Underground gas detection device and detection method

Abstract

The invention relates to an underground gas detection device and a detection method, and relates to the technical field of gas detection. Comprising a detection box, a lower detection part and a detection part, the detection part comprises a detection block and detection capsules clamped and mounted on the detection block at equal intervals, and a control piece for controlling the detection block and the detection capsules to move is arranged in the detection box; the control piece comprises a circulating driving rope for controlling the detection capsules to circularly move, and the detection capsules are movably arranged on the circulating driving rope at equal intervals; the device can solve the following problems in the prior art: firstly, an existing device cannot perform simultaneous fixed-point quantitative measurement on areas with different depths in a well, measurement equipment needs to be controlled to ascend and descend in a reciprocating manner, and a large amount of gas in the well flows during ascending and descending measurement, so that the accuracy of a detection result is influenced; secondly, an existing device is poor in detection effect and cannot detect different types of gas at the same time, and equipment needed for detection is tedious to maintain and replace.

Description

Technical Field

[0001] The present invention relates to the technical field of gas detection, and in particular to a downhole gas detection device and a detection method. Background Art

[0002] Underground gas detection devices are important equipment used to monitor gas concentrations in underground environments such as coal mines, tunnels, and mines. Their main purpose is to ensure the safety of workers and prevent accidents caused by gas leaks or excessive concentrations.

[0003] For example, Chinese patent publication number CN117783451A discloses an underground gas detection device, which relates to the technical field of coal mine monitoring equipment. The device includes a tunneling machine with a fixed gas storage box. An air inlet and an air outlet are provided on a set of opposite side walls of the gas storage box. An air inlet valve and an air outlet are slidably mounted on the side walls of the gas storage box. The air inlet valve can block the air inlet, and the air outlet valve can block the air outlet. A fan blade is rotatably mounted in the gas storage box, and the fan blade is located between the air inlet and the air outlet. The fan blade is coaxially fixedly connected to a transmission mechanism connected to the tunneling machine, and the transmission mechanism is used to drive the fan blade to rotate. The gas storage box is provided with a control mechanism and a detection mechanism. The control mechanism is used to control the opening and closing of the air inlet and the air outlet, and the detection mechanism is used to detect the gas in the gas storage box. This device has the effect of improving the real-time accuracy of the detection results.

[0004] However, the above-mentioned downhole gas detection device still has some shortcomings in actual use: 1. First, the above-mentioned downhole gas detection device can collect and detect the gas at the bottom of the well, but it cannot perform fixed-point quantitative detection at different depths in the well, resulting in inaccurate detection results.

[0005] 2. Secondly, when the existing device is used for downhole gas detection, it is easy to cause gas from the previous test to remain inside the gas storage box for collecting gas, which further leads to poor purity of the collected gas and ultimately affects the accuracy of subsequent gas detection.

[0006] 3. In addition, the existing device has poor detection effect and cannot detect different types of gases at the same time. When replacing or maintaining the gas detection components for gas detection, it is necessary to open the protective shell of the device and then rotate the screws and nuts to separate the fixed gas detection components before replacing the corresponding gas detection components. This makes the maintenance and replacement of the equipment required for detection more cumbersome, especially since the gas detection components are precision parts and are easily damaged during the replacement process.

[0007] Therefore, based on the above-stated viewpoint, there is still room for improvement in the existing downhole gas detection devices. Summary of the Invention

[0008] In order to solve the above problems, the present invention provides a downhole gas detection device and detection method, which adopts the following technical solutions: In a first aspect, the present application relates to a downhole gas detection device, comprising a portable detection box.

[0009] The down-probing part is used to detect the depth from the wellhead to the bottom of the well and is arranged in the detection box. The down-probing part includes a vertically downward down-probing cone and a telescopic rope connected to the top of the down-probing cone. The telescopic rope is used to control the down-probing depth of the down-probing cone to detect the depth of the well.

[0010] The detection part is arranged in the detection box. The detection part includes a detection block and a detection capsule mounted on the detection block. The detection capsule is used to collect gas in different areas of the well.

[0011] The detection blocks and the detection capsules are arranged at equal intervals in the detection box, and a control member for controlling the movement of the detection blocks and the detection capsules is provided in the detection box.

[0012] The control component comprises a circulating driving rope for controlling the cyclic movement of the detection capsules, and the detection capsules are arranged on the circulating driving rope at equal intervals.

[0013] Preferably, the downward exploration part also includes a winding roller that is rotatably connected inside the detection box, the end of the telescopic rope away from the downward exploration cone is connected to the winding roller, and the telescopic rope is wound around the winding roller. A winding motor connected to the winding roller is also provided in the detection box.

