Abstract:
In response to the severe problem of coal powder production in some coalbed methane wells during the development process of coalbed methane, a set of coal powder dynamic settlement experimental platform as been developed; based on the on-site production conditions of coalbed methane wells and the characteristics of coal powder production, experimental conditions were designed to meet the on-site production characteristics, and the migration and settlement laws of coal powder in the unidirectional flow stage of coalbed methane wells were explored. The results show that the tuning fork resonant density sensor can achieve real-time monitoring of underground coal powder mass concentration; 180-250 μm coal powder particles will be carried and transported when the fluid velocity is greater than or equal to 0.020 m/s; 150-180 μm coal powder particles will be carried and transported when the fluid velocity is greater than or equal to 0.010 m/s. When the mass concentration of coal powder is constant, the increase in flow rate will cause the increase in the mass concentration of coal powder in the wellbore, which proves that the increase of drainage speed is helpful to discharge the settled coal from the shaft.