Well impairment by fines migration in gas fields

Well productivity decline has been widely observed for gas wells producing reservoir fines. The phenomenon has been explained by lifting, migration and subsequent plugging of the pores by the fine particles, finally resulting in permeability decrease. It has been observed in numerous core flood tests and field cases. The new basic equations for the detachment of fine particles, their migration and size exclusion, causing the rock permeability decline during gas production, have been derived. The analytical model developed for the regime of steady state gas production with a gradual accumulation of strained particles, exhibits linear skin factor growth versus the amount of produced reservoir fines. The modelling results are in a good agreement with the well production history. (c) 2012 Elsevier B.V. All rights reserved.