Measurement-while-drilling method and device for assessing outburst risk of coal seam

A measurement-while-drilling device for a coal seam outburst risk, comprising a compartment (20), a pressure sensor (17), a temperature sensor (16), a wave velocity measurement module including a vibration source (5) and a vibration pickup (6), an electromagnetic sensor (19), an acoustic wave sensor (18), a borehole sealing module, a flow measurement module, a communication interface (9), a monitoring and control module (12), and a power supply compartment (11) that has an electric charging interface and can be removed and mounted quickly, the power supply compartment (11) supplies power to the monitoring and control module (12) and the power utilization modules or sensors connected to the monitoring and control module;

• the compartment (20) is a rod body that has a variety of sensors and modules fixed thereon, is hollow and has a water flow hole and a threading hole, with two ends connected with a drill bit (1) and a measurement-while-drilling inclinometer (24) and a first drill pipe (23) respectively in a sealed manner;
• the pressure sensor (17), the temperature sensor (16), the flow measurement module, the wave velocity measurement module, the electromagnetic sensor (19), the acoustic wave sensor (18), the power supply compartment (11), and communication interface (9) are connected to corresponding interfaces of the monitoring and control module respectively;
• the borehole sealing module comprises two borehole sealing rubber balloons (14) wrapped on rims of the compartment (20), a main water circuit switch (15) and a borehole sealing rubber balloon water circuit switch (8) that are mounted on a front end of a hollow water pipe and attain a cut-off effect during borehole sealing;
• the vibration source (5) of the wave velocity measurement module is mounted on one of the two borehole sealing rubber balloons (14) and emits vibration waves, the vibration pickup (6) is mounted on the other of the borehole sealing rubber balloons (14) and receives vibration waves, a wave velocity in a coal mass at a measuring point can be calculated from a distance and signal time difference between the vibration source (5) and the vibration pickup (6);
• the monitoring and control module (12) comprises a variety of sensors and module interfaces, a data storage unit, a timer, a monitoring and control CPU, and a monitoring and control circuit;
• wherein, the sensors comprise a flow sensor, a temperature sensor, a pressure sensor, and a acoustic emission sensor, the sensors are connected in shunt and operate separately from each other without any interference, and they are connected via their interfaces to corresponding interfaces of the monitoring and control module, and have functions of monitoring signal conversion, data acquisition triggering, periodical data acquisition, data analysis and control;
• and
• the flow measurement module comprises a gas flow hole (2), and a gas circuit switch (4) and a flow sensor (3) that are installed in the gas flow hole.