[0014] Preferably, an I-shaped column is installed at the bottom of the lower cone, and a lifting hole is provided at the bottom of the lower cone for the I-shaped column to be lifted and lowered along the height direction. A linkage spring installed in the lifting hole is provided between the top of the I-shaped column and the lower cone. The linkage spring always has the force to drive the I-shaped column downward, and contact sensors are respectively provided between the I-shaped column and the inner wall of the lower cone. The start and stop of the winding motor are controlled by opening and closing the two contact sensors.

[0015] Preferably, the control component includes two groups of symmetrical sliders slidably installed on the inner wall of the detection box along the length direction, a telescopic roller is rotatably provided between the two groups of sliders, and the middle part of the circulating drive rope is provided on the telescopic roller.

[0016] A moving frame which moves along the height direction is also slidably provided in the detection box. A release roller is rotatably provided on the moving frame. One end of the circulating driving rope is sleeved on the release roller.

[0017] A No. 1 telescopic tension spring is provided between the movable frame and the inner wall of the detection box, and a No. 2 telescopic tension spring is provided between the sliding block and the inner wall of the detection box.

[0018] Preferably, one end of the telescopic rope close to the lower cone is connected to the circulating drive rope through a linkage column, the circulating drive rope slides through the linkage column, and a collecting motor that moves along the inner wall of the detection box is installed on the telescopic roller.

[0019] Preferably, a plurality of engaging grooves are formed at equal intervals on a side of the detection block close to the detection capsule, and a plurality of engaging serrations are formed at equal intervals on a side wall of the detection block located in the engaging groove.

[0020] A clamping block is integrated into one end of the detection capsule close to the detection block. The clamping block is provided with a deformable rack that movably engages with the clamping serrations. The movable end of the deformable rack is connected to a control rope that controls its deformation. The control rope slides through the clamping block and is located outside the clamping block.

[0021] Preferably, the detection capsule is composed of a capsule body and a capsule cover screwed to the upper end of the capsule body. A connecting column is installed at the bottom of the capsule cover, and a gas sensor is plugged into the connecting column to detect the gas type and gas concentration in the well.

[0022] Preferably, a detection port is opened on one side of the capsule body, the detection end of the gas sensor abuts against the detection port of the capsule body, and the power-on end of the gas sensor is close to one side of the clamping block.

[0023] A powered wire is also wound around the circulating drive rope, and a No. 1 metal conductive contact connected to the powered wire is installed on the detection block. The No. 1 metal conductive contact is located at the snap-fitting slot of the detection block, and a No. 2 metal conductive contact is provided on the snap-fitting block, which is movably connected to the No. 1 metal conductive contact.

[0024] The power supply end of the gas sensor is movably connected to an end of the second metal conductive contact away from the first metal conductive contact.

[0025] Preferably, the detection port of the capsule body is equipped with an opening and closing sealing door, and a cleaning brush is provided on one side of the sealing door close to the detection end of the gas sensor.

[0026] In a second aspect, the present application also relates to a downhole gas detection method, which is as follows: S1. Preparation: First, install the detection box near the wellhead or just above the wellhead through the bracket; S2. Detection switching: When detecting different gases in different wells, quickly open the detection capsule, replace the gas detection device inside the detection capsule, and then close the detection capsule; S3. Bottom hole exploration: Start the lower exploration unit, and the lower exploration cone on the lower exploration unit moves toward the bottom of the well. The bottom of the lower exploration cone just touches the bottom of the well. The distance from the bottom of the well to the wellhead at this time is measured, which is the depth of the well. S4. Equipment positioning: As the probe moves toward the bottom of the well, the circulating drive rope of the detection unit also moves to the bottom of the well synchronously. The probe limits the circulating drive rope to ensure its stability. The circulating drive rope is then controlled to move to different heights in the well. S5. Gas detection: The equipment in the detection capsule is then started to perform regular detection of different areas in the well to determine what gases are contained in the well gas and the concentration of the gases contained.

[0027] In summary, this application includes at least one of the following beneficial technical effects: 1. The present invention wraps the gas sensor for detecting gas with a detection capsule to ensure the safety and stability of the gas sensor. The gas sensor in the detection capsule directly detects the gas at different depths in the well without collecting the gas, thereby effectively avoiding the gas flow caused by suction during gas collection, which affects the accuracy of gas detection.

[0028] 2. The exploration part of the present invention can detect the depth of the well in real time. While detecting the depth of the well, the exploration part can also work in conjunction with the detection part. The exploration part controls the circulating drive rope for traction to prepare for position adjustment and position movement of the detection part.

