Determination of water saturation parameters in a complex carbonate reservoir

in petrophysical evaluation , water saturation is calculated from reservoir rock electrical resistivity which by itself is a function of rock water saturation, porosity , and distribution and connetivity of pore space in the rock. The pore space distribution manner is expressed in archie equation through cementation factor(m) and saturation exponent (n) parameters. the study field is one of the very complex carbonate fields in which various types of vuggy and inter -granular porosities exist. this variety causes the pore spaces distrubution and consequently water saturation calculation parameters complexity in the reservoir. by classification of core data based on the geological layers the dispersal of water saturation parameters is reduced to some externt. in ordre to improve the water saturation calculation parameters , core data were classified based on the lithology that resulted in a decrease in core data dispersion. on this basis the dolomitic and anhydratic samples possess constant water saturation parameters while the cementation factor in calcite samples is rather variant and a function of rock porosity .

کلیدواژه ها:

petrophysical evaluation ، water saturation ، cementation factor ، saturation exponent ، electrofacies