A multi-parameter measurement while drilling system and measurement method for underground coal mines

Abstract

The present invention discloses a multi-parameter downhole measurement system and a measurement method for a coal mine. A measuring tube is provided, and a main control board component, a vibration measurement component and a data collection component are embedded in the outer wall of the measuring tube in sequence along the axial direction; the vibration measurement component measures the vibration frequency and amplitude of the drill tool and the flushing fluid pressure outside the measuring tube, and the vibration measurement component serves as a control switch for the data collection component and the main control board component; the data collection component collects measurement data of the vibration measurement component, and the data collection component collects the rotation speed of the drill tool and the flushing fluid pressure in the measuring tube; the main control board component integrates an inclinometer module to measure the dynamic posture data and static posture data of the drill tool, and at the same time encodes and modulates the drill tool posture data and the data collected by the data collection component; the present invention can measure the drilling pressure and torque data at different circumferential positions, truly reflect the stress state of each position of the drill tool in the hole, and effectively avoid the occurrence of accidents such as drill stuck and drill dropped during construction.

Description

Technical Field

[0001] The invention belongs to the technical field of engineering parameter measurement while drilling, and relates to a multi-parameter measurement while drilling system and a measurement method for an underground coal mine. Background Art

[0002] During underground coal mine drilling operations, current data on drill posture for directional drilling is primarily obtained from displays and drilling parameters such as torque, feed pressure, and pull-out pressure from drill rig instruments. For conventional drilling, only limited parameters such as speed, torque, feed pressure, and pull-out pressure are available from drill rig instruments or during operation. These parameters cannot directly reflect drilling parameters such as torque, weight on bit, annular pressure, speed, vibration, and temperature at the bottomhole tool during drilling. These drilling parameters are crucial for ensuring safe and efficient underground drilling, whether in conventional or directional drilling. With increasing borehole depths and diameters, drilling accidents such as stuck drill bits, drill drops, and instrument damage are becoming more frequent. Most of these accidents are not instantaneous, but rather result from a lack of accurate understanding of the borehole conditions during operation, making it impossible to accurately predict them. Therefore, accurate, real-time measurement of multiple parameters of the drill tool within the hole allows for analysis, assessment, and resolution of the drilling process, guiding the entire drilling process and ensuring risk-free drilling.

[0003] The interaction between the drill string and the wellbore wall during drilling operations is complex. The torque and weight on bit (WOB) applied by the drilling rig to the drill string, as transmitted, are significantly affected by factors such as wellbore friction, hole regularity, and geological conditions. The data displayed by the borehole instrument does not accurately reflect the actual forces acting on the drill string behind the drill bit. The increasing use of precision instrumentation during drilling has also necessitated certain limits on drill string vibration and in-hole temperature. Prolonged exposure to high temperatures and intense vibration can damage the instrument, yet current instruments do not display these parameters. Furthermore, in-hole flushing fluid pressure is typically measured using the pressure reading on the mud pump truck, failing to monitor real-time pressure changes within the drill string and the borehole annulus. In short, due to the inaccuracy, lag, and single-dimensional nature of instrumentation, these measurements fail to fully reflect the true forces acting on the drill string and the environmental characteristics within the hole. Any abnormality in any parameter could potentially lead to an accident.

[0004] During drilling, the changes in inclination and azimuth along the wellbore must be monitored at all times to better monitor and adjust the wellbore trajectory to ensure it extends as close to the planned trajectory as possible. Furthermore, by monitoring the changes in inclination and azimuth along the wellbore, wellbore curvature can be calculated, effectively controlling "dogleg" and thus preventing downhole accidents. Currently, mining measurement while drilling systems commonly use triaxial accelerometers and triaxial magnetometers for inclination and azimuth measurements. These systems require static measurements after drilling is stopped. These systems accurately reflect the drill string's attitude data at a specific point in time after the completion of a single drill pipe. However, during drilling, the measurement module is affected by drill string vibration, impact, and rotation, making it impossible to accurately and accurately measure the dynamic attitude data of the drill string during drilling in real time.

[0005] While engineering parameter measurement technology is relatively mature in the petroleum industry, it is still relatively new in drilling applications, such as underground coal mines, with no relevant instruments or research reports. Due to the unique nature of underground coal mine drilling, aperture size and coal safety requirements limit the use of petroleum-based instruments in underground coal mines. Summary of the Invention

[0006] The purpose of the present invention is to provide a multi-parameter measurement while drilling system and measurement method for coal mines, which can measure the drilling pressure and torque data at different positions in the circumferential direction, truly reflect the stress state of each position of the drill tool in the hole, and effectively avoid the occurrence of accidents such as drill sticking and drill falling during construction.

