Equipment and method for monitoring deformation-on-way negative pressure of gas extraction drill hole in real time

Abstract

The invention discloses a device and method for monitoring gas extraction drill hole deformation-on-way negative pressure in real time, the device comprises a gas extraction pipe, an optical fiber tester and a negative pressure monitor, a plurality of signal optical fibers and a plurality of hard rubber pipes are arranged outside the gas extraction pipe in the axial direction, a plurality of grating sensors are arranged on each signal optical fiber at intervals, and the grating sensors are arranged on the hard rubber pipes. The outer end of the signal optical fiber is connected with an optical fiber tester, an inner port of each hard rubber pipe is correspondingly connected with one monitoring small hole and is in sealing connection with the gas extraction pipe, and an outer port of each hard rubber pipe extends out of the gas extraction drill hole and is connected with a negative pressure monitor. On one hand, the drilling hole can be accurately repaired by monitoring the deformation position of the extraction drilling hole, and on the other hand, the negative pressure change rule in the hole can be accurately mastered by monitoring the on-way negative pressure distribution in the hole. According to the method, accurate position information is provided for directionally repairing the drill hole by adopting repairing measures, and the extraction negative pressure in the extraction drill hole can be accurately regulated and controlled, so that the gas extraction effect is improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of coal mine safety production, and particularly relates to an equipment and method for real-time monitoring of the deformation and along-hole negative pressure of gas drainage boreholes. Background Art

[0002] Coal is the main energy resource in China, and its strategic position cannot be replaced in the national economic system of China. However, with the continuous increase of mining depth and intensity, the problem of gas disasters has become increasingly prominent, seriously restricting the high-quality development of the coal industry.

[0003] Borehole gas drainage is one of the important measures for coal mine gas disaster control, and the gas drainage radius and the distribution of the negative pressure in the borehole are the core technical parameters determining the gas drainage effect of the borehole. At present, the gas drainage radius is mainly obtained by on-site measurement. However, during the actual measurement process, the test boreholes are prone to caving or severe deformation, affecting the accuracy of the determination of the gas drainage radius. To ensure the accurate acquisition of the drainage radius, it is particularly important to take effective repair measures for the boreholes with caving or severe deformation. However, the key to repairing the caving or severely deformed boreholes is to accurately determine the deformation position of the borehole. In addition, the distribution of the negative pressure of gas drainage in the borehole directly affects the gas drainage effect. Especially for the gas drainage of long boreholes, due to the along-hole loss of negative pressure, there is an extremely easy phenomenon of no negative pressure at the inner end of the borehole. Therefore, understanding the distribution of the along-hole negative pressure inside the borehole is crucial for accurately regulating the drainage negative pressure.

[0004] Based on this, in order to real-time master the deformation situation of the gas drainage pipe and the distribution of the negative pressure along the borehole of the gas drainage borehole, it is necessary to design an equipment and method for real-time monitoring of the deformation and along-hole negative pressure of the gas drainage borehole. This equipment can not only provide accurate deformation position information, but also accurately regulate the negative pressure of gas drainage in the borehole, providing a guarantee for taking repair measures to direct the repair of the borehole and accurately regulate the negative pressure of gas drainage. Summary of the Invention

[0005] In order to real-time master the deformation situation of the gas drainage pipe and the distribution of the negative pressure along the borehole of the gas drainage borehole, the present invention provides an equipment and method for real-time monitoring of the deformation - along-hole negative pressure of the gas drainage borehole, which can not only provide accurate deformation position information, but also accurately regulate the negative pressure of gas drainage in the borehole, providing a guarantee for taking repair measures to direct the repair of the borehole and accurately regulate the negative pressure of gas drainage.

[0006] To achieve the above object, the present invention adopts the following technical solution: An equipment for real-time monitoring of the deformation - along-channel negative pressure of gas drainage boreholes, including a gas drainage unit, an optical fiber tester, and a negative pressure monitor. The gas drainage unit is installed inside the gas drainage borehole, and the optical fiber tester and the negative pressure monitor are arranged outside the gas drainage borehole. The gas drainage unit includes a gas drainage pipe. Along the axial direction outside the gas drainage pipe, multiple signal optical fibers and multiple rigid rubber hoses are arranged. On each signal optical fiber, several grating sensors are arranged at intervals. The outer end of the signal optical fiber is connected to the optical fiber tester. Along the axial direction of the gas drainage pipe, several monitoring holes are provided. The inner port of each rigid rubber hose is correspondingly connected to a monitoring hole and forms a sealed connection with the gas drainage pipe. The outer port of the rigid rubber hose extends out of the gas drainage borehole and is connected to the negative pressure monitor.