[0029] 3. The detection unit of the present invention can quickly detect gas in areas of different depths in the well, and the several detection airbags of the detection unit can be quickly disassembled and installed. Furthermore, the gas sensors installed in the detection airbags can also be quickly replaced, ensuring that the detection airbags can accurately identify toxic substances and other substances in the gas in the well.

[0030] At the same time, the rapid replacement of gas sensors can greatly improve the efficiency of the entire equipment maintenance and ensure the applicability of the entire device. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The present invention will be further described below with reference to the accompanying drawings and examples.

[0032] Figure 1 It is a schematic diagram of the main structure of the present invention.

[0033] Figure 2 It is a first-view structural schematic diagram of the downward probe portion of the present invention.

[0034] Figure 3 It is a second perspective structural schematic diagram of the downward probe portion of the present invention.

[0035] Figure 4 It is a schematic diagram of the downward cone and its internal structure of the present invention.

[0036] Figure 5 It is a structural diagram between the detection part and the control part of the present invention.

[0037] Figure 6 It is a partial enlarged view between the detection part and the control part of the present invention.

[0038] Figure 7This invention Figure 6 A partial enlarged view of point A in the figure.

[0039] Figure 8 It is a schematic structural diagram of the detection capsule of the present invention from a first perspective.

[0040] Figure 9 It is an exploded view of the structure of the detection capsule of the present invention.

[0041] Figure 10 It is a schematic diagram of the structure among the clamping block, the deformable rack, the control rope and the second metal conductive contact of the present invention.

[0042] Figure 11 2 is a schematic structural diagram of the detection capsule of the present invention from a second viewing angle.

[0043] Figure 12 It is a flow chart of the downhole gas detection method of the present invention.

[0044] Explanation of reference numerals: 1. Detection box; 2. Probing part; 20. Telescopic rope; 21. Probing cone; 3. Detection part; 30. Detection block; 31. Detection capsule; 4. Control part; 40. Circular drive rope; 22. Winding roller; 23. Winding motor; 210. I-shaped column; 211. Lifting hole; 212. Linkage spring; 213. Contact sensor; 46. Slider; 41. Telescopic roller; 42. Moving frame; 43. Release roller; 44. Telescopic roller No. 1 Tension spring; 45. No. 2 telescopic tension spring; 5. Linkage column; 6. Collection motor; 32. Snap-in slide; 33. Snap-in serrations; 34. Snap-in block; 35. Deformation rack; 36. Control rope; 310. Capsule body; 311. Capsule cover; 312. Gas sensor; 317. Connecting column; 313. Detection port; 314. Power-carrying wire; 315. No. 1 metal conductive contact; 316. No. 2 metal conductive contact; 7. Sealing door; 8. Cleaning brush. DETAILED DESCRIPTION

[0045] The following combination Figures 1-12 This application is described in further detail.

[0046] The embodiments of the present application disclose a downhole gas detection device and a detection method, which are mainly used in the process of drilling operations or downhole work. During drilling operations, the downhole gas detection device is used to regularly detect areas at different depths in the well to avoid gas leakage. Furthermore, during downhole operations, the downhole gas detection device regularly detects gas at areas at different depths in the well to ensure whether the well is safe before going down to the well.

[0047] However, in the prior art, there are indeed the following problems: First, the above-mentioned downhole gas detection device can collect and detect the gas at the bottom of the well, but it cannot perform fixed-point quantitative detection of different depth areas in the well, resulting in inaccurate detection results.

[0048] Secondly, when existing devices are used for downhole gas detection, gas from the previous test may remain inside the gas storage box for collecting gas, which further leads to poor purity of the collected gas and ultimately affects the accuracy of subsequent gas detection.

[0049] In addition, the existing device has poor detection effect and cannot detect different types of gases at the same time. When replacing or maintaining the gas detection components for gas detection, it is necessary to open the protective shell of the device, and then rotate the screws and nuts to separate the fixed gas detection components before replacing the corresponding gas detection components. This makes the maintenance and replacement of the equipment required for detection more cumbersome, especially since the gas detection components are precision parts and are easily damaged during the replacement process.

[0050] Therefore, the present application proposes a downhole gas detection device to solve the above problems.

[0051] Example 1: Reference Figure 1 and Figure 2 , which is a schematic diagram of the main structure of the downhole gas detection device in this application; a downhole gas detection device includes a detection box 1.

[0052] The down-going probe part 2 is used to detect the depth from the wellhead to the bottom of the well and is arranged in the detection box 1. The down-going probe part 2 includes a vertically downward down-going cone 21 and a telescopic rope 20 connected to the top of the down-going cone 21. The telescopic rope 20 controls the down-going depth of the down-going cone 21, and the depth of the well is detected by the down-going cone 21.

