325-328<span style="font-size:11.0pt;line-height:115%;
font-family:" calibri","sans-serif";mso-ascii-theme-font:minor-latin;mso-fareast-font-family:="" "times="" new="" roman";mso-fareast-theme-font:minor-fareast;mso-hansi-theme-font:="" minor-latin;mso-bidi-font-family:"times="" roman";mso-ansi-language:en-us;="" mso-fareast-language:en-us;mso-bidi-language:ar-sa"="">An experimental
investigation has been carried out using surfactant solutions to displace Nubia
crude oil (October field).The effect of surfactant concentration and slug size
has been investigated. The effect of oil saturation at the start of surfactant
injection is also studied. The results indicate that the oil <span style="font-size:11.0pt;line-height:
115%;font-family:" calibri","sans-serif";mso-ascii-theme-font:minor-latin;="" mso-fareast-font-family:"times="" new="" roman";mso-fareast-theme-font:minor-fareast;="" mso-hansi-theme-font:minor-latin;mso-bidi-font-family:"times="" roman";="" mso-ansi-language:en-us;mso-fareast-language:en-us;mso-bidi-language:ar-sa"="">recovery
factor increases with increasing the oil saturation at the start of surfactant
injection. The maximum surfactant recover ability is obtained by a slug size of
10%of the pore volume with 5000ppm surfactant concentration. It is also found
that the oil recovery factor obtained by a small slug size with a high
surfactant concentration is higher than that resulted by a big slug size with a
lower surfactant concentration.</span