A method for in-situ detection of coal seam gas extraction drilling holes

Abstract

The present application relates to an in-situ detection method for coal seam gas extraction boreholes, the method comprising the following steps: after extending a gas extraction pipe into an extraction borehole, the extraction borehole is sealed; a wireless terminal and a probe are started, and the wireless terminal is connected to the probe pipe by wireless communication; a three-way pipe is connected to the pipe mouth of the gas extraction pipe, and the probe pipe is inserted into the gas extraction pipe by a push rod, and the push rod and the three-way pipe are sealed by a sealing sleeve to start gas extraction; the probe pipe synchronously and continuously measures the methane concentration information and extraction negative pressure information of each measuring point in the extraction borehole; the methane concentration information and extraction negative pressure information of each measuring point are received and viewed on the wireless terminal, and after fitting into a methane concentration curve and an extraction negative pressure curve, it is determined whether the sealed extraction borehole is leaking. The method of the present application detects parameters such as gas concentration and extraction negative pressure at different parts of the extraction borehole in situ through a probe pipe, analyzes the distribution position of the fracture zone, and then determines a reasonable sealing depth, and the determined sealing depth is reasonable and reliable.

Description

Technical Field

[0001] The present application relates to the technical field of coal seam gas extraction, and in particular to an in-situ detection method for coal seam gas extraction drilling. Background Art

[0002] As the mining depth of the mine increases, the gas problem in coal mines becomes more and more prominent, mainly manifested in high gas pressure and high gas content. Coal mine regulations require that the gas pressure and content in the coal seam must be reduced to below the safe value before excavation and mining. In practice, drilling and gas extraction has become an important means of gas control in coal mines.

[0003] In the gas extraction process, the sealing depth of the gas extraction borehole has a crucial impact on the effect of gas extraction. If the sealing depth is shallow, the sealing section is in the pressure relief fracture area, and the outside air will be sucked into the extraction pipeline along the coal seam fracture, causing air flow short circuit, resulting in a significant reduction in gas extraction concentration, thus failing to achieve the ideal extraction effect. If the sealing depth is deep, not only will it cause a waste of sealing materials, but it will also cause the gas in the coal body from the boundary of the pressure relief zone to the end of the sealing section to be unable to be extracted, leaving safety hazards for future production.

[0004] How to determine the reasonable sealing depth to ensure the gas extraction concentration has become a difficult problem for mining technology researchers. At present, there is no unified method to determine the reasonable sealing depth of gas extraction boreholes. Each coal mine generally determines the sealing depth based on its own experience.

[0005] Chinese patent CN104636532A discloses "a method for determining the depth and length of sealing holes for coal mine gas extraction", which measures the data of drill cuttings and drill hole depth, fits the curve of the change law of drill cuttings with drill hole depth, and obtains the depth of the pressure relief zone and the depth of the stress concentration zone by fitting the curve, so as to determine the depth of drilling hole sealing. This method has cumbersome steps in practical application, is time-consuming and labor-intensive, and the sealing depth is indirectly determined by measured data, which has certain errors. At the same time, the sealing depth in this method is determined according to the stress distribution around the roadway, without considering the fracture development channel of the coal body around the roadway. Summary of the invention

[0006] The embodiment of the present application provides an in-situ detection method for coal seam gas extraction drilling holes to solve the problem that the reasonable sealing depth of the gas extraction drilling holes is difficult to detect in the gas extraction process in the related art.

[0007] The present invention provides a method for in-situ detection of coal seam gas extraction drilling holes, the method comprising the following steps:

[0008] After the gas extraction pipe is inserted into the extraction borehole, the extraction borehole is sealed. The sealing position is X meters away from the borehole mouth, and the designed detection depth is X+N meters;

[0009] Start the wireless terminal and the probe tube, connect the wireless terminal and the probe tube by wireless communication, set the working parameters of the probe tube, and calibrate the time of the wireless terminal and the probe tube clock module;

[0010] Connect a tee pipe to the mouth of the gas extraction pipe, insert the probe into the gas extraction pipe using a push rod, and start extracting gas after the push rod and the tee pipe are sealed with a sealing sleeve;

[0011] Each time a push rod is extended, the insertion depth of the probe is recorded on the wireless terminal. The probe continuously measures the methane concentration information and extraction negative pressure information of each measuring point in the extraction borehole until the designed detection depth is reached.

[0012] The methane concentration information and extraction negative pressure information of each measuring point are received and viewed on the wireless terminal, and are fitted into a methane concentration curve and an extraction negative pressure curve. Whether the sealed extraction borehole is leaking is determined based on the trend changes of the methane concentration curve and the extraction negative pressure curve.

[0013] In some embodiments, the method further comprises the following steps:

[0014] If the methane concentration curve and the drainage negative pressure curve have no obvious fluctuations from the borehole mouth to the detection end point, it is judged that the sealed drainage borehole has no gas leakage;

[0015] If there is no obvious fluctuation in the methane concentration curve and the extraction negative pressure curve from the borehole mouth to the sealing end point, and the gas concentration gradually increases from the sealing end point to the detection end point, it is judged that the sealed extraction borehole is leaking.