[0053] A circular hole is provided at the bottom of the detection box 1 for the extension and retraction of the lowering cone 21. When gas detection is required in the well, the detection box 1 is moved to the wellhead or covers the top of the wellhead. Then the telescopic rope 20 controls the lowering cone 21 to move downward until the bottom of the lowering cone 21 touches the bottom of the well. During this process, the telescopic rope 20 is in a vertical state. The combined length of the lowering cone 21 and the straightened telescopic rope 20 is the depth from the wellhead to the bottom of the well.

[0054] At this time, the probe unit 2 can detect the depth of the well. In addition, the probe unit 2 can also control the detection unit 3 to operate synchronously.

[0055] See Figure 3As shown, it is a schematic diagram of the structure for controlling the extension and retraction of the telescopic rope 20 in this application; the downward probe part 2 also includes a winding roller 22 that is rotatably connected to the inside of the detection box 1 through a bearing, and the end of the telescopic rope 20 away from the downward cone 21 is connected to the winding roller 22, and the telescopic rope 20 is wound on the winding roller 22. A winding motor 23 connected to the winding roller 22 is also installed in the detection box 1 through a motor seat.

[0056] In the specific implementation, the winding motor 23 is started, and the winding motor 23 drives the winding roller 22 to rotate counterclockwise, and the telescopic rope 20 wound on the winding roller 22 begins to be released downward, so that the lowering cone 21 moves into the well; on the contrary, the winding roller 22 rotates clockwise, and the telescopic rope 20 on the winding roller 22 begins to be released downward. It starts to shrink and winds up onto the winding roller 22, causing the lowering cone 21 to move toward the wellhead.

[0057] See Figure 3 and Figure 4 As shown, it is a structural diagram of the start-up of the winding motor 23 in this application; an I-shaped column 210 is installed at the bottom of the downward cone 21, and a lifting hole 211 is provided at the bottom of the downward cone 21 for the I-shaped column 210 to be lifted and lowered in the height direction, and a linkage spring 212 installed in the lifting hole 211 is provided between the top of the I-shaped column 210 and the downward cone 21. The linkage spring 212 always has the force to drive the I-shaped column 210 downward, and a contact sensor 213 is provided between the I-shaped column 210 and the inner wall of the downward cone 21, and the start and stop of the winding motor 23 are controlled by opening and closing the two contact sensors 213.

[0058] During specific implementation, when the lower exploration cone 21 moves downward along the well wall, the I-shaped column 210 at the bottom of the lower exploration cone 21 protrudes outward, and the two contact sensors 213 separate from each other. When the lower exploration cone 21 contacts the bottom of the well, the I-shaped column 210 first contacts the bottom of the well and contracts into the lifting hole 211 of the lower exploration cone 21 under the action of the squeezing force. At this time, the contact sensor 213 at the bottom of the I-shaped column 210 contacts the contact sensor 213 on the inner wall of the lower exploration cone 21 and transmits the signal to the existing known controller in the detection box 1, indicating that the lower exploration cone 21 has just reached the bottom of the well. At this time, the retractable rope 20 is in a stretched state, and the contact sensor 213 cooperates with the controller at the same time to detect the depth of the well.

[0059] It should be noted that the controller is an existing known structure and is not shown in the figure. The controller mainly includes a display screen and various processing chips.

[0060] Secondly, the contact sensor 213 in the present application can also detect the state of the lower cone 21. If the retractable rope 20 continues to extend outward after the lower cone 21 reaches the bottom of the well, the retractable rope 20 will be in a relaxed state. At this time, the lower cone 21 cannot maintain balance due to its conical structure, causing the lower cone 21 to tilt. After the lower cone 21 tilts, the I-shaped column 210 at its bottom loses the support force of the soil at the bottom of the well, causing the contact sensor 213 on the I-shaped column 210 to separate from the contact sensor 213 on the inner wall of the lower cone 21 under the action of the linkage spring 212. At this time, the two are disconnected and the circuits to which they are connected are powered off. At this time, if the controller in the detection box 1 immediately powers off after discovering that the contact sensor 213 is powered on, it means that the lower cone 21 has shifted after touching the bottom. It is then determined that the lower cone 21 is tilted and the retractable rope 20 has been released too much. The retractable rope 20 can be retracted in time to ensure that the bottom of the lower cone 21 just touches the bottom of the well. This avoids errors in well depth detection and ensures the accuracy of the detection results.

[0061] When the lower probe cone 21 is moving downward, the detection unit 3 also works synchronously, as shown below: See Figure 5 、 Figure 6 and Figure 7 As shown, the detection part 3 is arranged in the detection box 1, and the detection part 3 is linked with the down-exploring part 2. While the down-exploring part 2 detects the well depth, the detection part 3 collects and detects the gas at different depths in the well. The detection part 3 includes a detection block 30 and a detection capsule 31 that is snap-fitted onto the detection block 30. The detection capsule 31 is used to collect gas in different areas in the well.

