AU2023328211A1

AU2023328211A1 - Multi-parameter measurement-while-drilling system for underground coal mines, and measurement method

Info

Publication number: AU2023328211A1
Application number: AU2023328211A
Authority: AU
Inventors: Long Chen; Xiang Chen; Jianyu FENG; Quanxin Li; Dongdong YANG; Jiguan ZHANG
Original assignee: CCTEG Xian Research Institute Group Co Ltd
Current assignee: Ccteg Xi'an Research Institute Group Co Ltd
Priority date: 2022-08-24
Filing date: 2023-09-22
Publication date: 2025-01-09
Also published as: WO2024041667A1; CN115434694A

Abstract

A multi-parameter measurement-while-drilling system for underground coal mines, and a measurement method. The system is provided with a measurement tube (1), and a main control board assembly (3), a vibration measurement assembly (4) and a data collection assembly (5) are successively embedded in the axial direction in the outer wall of the measurement tube (1); the vibration measurement assembly (4) measures the vibration frequency and amplitude of a drilling tool and the washing fluid pressure outside the measurement tube, and the vibration measurement assembly (4) also serves as a control switch of the data collection assembly (5) and the main control board assembly (3); the data collection assembly (5) collects measured data of the vibration measurement assembly (4), and simultaneously the data collection assembly (5) collects the rotation speed of the drilling tool and the washing fluid pressure inside the measurement tube; the main control board assembly (3) is integrated with an inclination measuring module for measuring dynamic pose data and static pose data of the drilling tool, and encodes and modulates the pose data of the drilling tool and the data collected by the data collection assembly. The system can measure drilling pressure and torque data at different positions in the circumferential direction, which truly reflects the stress state of each position of in-hole drilling tools, thus effectively preventing accidents such as drilling tool sticking and drilling tool dropping during the construction process.

Description

MULTI-PARAMETER MEASUREMENT-WHILE-DRILLING SYSTEM FOR UNDERGROUND COAL MINES AND MEASUREMENT METHOD TECHNICAL FIELD

[1] The disclosure belongs to the technical field of engineering parameter measurement-while

drilling, and relates to a multi-parameter measurement-while-drilling system for underground

coal mines and a measurement method.

BACKGROUND OF THE INVENTION

[2] Currently, during drilling construction in underground coal mines, for directional drilling, drilling

pose data are mainly obtained from a monitor, and relevant drilling parameters such as torque,

feed pressure, and pull-up pressure are obtained from a drilling rig instrument. For conventional

drilling, basically, only some of the drilling parameters such as rotational speed, torque, feed

pressure and pull-out pressure can be obtained from the drilling rig instruments or during

drilling rig operation. However, drilling parameters such as torque, bit pressure, inner and outer

annular pressure, rotational speed, vibration and temperature of a drilling tool at the bottom of

a hole during drilling cannot be directly reflected. Whether conventional or directional drilling,

these drilling parameters are important indicators for safe and efficient underground drilling. As

a depth and a hole size of a borehole increase, drilling accidents such as drill blocking, drill

dropping and instrument damage occur frequently. Most of the accidents are not instantaneous

and are basically due to the inability to accurately predict the situation in the hole with little

information during construction. So, by measuring a drilling tool in the hole accurately in real

time with multiple parameters, a drilling process can be analyzed, determined and processed.

Accordingly, the whole drilling process is guided, and risk-free drilling is achieved.

[3] Conditions of interaction between the drilling tool and a borehole wall during drilling

construction are complex. A decay tendency of the torque and bit pressure applied by the

drilling rig to the drilling tool in a transmission process is greatly influenced by factors such as

friction on the borehole wall, a degree of regularity of the borehole, and geological conditions.

The data displayed by an orifice instrument is not a true stress on the drilling tool behind a

drilling bit. With cooperative use of precision instruments in a drilling process, some

requirements are also put on the vibration of the drilling tool and the temperature in the hole.

Prolonged exposure to high temperatures and strong vibration makes the instruments highly susceptible to damage. However, data such as temperature and vibration cannot be displayed on the instrument at present. Moreover, a pressure of flushing fluid in the hole is typically obtained according to a display on a pressure gauge of a mud pump truck. Changes of pressures of flushing fluid in the drilling tool and in an annular space of the borehole cannot be monitored in real time. In short, due to inaccurate, lagging and single measurement data from the instrument, a true stress state of the drilling tool in the hole and characteristics of an environment in which the drilling tool is located cannot be fundamentally reflected. The abnormality of any parameter may lead to accidents.

[4] In the construction process, changes in a hole deviation angle and an azimuth with the well bore should be monitored at any time, in order to better monitor and adjust a borehole trajectory to extend it as far as possible along a designed trajectory. In addition, by monitoring the changes in the hole deviation angle and the azimuth with the well bore, curvature of the borehole can be calculated, and a "dogleg degree" can be reasonably controlled, so underground accidents can be prevented. Currently, a mining measurement-while-drilling system commonly uses a three axis accelerometer and a three-axis magnetometer for hole deviation and azimuth measurements. The measurement with drilling system requires static measurements after drilling stops, and can accurately reflect pose data of the drilling tool at a time point after construction of a single drill pipe is completed. In the construction process, affected by the vibration, impact and rotation of the drilling tool, a measurement module cannot measure dynamic pose data of the drilling tool in real time and accurately during drilling.

