measurement device and method have the problems of slow gas flow field equilibrium speed and long observation time.

Description of drawings

Fig. 1 is a schematic diagram of a device and method for shortening the observation time of coal seam gas pressure measurement according to the present invention.

In the figure: 1-roof rock layer; 2-coal seam; 3-bottom rock layer; 4-nozzle; 5-capsule; 6-baffle plate; 7-grouting pump; 8-grouting pipe; A pressure test pump; 11-pressure gauge; 12-pressure test tube; 13-second pressure test pump; 14-injection tube.

Detailed ways

The technical solution in the embodiment of the application will be clearly and completely described below in conjunction with the accompanying drawings in the embodiment of the application. Please refer to Figure 1. This embodiment provides a device for shortening the observation time of coal seam gas pressure measurement , including the grouting mechanism, also includes:

A capsule 5 located in the borehole, the surface of the capsule 5 is wrapped with light, flexible, water-absorbing materials, and the top of the capsule 5 is provided with several spray heads 4; and

A pressure measuring mechanism, the pressure measuring mechanism is provided with a pressure measuring tube 12 for pushing the capsule 5 to move in the borehole; and

A water delivery mechanism, the water delivery mechanism is provided with a water injection pipe 9, the water outlet end of the water injection pipe 9 is connected to the lower end of the capsule 5, and is used to drive the nozzle 4 to spray water to light, flexible, water-absorbing materials; and

Expansion fluid delivery mechanism, the expansion fluid delivery mechanism is provided with a liquid injection pipe 14, the liquid outlet end of the liquid injection pipe 14 is connected to the lower end of the capsule 5, used to deliver the expansion liquid to the capsule 5, and used to drive the capsule 5 to expand and adhere to the coal wall Combined, thereby hindering the gas flow in the coal seam.

In the above technical scheme, workers drill holes from the floor rock layer 3 to the coal seam 2 as required. The coal seam 2 is located between the floor rock layer 3 and the roof rock layer. After the drilling is in place, the pressure measuring tube 12 is used to push the capsule 5 to the coal seam 2 , the pressure measuring tube 12 is a rigid hollow tube with high strength, which can be used to send the capsule 5 into the front of the borehole.

Please refer to Figure 1, further, the capsule 5 is in the shape of a cylinder, and the side is wrapped with a layer of light, flexible, water-absorbing material (such as sponge, cotton, etc.), "light weight" can reduce the difficulty of feeding into the drilling hole, "Flexible" can make it close to the coal wall, and "absorbent" can strengthen its suppression effect on coal wall gas gushing.

Please refer to Fig. 1, further, when the capsule 5 is inflated with liquid, the side can be close to the coal wall, hindering the coal seam 2 gas around the drill hole from gushing to the drill hole, and after a little release of the expansion liquid, it will shrink itself, and the side will be in contact with the coal wall separate and occupy most of the space in the pressure chamber.

Please refer to Fig. 1, further, the contours of the nozzles 4 are all designed as "umbrella" and evenly distributed on the top of the capsule 5, which is used to reduce the diameter of the water flow ejected from the nozzle 4 and convert the incoming water flow It can ensure that the wrapping material on the side of the capsule 5 can absorb moisture evenly.

Please refer to Fig. 1, as an embodiment of the present application, the pressure measuring mechanism is also provided with a pressure gauge 11, the pressure measuring tube 12 is connected with the pressure gauge 11, and the front end and the lower end of the pressure measuring tube 12 are respectively arranged There are several liquid inlet holes and liquid outlet holes, and the slurry in the borehole enters the pressure measuring tube 12 through several liquid inlet holes, and flows out from the liquid outlet holes.

Please refer to FIG. 1 , as an embodiment of the present application, the water delivery mechanism is further provided with a first pressure test pump 10 , and the water inlet end of the water injection pipe 9 is connected to the first pressure test pump 10 .

Please refer to FIG. 1 , as an embodiment of the present application, the expansion liquid delivery mechanism is further provided with a second pressure test pump 13 , and the liquid inlet end of the liquid injection pipe 14 is connected to the second pressure test pump 13 .

Please refer to Figure 1, as an embodiment of the present application, the grouting mechanism includes:

A grouting pipe 8, the grouting port at one end of the grouting pipe 8 is located in the borehole; and

A grouting pump 7, the grouting port at the other end of the grouting pipe 8 communicates with the grouting pump 7, and is used to transport grout into the borehole.

