Characteristics and generation mechanisms of coal fines in coalbed methane wells in the southern Qinshui Basin, China

摘要: Abstract Coal fines produced in coalbed methane (CBM) wells from various geologic settings at different well production stages coal seam #3 the southern Qinshui Basin were investigated. Particle size measurements, micro-morphology and mineralogy using grain analysis, environmental scanning electronic microscopy (ESEM), X-ray diffraction (XRD), a transport experiment performed. By comparing compositions of underground mines drill cuttings, genetic types mechanisms CBM described, their significance to was discussed. The results indicate significant differences particle size, micro-morphology, mineralogy, type during wells. During water stage, are primarily by washing fracture surfaces with fracturing proppant. this relatively small have sheet flat block shapes because grinding Brittle minerals, such as quartz pyrite, major minerals these intermixing proppant preferential mineral enrichment pulverization; additionally, brittle content exceeds that raw factor five or more. gas consist originally crushed tectonic stress, generated between partings floor fault zone. formed shearing along via bed fragmentation rock folding. In case, large thick, shapes, suggesting not experienced strong after formation. Similar mostly brittle, although degree is low. Overall, characteristics determine total quantity, extent which they can be transported fluids. play an important role determining structure, development deposit, parameters management control.