Pulverized coal-controlling method based on supermolecular film in CBM well

Aiming at the problem of stuck pump induced by coal dust blocking in CBM well, this paper proposes a method of coal dust control in CBM well by using the three-dimensional space network structure formed by supermolecular film(SMF) to prevent the transport of large coal particles. The laboratory experiment of SMF pulverized coal control effect was carried out with No.3 coal in Qinshui basin as the object. The experimental results showed that the supermolecular film could effectively adsorb pulverized coal into smaller pulverized coal groups and settle them to achieve the purpose of pulverized coal control. There exists reasonable dosage of supermolecular films corresponding to different pulverized coal mass fraction. When the pulverized coal mass fraction is 1%-10%, the volume fraction of agent A in SMF is 5%-15%, the dosage ratio of mixture with pulverized coal is 15:1-4:1, the volume fraction of agent B in SMF is 6%-9%, and the dosage ratio of agent A is 1:1-3:1. When the pulverized coal is piled up too much, the acidic gelling agent is added to break the ring network structure, so that the pulverized coal can recover the centralized discharge of individual particles. This method is easy to operate and can be carried out regularly. It is a kind of pulverized coal control technology which theoretically can greatly extend the CBM well inspection pump cycle by more than 10 times.