[0007] There are four signal optical fibers, and the four signal optical fibers are evenly arranged along the circumferential direction of the gas drainage pipe; A clamp is arranged at a certain distance outside the gas drainage pipe, the signal optical fiber, and the rigid rubber hose, so as to closely attach and fix the signal optical fiber and the rigid rubber hose to the outer wall of the gas drainage pipe.

[0008] Outside the gas drainage pipe, there is a "two-blocks-one-injection" bladder-type hole packer. The "two-blocks-one-injection" bladder-type hole packer includes an inner bladder, an outer bladder, a grouting pipe, a slurry return pipe, and a blasting valve. The inner bladder and the outer bladder are respectively sleeved on the gas drainage pipe. The grouting pipe and the slurry return pipe are both parallel to the gas drainage pipe. The grouting pipe passes through the outer bladder and the inner bladder. The grouting pipe is respectively provided with a first slurry outlet and a second slurry outlet inside the outer bladder and the inner bladder. The blasting valve is located on the grouting pipe between the outer bladder and the inner bladder. The slurry return pipe is located above the gas drainage pipe. The slurry return pipe passes through the outer bladder, and the inner port of the slurry return pipe is adjacent to the outside of the inner bladder.

[0009] Both the optical fiber tester and the negative pressure monitor are connected to the monitoring center through a host computer. The grating sensor real-time tests the stress and displacement of the monitoring points on the gas drainage pipe and transmits the signals to the optical fiber tester. The negative pressure monitor real-time tests the negative pressure of the monitoring points on the gas drainage pipe. The stress, displacement, and negative pressure data are uploaded to the monitoring center in real time. By analyzing the stress, displacement, and negative pressure, the specific position of the deformation point of the drainage borehole can be obtained.

[0010] A method for real-time monitoring of the deformation - along-channel negative pressure of gas drainage boreholes is implemented by using the above-mentioned equipment, including the following steps: S1. Insert the equipment for real-time monitoring of the deformation - along-channel negative pressure of gas drainage boreholes and the "two-blocks-one-injection" bladder-type hole packer into the gas drainage borehole; S2. Grout and seal the hole; S3. Connect the signal optical fiber to the optical fiber tester, connect multiple rigid rubber hoses to the negative pressure monitor. At the same time, connect the optical fiber tester and the negative pressure monitor to the monitoring center through a host computer, and connect the outer port of the gas drainage pipe to the gas drainage pipeline; S4. Gas drainage, while monitoring the gas drainage boreholes and recording the monitoring data.

[0011] Step S1 is specifically as follows: Insert the gas drainage pipes one by one into the gas drainage boreholes. The inner port of the first gas drainage pipe is wrapped with gauze to prevent coal from entering the gas drainage pipe and blocking it. The pipe walls of the gas drainage pipes inserted into the coal seam are all provided with sieve holes for extracting gas from the coal seam. While inserting the gas drainage pipes, according to the predetermined design plan, several monitoring small holes are processed on the pipe walls of the gas drainage pipes. Each monitoring small hole is hermetically connected to one end of a rigid rubber pipe. Four signal optical fibers arranged with grating sensors are also lowered into the gas drainage boreholes along with the gas drainage pipes. The signal optical fibers and the rigid rubber pipes are closely attached to the outer walls of the gas drainage pipes. At certain intervals, the signal optical fibers and the rigid rubber pipes are fixed to the gas drainage pipes with clamps; According to the predetermined on-site test plan, the "two-block-one-injection" bladder-type hole sealer is fixed to the gas drainage pipe. Among them, the inner port of the slurry return pipe is near the inner bladder. The "two-block-one-injection" bladder-type hole sealer and the gas drainage pipe are inserted into the borehole together to a suitable position.