[0007] To achieve the above-mentioned purpose, the technical solutions adopted by the present invention include:

[0008] A multi-parameter measurement while drilling system for a coal mine is provided, wherein a measuring tube is provided, and a main control board component, a vibration measurement component and a data collection component are sequentially embedded in the outer wall of the measuring tube along the axial direction;

[0009] The vibration measurement component measures the vibration frequency and amplitude of the drilling tool and the flushing fluid pressure outside the measuring tube. At the same time, the vibration measurement component serves as a control switch for the data collection component and the main control board component.

[0010] The data collection component collects the measurement data of the vibration measurement component, and at the same time, the data collection component collects the rotation speed of the drilling tool and the flushing fluid pressure in the measuring pipe;

[0011] The main control board component integrates an inclinometer module to measure the dynamic and static attitude data of the drill tool, and at the same time encodes and modulates the drill tool attitude data and the data collected by the data collection component.

[0012] Optionally, the measuring tube is a tube body with a hollow channel; a support sleeve is axially embedded in one end of the measuring tube, and a cable reducer is axially arranged on the top of the support sleeve; the cable reducer is electrically connected to the main control board assembly, vibration measurement assembly and data collection assembly through the support sleeve.

[0013] Optionally, the support sleeve is provided with an insulating seat, a cylinder body is provided outside the insulating seat, and a first contact male head is provided inside the insulating seat; and a cable reducer is provided in electrical connection with the first contact male head.

[0014] Optionally, a plurality of connectors are radially provided in the cylinder body, and every two connectors form a fan-shaped cavity; the insulating seat is located at the radial terminal end of the connector; a first wire passing hole is provided on the connector, and a second wire passing hole is provided on the outer wall of the insulating seat, and the side wall of the first contact male head is connected to the second wire passing hole and the first wire passing hole.

[0015] Optionally, the cable reducer is provided with a cable tube body, a female contact is provided in one end of the cable tube body, and a second male contact is provided in the other end; an annular boss is provided at the waist of the cable tube body, and the cable reducer is axially tightened and fixed by a fixing ring.

[0016] Optionally, the main control board assembly includes a main control board embedded in the outer wall of the measuring tube, and a first cover plate is provided on the main control board; an inclinometer module is written on the main control board, and the inclinometer module integrates a 3-axis accelerometer and a 3-axis magnetometer.

[0017] Optionally, the vibration measurement assembly includes a vibration sensor embedded in the wall of the measuring tube, covering a first pressure cover set on the vibration sensor; and also includes a first pressure sensor embedded in the wall of the measuring tube, covering a second pressure cover set on the first pressure sensor; the vibration sensor and the first pressure sensor are arranged along the circumference of the measuring tube, and the two are connected through a second bridge line hole.

[0018] Optionally, the data collection component includes a data acquisition board embedded in the outer wall of the measuring tube, and a second cover plate is provided on the data acquisition board; a speed plate and a second pressure sensor are provided adjacent to the data acquisition board; the second pressure sensor is used to measure the flushing fluid pressure in the central channel of the measuring tube, the speed plate is used to measure the rotational speed of the drill bit at this position, and the data acquisition board collects measurement data.

[0019] Optionally, a torque pressure measurement assembly is embedded circumferentially on the measuring tube, and the torque pressure measurement assembly is evenly arranged at 90° along the circumference. The torque pressure measurement assembly consists of two high-precision single-feather strain gauges and one high-precision shear double-feather strain gauge; the two high-precision single-feather strain gauges are arranged to ensure that their axes are parallel and perpendicular to the axis of the measuring tube, respectively, and are used to measure the torque exerted on the drill tool at that position; the axis of the high-precision shear double-feather strain gauge is parallel to the axis of the measuring tube, and is used to measure the drilling pressure exerted on the drill tool at that position.

[0020] A dynamic measurement method for a multi-parameter measurement while drilling system in a coal mine, comprising:

[0021] Step 1: During the drilling process, only the data collected by the axial accelerometer and radial magnetometer of the drill bit are continuously recorded within one working time, including the axial accelerometer data V z and two radial magnetometer data B x and B y ;

[0022] Step 2: Process the acceleration data V measured by the axial accelerometer z , obtain the interference-free axial accelerometer measurement v z ; The method of removing the radial acceleration component is the sliding average filter method, and the calculation method is as follows:

[0023]

[0024] Wherein, 2n+1 represents the number of points of the sliding average filter, which is determined by the instrument rotation speed and recording frequency;

[0025] Step 3: Use the non-interfering axial accelerometer to measure the data v z and the local total gravity acceleration field value G, calculate the dynamic well inclination angle θ;

[0026]

[0027] Step 4: Calculate the vertical component of the geomagnetic field B based on the local total geomagnetic field value B0 and the geomagnetic inclination β v and the north component B N ;

[0028] B v =sinβ×B0;

[0029] According to the local total geomagnetic field value B0 and the radial magnetometer measurement data B x 、B y , calculate the magnetic field component B along the axial direction of the drill bit z , and then according to B z Calculate the horizontal magnetic field component B in the projection direction of the drilling tool axis on the horizontal plane H ;

[0030]

