Formation damage during drilling and completion practices - a review

Abstract

A review of formation damage during drilling indicates that the mechanism of fluid filtration occur in 3 stages i.e. invasion by spurt loss: initial external and internal bridging and filter cake build up. The constituent of the filter cake build up. The constituent of the filter cake and its deposition mechanism crucially controls the extend of formation damage, but during drilling process continues erosion of the surface of the cake occur resulting in dynamic filtration. Fluid filtration onto the formation will causes particle plugging, clay swelling, scale deposition, water blocking, oil wetting or emulsion blocking. A formation damage research programme is drawnup to elucidate borehole filtration and the subsequent damage to the formation.