WATERFLOODING WITH THICKENED SURFACTANT SOLUTION CONTAINING A SULFONATED POLYETHOXYLATED ALIPHATIC ALCOHOL

摘要

OIL RECOVERY BY WATERFLOODING WITHTHICKENED SURFACTANT SOLUTIONSAbstract of the DisclosureWaterflooding process for the recovery of oilfrom a subterranean formation in which at least a portionof the injected water is thickened by the addition of asulfonated polyethoxylated aliphatic alcohol surfactant.The thickened water has a salinity within the range of5-18 percent. The sulfonated polyethoxylated aliphaticalcohol has at least two ethylene oxide units to providean HLB within the range of 10.0-14.0 and the lipophilicbase contains from 16 to 20 carbon atoms. The thickenedsurfactant slug may be preceded by the injection of arelatively low viscosity surfactant slug and viscositygradation of the thickened surfactant slug may beaccomplished by varying the salinity and/or the concentrationof the sulfonated polyethoxylated aliphatic alcohol.-1-