[0031]

[0032] Step 5: According to the horizontal magnetic field component B in the horizontal projection direction of the drilling tool axis H and the northerly component of the geomagnetic field, B N , calculate the dynamic azimuth angle γ;

[0033]

[0034] The beneficial effects of the present invention are:

[0035] ① The multi-parameter measurement while drilling system of the present invention has multiple drilling pressure and torque sensors evenly distributed circumferentially to form a ring circuit bridge, which can measure drilling pressure and torque data at different positions in the circumference, truly reflect the stress state of each position of the drill tool in the hole, and effectively avoid the occurrence of accidents such as drill stuck and drill dropped during construction; ② The drilling pressure, torque data, drill tool vibration data, speed data, drill tool inner and outer annular pressure data, circuit board temperature and other multi-parameter data are collected, filtered and encoded by the data acquisition board and then decoded by the main control board. The decoded data are packaged together with the drilling posture data measured by the integrated module of the main control board, and then encoded and modulated again, and finally transmitted to the computer through wired transmission. The data signal transmission is stable and continuous, which effectively solves the problems of inaccurate measurement data of orifice instruments in coal mines, serious lag, and single data; ③ The circuit boards, sensors, wire holes, bridge wire holes and plug-in components involved in this system are all sealed, and local glue injection and sealing insulation are performed to ensure the sealing performance of the system and effectively solve the problem of core component failure caused by mud leakage; ④ This dynamic measurement method does not collect the gravity field component along the radial direction of the drill bit during construction, avoiding the influence of centrifugal acceleration and radial vibration generated by the rotation of the drill bit on the radial gravity field component, and ensuring the accuracy of the dynamic posture data of the drill bit during construction; ⑤ By controlling the working status of the data acquisition board and the data acquisition mode of the control board through the vibration switch, the overall power consumption of the system can be effectively reduced, and the effective switching of the dynamic posture data and static posture data of the drill bit can be realized, which not only ensures the collection and transmission of multi-parameter data during construction, but also ensures the accurate adjustment of the tool face angle after stopping drilling and adding drill pipe. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] The accompanying drawings are used to provide a further understanding of the present disclosure and constitute a part of the specification. Together with the following detailed description, they are used to explain the present disclosure but do not constitute a limitation of the present disclosure. In the accompanying drawings:

[0037] Figure 1 This is a cross-sectional view of the multi-parameter measurement while drilling system for coal mines of the present invention;

[0038] Figure 2 yes Figure 1 A top view of

[0039] Figure 3 for Figure 1 AA section view in the figure;

[0040] Figure 4 for Figure 1 BB section view in the figure;

[0041] Figure 5 for Figure 2 CC section view in the figure;

[0042] Figure 6 for Figure 5 Schematic diagram of the arrangement of sensors in the torque pressure measurement assembly in the a direction;

[0043] Figure 7 for Figure 2 DD section view in;

[0044] Figure 8 is a longitudinal sectional view of the support sleeve of the present invention;

[0045] Figure 9 yes Figure 8 EE cross-sectional view;

[0046] Figure 10 This is an enlarged view of the cable reducer structure of the present invention;

[0047] Figure 11 This is a flow chart of a dynamic measurement method of a multi-parameter measurement while drilling system for underground coal mines according to the present invention;

[0048] Description of the numbers in the figure:

[0049] 1- measuring tube, 11- positioning bolt, 2- support sleeve, 21- cylinder body, 211- connector, 212- fan-shaped cavity, 213- annular bevel, 214- sealing groove, 215- positioning hole, 216- first through hole, 22- insulation seat, 221- second through hole, 23- first contact male head, 3- main control board assembly, 31- first cover plate, 32- main control board, 4- vibration measurement assembly, 41- vibration sensor, 42- first pressure cover, 43- first pressure sensor Sensor, 44-second pressure cover, 45-second bridge line hole, 5-data collection assembly, 51-second cover plate, 52-data acquisition board, 53-speed board, 54-second pressure sensor, 6-fixing ring, 7-cable reducer, 71-contact female, 72-cable tube body, 73-second contact male, 8-torque pressure measurement assembly, 81-torque pressure sensor, 811-high-precision single-feather strain gauge, 812-high-precision shear double-feather strain gauge, 82-first bridge line hole. DETAILED DESCRIPTION

[0050] The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0051] The directional words such as "circumferential", "axial", "radial", "direction", "front, back, left, right, up, down, top, bottom" mentioned in the present invention are all explained based on the drawings facing the specification, and the meanings they represent are the directional meanings generally recognized in the art.

