Water-Gas Imbibition Relative Permeability: Literature Review, Direct versus Indirect Methods and Experimental Recommendations

When an active aquifer encroaches into a gas bearing reservoir or when oil rim sweeps during late depletion of the cap, displacement by liquid is important for estimating recovery. In water displacing condition, viscosity ratio extremely favorable, resulting in sharp waterfront matrix: it results that changing relative permeability Kr shape has negligible effect, while endpoints Krw Max and residual saturation Sgr are much more to understand flow performance estimation recovery with productivity decline after breakthrough. Three main methods used determine water/gas curves: imbibition unsteady-state, steady-state indirect approaches such as co-current spontaneous if transient data available. One other popular called Brooks-Corey approach: measuring drainage Pc curve using centrifuge porous plate methods, possible calculate pore size distribution index c. This coefficient model curve. It also required measure relationship between initial Sgi relationship. Finally, accepted there no hysteresis on curve, always wetting phase gas/water couple. As non-wetting phase, exhibits strong therefore necessary apply correction Krg build one correcting models. The aim this paper compare clastic rocks direct waterflooding information approach model. shown leads like those experimentally obtained. Also, additional numerical simulations proposed discuss relevance entire water-gas approach.