Experimental Study of Authigenic Fines Detachment by Breakage

Detachment of authigenic reservoir fines by breakage with consequent migration in rock, straining, and permeability decline has been widely reported for several technological and natural processes. This phenomenon particularly calls for strong attention due to decline in well production and injection rates. This paper presents laboratory corefloods performed in a wide range of flow rates with monitoring of breakthrough fines concentrations and pressure drops across the overall core and its first section. The corefloods are accompanied by X-ray diffraction (XRD) analysis and optical microscopy imaging. The data are tuned with a mathematical model for fines migration, resulting in the quantification of particle detachment across the range of studied velocities. The variation of particle detachment over velocity shows two distinct regions of detachment supporting the hypothesis of two mechanisms of fines detachment by: (i) breakage due to particle deformation and induced stresses and (ii) viscous drag that exceeds the attaching electrostatic forces. This allows determining the attached concentrations separately for authigenic and detrital fines. The results have important implications for understanding the susceptibility of natural rocks to formation damage by fines migration as well as in designing prevention and remediation strategies.