摘要 |
The invention is a foam method for improving conformance during a steam flood or carbon dioxide flood in an underground hydrocarbon formation penetrated by at least one injection well and at least one production well, which comprises injecting into an injection well about 0.05% to about 2% by weight aqueous surfactant solution, and then injecting into the injection well a flooding medium of steam or carbon dioxide, said surfactant solution comprising a surfactant having the formula R(C2H4O)nSO4 M+ where R is a lignin phenol produced by reducing lignin in the presence of a reducing agent of carbon monoxide or hydrogen at a temperature greater than about 200 DEG C. and a pressure greater than about 100 psi, n has an average value of about 2 to about 25, and M+ is an alkali metal or ammonium cation.
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