[5] Currently, the engineering parameter measurement technology is comparatively mature in the petroleum field, but is still blank in the drilling field such as underground coal mines, and no relevant instruments or papers have been reported. Due to particularity of drilling construction in underground coal mines, a hole size and "coal safety" requirements limit the potential use of petroleum-based instruments in the underground coal mines.

SUMMARY OF THE INVENTION

[6] An objective of the disclosure is to provide a multi-parameter measurement-while-drilling system for underground coal mines and a measurement method. Bit pressures and torque data at different positions in a circumferential direction can be measured, a stress state of each position of a drilling tool in a hole can be truly reflected, and accidents such as that the drilling tool is jammed or dropped in a construction process can be effectively avoided.

[7] In order to achieve the above objective, the disclosure uses the technical solutions as follows.

[8] A multi-parameter measurement-while-drilling system for underground coal mines is provided, in which a measurement tube is arranged, and a main control board assembly, a vibration measuring assembly and a data collecting assembly are embedded in an outer wall of the measurement tube in sequence in an axial direction,

[9] the vibration measuring assembly measures a vibration frequency and an amplitude of a drilling tool and a pressure of a flushing fluid outside the tube, and the vibration measuring assembly serves as a control switch of the data collecting assembly and the main control board assembly,

[10]the data collecting assembly collects measurement data from the vibration measuring assembly, and the data collecting assembly collects a rotational speed of the drilling tool and a pressure of a flushing liquid inside the tube, and

[11]the main control board assembly is integrated with an inclination measuring module for measuring dynamic pose data and static pose data of the drilling tool, and encodes and modulates the pose data of the drilling tool and data collected by the data collecting assembly.

[12]Optionally, the measurement tube is a tube with a hollow channel, in which a support sleeve is embedded in one end of the measurement tube in an axial direction, and the support sleeve is internally provided with a cable reducing joint in an axial direction in an abutting manner, and in which the cable reducingjoint is electrically connected to the main control board assembly, the vibration measuring assembly and the data collecting assembly through the support sleeve.

[13]Optionally, the support sleeve is provided with an insulating seat sleeved with a cylinder, in which a first male contact is arranged in the insulating seat, and the cable reducing joint is electrically connected to the first male contact.

[14]Optionally, the cylinder is internally provided with a plurality of connectors in a radial direction, and every two connectors define a sector-shaped cavity, in which the insulating seat is located at radial stop ends of the connectors, in which a first wire hole is provided in the connector, a second wire hole is provided in an outer wall of the insulating seat, and a side wall of the first male contact is in communication with the second wire hole and the first wire hole.

[15]Optionally, the cable reducing joint is provided with a cable tube, one end of the cable tube being internally provided with a female contact, and an other end of the cable tube being internally provided with a second male contact, in which an annular boss is arranged at a waist portion of the cable tube, and the cable reducing joint is tightly pressed and fixed in an axial direction through a fixing ring.

[16]Optionally, the main control board assembly includes a main control board embedded in the outer wall of the measurement tube, and a first cover plate covering the main control board, in which the inclination measuring module is written on the main control board, and the inclination measuring module is integrated with a three-axis accelerometer and a three-axis magnetometer.

[17]Optionally, the vibration measuring assembly includes a vibration sensor embedded in a tube wall of the measurement tube, and a first compression cover arranged to cover the vibration sensor, and the vibration measuring assembly further includes a first pressure sensor embedded in the tube wall of the measurement tube, and a second compression cover arranged to cover the first pressure sensor, in which the vibration sensor and the first pressure sensor are arranged in a circumferential direction of the measurement tube, and are connected to each other through a second bridge wire hole.

[18]Optionally, the data collecting assembly includes a data collecting board embedded in the outer wall of the measurement tube, a second cover plate covering the data collecting board, and a rotational speed board and a second pressure sensor arranged adjacent to the data collecting board, in which the second pressure sensor is configured to measure the pressure of the flushing fluid in a central passage of the measurement tube, the rotational speed board is configured to measure a rotational speed of the drilling tool at a position where the rotational speed board is located, and the data collecting board collects measurement data.

[19]Optionally, torque and pressure measuring assemblies are embedded in the measurement tube in a circumferential direction, in which the torque and pressure measuring assemblies are evenly arranged every 90° in the circumferential direction, and each torque and pressure measuring assembly consists of two high-precision single-grid strain gauges and one high-precision dual grid shear strain gauge, in which the two high-precision single-grid strain gauges are arranged to guarantee that axes of the two high-precision single-grid strain gauges are parallel and perpendicular to an axis of the measurement tube respectively, and are configured to measure torque received by the drilling tool at a position where the two high-precision single-grid strain gauges are located, and the high-precision dual-grid shear strain gauge has an axis parallel to the axis of the measurement tube and is configured to measure a bit pressure received by the drilling tool at a position where the high-precision dual-grid shear strain gauge is located.

[20]A dynamic measurement method for a multi-parameter measurement-while-drilling system for underground coal mines includes:

[21]step 1, continuously recording data collected by an accelerometer in an axial direction of a drilling tool and a magnetometer in a radial direction of the drilling tool in one period of working time merely during drilling, in which the data includes one piece of axial accelerometer data V, and two pieces of radial magnetometer data Bx and B,

[22]step 2, processing acceleration data V, measured by the axial accelerometer, and obtaining an interference-free axial accelerometer measurement result v, in which a moving average filtering method is selected as a method for removing a radial acceleration component selects, a calculation method being as follows: n

v 2n+1 z(k) Vz(k+1+j),k=n+l,n+2,......

