Spontaneous imbibition in coal with in-situ dynamic micro-CT imaging

The gas/fluid flowing behavior and fluid distribution under capillary forces in porous media are essential for evaluating the pore-fracture characteristics of coal. Capillary force is crucial flow-back efficiency after hydraulic fracturing during enhanced coalbed methane (CBM) production. In this work, situ dynamic X-ray micro-computed tomography (X-ray ?-CT), field emission scanning electron microscopy (FE-SEM) combined with mercury intrusion porosimetry (MIP) were used on two coal samples different wettability to explore spontaneous imbibition. results show that both mineral content could affect imbibition coal, which former has played a major role. process can be divided into 4 stages reveal flow by at time steps. gas relative permeability attenuates exponentially result based fractal theory (the reduces its value from 0.72 mD 0.01 WD, 0.5 0.08 WZX). A low rate would lead severe damage. longer return drainage time, more • IEffect was studied. Spontaneous four studying change water force.