[0052] Combine Figure 1-10The multi-parameter downhole measurement system for coal mines of the present invention is provided with a measuring tube 1. The left end of the measuring tube 1 is connected in sequence to a non-magnetic drill rod, a screw motor, and a drill bit, and the other end is connected in sequence to a non-magnetic cable drill rod, a cable drill rod, a cable water feeder, and an orifice computer. A main control board assembly 3, a vibration measurement assembly 4, and a data collection assembly 5 are sequentially embedded axially on the outer wall of the measuring tube 1. The vibration measurement assembly 4 measures the vibration frequency and amplitude of the drill tool and the pressure of the flushing fluid outside the measuring tube, while the vibration measurement assembly 4 serves as a control switch for the data collection assembly 5 and the main control board assembly 3. The data collection assembly 5 collects the measurement data of the vibration measurement assembly 4 and simultaneously collects the rotation speed of the drill tool and the flushing fluid pressure in the measuring tube. The main control board assembly 3 integrates an inclinometer module to measure the dynamic and static attitude data of the drill tool, and simultaneously encodes and modulates the drill tool attitude data and the data collected by the data collection assembly. The multi-parameter measurement while drilling system of the present invention has multiple drilling pressure and torque sensors evenly distributed around the circumference to form a ring circuit bridge. It can measure drilling pressure and torque data at different positions around the circumference, truly reflecting the stress state of each position of the drill tool in the hole, and can effectively avoid accidents such as drill sticking and drill dropping during construction.

[0053] Combine Figure 1 、 8 and 9. In the embodiments of the present disclosure, the measuring tube 1 is a tube body with a hollow channel; a support sleeve 2 is axially embedded in one end of the measuring tube 1, and a cable reducer 7 is axially arranged on the top of the support sleeve 2; the cable reducer 7 is electrically connected to the main control board assembly 3, the vibration measurement assembly 4 and the data collection assembly 5 through the support sleeve 2.

[0054] Specifically, the support sleeve 2 is plugged into the right end of the measuring tube 1 , and the cable reducer 7 is plugged into the support sleeve 2 and fixed in the central channel of the right end of the measuring tube 1 through the fixing ring 6 .

[0055] In the embodiment of the present disclosure, an insulating seat is provided on the support sleeve 2, and a cylinder body 21 is provided outside the insulating seat. Three connectors 211 are radially provided in the inner radial direction of the cylinder body 21. The three connectors form a fan-shaped cavity 212 in pairs, which serves as a channel for the flow of flushing liquid. Preferably, the insulating seat 22 is located at the axial center position formed by the three connectors, that is, the radial terminal end of the three connectors 211; the insulating seat is annular, and a first contact male head 23 is provided at the center of the ring of the insulating seat. The first contact male head 23 is insulated and isolated from other metal parts by the insulating seat 22, and the side wall of the first contact male head 23 is connected to the second wire hole 221; one of the connectors 211 is provided with a first wire hole 216, and the outer walls of the cylinder bodies corresponding to the other two connectors are respectively provided with a positioning hole 215, and the outer wall of the insulating seat 22 is provided with a second wire hole 221. The insulating seat 22 is inserted into the cylinder body 21 and fixed with glue. The axis of the first wire hole 216 and the second wire hole 221 are consistent and connected to each other.

[0056] like Figure 10 As shown, the cable reducer 7 is provided with a cable tube body 72, one end of the cable tube body 72 is a male connector, the outside of the male connector is provided with a double-layer sealing ring structure, the other end of the cable tube body 72 is a female connector, a contact female head 71 is provided in the male connector, and a second contact male head 73 is provided in the female connector. The cable tube body 72 is made of non-metallic material and has a through hole inside. An insulated wire is provided in the through hole for connecting the contact female head 71 and the second contact male head 73. An annular boss is provided at the waist of the cable tube body 72, and the cable reducer 7 is axially tightened and fixed by a fixing ring 6.

[0057] Combine Figure 2 The outer wall of the measuring tube 1 is provided with a first rectangular groove and a second rectangular groove. A first annular groove is provided between the axes of the first and second rectangular grooves. A fourth wire hole is provided between the first rectangular groove and the first annular groove. A fifth wire hole is provided between the second rectangular groove and the first annular groove. A third wire hole is provided at the right end of the first rectangular groove. Two first positioning holes are provided on the right end wall of the measuring tube 1. The two first positioning holes and the third wire hole are evenly spaced 120 degrees circumferentially. A bell mouth is provided at the left end of the positioning holes. The second rectangular groove is composed of a small rectangular groove on the left end and a large rectangular groove on the right end. A wire hole is provided between the small rectangular groove and the large rectangular groove on the right end. A pressure guide hole is provided in the middle of the small rectangular groove, which connects to the central channel of the measuring tube 1. Four second annular grooves are provided at the left end of the second rectangular groove. The first cover plate 31 is placed in the rectangular groove corresponding to the main control board 32 and is fixed to the outer wall of the measuring tube 1 by hexagon socket bolts. The second cover plate 51 is placed in the rectangular groove corresponding to the data acquisition board 52 and is fixed to the outer wall of the measuring tube 1 by hexagon socket bolts.

