Experimental investigation on the impact of coal fines generation and migration on coal permeability

摘要: Abstract Measurements of the coal fines production and impact these on permeability two coals from Bowen Basin, Australia, were performed at different flow conditions (single-phase water or gas, two-phase gas) pressure conditions. The collected each samples ranged in size 1 μm to 14 μm. For both samples, during first 50 h, decreases 0.005 mD 0.048 by 60.9% 85%, respectively, followed gradual decline with fluctuations. By end injection, drops 88% 89%, respectively. This phenomenon is attributed counteraction between formation damage (cleats plugging settlement) breakthrough (widened cleats). It was found that volumetric proportional third power velocity once paths for are established. critical velocities also obtained. hydrophobic coal, water-drive-gas introduces abrupt loss due generation migration. Furthermore, pauses (well shut-in) experiments cause slight drops. A comparison indicates narrower less connected cleating system results more frequent migration, resulting significant fluctuations general decreasing trend. Tortuosity cleats can enhance deterioration behaviours. study delivers fundamental understandings migration CSG process, useful guidelines suggested be implemented field minimize induced