Dynamic migration and settlement law of pulverized coal in vertical wellbore of coalbed methane well

Through the dynamic settlement and migration simulation test system of coal powder in coalbed methane wells, the liquid flow rate and gas flow rate are changed to simulate and test the settlement and migration state of coal powder in the wellbore at different production stages in the actual production process of coalbed methane wells. The concentration of coal powder in the whole experiment process is obtained by the concentration meter of the wellbore device, so as to obtain the critical carrying flow rate of different coal powder particles. The conclusions are as follows: For 40-60 mesh pulverized coal, it is easier to be carried and transported at a drainage speed of about 0.025 m / s. For 60-80 mesh pulverized coal, it will be carried and transported at a speed of about 0.015 m / s. For 100-200 mesh pulverized coal, it will be carried and transported at a speed of about 0.006 m / s.