[0058] In the embodiment disclosed herein, the main control board assembly 3 includes a main control board 32 embedded within the outer wall of the measuring tube 1. A first cover plate 31 is provided over the main control board 32. An inclinometer module is written onto the main control board 32, which integrates a 3-axis accelerometer and a 3-axis magnetometer. A rectangular groove is defined within the first cover plate 31. After the first cover plate 31 is secured to the outer wall of the measuring tube, the rectangular groove connects to the first rectangular groove. A third wire hole is located below the rectangular groove, thereby connecting the first rectangular groove, the third wire hole, the first wire hole, the second wire hole, and finally the first contact male connector 23. The support sleeve 2 is inserted into the measuring tube 1 so that its annular bevel 213 matches the bell mouth of the measuring tube 1. The slope of the annular bevel 213 is consistent with the slope of the bell mouth. After the positioning bolt 11 is threaded into the first positioning hole on the measuring tube 1, one end of the threaded section remains exposed. The exposed portion is inserted into the positioning hole 215 on the cylinder body 21, thereby securing the support sleeve 2 in place.

[0059] In the embodiment of the present disclosure, the data collection assembly 5 includes a data acquisition board 52 embedded in the outer wall of the measuring tube 1, and a second cover plate 51 is provided on the data acquisition board 52; a rotation speed plate 53 and a second pressure sensor 54 are provided adjacent to the data acquisition board 52; the second pressure sensor 54 measures the pressure of the flushing fluid in the measuring tube 1, the rotation speed plate 53 measures the rotation speed of the drill bit, and the data acquisition board 52 collects the measurement data. A rectangular groove is provided on the inner side of the second cover plate 51, the size of the rectangular groove being determined by the size of the sensors arranged in the second rectangular groove. The second pressure sensor 54 is placed in the small rectangular groove on the left side of the second rectangular groove, and the pressure guide hole is connected to the second pressure sensor 54, so that the flushing fluid pressure in the central channel of the drill bit can be monitored during construction. The rotation speed plate 53 is placed at the left end of the large rectangular groove to the right of the second rectangular groove, and the data acquisition board 52 is placed at the right end of the large rectangular groove to the right of the second rectangular groove and fixed by screws.

[0060] In the embodiment of the present disclosure, the vibration measurement assembly 4 includes a vibration sensor 41 embedded in the wall of the measuring tube 1, and a first pressure cap 42 covering the vibration sensor 41; it also includes a first pressure sensor 43 embedded in the wall of the measuring tube 1, and a second pressure cap 44 covering the first pressure sensor 43; the vibration sensor 41 and the first pressure sensor 43 are arranged along the circumference of the measuring tube 1, and the two are connected by a second bridge wire hole 45. The vibration sensor 41 is placed in the first annular groove and sealed by the first pressure cap 42, the first pressure sensor 43 is placed in the third annular groove and sealed by the second pressure cap 44, and a pressure guide hole is provided in the middle of the second pressure cap 44 for communicating with the outer annulus of the drill tool and the first pressure sensor 43. The vibration sensor 41 and the first pressure sensor 43 are connected in series through the insulated wire in the second bridge wire hole 45, and the main control board 32 is placed in the first rectangular groove and fixed by screws.

[0061] Among them, the second pressure sensor 54 is used to measure the flushing fluid pressure in the central channel of the measuring tube 1, the speed board 53 is used to measure the rotational speed of the drill tool at this position, and the data acquisition board 52 is mainly used to collect, filter, and encode the data measured by each sensor. At the same time, the data acquisition board 52 is integrated with a temperature sensor for detecting the temperature of the data acquisition board 52. The vibration sensor 41 is used to measure the vibration frequency and amplitude of the drill tool near the drill bit. At the same time, the vibration sensor 41 can serve as a control switch for the data acquisition board 52 and the main control board 32. The first pressure sensor 43 is used to measure the flushing fluid pressure in the outer annulus between the drill tool and the borehole. The main control board 32 is integrated with an inclinometer module. The inclinometer module integrates a 3-axis accelerometer (X, Y, Z axes) and a 3-axis magnetometer (X, Y, Z axes). It can measure the dynamic posture data of the drill tool in the hole during drilling and the static posture data of the drill tool after the construction of a single drill rod is completed. The main control board 32 also encodes and modulates the drill tool posture data and the packaged data of the data acquisition board 52.