[0016] In some embodiments, the method further comprises the following steps:

[0017] After judging that the sealed extraction borehole has no gas leakage, reduce the depth of the sealed hole position from the hole mouth to XM meters;

[0018] Measure and check the methane concentration curve and drainage negative pressure curve of each measuring point again, and judge whether the sealed drainage borehole is leaking according to the trend changes of the methane concentration curve and the drainage negative pressure curve;

[0019] If the extraction borehole leaks, the sealing depth should be X meters. If the extraction borehole does not leak, repeat the above steps until a reasonable sealing depth is determined.

[0020] In some embodiments, the method further comprises the following steps:

[0021] After determining that the sealed extraction borehole is leaking, increase the depth of the sealed hole position from the hole mouth to X+M meters;

[0022] Measure and check the methane concentration curve and drainage negative pressure curve of each measuring point again, and judge whether the sealed drainage borehole is leaking according to the trend changes of the methane concentration curve and the drainage negative pressure curve;

[0023] If the extraction borehole does not leak, the sealing depth should be X+M meters. If the extraction borehole leaks, repeat the above steps until a reasonable sealing depth is determined.

[0024] In some embodiments: the probe comprises a measuring segment, a main control segment and a power supply segment connected in sequence from front to back;

[0025] The power supply segment includes a first outer tube, and a probe battery pack and a negative pressure measurement module located in the first outer tube;

[0026] The main control segment comprises a second outer tube coaxially and detachably connected to the first outer tube, wherein a main control circuit board, a track measurement module and a Bluetooth module are arranged in the second outer tube;

[0027] The measuring segment comprises a third outer tube which is coaxially and detachably connected to the second outer tube, and a gas concentration sensor which is connected to the main control circuit board is arranged in the third outer tube.

[0028] In some embodiments: one end of the first outer tube is provided with a push rod connector for connecting the push rod, and the other end is provided with an aviation plug male connector for electrically connecting the main control segment, and the probe battery pack and / or the extraction negative pressure measurement module are sealed in the first outer tube by silicone potting;

[0029] The first outer tube has one end away from the push rod connector that is threadedly connected to the first connector, and the aviation plug male connector is electrically connected to the probe battery pack and the extraction negative pressure measurement module and then fixed in the first connector;

[0030] A second connector is threadedly connected to one end of the second outer tube close to the first outer tube, and an aviation plug female connector connected to the power supply segment is arranged inside the second connector;

[0031] The first connector is rotatably sleeved with a sleeve for inserting the male aviation plug into the female aviation plug, and one end of the sleeve is threadedly connected to the second connector.

[0032] In some embodiments: the main control circuit board includes a microprocessor, a storage module and a clock module, a power management module, and an interface module connected to a drainage negative pressure measurement module, a gas concentration sensor, a trajectory measurement module, and a Bluetooth module;

[0033] The microprocessor obtains the collected information of the extraction negative pressure measurement module, the gas concentration sensor, and the trajectory measurement module and stores it in the storage module, and wirelessly sends the collected information in the storage module to the wireless terminal via the Bluetooth module.

[0034] In some embodiments: the probe battery pack is provided with an intrinsically safe power management module, which is connected to the probe battery pack and distributes the electrical energy of the probe battery pack to the microprocessor, storage module, clock module, interface module, extraction negative pressure measurement module, trajectory measurement module, gas concentration sensor and Bluetooth module.

[0035] In some embodiments: one end of the second outer tube close to the third outer tube is threadedly connected to a connecting sleeve, and one end of the third outer tube close to the second outer tube is threadedly connected to the connecting sleeve;

[0036] The main control circuit board, the track measurement module and the Bluetooth module are fixed in the second outer tube through a circuit board fixing seat, and are arranged in sequence along the axial direction of the second outer tube.

[0037] In some embodiments: the extraction negative pressure measurement module is a miniature air pressure sensor, and the gas concentration sensor is a miniature laser methane gas sensor;

[0038] The second outer tube is made of non-metallic material, and a Bluetooth antenna connected to the Bluetooth module is arranged inside the second outer tube.

[0039] The beneficial effects of the technical solution provided by this application include:

[0040] The embodiment of the present application provides a method for in-situ detection of coal seam gas extraction boreholes. The method for in-situ detection of coal seam gas extraction boreholes of the present application first extends a gas extraction pipe into the extraction borehole and then seals the extraction borehole. The sealing position is X meters away from the hole mouth, and the designed detection depth is X+N meters. Then, the wireless terminal and the probe are started, the wireless terminal is connected to the probe tube by wireless communication, the working parameters of the probe tube are set, and the time of the wireless terminal and the probe tube clock module is calibrated. Next, a three-way pipe is connected to the pipe mouth of the gas extraction pipe, and the gas extraction pipe is connected to the three-way pipe by wireless communication. Use a push rod to insert the probe into the gas extraction pipe. After the push rod and the three-way pipe are sealed with a sealing sleeve, gas extraction begins. Each time a push rod is extended, the insertion depth of the probe is recorded on the wireless terminal. The probe synchronously and continuously measures the methane concentration information and extraction negative pressure information of each measuring point in the extraction borehole until the designed detection depth is reached. Finally, the methane concentration curve and extraction negative pressure curve of each measuring point are received and viewed on the wireless terminal, and whether the sealed extraction borehole is leaking is determined based on the trend changes of the methane concentration curve and the extraction negative pressure curve.