[23] j=

[24]in which 2n + 1 represents a number of moving average filtering points, and the number of moving average filtering points is determined according to an instrument rotational speed and a recording frequency, and k represents a number of points of the axial acceleration Vz collected by the axial accelerometer,

[25]step 3, calculating a dynamic hole deviation angle 6 by using the interference-free axial accelerometer measurement data v, and a total field value G of local gravity acceleration, in which

0 = arccos

[26] (VZ) G

[27]step 4, calculating a vertical component Bv and a north component BN of a geomagnetic field according to a local total geomagnetic field value Bo and a local geomagnetic inclination @, in which

Bvsinf x B0

[28] , and

[29]calculating a magnetic field component B, in the axial direction of the drilling tool according to the local total geomagnetic field value Bo and radial magnetometer measurement data Bx and By, and calculating a horizontal magnetic field component BH in a direction of a projection of the drilling tool in the axial direction on a horizontal plane according to Bz, in which

[30]B , YO:(B+B and Bz-Bv cos 0

[31] sin 0 ,and

[32]step 5, calculating a dynamic azimuth angle y according to the horizontal magnetic field component BH in the direction of the projection of the drilling tool in the axial direction on the horizontal plane and the north component BN of the geomagnetic field, in which BH

[33] yBN

[34]The disclosure has the beneficial effects as follows:

[35](1) According to the multi-parameter measurement-while-drilling system in the disclosure, an annular circuit bridge is formed with a plurality of bit pressure and torque sensors uniformly distributed circumferentially, which can measure the bit pressures and the torque data at different positions circumferentially, truly reflecting the stress state at each position of the drilling tool in a hole, and can effectively avoid accidents such as that the drilling tool is jammed or dropped in a construction process. (2) Data of a plurality of parameters such as bit pressure and torque data, drilling tool vibration data, rotational speed data, drilling tool inner and outer annular pressure data, circuit board temperature are collected, filtered and encoded by the data collecting board, and then are decoded by the main control board. Decoded data and the drilling pose data measured by the main control board integration module are packaged together, then encoded and modulated again, and then transmitted to a computer in a wired transmission mode. Data signal transmission is stable and continuous, and problems of inaccurate, lagging and single measurement data from an orifice instrument of an underground coal mine are effectively solved. (3) The circuit board, the sensors, the wire holes, the bridge wire holes and plug-in matching components involved in the system are sealed, and local glue injection for sealing insulation is performed to guarantee sealing performance of the system, such that the problem of a core element failure caused by mud leakage is effectively solved. (4) The dynamic measurement method does not collect a gravity field component in the radial direction of the drilling tool in a construction process, such that an influence of centrifugal acceleration and radial vibration generated by rotational of the drilling tool on the gravity field component in the radial direction is avoided, and accuracy of the dynamic pose data of the drilling tool in the construction process is guaranteed. (5) A working state of the data collecting board and a data collecting mode of the control board are controlled through a vibration switch, thus overall power consumption of the system can be effectively reduced, and effective switching between the dynamic pose data and the static pose data of the drilling tool can be implemented. Not only multi-parameter data collection and transmission are guaranteed in the construction process, but also accurate adjustment of a tool facing angle after drilling is stopped and a drilling pipe is connected isguaranteed.

BRIEF DESCRIPTION OF DRAWINGS

[36]The drawings, which are used for providing further understanding of thedisclosure and constitute part of the description, serve to explain the disclosure along with the following detailed embodiments, instead of limiting the disclosure. In the figures:

[37] Fig. 1 is a sectional view of a multi-parameter measurement-while-drilling system for underground coal mines according to the disclosure,

[38] Fig. 2 is a top view of Fig. 1,

[39]Fig. 3 is a sectional view in direction A-A in Fig. 1,

[40] Fig. 4 is a sectional view in direction B-B in Fig. 1,

[41] Fig. 5 is a sectional view in direction C-C in Fig. 2,

[42] Fig. 6 is a schematic diagram of arrangement of sensors of a torque and pressure measuring assembly in Fig. 5 in direction a,

[43] Fig. 7 is a sectional view in direction D-D in Fig. 2,

[44]Fig. 8 is a longitudinal sectional view of a support sleeve according to the disclosure,

[45] Fig. 9 is a sectional view in direction E-E in Fig. 8,

[46]Fig. 10 is an enlarged view of a structure of a cable reducing joint according to the disclosure, and

[47] Fig. 11 is a flowchart of a dynamic measurement method for a multi-parameter measurement while-drilling system for underground coal mines according to the disclosure.

Reference numerals:

1-measurement tube, 11-locating bolt, 2-support sleeve, 21-cylinder, 211-connector, 212-sector shaped cavity, 213-annular inclined surface, 214-sealing groove, 215-locating hole, 216-first wire hole, 22-insulating seat, 221-second wire hole, 23-first male contact, 3-main control board assembly, 31-first cover plate, 32-main control board, 4-vibration measuring assembly, 41 vibration sensor, 42-first compression cover, 43-first pressure sensor, 44-second compression cover, 45-second bridge wire hole, 5-data collecting assembly, 51-second cover plate, 52-data collecting board, 53-rotational speed board, 54-second pressure sensor, 6-fixing ring, 7-cable reducing joint, 71-female contact, 72-cable tube, 73-second male contact, 8-torque and pressure measuring assembly, 81-torque and pressure sensor, 811-high-precision single-grid strain gauge,

812-high-precision dual-grid shear strain gauge, and 82-first bridge wire hole.