[0062] The detection blocks 30 and the detection capsules 31 are arranged at equal intervals in the detection box 1 , and a control member 4 for controlling the movement of the detection blocks 30 and the detection capsules 31 is provided in the detection box 1 .

[0063] The control member 4 includes a circulating driving rope 40 for controlling the detection capsules 31 to move in a circular manner. The detection capsules 31 are movably arranged on the circulating driving rope 40 at equal intervals.

[0064] During specific implementation, after the lowering cone 21 moves downward to the bottom of the well, one end of the circulating drive rope 40 moves synchronously to the bottom of the well following the lowering cone 21. At this time, one end of the circulating drive rope 40 is set in the detection box 1, and the other end is positioned due to the weight of the lowering cone 21, so that the other end of the circulating drive rope 40 is distributed at a position close to the bottom of the well.

[0065] When it is necessary to detect gas at different depths in the well bottom, the circulating drive rope 40 rotates, causing the detection capsules 31 arranged at equal intervals on its upper end to rotate to the specified position. The detection capsules 31 then collect gas at different depths in the well, and the detection block 30 then detects the gas inside the detection capsules 31, thereby achieving synchronous detection of gas at different depths in the well, avoiding the situation where the movement of the circulating drive rope 40 causes the gas in the well to flow, which in turn causes the gas in the well to affect the concentration of the gas collected at a fixed point due to the flow, further affecting the accuracy of the detection results.

[0066] Replay Figure 5 and Figure 6 As shown, it is a schematic diagram of the structure for controlling the extension of the circulating drive rope 40 in the well in the present application; specifically, the control component 4 includes two groups of symmetrical sliders 46 slidingly installed along the length direction on the inner wall of the detection box 1, and a telescopic roller 41 is rotatably provided between the two groups of sliders 46, and the middle part of the circulating drive rope 40 is provided on the telescopic roller 41.

[0067] A movable frame 42 is slidably provided in the detection box 1 and moves along its height direction. A release roller 43 is rotatably provided on the movable frame 42 , and one end of the circulating drive rope 40 is sleeved on the release roller 43 .

[0068] A first telescopic tension spring 44 is provided between the movable frame 42 and the inner wall of the detection box 1 , and a second telescopic tension spring 45 is provided between the sliding block 46 and the inner wall of the detection box 1 .

[0069] During specific implementation, after the lower exploration cone 21 drives one end of the circulating drive rope 40 to move to the bottom of the well through the linkage column 5, the circulating drive rope 40 is in a vertical state. During this process, the release roller 43 on the movable frame 42 first moves upward along the detection box 1. When the release roller 43 moves to the maximum stroke, the telescopic rollers 41 on the two sliders 46 approach each other until one end of the circulating drive rope 40 moves to the bottom of the well.

[0070] The end of the circulating drive rope 40 is connected to the end, forming a ring, and one end of the circulating drive rope 40 is connected to the telescopic rope 20 through the linkage column 5, and the other end of the circulating drive rope 40 is mounted on the release roller 43. The release roller 43 is equipped with a collection motor 6 that moves along the inner wall of the detection box 1.

[0071] When the retractable rope 20 pulls the circulating drive rope 40, one end of the circulating drive rope 40 moves into the well following the retractable rope 20, while the other end of the circulating drive rope 40 begins to gradually release the part of the circulating drive rope 40 area collected by the release roller 43 and the retractable rope 20 through support due to the pulling of the external force.

[0072] Replay Figure 5As shown, specifically, the end of the telescopic rope 20 near the lower cone 21 is connected to the circulating drive rope 40 through the linkage column 5, and the circulating drive rope 40 slides through the drive column. A collection motor 6 is installed on the telescopic roller 41 and moves along the inner wall of the detection box 1.

[0073] After the circulating drive rope 40 extends to the bottom of the well, the collection motor 6 is started, and the collection motor 6 drives the telescopic roller 41 on one side to rotate. The telescopic roller 41 controls the uniform rotation of the circulating drive rope 40 while rotating. During the rotation of the circulating drive rope 40, the upper end of the detection capsule 31 connected to the detection block 30 moves into the well until several detection capsules 31 move to the designated position. The detection capsule 31 starts to collect gas and detect the collected gas.

[0074] Reference Figure 7 、 Figure 8 and Figure 9 As shown, when the detection capsule 31 moves to the specified position, the gas contained in the well can be detected. Specifically, the detection capsule 31 is composed of a capsule body 310 and a capsule cover 311 screwed to the upper end of the capsule body 310. A connecting column 317 is installed at the bottom of the capsule cover 311, and a gas sensor 312 is plugged into the connecting column 317. The gas type and gas concentration in the well are detected by the gas sensor 312.