[0012] Step S2 is specifically as follows: Connect the grouting pipe to the grouting pump and start the grouting pump. The slurry enters the outer bladder and the inner bladder respectively through the first slurry outlet and the second slurry outlet of the grouting pipe until the outer bladder and the inner bladder are propped up. When the pressure in the grouting pipe reaches 0.8 MPa - 1.2 MPa, the blasting valve ruptures, and the slurry enters the borehole between the outer bladder and the inner bladder and gradually rises from the low place to the high place, while filling the surrounding fissures. When the slurry rises to the inner port of the slurry return pipe, the slurry returns through the slurry return pipe from the inner port of the slurry return pipe. At this time, it indicates that the slurry has been filled. Fold the outer port of the slurry return pipe and tie it with wire at the same time. Wait for the slurry to solidify, and then the hole sealing operation is completed.

[0013] Step S4 is specifically as follows: During gas drainage, mining stress will affect the gas drainage boreholes. The gas drainage boreholes will then deform and act on the gas drainage pipes. The grating sensors on the pipe walls of the gas drainage pipes receive signals and transmit optical signals to the optical fiber tester in real time through the signal optical fibers. The negative pressure at each test point is collected through the negative pressure monitor. The stress, displacement, and negative pressure data at different positions can be obtained through the monitoring center; By using the stress and displacement data, the position information of the borehole deformation in the gas drainage borehole can be analyzed, and the distribution law of the along-hole negative pressure in the borehole can be obtained through the negative pressure data.

[0014] Adopting the above technical solution, compared with the prior art, it has the following technical effects: On the one hand, the present invention can accurately repair the borehole by monitoring the deformation position of the gas drainage borehole. On the other hand, it can accurately master the variation law of the negative pressure in the borehole by monitoring the distribution of the negative pressure along the borehole. Combining with the abnormal deformation monitoring data of the gas drainage borehole, which will lead to the abnormal variation law of the negative pressure in the borehole. After taking repair measures, if the variation law of the negative pressure in the borehole becomes normal, it indicates that the deformation of the gas drainage borehole causes the abnormal variation law of the negative pressure in the borehole. After taking repair measures, if the variation law of the negative pressure in the borehole is still abnormal, it indicates that there is also abnormal variation law of the negative pressure in the borehole caused by insufficient pumping negative pressure of the pumping pump. If there is no deformation in the gas drainage borehole and the variation law of the negative pressure in the borehole is abnormal, it indicates that the abnormal variation law of the negative pressure in the borehole is caused by insufficient pumping negative pressure of the pumping pump. It provides accurate position information for taking repair measures to repair the borehole directionally, and can accurately regulate the pumping negative pressure in the gas drainage borehole, thereby improving the gas drainage effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 is a schematic structural diagram of the present invention.

[0016] Figure 2 is a schematic diagram of the present invention installed in a gas drainage borehole. DETAILED DESCRIPTION OF THE INVENTION

[0017] As Figure 1 - Figure 2 shown, an equipment for real-time monitoring of the deformation - negative pressure along the borehole of gas drainage of the present invention includes a gas drainage unit, an optical fiber tester 1 and a negative pressure monitor 2. The gas drainage unit is installed in a gas drainage borehole 3, and the optical fiber tester 1 and the negative pressure monitor 2 are arranged outside the gas drainage borehole 3. The gas drainage unit includes a gas drainage pipe 4. Along the axial direction of the outside of the gas drainage pipe 4, a plurality of signal optical fibers 5 and a plurality of rigid rubber hoses 6 are arranged. A plurality of grating sensors 7 are arranged at intervals on each signal optical fiber 5. The outer end of the signal optical fiber 5 is connected to the optical fiber tester 1. A plurality of monitoring small holes 8 are axially opened in the gas drainage pipe 4. The inner port of each rigid rubber hose 6 is correspondingly connected to a monitoring small hole 8 and forms a sealed connection with the gas drainage pipe 4. The outer port of the rigid rubber hose 6 extends out of the gas drainage borehole 3 and is connected to the negative pressure monitor 2.

[0018] Four signal optical fibers 5 are provided, and the four signal optical fibers 5 are evenly arranged along the circumferential direction of the gas drainage pipe 4. Clamps 9 are arranged at a certain distance outside the gas drainage pipe 4, the signal optical fibers 5 and the rigid rubber hoses 6, so as to closely attach and fix the signal optical fibers 5 and the rigid rubber hoses 6 to the outer wall of the gas drainage pipe 4.