[0041] Therefore, the coal seam gas extraction borehole in-situ detection method of the present application uses a probe tube to extend into the extraction borehole, and the probe tube measures the gas concentration information and extraction negative pressure information along the extraction borehole to determine the spatial distribution of gas parameters. The methane concentration information and extraction negative pressure information of each measuring point are fitted to obtain the methane concentration curve and the extraction negative pressure curve. The trend changes of the methane concentration curve and the extraction negative pressure curve are used to determine whether the sealed extraction borehole is leaking, so as to more reasonably determine whether the sealing depth is accurate, thereby improving the gas extraction rate.

[0042] The present application can provide a corresponding sealing depth for each borehole, and has wide practicability in this technical field. In addition, the detection method has simple steps, the device is easy to use, and the requirements for technical personnel are not high; the data collection and analysis in the present application can be automatically completed by the program, avoiding the influence of human factors on the results, and the results are more reliable. The measured data is stored in the probe tube, and the probe tube and the wireless terminal are wirelessly transmitted without the need for cable connection, avoiding data loss caused by cable disconnection due to movement during the measurement process. The components in the probe tube use a miniaturized extraction negative pressure measurement module and a gas concentration sensor, combined with the split design of the probe tube structure, which not only realizes the real-time and accurate measurement of gas concentration and extraction negative pressure, but also ensures that the probe tube diameter is small enough to be suitable for in-situ measurement in the gas extraction pipe. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0044] Figure 1 A schematic diagram of an embodiment of the present application in which a probe is inserted into a gas extraction pipe for in-situ detection;

[0045] Figure 2 A structural cross-sectional view of a probe tube according to an embodiment of the present application;

[0046] Figure 3 A structural cross-sectional view of a power supply segment according to an embodiment of the present application;

[0047] Figure 4 This is a schematic diagram of the structure of the main control segment and the measurement segment of an embodiment of the present application.

[0048] Reference numerals:

[0049] 1. Probe tube; 2. Gas extraction pipe; 3. Push rod; 4. Tee pipe; 5. Sealing sleeve; 6. Wireless terminal;

[0050] 110, power supply section; 111, push rod connector; 112, air vent; 113, air chamber; 114, filter; 115, extraction negative pressure measurement module; 116, first outer tube; 117, probe battery pack; 118, first connector; 119, casing;

[0051] 120. Main control section; 121. Male aviation plug; 122. Female aviation plug; 123. Second connector; 124. Circuit board fixing seat; 125. Second outer tube; 126. Main control circuit board; 127. Bluetooth module; 128. Connecting sleeve; 130. Measuring section; 131. Third outer tube; 132. Gas concentration sensor; 133. Protective net. DETAILED DESCRIPTION

[0052] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0053] The embodiment of the present application provides a method for in-situ detection of coal seam gas extraction drilling holes, which can solve the problem that the reasonable sealing depth of gas extraction drilling holes is difficult to detect in the gas extraction process in the related art.

[0054] See also Figure 1 As shown, the embodiment of the present application provides a method for in-situ detection of coal seam gas extraction drilling, the method comprising the following steps:

[0055] Step 101, after extending the gas extraction pipe 2 into the extraction borehole, the extraction borehole is sealed. The sealing method can be grouting or other methods to seal the gap between the gas extraction pipe 2 and the extraction borehole to prevent the air in the orifice range of the extraction borehole from entering the extraction borehole. The sealing position is X meters away from the orifice, and the designed detection depth is X+N meters.

[0056] Step 102, start the wireless terminal 6 and the probe 1, the wireless terminal 6 is connected to the probe 1 by wireless communication, the gas parameter data collected by the probe 1 is wirelessly sent to the wireless terminal 6, the working parameters of the probe 1 are set, and the time of the clock module of the wireless terminal 6 and the probe 1 is calibrated to synchronize the clock of the probe 1 with the clock of the wireless terminal 6.

[0057] Step 103, connect the tee pipe 4 to the pipe mouth of the gas extraction pipe 2, insert the probe 1 into the gas extraction pipe 2 through the tee pipe 4 using the push rod 3, and start extracting gas after the push rod 3 and the tee pipe 4 are sealed by the sealing sleeve 5. The gas extraction equipment is connected to the branch pipe of the tee pipe 4 through a pipeline to extract the gas in the extraction borehole under negative pressure.

[0058] Step 104, each time a push rod 3 is extended, the insertion depth of the probe tube 1 is recorded on the wireless terminal 6, and the probe tube 1 synchronously and continuously measures and stores the methane concentration information and the extraction negative pressure information of each measuring point in the extraction borehole until the designed detection depth is reached.