DETAILED DESCRIPTION OF THE INVENTION

[48]The disclosure will be described in detail below with reference to the accompanying drawings

and particular embodiments.

[49]The azimuth words such as "circumferential direction", "axial direction", "radial direction",

"lateral direction", "front", "rear", "left", "right", "upper", "lower", "top" and "bottom"

mentioned in the disclosure are described with reference to facing the drawings of the

description, and the meanings expressed are generally recognized in the art.

[50]With reference to Figs. 1-10, the multi-parameter measurement-while-drilling system for

underground coal mines in the disclosure is provided with a measurement tube 1. A left end of

the measurement tube l is connected to a lower non-magnetic drill pipe, a screw motor and a

drill bit in sequence, and the other end is connected to an upper non-magnetic cable drill pipe, a

cable drill pipe, a cable water feeder and an orifice computer in sequence. A main control board

assembly 3, a vibration measuring assembly 4 and a data collecting assembly 5 are embedded in

an outer wall of the measurement tube I in sequence in an axial direction. The vibration

measuring assembly 4 measures a vibration frequency and an amplitude of a drilling tool and a

pressure of a flushing fluid outside the measurement tube, and the vibration measuring

assembly 4 serves as a control switch of the data collecting assembly 5 and the main control

board assembly 3. The data collecting assembly 5 collects measurement data from the vibration

measuring assembly 4, and the data collecting assembly 5 collects a rotational speed of the

drilling tool and a pressure of a flushing fluid inside the measurement tube. The main control

board assembly 3 is integrated with an inclination measuring module for measuring dynamic

pose data and static pose data of the drilling tool, and encodes and modulates the pose data of

the drilling tool and the data collected by the data collecting assembly. According to the multi

parameter measurement-while-drilling system in the disclosure, an annular circuit bridge is

formed with a plurality of bit pressure and torque sensors uniformly distributed circumferentially, which may measure bit pressures and torque data at different positions circumferentially, truly reflecting a stress state at each position of the drilling tool in a hole, and can effectively avoid accidents such as that the drilling tool is jammed or dropped in a construction process.

[51]With reference to Figs. 1, 8 and 9, in an example of the disclosure, the measurement tube 1 is a tube with a hollow channel. A support sleeve 2 is embedded in one end of the measurement tube 1 in an axial direction, and the support sleeve 2 is internally provided with a cable reducing joint 7 in an axial direction in an abutting manner. The cable reducing joint 7 is electrically connected to the main control board assembly 3, the vibration measuring assembly 4 and the data collecting assembly 5 through the support sleeve 2.

[52]Specifically, the support sleeve 2 is inserted in a right end of the measurement tube I in a matching manner. The cable reducingjoint 7 is inserted in the support sleeve 2 in a matching manner and is limited and fixed in a central passage at the right end of the measurement tube 1 through a fixing ring 6.

[53]In the example of the disclosure, the support sleeve 2 is provided with an insulating seat. The insulating seat is sleeved with a cylinder 21. Three connectors 211 are arranged in the cylinder 21 in a radial direction. Every two of the three connectors define a sector-shaped cavity 212 to function as an inflow channel for flushing liquid. Preferably, the insulating seat 22 is located at an axial center position formed by the three connectors, that is, at a radial stop end of the three connectors 211. The insulating seat is annular. A first male contact 23 is arranged at an annular center of the insulating seat. The first male contact 23 is insulated from other metal parts by the insulating seat 22. A side wall of the first male contact 23 is in communication with a second wire hole 221. One of the connectors 211is provided with a first wire hole 216, and positions of an outer wall of the cylinder corresponding to the other two connectors are each provided with a locating hole 215. An outer wall of the insulating seat 22 is provided with the second wire hole 221. The insulating seat 22 is inserted into the cylinder 21 and fixed by glue injection. The first wire hole 216 and the second wire hole 221 have a same axis and are in communication with each other.

[54]As shown in Fig. 10, the cable reducing joint 7 is provided with a cable tube 72. One end of the cable tube 72 is a male joint. An exterior of the male joint is provided with a double-layer sealing ring structure. The other end of the cable tube 72 is a female joint. The male joint is internally provided with a female contact 71. The female joint is internally provided with a second male contact 73. The cable tube 72 is made of non-metallic material and internally provided with a through hole. An insulated wire is arranged in the through hole for communicating the female contact 71 and the second male contact 73. An annular boss is arranged at a waist portion of the cable tube 72. The cable reducing joint 7 is tightly pressed and fixed in an axial direction through the fixing ring 6.

[55]With reference to Fig. 2, the outer wall of the measurement tube 1 is provided with a first rectangular groove and a second rectangular groove. A first annular groove is arranged between axes of the first rectangular groove and the second rectangular groove. A fourth wire hole is arranged between the first rectangular groove and the first annular groove. A fifth wire hole is arranged between the second rectangular groove and the first annular groove. A third wire hole is arranged at a right end of the first rectangular groove. Two first locating holes are arranged on a tube wall at the right end of the measurement tube 1. The two first locating holes and the third wire hole are uniformly distributed at an angle of 120° in a circumferential direction. A bell mouth is arranged at a left end of the locating hole. The second rectangular groove is composed of a smaller rectangular groove at a left end and a larger rectangular groove at a right end. A wire hole is arranged between the smaller rectangular groove and the larger rectangular groove at the right end, in which a pressure guiding hole is arranged in the middle of the smaller rectangular groove and the pressure guiding hole is in communication with the central passage of the measurement tube 1. Four second annular grooves are arranged at a left end of the second rectangular groove. The first cover plate 31 is arranged in a rectangular groove corresponding to the main control board 32 and fixed to the outer wall of the measurement tube 1 by a hexagon socket bolt. The second cover plate 51 is arranged in a rectangular groove corresponding to the data collecting board 52 and fixed to the outer wall of the locating tube 1 by a hexagon socket bolt.