[0019] An "injecting at two ends and plugging in the middle" bladder packer is provided outside the gas drainage pipe 4. The "injecting at two ends and plugging in the middle" bladder packer includes an inner bladder 10, an outer bladder 11, a grouting pipe 12, a slurry return pipe 13 and a blasting valve 14. The inner bladder 10 and the outer bladder 11 are respectively sleeved on the gas drainage pipe 4. The grouting pipe 12 and the slurry return pipe 13 are both parallel to the gas drainage pipe 4. The grouting pipe 12 passes through the outer bladder 11 and the inner bladder 10. The grouting pipe 12 is respectively provided with a first slurry outlet and a second slurry outlet inside the outer bladder 11 and the inner bladder 10. The blasting valve 14 is located on the grouting pipe 12 between the outer bladder 11 and the inner bladder 10. The slurry return pipe 13 is located above the gas drainage pipe 4. The slurry return pipe 13 passes through the outer bladder 11. The inner port of the slurry return pipe 13 is adjacent to the outer side of the inner bladder 10.

[0020] The optical fiber tester 1 and the negative pressure monitor 2 are both connected to the monitoring center through a host computer. The grating sensor 7 tests the stress and displacement of the monitoring points on the gas drainage pipe 4 in real time and transmits the signals to the optical fiber tester 1. The negative pressure monitor 2 tests the negative pressure of the monitoring points on the gas drainage pipe 4 in real time. The stress, displacement and negative pressure data are uploaded to the monitoring center in real time. The specific position of the deformation point of the drainage borehole can be obtained by analyzing the stress, displacement and negative pressure.

[0021] A method for real-time monitoring of the deformation - along - path negative pressure of a gas drainage borehole 3 is implemented by using the described equipment, and includes the following steps: S1. Insert the equipment for real - time monitoring of the deformation - along - path negative pressure of the gas drainage borehole 3 and the "injecting at two ends and plugging in the middle" bladder packer into the gas drainage borehole 3; S2. Grout and seal the hole; S3. Connect the signal optical fiber 5 to the optical fiber tester 1, connect multiple rigid rubber hoses 6 to the negative pressure monitor 2. At the same time, connect the optical fiber tester 1 and the negative pressure monitor 2 to the monitoring center through a host computer, and connect the outer port of the gas drainage pipe 4 to the gas drainage pipeline 4; S4. Conduct gas drainage, and at the same time monitor the gas drainage borehole 3 and record the monitoring data.

[0022] Step S1 is specifically as follows: The gas drainage pipes 4 are inserted into the gas drainage boreholes 3 one by one. The inner port of the first gas drainage pipe 4 is wrapped with a gauze 15 to prevent coal from entering the gas drainage pipe 4 and blocking it. The pipe walls of the gas drainage pipes 4 inserted into the coal seam are all provided with sieve holes for draining the gas in the coal seam. While inserting the gas drainage pipes 4, according to a predetermined design scheme, a number of monitoring small holes 8 are processed on the pipe walls of the gas drainage pipes 4. Each monitoring small hole 8 is hermetically connected to one end of a rigid rubber pipe 6. The signal optical fibers 5 arranged with grating sensors 7 are also lowered into the gas drainage boreholes 3 along with the gas drainage pipes 4. The signal optical fibers 5 and the rigid rubber pipes 6 are closely attached to the outer walls of the gas drainage pipes 4. The signal optical fibers 5 and the rigid rubber pipes 6 are fixed to the gas drainage pipes 4 with clamps 9 at certain intervals; according to the predetermined on-site test scheme, the "two-blocks-one-injection" bladder type hole-sealing device is fixed to the gas drainage pipe 4. Among them, the inner port of the slurry return pipe 13 is located near the inner bladder 10. The "two-blocks-one-injection" hole-sealing device and the gas drainage pipe 4 are inserted into the borehole together to a proper position.