[0059] Step 105: Receive and view the methane concentration information and extraction negative pressure information of each measuring point on the wireless terminal 6, and fit them into a methane concentration curve and an extraction negative pressure curve. According to the trend changes of the methane concentration curve and the extraction negative pressure curve, determine whether the sealed extraction borehole is leaking, and then determine whether the sealing depth is reasonable.

[0060] The in-situ detection method for coal seam gas extraction drilling in the embodiment of the present application uses a probe tube 1 to extend into the extraction drilling hole. The probe tube 1 measures the gas concentration information and the extraction negative pressure information along the extraction drilling hole to determine the spatial distribution of the gas parameters. The methane concentration curve and the extraction negative pressure curve are obtained by fitting based on the methane concentration information and the extraction negative pressure information of each measuring point measured.

[0061] The trend changes of the methane concentration curve and the negative pressure curve of the extraction are used to determine whether the sealed extraction borehole is leaking, so as to more reasonably determine whether the sealing depth is accurate and reasonable, thereby improving the gas extraction rate. If there is no sudden change in the trend changes of the methane concentration curve and the negative pressure curve of the extraction, it is judged that the extraction borehole is not leaking and the sealing position is reasonable. Otherwise, it is judged that the extraction borehole is leaking and the sealing position depth needs to be reset.

[0062] The embodiment of the present application can provide a corresponding sealing depth for each borehole, and has wide applicability in the technical field. In addition, the detection method has simple steps, the device is easy to use, and the requirements for technical personnel are not high. The data collection and analysis in the present application can be automatically completed by the program, avoiding the influence of human factors on the results, and the results are more reliable.

[0063] In some optional embodiments: the present application embodiment provides a method for in-situ detection of coal seam gas extraction drilling, the method further comprising the following steps:

[0064] Step 106: If there is no obvious fluctuation in the methane concentration curve and the extraction negative pressure curve from the borehole mouth to the detection end point, it is judged that the sealed extraction borehole has no leakage, indicating that the sealing depth is accurate or too deep. Whether there is obvious fluctuation is determined based on the absolute value of the difference between the measured values ​​of two adjacent measuring points. If the absolute value of the difference is greater than the set value, it is judged that the fluctuation is large. If the sealing depth is too deep, the sealing depth needs to be reduced to prevent the sealing from being too deep, resulting in the gas in the coal seam not being completely extracted, leaving safety hazards for future production.

[0065] Step 107: If the methane concentration curve and the extraction negative pressure curve do not fluctuate significantly from the borehole mouth to the end point of the sealing hole, but the gas concentration gradually increases from the end point of the sealing hole to the end point of the detection, it is determined that the sealed extraction borehole is leaking. The leakage section is from the end point of the sealing hole to the end point of the detection, and the sealing depth needs to be increased to prevent the section from continuing to leak, so as to prevent the outside air from being sucked into the extraction pipeline along the coal seam fissures, causing a short circuit of the wind flow, and causing a significant reduction in the gas extraction concentration, thereby failing to achieve the ideal extraction effect.

[0066] In some optional embodiments: the present application embodiment provides a method for in-situ detection of coal seam gas extraction drilling, the method further comprising the following steps:

[0067] Step 106a, after determining that the sealed extraction borehole has no gas leakage, reduce the depth of the sealed position from the borehole mouth to XM meters, where M is preferably 1 meter.

[0068] Step 106b, repeat the above steps 102 to 105, measure and check the methane concentration information and extraction negative pressure information of each measuring point again, and fit them into a methane concentration curve and an extraction negative pressure curve, and judge whether the sealed extraction borehole is leaking based on the trend changes of the methane concentration curve and the extraction negative pressure curve.

[0069] Step 106c: if the extraction borehole is leaking, determine that the sealing depth should be X meters; if the extraction borehole is not leaking, repeat steps 106a to 106b until a reasonable sealing depth is determined.

[0070] In some optional embodiments: the present application embodiment provides a method for in-situ detection of coal seam gas extraction drilling, the method further comprising the following steps:

[0071] Step 107a, after determining that the sealed extraction borehole is leaking, increase the depth of the sealed hole position from the hole mouth to X+M meters, where M is preferably 1 meter.

[0072] Step 107b, repeat the above steps 102 to 105, measure and check the methane concentration information and extraction negative pressure information of each measuring point again, and fit them into a methane concentration curve and an extraction negative pressure curve, and judge whether the sealed extraction borehole is leaking based on the trend changes of the methane concentration curve and the extraction negative pressure curve.

[0073] Step 107c: if the extraction borehole is not leaking, determine that the sealing position depth should be X+M meters; if the extraction borehole is leaking, repeat the above steps 107a to 107b until a reasonable sealing position depth is determined.

[0074] In some alternative embodiments: See Figures 2 to 4 As shown, an embodiment of the present application provides a method for in-situ detection of coal seam gas extraction drilling holes, wherein the probe tube 1 used in the method includes a measurement segment 130, a main control segment 120 and a power supply segment 110 connected in sequence from front to back.