[0075] A detection port 313 is formed on one side of the capsule body 310 . The detection end of the gas sensor 312 contacts the detection port 313 of the capsule body 310 , and the power supply end of the gas sensor 312 is close to one side of the clamping block 34 .

[0076] During specific implementation, the detection port 313 on the side wall of the capsule body 310 is opened, and then multiple gas sensors 312 at different heights are energized to absorb gas from different height areas in the well, and detect the toxic gas and non-toxic gas contained in the gas. The components contained in the gas and the concentrations contained in the gas are detected one by one to ensure that the gas in different depth areas in the well can be analyzed in detail, and the detected data is uniformly transmitted to the electronic display screen in the detection box 1 for display.

[0077] It should be noted that the detection capsule 31 is composed of two parts: a capsule body 310 and a capsule cover 311. Multiple detection capsules 31 are installed at equal intervals on one side of the detection block 30. Multiple detection capsules 31 perform gas detection at the same time to ensure that the data after gas detection is compared, to ensure the accuracy of the detection results, and to avoid damage to a gas sensor 312 during detection, resulting in detection deviation.

[0078] Secondly, the gas sensors 312 in the multiple detection capsules 31 can also be replaced to perform precise concentration detection on a single gas, thereby ensuring the accuracy of the concentration detection results.

[0079] Gas sensor 312 is a device used to detect the type or concentration of specific gases in the environment. It is widely used in industrial safety, environmental monitoring, smart home, medical health and other fields.

[0080] Gas sensors 312 include the following: Electrochemical sensors operate on the principle that an oxidation / reduction reaction between gas and electrodes generates a current proportional to the gas concentration. Applicable gases include toxic or flammable gases such as CO, H2S, NO2, and O2.

[0081] Semiconductor sensors work by shifting the resistance of a semiconductor when gas adsorbs onto its surface. Applicable gases include VOCs (volatile organic compounds), alcohol, and smoke.

[0082] Infrared sensors work by absorbing infrared light of a specific wavelength, detecting concentration based on the attenuation of light intensity. Applicable gases include non-polar gases such as CO2 and methane (CH4).

[0083] Catalytic combustion sensors work by generating heat when combustible gas burns on the catalyst surface, causing a change in resistance. Applicable gases: methane, propane, and other combustible gases.

[0084] Photoionization detectors work by using ultraviolet light to ionize gas molecules and detecting the ion current. Applicable gases: VOCs, benzene, and other volatile organic compounds.

[0085] In summary, when detecting underground gas, the corresponding gas sensor 312 can be installed in the detection capsule 31, which can protect it and ensure the safety of the gas sensor 312 when moving in the well, avoiding damage due to bumps during movement, and also preventing damage from rain.

[0086] Furthermore, the gas sensor 312 inside the detection capsule 31 can be quickly replaced by opening the detection capsule 31 .

[0087] Reference Figure 9 、 Figure 10 and Figure 11 As shown, specifically, a power-carrying wire 314 is wound around the circulating drive rope 40, and a metal conductive contact No. 1 315 connected to the power-carrying wire 314 is installed on the detection block 30, and the metal conductive contact No. 1 315 is arranged at the snap-fitting groove 32 of the detection block 30, and a metal conductive contact No. 2 316 is provided on the snap-fitting block 34, and the metal conductive contact No. 2 316 is movably connected to the metal conductive contact No. 1 315.

[0088] The power supply end of the gas sensor 312 is movably connected to an end of the second metal conductive contact 316 away from the first metal conductive contact 315 .

[0089] During specific implementation, when replacing different types of gas sensors 312, the capsule cover 311 at the upper end of the capsule body 310 is rotated. At this time, the capsule cover 311 is separated from the capsule body 310, and then the capsule cover 311 is moved upward. The connecting column 317 at the bottom of the capsule cover 311 drives the gas sensor 312 plugged in at the upper end to separate from the capsule body 310. After the gas sensor 312 is separated from the capsule body 310, the gas sensor 312 is removed from the connecting column 317, and a new gas sensor 312 is plugged into the connecting column 317.

[0090] However, it should be noted that when the gas sensor 312 is installed, the power-on end of the gas sensor 312 needs to be located on the side close to the second metal conductive contact 316, and the detection end of the gas sensor 312 is close to the detection port 313 of the capsule body 310. When the capsule cover 311 is rotated onto the capsule body 310, the power-on end of the new gas sensor 312 can be controlled to contact the second metal conductive contact 316, thereby supplying power to the gas sensor 312.