[0023] Step S2 is specifically as follows: Connect the grouting pipe 12 to the grouting pump 16, start the grouting pump 16, and the slurry enters the outer bladder 11 and the inner bladder 10 respectively through the first slurry outlet and the second slurry outlet of the grouting pipe 12 until the outer bladder 11 and the inner bladder 10 are propped up. When the pressure in the grouting pipe 12 reaches 0.8 MPa - 1.2 MPa, the blasting valve 14 ruptures, and the slurry enters the borehole between the outer bladder 11 and the inner bladder 10 and gradually rises from the low place to the high place, while filling the surrounding fissures. When the slurry rises to the inner port of the slurry return pipe 13, the slurry returns through the slurry return pipe 13 from the inner port of the slurry return pipe 13. At this time, it indicates that the slurry has been filled. Fold the outer port of the slurry return pipe 13 and tie it with iron wire at the same time. After waiting for the slurry to solidify, the hole-sealing operation is completed.

[0024] Step S4 is specifically as follows: During gas drainage, the mining stress will affect the gas drainage boreholes, and the gas drainage boreholes 3 will then deform and act on the gas drainage pipes 4. The grating sensors 7 on the pipe walls of the gas drainage pipes 4 receive signals and transmit optical signals to the optical fiber tester 1 in real time through the signal optical fibers 5. The negative pressure at each test point is collected by the negative pressure monitor 2. The stress, displacement and negative pressure data at different positions can be obtained through the monitoring center; by using the stress and displacement data, the position information of the borehole deformation in the gas drainage boreholes 3 can be analyzed, and the distribution law of the along-hole negative pressure in the boreholes can be obtained through the negative pressure data.

[0025] The above embodiments are only used to illustrate rather than limit the technical solutions of the present invention. Although the present invention has been described in detail with reference to the above embodiments, those of ordinary skill in the art should understand that; modifications or equivalent replacements can still be made to the present invention, and any modification or partial replacement without departing from the spirit and scope of the present invention shall be covered by the scope of the claims of the present invention.

Claims

1. A device for real-time monitoring of gas extraction borehole deformation and negative pressure along the way, characterized in that: It includes a gas extraction unit, an optical fiber tester and a negative pressure monitor. The gas extraction unit is installed in the gas extraction borehole, and the optical fiber tester and the negative pressure monitor are arranged outside the gas extraction borehole. The gas extraction unit includes a gas extraction pipe. A plurality of signal optical fibers and a plurality of hard rubber tubes are arranged axially outside the gas extraction pipe. A plurality of grating sensors are arranged on each signal optical fiber at intervals. The outer end of the signal optical fiber is connected to the optical fiber tester. A plurality of monitoring holes are opened in the axial direction of the gas extraction pipe. The inner port of each hard rubber tube is connected to a corresponding monitoring hole and forms a sealed connection with the gas extraction pipe. The outer port of the hard rubber tube extends out of the gas extraction borehole and is connected to the negative pressure monitor.

2. The equipment for real-time monitoring of gas extraction borehole deformation and negative pressure along the way according to claim 1, characterized in that: There are four signal optical fibers, which are evenly arranged along the circumference of the gas extraction pipe; a clamp is arranged at a certain interval outside the gas extraction pipe, the signal optical fiber and the hard rubber hose to tightly adhere and fix the signal optical fiber and the hard rubber hose to the outer wall of the gas extraction pipe.

3. The equipment for real-time monitoring of gas extraction borehole deformation and negative pressure along the way according to claim 2, characterized in that: A "two-blocking and one-injection" bag-type sealer is provided on the outside of the gas extraction pipe. The "two-blocking and one-injection" bag-type sealer includes an inner bag, an outer bag, a grouting pipe, a return grouting pipe and a bursting valve. The inner bag and the outer bag are respectively mounted on the gas extraction pipe. The grouting pipe and the return grouting pipe are parallel to the gas extraction pipe. The grouting pipe passes through the outer bag and the inner bag. The grouting pipe is provided with a first slurry outlet and a second slurry outlet inside the outer bag and the inner bag respectively. The bursting valve is located on the grouting pipe between the outer bag and the inner bag. The return slurry pipe is located above the gas extraction pipe. The return slurry pipe passes through the outer bag, and the inner port of the return slurry pipe is adjacent to the outer side of the inner bag.

