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Chemical waterflooding techniques using complex surfactants

Patent ·
OSTI ID:7301217

A partial complex of an anionic surfactant with a moderate molecular weight amino-nitrogen-containing salt and/or an anionic surfactant plus a low-water solubility N-substituted ammonium salt of an anionic surfactant are capable of enhanced oil recovery in an aqueous slug. The efficiency of a partially complexed system (sodium dodecylbenzene sulfonate and m-toluidine hydrochloride) is 0.9 with respect to the oil recovery capacity of Bryton petroleum sulfonate (molecular weight 430) plus sodium chlorides, as determined by thin layer chromatography. An aqueous slug of a second partially complexed system (mixtures of C/sub 12/-C/sub 15/ hydroformulation alcohol sulfates and aniline hydrochloride) was followed by a sodium chloride slug on a sand pack, reducing the residual oil to 3 percent PV. This surfactant solution is tolerant to at least 0.8M sodium chloride and 0.01M calcium chloride.

Assignee:
Shell Oil Co.
Patent Number(s):
US 3515214
OSTI ID:
7301217
Country of Publication:
United States
Language:
English