[0062] The torque and pressure measurement assembly 8 adopts 4 groups of uniformly arranged 90° around the circumference and respectively set in the 4 second annular grooves. Among them, the torque and pressure measurement assembly 8 adopts 2 high-precision single-feather strain gauges 811 and 1 high-precision shear double-feather strain gauge 812. The three strain gauges are all connected to the terminal in the second annular groove. The 2 high-precision single-feather strain gauges 811 are arranged to ensure that their axes are parallel and perpendicular to the axis of the measuring tube 1 respectively, and are used to measure the torque exerted on the drill tool at this position. The axis of the high-precision shear double-feather strain gauge is parallel to the axis of the tube body, and is used to measure the drilling pressure exerted on the drill tool at this position. The 4 groups of sensors obtain a total of 8 torque parameters and 4 drilling pressure parameters. The 4 groups of torque and pressure measurement assemblies 8 are connected in series through the insulated wires in the first bridge wire hole 82 to form a ring circuit bridge, which can measure the drilling pressure and torque at different circumferential positions when the drill tool is in a bent state. The four second annular grooves are evenly arranged at 90° in the circumferential direction, and the four second annular grooves are connected to each other through the first bridge line hole 82. The small rectangular groove at the right end of the second annular groove is connected to the first bridge line hole 82 on its left side through the sixth wire hole. The first annular groove and the third annular groove are arranged at a 90° angle in the circumferential direction and are connected through the second bridge line hole 45.

[0063] The four torque pressure measurement components 8, the second pressure sensor 54, the speed board 53, the vibration sensor 41, the first pressure sensor 43 and the data acquisition board 52 are connected in series. The data acquisition board 52 is connected in series with the main control board 32 and the first contact male connector 203. Then, through the cable reducer 7 at the right end, the non-magnetic flux cable drill rod, the cable drill rod, the cable water feeder and the computer are connected in sequence to form a complete multi-parameter downhole measurement system.

[0064] Among them, the wires passing through the wire holes and bridge wire holes in the entire system are all insulated wires, and after the insulated wires are fully laid, they are injected with glue again for secondary insulation sealing. A U-shaped rubber gasket is provided between the first cover plate 31, the second cover plate 51 and the measuring tube 1 to prevent the flushing fluid from entering the first rectangular groove and the second rectangular groove during construction and corroding the internal data acquisition board 52 and the main control board 32 and other core electronic components. The second pressure sensor 54 mainly measures the flushing fluid pressure in the central channel of the measuring tube 1 through the pressure guide hole. Therefore, a high-pressure sealing ring is provided between the second pressure sensor 54 and the pressure guide hole. The first pressure cap 42 and the second pressure cap 44 involved in the embodiment are both threadedly connected to the tube body, and the non-threaded connection part is provided with an O-ring for sealing. Two sealing grooves 214 are provided at the upper and lower ends of the outer wall of the cylinder body 21, and multiple O-rings are used for radial sealing to effectively avoid the flushing fluid pressure at the inlet being too high, causing the flushing fluid to enter the first rectangular groove along the third wire guide hole.

[0065] In addition, the entire material of the measuring tube 1, the first cover plate 31, the second cover plate 51, the first pressure cap 42, the second pressure cap 44 and the corresponding accessories are all made of non-magnetic steel materials to avoid interference from the earth's magnetism and thus affect the accuracy of the inclinometer module in measuring the drilling tool attitude data.

[0066] The industrial control method of the multi-parameter measurement while drilling system for an underground coal mine of the present invention comprises the following steps:

[0067] Step 1: During the construction process, the drill tool vibrates. The vibration sensor 41 detects the vibration of the drill tool and controls the data acquisition board 52 to start and collect all the data. The drilling rig drives the drill tool in the hole to rotate and applies a certain drilling pressure to the drill tool. The torque and drilling pressure are transmitted to the multi-parameter downhole measurement system near the drill bit. The strain gauge in the torque pressure measurement component 8 is affected by the drilling pressure and torque, and the real-time drilling pressure and torque are converted into electrical signals and transmitted to the data acquisition board 52. The electrical signal contains a total of 4 groups of data, each group of data has 2 drilling pressure values ​​and 1 torque value; the vibration generated by the drill bit rotating to cut the rock formation and the vibration generated by the friction between the drill tool and the hole wall are collected in real time by the vibration sensor 41 and transmitted to the data acquisition board 52 in the form of electrical signals. The vibration sensor 41 can measure the vibration of the three axes X, Y, and Z in the axial and radial directions; the second pressure sensor 54 and the first pressure sensor The sensor 43 converts the flushing fluid pressure in the central channel of the system and the borehole annulus into an electrical signal and transmits it to the data acquisition board 52; the speed board 53 measures the rotation speed of the system near the drill bit in real time and transmits it to the data acquisition board 52 in the form of an electrical signal; the temperature sensor integrated on the data acquisition board 52 measures the temperature of the circuit board in real time, and the data acquisition board 52 collects, filters, encodes and packages the above electrical signals and sends them to the main control board 32, which decodes the packaged signals. At the same time, after the main control board 32 receives the drilling tool vibration data signal, the inclinometer module in the main control board 32 collects the dynamic posture data of the drilling tool. In the dynamic measurement mode, only one axial accelerometer of the three-axis accelerometer collects V z , the three-axis magnetometer only has two radial magnetometers to collect B x 、B y The main control board 32 encodes and modulates the above data again through low-voltage DC carrier technology, and then transmits it to the hole computer through the upper flux-free cable drill rod, cable drill rod, and cable water feeder. The computer finally demodulates the signal data to obtain all dynamic data parameters during the drilling process, among which the calculated dynamic drill tool attitude data parameters are azimuth and inclination.