Please refer to Fig. 1, further, a baffle plate 6 is also provided in the grouting mechanism, and the baffle plate 6 is installed at the opening of the drilled hole to prevent the grout from flowing backward from the orifice. The pipe 8, the water injection pipe 9, the pressure measuring pipe 12 and the liquid injection pipe 14 are all plugged and connected to the baffle 6. The baffle 6 is circular and can be directly inserted into the drilled hole to prevent the slurry from leaking out, and the baffle 6 Several holes are provided to facilitate the insertion of the grouting pipe 8, the water injection pipe 9, the pressure measuring pipe 12 and the liquid injection pipe 14.

A method for shortening the observation time of coal seam gas pressure measurement, including a device for shortening the observation time of coal seam gas pressure measurement described in any one of the above embodiments, including the following steps:

S1. The pressure measuring tube 12 pushes the capsule 5 in the borehole to a designated position;

S2, start the water delivery mechanism, water enters the top of the capsule 5 through the water injection pipe 9, and overflows through the nozzle 4, wets the light and flexible material wrapped on the side of the capsule 5, and closes the water delivery mechanism;

S3, start the expansion fluid delivery mechanism, the expansion fluid enters the capsule 5 through the liquid injection pipe 14, and forces the capsule 5 to expand, the flexible material on the side of the capsule 5 clings to the coal wall, hindering the gas in the coal seam from flowing toward the drilling direction;

S4. Start the grouting mechanism to enter the grout into the borehole. When the grout rises to the front end of the pressure measuring tube 12 in the pressure measuring mechanism, the grout entering from the front end of the pressure measuring tube 12 will flow out from the lower end under the action of gravity, and close the grouting mechanism, stop grouting and wait for the grout to solidify;

S5. Release part of the expansion fluid by adjusting the expansion fluid delivery mechanism, appropriately reduce the diameter of the capsule 5, the flexible material on the side of the capsule 5 is separated from the coal wall, read the pressure value through the pressure measurement mechanism, and wait for the gas flow field to be balanced.

When used in this application, before grouting and sealing the hole, the capsule 5 is sent into the layer where the coal seam 2 is located in the borehole, and high-pressure liquid is injected into the capsule 5, and the capsule 5 expands and clings to the coal wall around the borehole, hindering the borehole The gas in the surrounding coal seam gushes out to the borehole, reducing the amount of gas loss, thus creating a better basic condition for the balance of the gas flow field after the hole is sealed (Note: before the hole is sealed, a certain volume of gas flows out of the coal seam per unit time, After the hole is sealed, even if the high-pressure gas is injected for compensation, the time required for the compensated gas to go through percolation, adsorption, and equilibrium is much longer than the unit discharge time before the hole is sealed);

After grouting, slurry solidification, and installation of the pressure gauge 11, the liquid pressure inside the capsule 5 is slightly reduced, and the capsule 5 is separated from the coal wall to facilitate the communication between the drilling pressure chamber and the coal wall, but the capsule 5 still occupies a portion of the pressure chamber. In the process of gas flow field balance, it is equivalent to reducing the amount of gas pouring into the pressure chamber from the coal wall around the drilling hole, which can speed up the balance speed of the gas flow field and shorten the observation time.

To sum up, the capsule 5 fed into the front end of the borehole can not only cling to the coal wall around the borehole before the pressure measurement borehole is sealed, so as to prevent the gas from the coal seam around the borehole from gushing into the borehole, but also can be used during the pressure measurement. After the borehole is sealed, it occupies most of the space in the pressure measuring chamber, reduces the volume of the pressure measuring chamber, reduces the amount of gas pouring into the pressure measuring chamber from the coal wall around the borehole, speeds up the balance of the gas flow field, and shortens the observation time. The problems of slow gas flow field balance speed and long observation time in the existing coal seam gas pressure measuring device and method are solved.

It should be noted that although this description is described in terms of implementations, not every implementation includes only an independent technical solution. This description of the description is only for clarity, and those skilled in the art should regard the description as a On the whole, the technical solutions in each embodiment can also be appropriately combined to form other implementations that can be understood by those skilled in the art. The above-mentioned embodiments only express the preferred implementation of the technical solution, and its description is more specific and detailed. However, it should not be interpreted as a limitation on the patent scope of the technical solution. It should be noted that those skilled in the art can make several modifications, improvements and substitutions without departing from the concept of the present application, and these all belong to the protection scope of the technical solution.

