Feasibility study of super molecular film controlled coal powder in fracturing crack of coalbed methane well

Aiming at the problem of pulverized coal clogging in the fractures of coalbed methane wells, it is proposed to use super molecular film (SMF) to form a network structure in the cracks, induce the discharge of small particles of pulverized coal, prevent the migration of large particles of pulverized coal, and thus improve the permeability of cracks. The coal-fired powder test in the fracture of coalbed methane well was carried out with No. 3 coal in Qinshui Basin as a case study. The experimental results show that in the SMF, the concentration of A agent (mass fraction) is higher than 5%, and the concentration of B agent (mass fraction) is 2% to 9%, which can effectively control the coal powder agglomeration, and the coal powder mixture becomes clear. After SMF displacement, the core permeability is increased by three to six times. When the SMF combination concentration is moderate, the core permeability is increased by more than six times. In the core after displacement, the pulverized coal showed a distinct mass, and the liquid that was driven out was basically free of pulverized coal. And the damage rate of the liquid to the coal matrix is within 15%. It shows that the use of SMF can effectively improve the crack penetration rate after pulverized coal damage, and provides a new direction for the treatment of coal powder in the crack.