The Significance Of Permeability And Wettability Contrasts On Near Wellbore Flow Patterns Creating Formation Damage Effects

Abstract

The majority of hydrocarbon reservoirs are heterogeneous and any geological model that is unable to represent these heterogeneities will not capture the correct displacement physics. In particular, difficulties are encountered in the near wellbore area because these heterogeneities significantly affect fluid flow displacement patterns. If the physics of flow in the near wellbore region is understood and if this physics is then honoured in a simulator, the predictions should be valid. This paper aims to improve the understanding of near wellbore flow in hydrocarbon reservoirs by experimental demonstration of the differences in flow and displacement behaviour between heterogeneous and homogeneous porous media and then to model them by numerical simulation The heterogeneity under investigation is due to permeability and wettability differences with both miscible and immiscible flow. Capillary and viscous force differences ensure that the boundaries create flow distortions. The differences are very significant and their neglect in the past has led to many costly failures in well-bore stimulation. Experiments such as those reported here can suggest where and how the fluid will flow from the reservoir to the wellbore on production or into the formation when injecting fluids for well clean-up. Predictions by simulator could then be made for near wellbore damage so that remedial treatments can be developed