[0075] Specifically, the power supply segment 110 includes a first outer tube 116, and a probe battery pack 117 and an extraction negative pressure measurement module 115 located in the first outer tube 116; the probe battery pack 117 is used to supply power to all electronic devices in the probe 1, and the extraction negative pressure measurement module 115 is used to measure the gas pressure.

[0076] The main control segment 120 includes a second outer tube 125 coaxially and detachably connected to the first outer tube 116, and a main control circuit board 126, a track measurement module and a Bluetooth module 127 are arranged in the second outer tube 125. The main control circuit board 126 is used to obtain and store the collected information of the extraction negative pressure measurement module 115, the track measurement module and the gas concentration sensor 132.

[0077] The trajectory measurement module is used to measure the azimuth and inclination angle of the running trajectory of the probe 1 in the gas extraction pipe 2, and the Bluetooth module 127 is used to wirelessly transmit the collected information of the extraction negative pressure measurement module 115, the trajectory measurement module and the gas concentration sensor 132 obtained by the main control circuit board 126 to the external wireless terminal 6, so as to replace the existing technology in which the probe 1 is connected to the measuring instrument outside the hole through a cable.

[0078] The measuring segment 130 includes a third outer tube 131 which is coaxially and detachably connected to the second outer tube 125. A gas concentration sensor 132 connected to the main control circuit board 126 is provided in the third outer tube 131. The gas concentration sensor 132 is used to measure the concentration of gas. A protective net 133 is provided at one end of the third outer tube 131 away from the second outer tube 125. The protective net 133 is used to connect the gas concentration sensor 132 with the external environment and protect the gas concentration sensor 132 from collision.

[0079] The probe tube 1 of the embodiment of the present application is composed of a power supply segment 110, a main control segment 120 and a measuring segment 130 connected in sequence. It adopts a miniaturized extraction negative pressure measurement module 115 and a gas concentration sensor 132, combined with the split design of the probe tube 1 structure, which not only realizes real-time and accurate measurement of methane concentration and extraction negative pressure, but also ensures that the diameter of the probe tube 1 is small enough to be suitable for in-situ measurement in the gas extraction pipe 2.

[0080] The measurement data such as methane concentration, gas pressure and drilling trajectory collected by the gas concentration sensor 132, the extraction negative pressure measurement module 115 and the trajectory measurement module are stored in the probe 1. The probe 1 and the wireless terminal 6 transmit data wirelessly without the need for cable connection, thus avoiding data loss caused by cable disconnection due to movement during the measurement process, simplifying the device structure, and being more suitable for movement in the gas extraction pipe 2 to achieve in-situ measurement.

[0081] In some alternative embodiments: See Figures 2 to 4 As shown, the embodiment of the present application provides a method for in-situ detection of coal seam gas extraction drilling, wherein one end of the first outer tube 116 of the probe tube 1 used in the method is provided with a push rod connector 111 connected to the push rod 3, and the other end is provided with an aviation plug male head 121 electrically connected to the main control segment 120. The probe battery pack 117 and the extraction negative pressure measurement module 115 are sealed in the first outer tube 116 by silicone, and the probe battery pack 117 and the extraction negative pressure measurement module 115 are connected to the main control segment 120 after being connected to the aviation plug male head 121.

[0082] The push rod connector 111 is threadedly connected to the first outer tube 116, so as to facilitate the assembly of the probe battery pack 117 and the extraction negative pressure measurement module 115 in the first outer tube 116. The side wall of the push rod connector 111 is radially provided with an air vent 112 for the extraction negative pressure measurement module 115 to detect the external environmental air pressure. The push rod connector 111 is provided with an air chamber 113 connecting the air vent 112 and the extraction negative pressure measurement module 115, and the air chamber 113 is provided with a filter screen 114, which is used to protect the extraction negative pressure measurement module 115.

[0083] The first outer tube 116 is threadedly connected to the first connector 118 at one end away from the push rod connector 111, and the aviation plug male head 121 is fixed in the first connector 118 after being electrically connected to the probe battery pack 117 and the extraction negative pressure measurement module 115. The second outer tube 125 is threadedly connected to the second connector 123 at one end close to the first outer tube 116, and the second connector 123 is provided with an aviation plug female head 122 connected to the power supply segment 110. The first connector 118 is rotatably sleeved with a sleeve 119 for inserting the aviation plug male head 121 into the aviation plug female head 122, and one end of the sleeve 119 is threadedly connected to the second connector 123.

[0084] The first outer tube 116 and the second outer tube 125 of the embodiment of the present application are connected by the first connector 118 and the second connector 123, which facilitates the installation and removal of the power supply segment 110 and the main control segment 120. When the power supply segment 110 or the main control segment 120 fails, it is convenient for maintenance and replacement, thereby increasing the service life of the probe 1 and reducing the use cost.