[56]In the example of the disclosure, the main control board assembly 3 includes a main control board 32 embedded in the outer wall of the measurement tube 1, and the main control board 32 is covered with a first cover plate 31. The inclination measuring module is written on the main control board 32, and the inclination measuring module integrates a three-axis accelerometer and a three-axis magnetometer. A rectangular recess is formed in an inner side of the first cover plate 31. After the first cover plate 31 is fixed on the outer wall of the measurement tube in a matching manner, the rectangular recess is in communication with the first rectangular groove. The third wire hole is located below the rectangular recess, so as to communicate the first rectangular groove, the third wire hole, the first wire hole, the second wire hole and till the first male contact 23. The support sleeve 2 is inserted in the measurement tube 1 in a matching manner, such that an annular inclined surface 213 of the support sleeve 2 is fitted to the bell mouth of the measurement tube 1. A slope of the annular inclined surface 213 is consistent with a slope of the bell mouth. After a locating bolt 11 is screwed into the first locating hole on the measurement tube 1, a part of threaded section is still exposed, and the exposed part is inserted into the locating hole 215 on the cylinder 21 to limit and fix the support sleeve 2.

[57]In the example of the disclosure, the data collecting assembly 5 includes a data collecting board 52 embedded in the outer wall of the measurement tube 1, in which the data collecting board 52 is covered with a second cover plate 51, and a rotational speed board 53 and a second pressure sensor 54 arranged adjacent to the data collecting board 52. The second pressure sensor 54 measures the pressure of the flushing fluid in the measurement tube 1. The rotational speed board 53 measures a rotational speed of the drilling tool at a position where the rotational speed board is located. The data collecting board 52 collects measurement data. A rectangular recess is formed in an inner side of the second cover plate 51. A size of the rectangular recess is determined according to a size of a sensor arranged in the second rectangular groove. The second pressure sensor 54 is arranged in the smaller rectangular groove on a left side of the second rectangular groove. The pressure guiding hole is in communication with the second pressure sensor 54, such that the pressure of the flushing liquid in the central passage of the drilling tool can be monitored during construction. The rotational speed board 53 is arranged at a left end of the larger rectangular groove on a right side of the second rectangular groove. The data collecting board 52 is arranged at a right end of the larger rectangular groove on the right side of the second rectangular groove and fixed by screws.

[58]In the example of the disclosure, the vibration measuring assembly 4 includes a vibration sensor 41 embedded in a tube wall of the measurement tube 1, and a first compression cover 42 arranged to cover the vibration sensor 41. The vibration measuring assembly further includes a first pressure sensor 43 embedded in the tube wall of the measurement tube 1, and a second compression cover 44 arranged to cover the first pressure sensor 43. The vibration sensor 41 and the first pressure sensor 43 are arranged in a circumferential direction of the measurement tube 1, and are connected to each other through a second bridge wire hole 45. The vibration sensor 41 is arranged in the first annular groove and sealed by the first compression cover 42.

The first pressure sensor 43 is arranged in the third annular groove and sealed by the second compression cover 44. A pressure guiding hole is formed in the middle of the second compression cover 44 for communicating an outer annular space of the drilling tool with the first pressure sensor 43. The vibration sensor 41 and the first pressure sensor 43 are connected in series to each other by an insulated wire in the second bridge wire hole 45. The main control board 32 is arranged in the first rectangular groove and fixed by screws.

[59]The second pressure sensor 54 is configured to measure the pressure of the flushing fluid in the central passage of the measurement tube 1. The rotational speed board 53 is configured to measure a rotational speed of the drilling tool at the position. The data collecting board 52 is mainly configured to collect data measured by each sensor for collecting, filtering and coding. Moreover, a temperature sensor is integrated in the data collecting board 52 for measuring a temperature of the data collecting board 52. The vibration sensor 41 is configured to measure the vibration frequency and amplitude of a position of the drilling tool near a drill bit. Moreover, the vibration sensor 41may be used as the control switch of the data collecting board 52 and the main control board 32. The first pressure sensor 43 is configured to measure a pressure of flushing fluid in an outer annular space between the drilling tool and a borehole. The main control board 32 is internally integrated with an inclination measuring module. The inclination measuring module is integrated with the three-axis accelerometer (X, Y, and Z axes) and the three-axis magnetometer (X, Y, and Z axes), and may measure the dynamic pose data of the drilling tool in the hole during drilling and the static pose data of the drilling tool after construction by a single drill pipe is completed. The pose data of the drilling tool and packet data of the data collecting board 52 are encoded and modulated by the main control board 32 again.

