**7.2 Fines migration**

Fine particle migration is a major cause of fracture aperture blocking yet a very difficult phenomenon to study. Muggli et al. [110] introduced a simple, time saving experimental method to assess particle migration potential for different fracturing fluid compositions. They premised their method on the fact that behaviour of fine particles in the subsurface is a function of fracturing fluid composition. In their method, turbidity, capillary suction time behaviour and particle size distribution relative to the time and depth of particles are observed and recorded. Results from observations are then used to draw conclusions on the potential of particle migration and pore throat blocking. They tested their method using Eagle Ford Brine with and without additives. Low turbidity and capillary suction time were observed for brine without additives whiles higher values were recorded when additives were used. They explained that high turbidity was due to the inhibition of flocculation caused by the additives. Low capillary suction times therefore, may not always be desirable. In conclusion, they indicated that this experiment can be repeated using other fracturing fluid compositions to determine their impact on migration of fines.