[0085] The first connector 118 and the second connector 123 are provided with an aviation plug male head 121 and an aviation plug female head 122 that are plugged in and out of each other. When the sleeve 119 connects and fixes the first connector 118 and the second connector 123 together, the aviation plug male head 121 and the aviation plug female head 122 are plugged in to each other to realize the electrical connection between the power supply segment 110 and the main control segment 120.

[0086] In some alternative embodiments: See Figures 2 to 4 As shown, an embodiment of the present application provides a method for in-situ detection of coal seam gas extraction drilling holes. The main control circuit board 126 of the probe 1 used in the method includes a microprocessor, a storage module and a clock module, a power management module, and an interface module connecting the extraction negative pressure measurement module 115, the gas concentration sensor 132, the trajectory measurement module and the Bluetooth module 127.

[0087] The microprocessor is preferably an ARM microprocessor, which obtains the collected information of the extraction negative pressure measurement module 115, the gas concentration sensor 132, and the trajectory measurement module and stores it in the storage module, and wirelessly sends the collected information in the storage module to the wireless terminal 6 via the Bluetooth module 127.

[0088] The probe battery pack 117 is provided with an intrinsically safe power management module, which is connected to the probe battery pack 117 and distributes the electric energy of the probe battery pack 117 to the microprocessor, storage module, clock module, interface module, extraction negative pressure measurement module 115, trajectory measurement module, gas concentration sensor 132 and Bluetooth module 127.

[0089] The probe tube 1 of the embodiment of the present application has a built-in probe tube battery pack 117, which is protected by the intrinsic safety power management module such as current limiting and overcharging, and then generates the power required by each peripheral and internal device through the power management module on the main control circuit board 126 to supply power to each component. The microprocessor performs two-way data exchange with the extraction negative pressure measurement module 115, the gas concentration sensor 132, the trajectory measurement module and the Bluetooth module 127 through the interface module.

[0090] The clock module generates an accurate clock signal, which is used as the time reference for the internally collected sensor data after being synchronized with the initial clock of the external wireless terminal 6. The negative pressure data, gas concentration data, azimuth and inclination data of the trajectory are collected at the set time interval and are sequentially saved in the storage module together with the current time data.

[0091] In some alternative embodiments: See Figures 2 to 4As shown, an embodiment of the present application provides a method for in-situ detection of coalbed gas extraction drilling holes, wherein the method uses a probe 1 whose second outer tube 125 is threadedly connected to a connecting sleeve 128 at one end close to the third outer tube 131, and the third outer tube 131 is threadedly connected to the connecting sleeve 128 at one end close to the second outer tube 125.

[0092] The main control circuit board 126, the track measurement module and the Bluetooth module 127 are fixed in the second outer tube 125 through the circuit board fixing seat 124, and are arranged in sequence along the axis direction of the second outer tube 125. The extraction negative pressure measurement module 115 is a miniature air pressure sensor, and the gas concentration sensor 132 is a miniature laser methane gas sensor.

[0093] The second outer tube 125 is made of non-metallic material, such as a plastic tube. A Bluetooth antenna connected to the Bluetooth module 127 is disposed inside the second outer tube 125 . The Bluetooth antenna transmits the signal sent by the Bluetooth module 127 to the wireless terminal 6 .

[0094] The second outer tube 125 and the third outer tube 131 of the embodiment of the present application are connected by a connecting sleeve 128, which facilitates the installation and removal of the measuring segment 130 and the main control segment 120. When the measuring segment 130 or the main control segment 120 fails, it is convenient for maintenance and replacement, thereby increasing the service life of the probe 1 and reducing the use cost.

[0095] The main control circuit board 126, the track measurement module and the Bluetooth module 127 are fixed in the second outer tube 125 through the circuit board fixing seat 124, and are arranged in sequence along the axial direction of the second outer tube 125. While the main control circuit board 126, the track measurement module and the Bluetooth module 127 are fixed in the second outer tube 125, the outer diameter of the second outer tube 125 is reduced, so that the outer diameter of the second outer tube 125 is controlled within 22 mm.

[0096] Since the inner diameter of the gas extraction pipe 2 arranged in the extraction borehole is usually less than 30 mm, the diameter of the probe tube 1 is required to be small enough to facilitate the smooth advancement of the probe tube 1 in the gas extraction pipe 2; at the same time, the strength of the probe tube 1 must be ensured so that it will not be squeezed and deformed. Therefore, in this embodiment, the extraction negative pressure measurement module 115 is a miniature air pressure sensor, and the gas concentration sensor 132 is a miniature laser methane gas sensor. The extraction negative pressure measurement module 115 and the gas concentration sensor 132 are arranged at both ends of the probe tube 1 to make full use of the size space of each component and control the diameter of the probe tube 1 within 22 mm.