[60]Four torque and pressure measuring assemblies 8 are evenly arranged every 90° circumferentially and are arranged in four second annular grooves respectively. The torque and pressure measuring assembly 8 is provided with two high-precision single-grid strain gauges 811 and one high-precision dual-grid shear strain gauge 812. The three strain gauges are connected to a connection terminal in the second annular groove. The two high-precision single-grid strain gauges 811 are arranged to guarantee that axes of the two high-precision single-grid strain gauges are parallel and perpendicular to the axis of the measurement tube 1 respectively, and are configured to measure torque received by the drilling tool at a position where the two high precision single-grid strain gauges are located. The high-precision dual-grid shear strain gauge has an axis parallel to the axis of the tube and is configured to measure a bit pressure received by the drilling tool at the position where the high-precision dual-grid shear strain gauge is located. The four groups of sensors obtain 8 torque parameters and 4 bit pressure parameters in total. The four torque and pressure measuring assemblies 8 are connected in series through insulated wires in the first bridge wire holes 82 to form an annular circuit bridge, so as to measure bit pressures and torques at different positions in the circumferential direction in a bending state of the drilling tool. The four second annular grooves are evenly arranged every 90° circumferentially. The four second annular grooves are in communication with each other through the first bridge wire holes 82. The smaller rectangular groove at the right end of the second annular groove is in communication with the first bridge wire hole 82 at a left side of the smaller rectangular groove through a sixth wire hole. The first annular groove and the third annular groove are arranged at an included angle of 90° in the circumferential direction and are in communication with each other through the second bridge wire hole 45.

[61]The four torque and pressure measuring assemblies 8, the second pressure sensor 54, the rotational speed board 53, the vibration sensor 41, the first pressure sensor 43 and the data collecting board 52 are connected in series. The data collecting board 52, the main control board 32 and the first male contact 203 are connected in series. Then the upper non-magnetic drill pipe, the cable drill pipe, the cable water feeder and the computer are sequentially connected through the cable reducing joint 7 at the right end, such that a complete multi-parameter measurement-while-drilling system is formed.

[62]Insulated wires are used as wires passing through the wire holes and bridge wire holes in the entire system, and after the insulated wires are completely arranged, glue injection is performed again for secondary insulation sealing. Concentric-square-shaped rubber gaskets are arranged between the first cover plate 31, the second cover plate 51 and the measurement tube 1, so as to prevent the flushing liquid from entering the first rectangular groove and the second rectangular groove and corroding internal core electronic elements such as the data collecting board 52 and the main control board 32 during construction. The second pressure sensor 54 mainly measures the pressure of the flushing fluid in the central passage of the measurement tube 1 through the pressure guiding hole, so a high-pressure sealing ring is arranged between the second pressure sensor 54 and the pressure guiding hole. The first compression cover 42 and the second compression cover 44 involved in the example are both connected to the tube by threads, and a non-threaded connection portion is provided with an 0-shaped sealing ring for sealing. Two sealing grooves 214 are arranged at an upper end and a lower end of an outer wall of the cylinder 21, and a plurality of 0-shaped rings are used for radial sealing. Thus the flushing liquid is effectively prevented from entering the first rectangular groove along the third wire hole due to excessively high pressure of the flushing liquid at an inlet.

[63]Furthermore, the main body of the measurement tube 1, the first cover plate 31, the second cover plate 51, the first compression cover 42, the second compression cover 44 and the corresponding accessories are all made of non-magnetic steel, which avoids geomagnetic interference and an influence on accuracy of the inclination measuring module in measuring the pose data of the drilling tool.

[64]An industrial control method for a multi-parameter measurement-while-drilling system for underground coal mines according to the disclosure includes the following.

[65]Step 1: in a construction process, a drilling tool generates vibration, and a vibration sensor 41 detects the vibration of the drilling tool, so as to control a data collecting board 52 to start and collect all data. A drilling rig drives the drilling tool in the hole to rotate and applies a bit pressure on the drilling tool. A torque and the bit pressure are transmitted to the multi parameter measurement-while-drilling system near a drill bit. A strain gauge in a torque and pressure measuring assembly 8 is affected by the bit pressure and the torque, converts a real time bit pressure and torque into an electrical signal, and transmits the electrical signal to a data collecting board 52. The electrical signal includes four groups of data, and each group of data includes two bit pressure values and one torque value. Vibration generated by the drill bit rotating to cut rock formation and vibration generated by friction between the drilling tool and a hole wall are collected in real time by a vibration sensor 41 and transmitted to the data collecting board 52 in a form of electric signal. Vibration conditions of three axes X, Y, and Z in an axial direction and a radial direction may be measured by the vibration sensor 41. Pressures of flushing fluid in a central passage of the system and an annular space of a borehole are converted into electric signals by a second pressure sensor 54 and the first pressure sensor 43 and transmitted to the data collecting board 52. A rotational speed of the system near the drill bit is measured by a rotational speed board 53 in real time and transmitted to the data collecting board 52 in the form of electrical signal. A temperature of a circuit board is measured in real time by a temperature sensor integrated on the data collecting board 52. The electric signals are collected, filtered, encoded, packed and transmitted to a main control board 32 by the data collecting board 52. A packed signal is decoded by the main control board 32. After the main control board 32 receives a drilling tool vibration data signal, dynamic pose data of the drilling tool are collected by an inclination measuring module in the main control board 32. In a dynamic measurement mode, a three-axis accelerometer only has one accelerometer in an axial direction to collect V, a three-axis magnetometer only has two magnetometers in a radial direction to collect Bx and By. The above data are encoded and modulated by the main control board 32 again through a low-voltage direct-current carrier technology, and then transmitted to an orifice computer through an upper non-magnetic drill pipe, a cable drill pipe and a cable water feeder. The signal data are demodulated by the computer finally, so as to obtain all dynamic data parameters in the drilling process. The calculated dynamic pose data parameters of the drilling tool are azimuth and inclination.