4. The equipment for real-time monitoring of gas extraction borehole deformation and negative pressure along the way according to claim 3, characterized in that: Both the fiber optic tester and the negative pressure monitor are connected to the monitoring center through the host computer. The grating sensor tests the stress and displacement of the monitoring point on the gas extraction pipe in real time and transmits the signal to the fiber optic tester. The negative pressure monitor tests the negative pressure of the monitoring point on the gas extraction pipe in real time. The stress, displacement and negative pressure data are uploaded to the monitoring center in real time. The specific location of the deformation point of the extraction borehole can be known by analyzing the stress, displacement and negative pressure.

5. A method for real-time monitoring of gas extraction borehole deformation and negative pressure along the way, implemented using the equipment as claimed in claim 4, characterized in that: The following steps are involved: S1. Insert the equipment for real-time monitoring of gas extraction borehole deformation and negative pressure along the way and the "two blocking and one injection" bag-type sealer into the gas extraction borehole; S2, grouting and sealing; S3, connect the signal optical fiber to the optical fiber tester, connect multiple hard rubber hoses to the negative pressure monitor, connect the optical fiber tester and the negative pressure monitor to the monitoring center through the host computer, and connect the outer port of the gas extraction pipe to the gas extraction pipeline; S4, gas extraction, while monitoring the gas extraction boreholes and recording the monitoring data.

6. A method for real-time monitoring of gas extraction borehole deformation and negative pressure along the borehole according to claim 5, characterized in that: Step S1 specifically includes: inserting the gas extraction pipes one by one into the gas extraction borehole, wherein the inner port of the first gas extraction pipe is wrapped with gauze to prevent coal from entering the gas extraction pipe and clogging it, and the pipe wall of the gas extraction pipe inserted into the coal seam is provided with sieve holes for extracting gas from the coal seam, and while inserting the gas extraction pipe, a number of monitoring holes are processed on the pipe wall of the gas extraction pipe according to a predetermined design scheme, and each monitoring hole is sealed and connected with one end of the hard rubber hose, and the four arranged pipes are connected to the gas extraction pipe wall. The signal optical fiber with grating sensor is also lowered into the gas extraction borehole along with the gas extraction pipe. The signal optical fiber and hard rubber hose are close to the outer wall of the gas extraction pipe. The signal optical fiber and hard rubber hose are fixed to the gas extraction pipe with clamps at certain intervals. According to the predetermined plan of the on-site test, the "two-blocking and one-injection" bag-type sealer is fixed to the gas extraction pipe, among which the inner port of the return slurry pipe is located near the inner bag. The "two-blocking and one-injection" bag-type sealer and the gas extraction pipe are inserted into the borehole to the appropriate position.

7. A method for real-time monitoring of gas extraction borehole deformation and negative pressure along the borehole according to claim 6, characterized in that: Step S2 is specifically as follows: connect the grouting pipe to the grouting pump, start the grouting pump, and the slurry enters the outer bag and the inner bag respectively through the first slurry outlet and the second slurry outlet of the grouting pipe until the outer bag and the inner bag are propped up. When the pressure in the grouting pipe reaches 0.8 MPa~1.2 MPa, the bursting valve ruptures, and the slurry enters the borehole between the outer bag and the inner bag, and gradually rises from low to high, while filling the surrounding cracks. When the slurry rises to the inner port of the return slurry pipe, the slurry returns from the inner port of the return slurry pipe through the return slurry pipe. At this time, it means that the slurry has been filled. The outer port of the return slurry pipe is folded and tied with wire. After waiting for the slurry to solidify, the sealing operation is completed.

8. A method for real-time monitoring of gas extraction borehole deformation and negative pressure along the borehole according to claim 7, characterized in that: Step S4 is specifically as follows: during gas extraction, the mining stress will affect the extraction borehole, which will then deform and act on the gas extraction pipe. The grating sensor on the wall of the gas extraction pipe receives the signal and transmits the optical signal to the optical fiber tester in real time through the signal optical fiber. The negative pressure at each test point is collected through the negative pressure monitor, and the stress, displacement and negative pressure data at different positions can be obtained through the monitoring center; By using stress and displacement data, we can analyze and obtain the location information of borehole deformation in the gas extraction borehole, and the distribution law of negative pressure along the borehole can be obtained through negative pressure data.

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