[0097] How it works

[0098] The embodiment of the present application provides a method for in-situ detection of coal seam gas extraction boreholes. The method for in-situ detection of coal seam gas extraction boreholes of the present application first extends the gas extraction pipe 2 into the extraction borehole and then seals the extraction borehole. The sealing position is X meters away from the hole mouth, and the designed detection depth is X+N meters; then the wireless terminal 6 and the probe tube 1 are started, the wireless terminal 6 is connected to the probe tube 1 by wireless communication, the working parameters of the probe tube 1 are set, and the time of the wireless terminal 6 and the probe tube clock module is calibrated;

[0099] Next, a tee pipe 4 is connected to the pipe mouth of the gas extraction pipe 2, and the probe 1 is inserted into the gas extraction pipe 2 by using the push rod 3. The push rod 3 and the tee pipe 4 are sealed by the sealing sleeve 5 to start gas extraction; each time a push rod 3 is extended, the pushing depth of the probe 1 is recorded on the wireless terminal 6, and the probe 1 synchronously and continuously measures the methane concentration information and the extraction negative pressure information of each measuring point in the extraction borehole until the designed detection depth is reached; finally, the methane concentration curve and the extraction negative pressure curve of each measuring point are received and viewed on the wireless terminal 6, and whether the sealed extraction borehole is leaking is determined based on the trend changes of the methane concentration curve and the extraction negative pressure curve.

[0100] Therefore, the coal seam gas extraction borehole in-situ detection method of the present application uses a probe tube 1 to extend into the extraction borehole, and the probe tube 1 determines the spatial distribution of gas parameters by measuring the gas concentration information and extraction negative pressure information along the extraction borehole. The methane concentration curve and the extraction negative pressure curve are obtained by fitting the methane concentration information and extraction negative pressure information of each measuring point measured, and the trend changes of the methane concentration curve and the extraction negative pressure curve are used to determine whether the sealed extraction borehole is leaking, so as to more reasonably determine whether the sealing depth is accurate, thereby improving the gas extraction rate.

[0101] The present application can provide a corresponding sealing depth for each borehole, and has wide practicability in the technical field. In addition, the detection method has simple steps, the device is easy to use, and the requirements for technical personnel are not high; the data collection and analysis in the present application can be automatically completed by the program, avoiding the influence of human factors on the results, and the results are more reliable. The measured data is stored in the probe tube 1, and the probe tube 1 is wirelessly transmitted to the wireless terminal 6 without the need for cable connection, which avoids data loss caused by cable disconnection due to movement during the measurement process.

[0102] The components in the probe tube 1 adopt a miniaturized extraction negative pressure measurement module 115 and a gas concentration sensor 132, combined with the split design of the probe tube 1 structure, which not only realizes the real-time and accurate measurement of the gas concentration and extraction negative pressure, but also ensures that the diameter of the probe tube 1 is small enough to be suitable for in-situ measurement in the gas extraction pipe 2.

[0103] In the description of the present application, it should be noted that the terms "upper", "lower", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application. Unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be a connection between the two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to the specific circumstances.

[0104] It should be noted that, in this application, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the presence of other identical elements in the process, method, article or device including the elements.

[0105] The above description is only a specific implementation of the present application, so that those skilled in the art can understand or implement the present application. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to the embodiments shown herein, but will conform to the widest range consistent with the principles and novel features applied for herein.

Claims

1. A method for in-situ detection of coal seam gas extraction drilling, characterized in that: The following steps are involved: After the gas extraction pipe (2) is inserted into the extraction borehole, the extraction borehole is sealed. The sealing position is X meters away from the borehole mouth, and the designed detection depth is X+N meters; The wireless terminal (6) and the probe (1) are started, the wireless terminal (6) and the probe (1) are wirelessly connected, the working parameters of the probe (1) are set, and the time of the clock modules of the wireless terminal (6) and the probe (1) are calibrated; A tee pipe (4) is connected to the pipe opening of the gas extraction pipe (2), and the probe (1) is inserted into the gas extraction pipe (2) using a push rod (3). The push rod (3) and the tee pipe (4) are sealed by a sealing sleeve (5) to start extracting gas; Each time a push rod (3) is extended, the insertion depth of the probe tube (1) is recorded on the wireless terminal (6), and the probe tube (1) synchronously and continuously measures the methane concentration information and the extraction negative pressure information of each measuring point in the extraction borehole until the designed detection depth is reached; Receiving and viewing methane concentration information and extraction negative pressure information of each measuring point on a wireless terminal (6), and fitting them into a methane concentration curve and an extraction negative pressure curve, and judging whether the sealed extraction borehole is leaking according to the trend changes of the methane concentration curve and the extraction negative pressure curve; If the methane concentration curve and the drainage negative pressure curve have no obvious fluctuations from the borehole mouth to the detection end point, it is judged that the sealed drainage borehole has no gas leakage; If the methane concentration curve and the drainage negative pressure curve do not fluctuate significantly from the borehole mouth to the end point of the sealing hole, but the gas concentration gradually increases from the end point of the sealing hole to the end point of the detection, it is judged that the sealed drainage borehole is leaking; The probe (1) comprises a measuring segment (130), a main control segment (120) and a power supply segment (110) which are connected in sequence from front to back; The power supply segment (110) comprises a first outer tube (116), and a probe battery pack (117) and a negative pressure extraction measurement module (115) located inside the first outer tube (116); The main control segment (120) comprises a second outer tube (125) coaxially and detachably connected to the first outer tube (116), wherein a main control circuit board (126), a track measurement module and a Bluetooth module (127) are arranged in the second outer tube (125); The measuring segment (130) comprises a third outer tube (131) coaxially and detachably connected to the second outer tube (125); a gas concentration sensor (132) connected to the main control circuit board (126) is arranged in the third outer tube (131); One end of the first outer tube (116) is provided with a push rod connector (111) connected to the push rod (3), and the other end is provided with an aviation plug male connector (121) electrically connected to the main control segment (120); the probe battery pack (117) and / or the extraction negative pressure measurement module (115) are sealed in the first outer tube (116) by means of silicone; One end of the first outer tube (116) away from the push rod connector (111) is threadedly connected to a first connector (118); the aviation plug male connector (121) is electrically connected to the probe battery pack (117) and the extraction negative pressure measurement module (115) and then fixed in the first connector (118); A second connector (123) is threadedly connected to one end of the second outer tube (125) close to the first outer tube (116), and an aviation female connector (122) connected to the power supply segment (110) is disposed inside the second connector (123); A sleeve (119) is rotatably provided on the first connector (118) for inserting the male aviation plug (121) into the female aviation plug (122), and one end of the sleeve (119) is threadedly connected to the second connector (123); The push rod connector (111) is threadedly connected to the first outer tube (116) to facilitate the assembly of the probe battery pack (117) and the extraction negative pressure measurement module (115) in the first outer tube (116). A vent hole (112) is radially opened on the side wall of the push rod connector (111) to enable the extraction negative pressure measurement module (115) to detect the external environmental air pressure. An air chamber (113) is provided in the push rod connector (111) to connect the vent hole (112) and the extraction negative pressure measurement module (115). A filter screen (114) is provided in the air chamber (113). The filter screen (114) is used to protect the extraction negative pressure measurement module (115).