[0091] Reference Figure 9 As shown, the detection port 313 of the capsule body 310 is equipped with a sealing door 7 that opens and closes by rotating when powered, and a cleaning brush 8 is provided on one side of the sealing door 7 close to the detection end of the gas sensor 312.

[0092] It should be noted that the sealing door 7 is equipped with a small motor (not shown in the figure). When the small motor is powered, it can control the opening and closing of the sealing door 7. When the sealing door 7 is opened, the cleaning brush 8 wipes the detection end of the gas sensor 312 to prevent residual dust from affecting its detection accuracy. After the gas sensor 312 completes the detection, the sealing door 7 is closed, and the cleaning brush 8 wipes the detection end of the gas sensor 312 a second time to prevent dust and other impurities from being adsorbed on the detection end of the gas sensor 312.

[0093] See Figure 12 , which is a flow chart of the downhole gas detection method in this application, is as follows: S1. Preparation: First, install the detection box 1 near the wellhead or just above the wellhead through the bracket. The stability of the detection box 1 needs to be ensured.

[0094] S2. Detection switching: After the position of the detection box 1 is fixed, a gas sensor 312 that meets the requirements is installed in the corresponding detection capsule 31 according to the region and location of the well and the detection standards and requirements. The capsule cover 311 at the upper end of the capsule body 310 is rotated. At this time, the capsule cover 311 is separated from the capsule body 310. The capsule cover 311 is then moved upward. The connecting column 317 at the bottom of the capsule cover 311 drives the gas sensor 312 plugged in at the upper end to separate from the capsule body 310. After the gas sensor 312 is separated from the capsule body 310, the gas sensor 312 is removed from the connecting column 317 and a new gas sensor 312 is plugged into the connecting column 317.

[0095] S3. Bottom-hole exploration: After the gas sensor 312 in the capsule body 310 is replaced and maintained, the lowering section 2 is started. The retractable rope 20 of the lowering section 2 controls the lowering cone 21 connected to the bottom to move toward the bottom of the well until the bottom of the lowering cone 21 just touches the bottom of the well. The distance from the bottom of the well to the wellhead at this time is detected, which is the depth of the well.

[0096] S4. Equipment positioning: While the exploration part 2 moves toward the bottom of the well, the circulating drive rope 40 of the detection part 3 also moves to the bottom of the well synchronously, and the exploration part 2 limits it to ensure the stability of the circulating drive rope 40. Then the circulating drive rope 40 is controlled to move so that the detection capsule 31 on the circulating drive rope 40 moves to different areas in the well.

[0097] S5. Gas detection: The detection port 313 in the capsule body 310 is then opened, and the gas sensor 312 is activated to perform regular detection on different areas in the well to determine what gases are contained in the gas in the well and the concentration of the gases contained therein.

[0098] The embodiments of this specific implementation method are all preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Therefore, any equivalent changes made based on the structure, shape, and principle of the present invention should be included in the scope of protection of the present invention.

Claims

1. A downhole gas detection device, characterized in that: Includes a portable test box (1); The down-detecting part (2) is used to detect the depth from the wellhead to the bottom of the well and is arranged in the detection box (1). The down-detecting part (2) includes a vertically downward-facing down-detecting cone (21) and a telescopic rope (20) connected to the top of the down-detecting cone (21). The telescopic rope (20) controls the down-detecting depth of the down-detecting cone (21) to detect the depth of the well. A detection unit (3) is arranged in the detection box (1), and the detection unit (3) includes a detection block (30) and a detection capsule (31) mounted on the detection block (30), and the detection capsule (31) is used to collect gas from different areas in the well; The detection block (30) and the detection capsule (31) are arranged at equal intervals in the detection box (1), and a control member (4) for controlling the movement of the detection block (30) and the detection capsule (31) is provided in the detection box (1); The control member (4) includes a circulating driving rope (40) for controlling the cyclic movement of the detection capsules (31), and the detection capsules (31) are arranged on the circulating driving rope (40) at equal intervals.

2. A downhole gas detection device according to claim 1, characterized in that: The lower probe portion (2) further comprises a winding roller (22) rotatably connected to the interior of the detection box (1), an end of the telescopic rope (20) away from the lower probe cone (21) is connected to the winding roller (22), and the telescopic rope (20) is wound around the winding roller (22), and a winding motor (23) connected to the winding roller (22) is further provided in the detection box (1).

3. The downhole gas detection device according to claim 1, characterized in that: An I-shaped column (210) is installed at the bottom of the lower exploration cone (21), and a lifting hole (211) is provided at the bottom of the lower exploration cone (21) for the I-shaped column (210) to be lifted and lowered in a height direction. A linkage spring (212) is provided between the top of the I-shaped column (210) and the lower exploration cone (21) and is installed in the lifting hole (211). The linkage spring (212) always has a force to drive the I-shaped column (210) downward, and contact sensors (213) are respectively provided between the I-shaped column (210) and the inner wall of the lower exploration cone (21). The start and stop of the winding motor (23) is controlled by opening and closing the two contact sensors (213).