[66]Step 2: drilling is stopped, a drill pipe is connected, vibration of the drilling tool stops, and the vibration sensor 41 detects that vibration of the drilling tool stops to control the data collecting board 52 to stop collecting data, such that power consumption is reduced. In this case, after the main control board 32 receives no vibration data signal of the drilling tool, only static pose data of the drilling tool is collected by the inclination measuring module integrated in the main control board 32. In a static measurement mode, the three-axis accelerometer collects three dimensional accelerations Vx, Vy and V, and the three-axis magnetometer collects three dimensional magnetic field intensity Bx, By and Bz. The static pose data of the drilling tool is encoded and modulated by the main control board 32 through the low-voltage direct-current carrier technology, and then transmitted to the orifice computer through the upper non magnetic drill pipe, the cable drill pipe and the cable water feeder. The signal data are demodulated by the computer finally, and the static pose data parameters (azimuth, inclination and tool facing angle) of the drilling tool are calculated.

[67]In combination with Fig. 11, a dynamic measurement method for a multi-parameter measurement-while-drilling system for underground coal mines according to the disclosure includes the following.

[68]Step 1, during drilling, data collected by an accelerometer in an axial direction (Z axis) of a drilling tool and a magnetometer in a radial direction (X axis and Y axis) of the drilling tool are continuously recorded in one period of time (from start to stop of vibration detected by a vibration sensor) merely, in which measurement data includes one piece pf axial accelerometer data Vz and two pieces of radial magnetometer data Bx and By.

[69]Step 2, the acceleration data Vz measured by the axial accelerometer is processed, and an interference-free axial accelerometer measurement result vz is obtained. A moving average filtering method is selected as a method for removing a radial acceleration component, in which a calculation method is as follows: n v-(k)= h+1 Z..Vz(k+l+j),k=n+1,n+2,......

[70] j=

[71]2n + 1 represents a number of moving average filtering points, and the number of moving average filtering points is determined according to an instrument rotational speed and a recording frequency. Taking a rotational speed 60 r/min commonly used in a coal mine as an example, a rotational frequency is 1 Hz, a collecting frequency is 200 Hz, and then the number of moving average filtering points 2n + 1 should be greater than 200.

[72]Step 3, a dynamic hole deviation angle 6 is calculated by using the interference-free axial accelerometer measurement data vz and a total field value G of local gravity acceleration, in which

0 = arccos (VZ)

[73] G

[74]Step 4, a vertical component Bv and a north component BN (the north component BN is generally obtained from data queries or actual geographical locations) of a geomagnetic field are calculated according to a local total geomagnetic field value Bo and a local geomagnetic inclination @, in which

[75] B sin/§xB 0

[76]A magnetic field component Bz in the axial direction of the drilling tool is calculated according to the local total geomagnetic field value Bo and the radial magnetometer measurement data Bx and By, and a horizontal magnetic field component BH in a direction of a projection of the drilling tool in the axial direction on a horizontal plane is calculated according to Bz, in which

Bz =O B: (Bx2 + By)

[77] ,(and

Bz-Bv cos 0

[78] sin 0

[79]Step 5, a dynamic azimuth angle y is calculated according to the horizontal magnetic field component BH in the direction of the projection of the drilling tool in the axial direction on the horizontal plane and the north component BN of the geomagnetic field, in which y=arccos

[80] BN

[81] Preferred examples are selected and discussed in detail above in conjunction with the accompanying drawings and are not intended to limit the disclosure. Various specific technical features described above may be combined in any suitable manner without contradiction, which will not be repeated here. Simple modification means such as arbitrary combination or equivalent substitution used by any person skilled in the art on the technical solutions without departing from the scope of the technical solutions does not influence the essence of the technical solutions and still fall within the protection scope of the technical solutions represented by each example of the disclosure.