2. A method for in-situ detection of coal seam gas extraction drilling according to claim 1, characterized in that: The following steps are also included: After judging that the sealed extraction borehole has no gas leakage, reduce the depth of the sealed hole position from the hole mouth to XM meters; Measure and check the methane concentration curve and drainage negative pressure curve of each measuring point again, and judge whether the sealed drainage borehole is leaking according to the trend changes of the methane concentration curve and the drainage negative pressure curve; If the extraction borehole leaks, the sealing depth is determined to be X meters. If the extraction borehole does not leak, the above steps are repeated until a reasonable sealing depth is determined.

3. The method for in-situ detection of coal seam gas extraction drilling according to claim 1, characterized in that: The following steps are also included: After determining that the sealed extraction borehole is leaking, increase the depth of the sealed hole position from the hole mouth to X+M meters; Measure and check the methane concentration curve and drainage negative pressure curve of each measuring point again, and judge whether the sealed drainage borehole is leaking according to the trend changes of the methane concentration curve and the drainage negative pressure curve; If the extraction borehole does not leak, the sealing position depth is determined to be X+M meters. If the extraction borehole leaks, repeat the above steps until a reasonable sealing position depth is determined.

4. The method for in-situ detection of coal seam gas extraction drilling according to claim 1, characterized in that: The main control circuit board (126) comprises a microprocessor, a storage module and a clock module, a power management module, and an interface module connected to a drainage negative pressure measurement module (115), a gas concentration sensor (132), a trajectory measurement module, and a Bluetooth module (127); The microprocessor obtains the collected information of the extraction negative pressure measurement module (115), the gas concentration sensor (132), and the trajectory measurement module and stores the information in the storage module, and wirelessly transmits the collected information in the storage module to the wireless terminal (6) via the Bluetooth module (127).

5. A method for in-situ detection of coal seam gas extraction drilling holes according to claim 4, characterized in that: The probe battery pack (117) is provided with an intrinsically safe power management module, which is connected to the probe battery pack (117) and distributes the electric energy of the probe battery pack (117) to the microprocessor, the storage module, the clock module, the interface module, the extraction negative pressure measurement module (115), the trajectory measurement module, the gas concentration sensor (132) and the Bluetooth module (127).

6. A method for in-situ detection of coal seam gas extraction drilling according to claim 1, characterized in that: One end of the second outer tube (125) close to the third outer tube (131) is threadedly connected to a connecting sleeve (128), and one end of the third outer tube (131) close to the second outer tube (125) is threadedly connected to the connecting sleeve (128); The main control circuit board (126), the track measurement module and the Bluetooth module (127) are fixed in the second outer tube (125) via a circuit board fixing seat (124), and are arranged in sequence along the axial direction of the second outer tube (125).

7. The method for in-situ detection of coal seam gas extraction drilling according to claim 1, characterized in that: The extraction negative pressure measurement module (115) is a miniature air pressure sensor, and the gas concentration sensor (132) is a miniature laser methane gas sensor; The second outer tube (125) is made of non-metallic material, and a Bluetooth antenna connected to the Bluetooth module (127) is arranged inside the second outer tube (125).

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