4. The downhole gas detection device according to claim 1, characterized in that: The control member (4) comprises two sets of symmetrical sliders (46) slidably mounted on the inner wall of the detection box (1) along the length direction, a telescopic roller (41) is rotatably provided between the two sets of sliders (46), and the middle portion of the circulating drive rope (40) is provided on the telescopic roller (41); A movable frame (42) is also slidably provided in the detection box (1) and moves along its height direction. A release roller (43) is rotatably provided on the movable frame (42). One end of the circulating drive rope (40) is sleeved on the release roller (43). A No. 1 telescopic tension spring (44) is provided between the movable frame (42) and the inner wall of the detection box (1), and a No. 2 telescopic tension spring (45) is provided between the slider (46) and the inner wall of the detection box (1).

5. The downhole gas detection device according to claim 1, characterized in that: One end of the telescopic rope (20) close to the lower cone (21) is connected to the circulating drive rope (40) through the linkage column (5). The circulating drive rope (40) slides through the linkage column (5). A collecting motor (6) that moves along the inner wall of the detection box (1) is installed on the telescopic roller (41).

6. The downhole gas detection device according to claim 1, characterized in that: A plurality of engaging grooves (32) are formed at equal intervals on one side of the detection block (30) close to the detection capsule (31), and a plurality of engaging serrations (33) are formed at equal intervals on the side wall of the detection block (30) located at the engaging groove (32); A clamping block (34) is integrally provided at one end of the detection capsule (31) close to the detection block (30); a deformable rack (35) movably engaged with the clamping saw teeth (33) is provided on the clamping block (34); a control rope (36) for controlling its deformation is connected to the movable end of the deformable rack (35); the control rope (36) slides through the clamping block (34) and is located outside the clamping block (34).

7. The downhole gas detection device according to claim 1, characterized in that: The detection capsule (31) is composed of a capsule body (310) and a capsule cover (311) screwed to the upper end of the capsule body (310). A connecting column (317) is installed at the bottom of the capsule cover (311). A gas sensor (312) is plugged into the connecting column (317). The gas type and gas concentration in the well are detected by the gas sensor (312).

8. The downhole gas detection device according to claim 7, characterized in that: A detection port (313) is provided on one side of the capsule body (310), a detection end of the gas sensor (312) contacts the detection port (313) of the capsule body (310), and a power-on end of the gas sensor (312) is close to one side of the clamping block (34); A power conducting wire (314) is wound around the circulating driving rope (40), and a first metal conductive contact (315) connected to the power conducting wire (314) is installed on the detection block (30), and the first metal conductive contact (315) is arranged at the clamping slot (32) of the detection block (30), and a second metal conductive contact (316) is provided on the clamping block (34), and the second metal conductive contact (316) is movably connected to the first metal conductive contact (315); The energized end of the gas sensor (312) is movably connected to an end of the second metal conductive contact (316) away from the first metal conductive contact (315).

9. The downhole gas detection device according to claim 7, characterized in that: The detection port (313) of the capsule body (310) is provided with an opening and closing sealing door (7), and a cleaning brush (8) is provided on one side of the sealing door (7) close to the detection end of the gas sensor (312).

10. A downhole gas detection method, using a downhole gas detection device according to any one of claims 1 to 9, characterized in that: Downhole gas detection method is as follows: S1. Preparation: First, install the detection box (1) near the wellhead or just above the wellhead through the bracket; S2. Detection switching: when detecting different gases in different wells, quickly open the detection capsule (31), replace the gas detection device inside the detection capsule (31), and then close the detection capsule (31); S3, bottom well exploration: start the lower exploration part (2), and the lower exploration cone (21) on the lower exploration part (2) moves toward the bottom of the well. The bottom of the lower exploration cone (21) just touches the bottom of the well. The distance from the bottom of the well to the wellhead at this time is detected, which is the depth of the well. S4, equipment positioning: while the lowering part (2) moves toward the bottom of the well, the circulating drive rope (40) of the detection part (3) also moves to the bottom of the well synchronously, and the lowering part (2) limits it to ensure the stability of the circulating drive rope (40), and then controls the movement of the circulating drive rope (40) to move the detection capsule (31) on the circulating drive rope (40) to different height positions in the well; S5. Gas detection: The equipment in the detection capsule (31) is then started to perform regular detection on different areas in the well to determine what gases are contained in the gas in the well and the concentration of the gases contained.

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