[0068] Step 2: Stop drilling and connect the drill rod. The vibration of the drill tool stops. The vibration sensor 41 detects that the vibration of the drill tool has stopped and controls the data acquisition board 52 to stop collecting data, thereby reducing power consumption. At the same time, after the main control board 32 no longer receives the drill tool vibration data signal, the inclinometer module integrated in the main control board 32 only collects the static posture data of the drill tool. In the static measurement mode, the three-axis accelerometer collects the three-axis acceleration V x 、V y 、V z , the three-axis magnetometer collects the three-dimensional magnetic field strength B x 、B y 、B z The main control board 32 encodes and modulates the static posture data of the drill tool through low-voltage DC carrier technology, and then transmits it to the hole mouth computer through the upper flux-free cable drill rod, cable drill rod, and cable water feeder. The computer finally demodulates the signal data to calculate the static posture data parameters of the drill tool (azimuth, inclination, tool face angle).

[0069] Combine Figure 11 The dynamic measurement method of the multi-parameter measurement while drilling system for coal mines of the present invention comprises:

[0070] Step 1: During the drilling process, only the data collected by the accelerometer in the axial direction (Z axis) and the magnetometer in the radial direction (X axis, Y axis) of the drill bit are continuously recorded within a period of time (from the start of vibration detection to the stop of vibration by the vibration sensor). The measurement data includes an axial accelerometer data V z and two radial magnetometer data B x , B y ;

[0071] Step 2: Process the acceleration data V measured by the axial accelerometer z , obtain the interference-free axial accelerometer measurement v z ; The method of removing the radial acceleration component is the sliding average filter method, and the calculation method is as follows:

[0072]

[0073] Where 2n+1 represents the number of points in the sliding average filter. The number of points in the sliding average filter is determined by the instrument rotation speed and recording frequency. Taking the commonly used rotation speed of 60r / min in coal mines as an example, the rotation frequency is 1Hz, and the acquisition frequency is 200Hz, the number of points in the sliding average filter 2n+1 should be greater than 200.

[0074] Step 3: Use the non-interfering axial accelerometer to measure the data v z and the local total gravity acceleration field value G, calculate the dynamic well inclination angle θ;

[0075]

[0076] Step 4: Calculate the vertical component of the geomagnetic field B based on the local total geomagnetic field value B0 and the geomagnetic inclination β V and the north component B N (North component B N Generally obtained based on data query or actual geographical location);

[0077] B v =sinβ×B0;

[0078] According to the local total geomagnetic field value B0 and the radial magnetometer measurement data B x 、B y , calculate the magnetic field component B along the axial direction of the drill bit z , and then according to B z Calculate the horizontal magnetic field component B in the projection direction of the drilling tool axis on the horizontal plane H ;

[0079]

[0080]

[0081] Step 5: According to the horizontal magnetic field component B in the horizontal projection direction of the drilling tool axis H and the northerly component of the geomagnetic field, B N , calculate the dynamic azimuth angle γ;

[0082]

[0083] The above is a detailed discussion of the best embodiment in conjunction with the accompanying drawings, which is not intended to limit the present invention. The specific technical features described above can be combined in any suitable form without contradiction, and the present invention does not go into details one by one. Any person skilled in the art may adopt simple modifications or modifications such as arbitrary combination or equivalent replacement of the technical solution without departing from the scope of the technical solution, which does not affect the essence of the technical solution and still falls within the scope of protection of the technical solution represented by the various embodiments of the present invention.

Claims

1. A multi-parameter measurement while drilling system for coal mines, characterized in that: A measuring tube (1) is provided, and a main control board component (3), a vibration measurement component (4) and a data collection component (5) are sequentially embedded in the outer wall of the measuring tube (1) along the axial direction; The vibration measuring component (4) measures the vibration frequency and amplitude of the drilling tool and the pressure of the flushing fluid outside the measuring pipe, and the vibration measuring component (4) serves as a control switch for the data collection component (5) and the main control board component (3); The data collection component (5) collects the measurement data of the vibration measurement component (4), and at the same time, the data collection component (5) collects the rotation speed of the drilling tool and the pressure of the flushing fluid in the measuring pipe; The main control board component (3) integrates an inclinometer module to measure the dynamic attitude data and static attitude data of the drilling tool, and simultaneously encodes and modulates the drilling tool attitude data and the data collected by the data collection component; The measuring tube (1) is a tube body with a hollow channel; a support sleeve (2) is axially embedded in one end of the measuring tube (1), and a cable reducer (7) is axially mounted on the top of the support sleeve (2); the cable reducer (7) is electrically connected to the main control board assembly (3), the vibration measurement assembly (4) and the data collection assembly (5) through the support sleeve (2); The support sleeve (2) is provided with an insulating seat (22), a cylinder body (21) is provided outside the insulating seat (22), and a first contact male head (23) is provided inside the insulating seat (22); a cable reducer (7) is provided in electrical connection with the first contact male head (23); The cylinder body (21) is provided with a plurality of connectors (211) in the radial direction, and every two connectors (211) form a fan-shaped cavity (212); the insulating seat (22) is located at the radial terminal end of the connector (211); the connector (211) is provided with a first wire hole (216), the outer wall of the insulating seat (22) is provided with a second wire hole (221), and the side wall of the first contact male head (23) is connected to the second wire hole (221) and the first wire hole (216).

