RT Journal Article ID 4483fb307e680953 A1 Rostami, Behzad A1 Kharrat, Riyaz A1 Tabrizy, V. Alipour A1 Khosravi, M. A1 Ghotbi, C. T1 WETTABILITY EFFECTS IN GAS GRAVITY—ASSISTED FLOW AS RELATED TO DISPLACEMENT INSTABILITY JF Special Topics & Reviews in Porous Media: An International Journal JO STRPM YR 2010 FD 2010-03-05 VO 1 IS 1 SP 39 OP 47 K1 wettability K1 gravity forces K1 capillary forces K1 viscous forces K1 dimensionless numbers K1 displacement stability AB The drainage of oil under gravity forces is an efficient method because it can farther reduce the remaining oil saturation to below that obtained after water flooding. This paper describes a series of visual experiments under forced gas invasion with special attention to the effects of wettability. From oil production history and image analysis, we examine a threshold criterion for displacement stability that is consistent with the results of gradient percolation theory. The effect of the destabilized front velocity on oil recovery and residual saturation is investigated for both wettability conditions. Different recovery rates occur with different fluid morphologies, which depend on the matrix wettability and the balance between gravity and viscous and capillary forces. The dimensionless capillary and gravity numbers are used in analyzing the results. It has been shown that oil production decreases with displacement instability; however, this behavior would extremely depend on the wetting state. In addition, results indicated that the oil recovery depends linearly on the ratio of the gravity to viscous forces; however, the slope of this relationship in oil-wet porous media is more than twice of the water-wet system. PB Begell House LK https://www.dl.begellhouse.com/journals/3d21681c18f5b5e7,6f3839d03e388b44,4483fb307e680953.html