Methods of increasing amount of pressure-relief gas of protective layer

According to gas radial flow theory and energy conservation law, gas drainage model and flow network using surface drilling were established, and method of increasing amount of pressure-relief gas of protective layer by increasing resistance of the bottom of the wellbore was proposed. The engineering application results show that by increasing the flow resistance of the bottom of the wellbore, the amount of pressure-relief gas of protective layer can be significantly increased.