Claims (6)

1. A method for shortening the observation time of coal-bed gas pressure measurement, the method for shortening the observation time of coal-bed gas pressure measurement being realized by a device for shortening the observation time of coal-bed gas pressure measurement, characterized in that: the device for shortening the coal seam gas pressure measurement observation time comprises a grouting mechanism, a capsule (5) positioned in a drill hole, wherein the surface of the capsule (5) is wrapped with a light, flexible and water-absorbing material, and a plurality of spray heads (4) are arranged at the top end of the capsule (5); and

the pressure measuring mechanism is internally provided with a pressure measuring pipe (12) for pushing the capsule (5) to move in the drill hole; and

the water delivery mechanism is internally provided with a water injection pipe (9), and the water outlet end of the water injection pipe (9) is connected with the lower end of the capsule (5) and is used for driving the spray head (4) to spray water to the light, flexible and water-absorbing material; and

the expansion liquid conveying mechanism is internally provided with a liquid injection pipe (14), the liquid outlet end of the liquid injection pipe (14) is connected with the lower end of the capsule (5) and is used for conveying expansion liquid to the capsule (5) and driving the capsule (5) to expand and be attached to a coal wall so as to further obstruct the gas flow in the coal layer;

the outline of the spray heads (4) is designed into an umbrella shape and is uniformly distributed at the top of the capsule (5) for reducing the diameter of water flow sprayed by the spray heads (4);

the method for observing the time is realized by a device for shortening the coal bed gas pressure measurement observing time and comprises the following steps of:

s1, pushing a capsule (5) positioned in a drill hole to a designated position by a pressure measuring tube (12);

s2, starting a water delivery mechanism, enabling water to enter the top end of the capsule (5) through a water injection pipe (9) and overflow through a spray head (4), wetting light and flexible materials wrapped on the side face of the capsule (5), and closing the water delivery mechanism;

s3, starting an expansion liquid conveying mechanism, enabling expansion liquid to enter the capsule (5) through the liquid injection pipe (14), forcing the capsule (5) to expand, enabling flexible materials on the side face of the capsule (5) to cling to the coal wall, and preventing gas of a coal bed from flowing towards a drilling direction;

s4, starting a grouting mechanism to enter a drilled hole, when the grouting rises to the front end of a pressure measuring pipe (12) in the pressure measuring mechanism, allowing the grouting to flow out from the lower end under the action of gravity, closing the grouting mechanism, and stopping grouting to wait for solidification of the grouting;

s5, releasing part of the expansion liquid by adjusting the expansion liquid conveying mechanism, properly reducing the diameter of the capsule (5), separating the flexible material on the side surface of the capsule (5) from the coal wall, reading the pressure value by the pressure measuring mechanism, and waiting for the balance of the gas flow field.

2. A method for reducing observation time for coal seam gas pressure measurement according to claim 1, wherein: the grouting mechanism comprises:

the grouting device comprises a grouting pipe (8), wherein a grouting outlet at one end of the grouting pipe (8) is positioned in a drilling hole; and

and the grouting pump (7) is used for conveying the slurry into the drill hole, and a slurry inlet at the other end of the grouting pipe (8) is communicated with the grouting pump (7).

3. A method for reducing observation time for coal seam gas pressure measurement according to claim 1, wherein: the pressure measuring mechanism is further provided with a pressure gauge (11), the pressure measuring pipe (12) is connected with the pressure gauge (11), the front end and the lower end of the pressure measuring pipe (12) are respectively provided with a plurality of liquid inlet holes and liquid outlet holes, and slurry in the drilled holes enters the pressure measuring pipe (12) through the liquid inlet holes and flows out of the liquid outlet holes.

4. A method for reducing observation time for coal seam gas pressure measurement according to claim 1, wherein: the water delivery mechanism is also provided with a first pressure testing pump (10), and the water inlet end of the water injection pipe (9) is connected with the first pressure testing pump (10).

5. A method for reducing observation time for coal seam gas pressure measurement according to claim 1, wherein: the expansion liquid conveying mechanism is further provided with a second pressure testing pump (13), and the liquid inlet end of the liquid injection pipe (14) is connected with the second pressure testing pump (13).

6. A method for reducing observation time for coal seam gas pressure measurement according to claim 2, wherein: still be provided with baffle (6) in the slip casting mechanism, baffle (6) are installed in the drill hole's drill way department for prevent thick liquid from flowing backwards and overflowing from drill way department, slip casting pipe (8), water injection pipe (9), piezometer tube (12) and notes liquid pipe (14) all insert and close and connect on baffle (6).