Plugging effects by GPM based two-phase flow in gas drainage fracture: A simulation study

Mine gas drainage is the key measure to control gas disasters. Fractures in coal seams often lead to the failure of gas drainage. In order to improve plugging effects in such fracture, in this paper, the distribution of the solid waste material particles-coal gangue and modified bentonite-xanthan mucus (MBXM) is proposed and is simulated by using three kinds of cracks flow-solid coupling model of EDEM-Fluent. The results show that when particle production and gangue particle-mucus (GPM) velocity rises, the distance between the grouting mouth and the bridge blinding also increases; The plugging time of horizontal fractures and expansion fractures increases with a rise in particle production and velocity. However, the plugging time of shrinkage fractures firstly increases and decreases later; In the process of vertically downward strata migration, vertical compression and horizontal movement pattern can be observed. The length of bridge blinding is much longer and the plugging effect is much better; The stress concentration zone between particles and rock layers occurs at the contact point, as well as between particles; the velocity and particle size distribution have the greatest impact on the bridge blinding position and time respectively. The application of GPM as gas sealing is not only scientifically reasonable, but also highly relevant from an environmental protection perspective. And it has strong potential in practical engineering applications.