Prediction of Productivity Decline in Oil and Gas Wells Due to Fines Migration: Laboratory and Mathematical Modelling

Suspension-colloidal transport in porous media with the particle detachment usually exhibits a significant permeability decline. It occurs due to mobilisation and migration of detached colloidal or suspended fines with their straining in thin pores of the rock. Numerous laboratory coreflood tests show that the time for permeability stabilisation counts for hundreds of injected pore volumes, while the classical filtration theory assumes the released fines transport by the bulk of the carrier fluid yielding one pore volume injection to stabilise the permeability. In the current paper, the stabilisation delay effect is explained by slow drift of the mobilised fines near to pore walls. The basic flow equations for a single-phase particle transport in porous media with velocity lower than the carrier fluid velocity are proposed, and the analytical model for one dimensional flow with particle release and straining under the piece wise increasing velocity is derived. The laboratory data are in a good agreement with the results of mathematical modelling. The analytical model for well inflow performance is developed. It successfully matches several field cases.