Claims

Claims 1. A multi-parameter measurement-while-drilling system for underground coal mines, wherein a measurement tube (1) is arranged, and a main control board assembly (3), a vibration measuring assembly (4) and a data collecting assembly (5) are embedded in an outer wall of the measurement tube (1) in sequence in an axial direction, wherein the vibration measuring assembly (4) measures a vibration frequency and an amplitude of a drilling tool and a pressure of a flushing fluid outside the tube, and the vibration measuring assembly (4) serves as a control switch of the data collecting assembly (5) and the main control board assembly (3), wherein the data collecting assembly (5) collects measurement data from the vibration measuring assembly (4), and the data collecting assembly (5) collects a rotational speed of the drilling tool and a pressure of a flushing liquid inside the tube, and wherein the main control board assembly (3) is integrated with an inclination measuring module for measuring dynamic pose data and static pose data of the drilling tool, and encodes and modulates the pose data of the drilling tool and data collected by the data collecting assembly.
2. The multi-parameter measurement-while-drilling system for underground coal mines according to claim 1, wherein the measurement tube (1) is a tube with a hollow channel, wherein a support sleeve (2) is embedded in one end of the measurement tube (1) in an axial direction, and the support sleeve (2) is internally provided with a cable reducing joint (7) in an axial direction in an abutting manner, and wherein the cable reducing joint (7) is electrically connected to the main control board assembly (3), the vibration measuring assembly (4) and the data collecting assembly (5) through the support sleeve (2).
3. The multi-parameter measurement-while-drilling system for underground coal mines according to claim 2, wherein the support sleeve (2) is provided with an insulating seat (22) sleeved with a cylinder (21), wherein a first male contact (23) is arranged in the insulating seat (22), and the cable reducing joint (7) is electrically connected to the first male contact (23).
4. The multi-parameter measurement-while-drilling system for underground coal mines according to claim 3, wherein the cylinder (21) is internally provided with a plurality of connectors (211) in a radial direction, and every two connectors (211) define a sector-shaped cavity (212), wherein the insulating seat (22) is located at radial stop ends of the connectors (211), wherein a first wire hole (216) is provided in the connector (211), a second wire hole (221) is provided in an outer wall of the insulating seat (22), and a side wall of the first male contact (23) is in communication with the second wire hole (221) and the first wire hole (216).
5. The multi-parameter measurement-while-drilling system for underground coal mines according to claim 2, 3 or 4, wherein the cable reducing joint (7) is provided with a cable tube (72), one end of the cable tube (72) being internally provided with a female contact (71), and an other end of the cable tube being internally provided with a second male contact (73), wherein an annular boss is arranged at a waist portion of the cable tube (72), and the cable reducing joint (7) is tightly pressed and fixed in an axial direction through a fixing ring (6).
6. The multi-parameter measurement-while-drilling system for underground coal mines according to claim 1, 2, 3 or 4, wherein the main control board assembly (3) comprises a main control board (32) embedded in the outer wall of the measurement tube (1), and a first cover plate (31) covering the main control board (32), wherein the inclination measuring module is written on the main control board (32), and the inclination measuring module is integrated with a three-axis accelerometer and a three-axis magnetometer.
7. The multi-parameter measurement-while-drilling system for underground coal mines according to claim 1, 2, 3 or 4, wherein the vibration measuring assembly (4) comprises a vibration sensor (41) embedded in a tube wall of the measurement tube (1), and a first compression cover (42) arranged to cover the vibration sensor (41), and the vibration measuring assembly further comprises a first pressure sensor (43) embedded in the tube wall of the measurement tube (1), and a second compression cover (44) arranged to cover the first pressure sensor (43), wherein the vibration sensor (41) and the first pressure sensor (43) are arranged in a circumferential direction of the measurement tube (1), and are connected to each other through a second bridge wire hole (45).
8. The multi-parameter measurement-while-drilling system for underground coal mines according to claim 1, 2, 3 or 4, wherein the data collecting assembly (5) comprises a data collecting board (52) embedded in the outer wall of the measurement tube (1), a second cover plate (51) covering the data collecting board (52), and a rotational speed board (53) and a second pressure sensor (54) arranged adjacent to the data collecting board (52), wherein the second pressure sensor (54) measures the pressure of the flushing fluid in the measurement tube 1, the rotational speed board (53) measures the rotational speed of the drilling tool, and the data collecting board (52) collects measurement data.
9. The multi-parameter measurement-while-drilling system for underground coal mines according to claim 1, wherein torque and pressure measuring assemblies (8) are embedded in the measurement tube (1) in a circumferential direction, wherein the torque and pressure measuring assemblies (8) are evenly arranged every 900 in the circumferential direction, and each torque and pressure measuring assembly (8) consists of two high-precision single-grid strain gauges (811) and one high-precision dual-grid shear strain gauge (812), wherein the two high-precision single-grid strain gauges (811) are arranged to guarantee that axes of the two high-precision single-grid strain gauges are parallel and perpendicular to an axis of the measurement tube (1) respectively, and are configured to measure torque received by the drilling tool at a position where the two high-precision single-grid strain gauges are located, and the high-precision dual-grid shear strain gauge (812) has an axis parallel to the axis of the measurement tube (1) and is configured to measure a bit pressure received by the drilling tool at a position where the high-precision dual-grid shear strain gauge is located.
10. A dynamic measurement method for a multi-parameter measurement-while-drilling system for underground coal mines, comprising: step 1, during drilling, continuously recording data collected by an accelerometer in an axial direction of a drilling tool and a magnetometer in a radial direction of the drilling tool in one period of working time merely, wherein the data comprises one piece of axial accelerometer data V, and two pieces of radial magnetometer data Bx and By, step 2, processing acceleration data V, measured by the axial accelerometer, and obtaining an interference-free axial accelerometer measurement result v, wherein a moving average filtering method is selected as a method for removing a radial acceleration component, a calculation method being as follows: n v- (k) = 1 2n+1 Y, *

Vz(k+1+j),k=n+l,n+2,...... j=-n wherein 2n + 1 represents a number of moving average filtering points, and the number of moving average filtering points is determined according to an instrument rotational speed and a recording frequency, step 3, calculating a dynamic hole deviation angle 6 by using the interference-free axial accelerometer measurement data v, and a total field value G of local gravity acceleration, wherein

0 = arccos(1) G, step 4, calculating a vertical component B, and a north component BN of a geomagnetic field according to a local total geomagnetic field value Bo and a local geomagnetic inclination, wherein

Bv = sin§l x BO , and calculating a magnetic field component B, in the axial direction of the drilling tool according to the local total geomagnetic field value Bo and radial magnetometer measurement data Bx and By, and calculating a horizontal magnetic field component BH in a direction of a projection of the drilling tool in the axial direction on a horizontal plane according to Bz, wherein

Bz =O B: (Bx2 + By) and

Bz-Bv cos 0 sin0 ,and step 5, calculating a dynamic azimuth angle y according to the horizontal magnetic field component BH in the direction of the projection of the drilling tool in the axial direction on the horizontal plane and the north component BN of the geomagnetic field, wherein BH y = arccos (

BN2.