2. The multi-parameter measurement while drilling system for coal mines according to claim 1, characterized in that: The cable reducer (7) is provided with a cable tube body (72), one end of the cable tube body (72) is provided with a female contact head (71), and the other end is provided with a second male contact head (73); An annular boss is provided at the waist of the cable tube body (72), and the cable reducer (7) is axially tightened and fixed by a fixing ring (6).

3. The multi-parameter measurement while drilling system for coal mines according to claim 1 or 2, characterized in that: The main control board assembly (3) comprises a main control board (32) embedded in the outer wall of the measuring tube (1), and a first cover plate (31) is provided on the main control board (32); An inclinometer module is written on the main control board (32), and the inclinometer module integrates a 3-axis accelerometer and a 3-axis magnetometer.

4. The multi-parameter measurement while drilling system for coal mines according to claim 1 or 2, characterized in that: The vibration measurement assembly (4) comprises a vibration sensor (41) embedded in the wall of the measuring tube (1), and a first gland (42) provided to cover the vibration sensor (41); It also includes a first pressure sensor (43) embedded in the wall of the measuring tube (1), and a second pressure cover (44) provided to cover the first pressure sensor (43); The vibration sensor (41) and the first pressure sensor (43) are arranged along the circumference of the measuring tube (1), and the two are connected through a second bridge hole (45).

5. The multi-parameter measurement while drilling system for coal mines according to claim 1 or 2, characterized in that: The data collection assembly (5) includes a data acquisition board (52) embedded in the outer wall of the measuring tube (1), and a second cover plate (51) is provided on the data acquisition board (52); a speed plate (53) and a second pressure sensor (54) are provided adjacent to the data acquisition board (52); The second pressure sensor (54) measures the pressure of the flushing fluid in the measuring tube 1, the rotation speed board (53) measures the rotation speed of the drilling tool, and the data acquisition board (52) collects measurement data.

6. The multi-parameter measurement while drilling system for coal mines according to claim 1 or 2, characterized in that: A torque pressure measurement assembly (8) is embedded in the measuring tube (1) along the circumferential direction. The torque pressure measurement assembly (8) is evenly arranged at 90 degrees along the circumferential direction. The torque pressure measurement assembly (8) is composed of two high-precision single-feather strain gauges (811) and one high-precision shear double-feather strain gauge (812). Two high-precision single-feather strain gauges (811) are arranged to ensure that their axes are parallel and perpendicular to the axis of the measuring tube (1), respectively, and are used to measure the torque exerted on the drilling tool at the location of the multi-parameter measurement while drilling system in the coal mine; The axis of the high-precision shear double-feather strain gauge (812) is parallel to the axis of the measuring tube (1) and is used to measure the bit pressure exerted on the drilling tool at the location of the multi-parameter measurement while drilling system in the coal mine.

7. A dynamic measurement method for a multi-parameter measurement while drilling system in a coal mine, characterized in that: The method is completed by using the coal mine underground multi-parameter measurement while drilling system according to any one of claims 1 to 6, specifically comprising: Step 1: During the drilling process, only the data collected by the axial accelerometer and radial magnetometer of the drill bit are continuously recorded within one working time, including the axial accelerometer data V z and two radial magnetometer data B x and B y ; Step 2: Process the acceleration data V measured by the axial accelerometer z , obtain the interference-free axial accelerometer measurement v z ; The method of removing the radial acceleration component is the sliding average filter method, and the calculation method is as follows: Wherein, 2n+1 represents the number of points of the sliding average filter, which is determined by the instrument rotation speed and recording frequency; Step 3: Use the non-interfering axial accelerometer to measure the data v z and the local total gravity acceleration field value G, calculate the dynamic well inclination angle θ; Step 4: Calculate the vertical component of the geomagnetic field B based on the local total geomagnetic field value B0 and the geomagnetic inclination β v and the north component B N ; B v =sinβ×B0; According to the local total geomagnetic field value B0 and the radial magnetometer measurement data B x 、B y , calculate the magnetic field component B along the axial direction of the drill bit z , and then according to B z Calculate the horizontal magnetic field component B in the projection direction of the drilling tool axis on the horizontal plane H ; Step 5: According to the horizontal magnetic field component B in the horizontal projection direction of the drilling tool axis H and the northerly component of the geomagnetic field, B N , calculate the dynamic azimuth angle γ;

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