Method for recovering high asphaltene content petroleum using surfactants
AssigneeTexaco Inc.
InventorsJoseph T. Carlin, Ricardo L. Cardenas
Life of this patent
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Abstract
Surfactant flooding is frequently ineffective for recovering highly asphaltic petroleum because the asphaltic constituents of the petroleum have a strong affinity for the mineral surfaces such as sand grains present in the subterranean formation, and so are inefficiently displaced by passage of a surfactant containing solution through the pore spaces of the formation. Surfactant flooding is effective for asphaltic crudes if an effective solvent for the asphaltic petroleum which has a moderate water solubility is included in the preflush solution which preceded the surfactant solution or in the surfactant solution itself. Effective materials include quinoline and crude coal tar bases which contain substantial amounts of quinoline.
Claims12
A method of recovering asphaltic petroleum from a subterranean formation wherein an aqueous surfactant solution is injected into the formation, the improvement for increasing the oil recovery efficiency which comprises,
- contacting the asphaltic petroleum prior to injecting the surfactant solution or simultaneously therewith with an aqueous solution containing a solvent for petroleum which has a solubility of from about 0.01 to about 10% by weight in fresh water at 75.degree.F., and which has a solubility in the asphaltic petroleum substantially greater than the solubility in water.
Dependencies are inferred from the claim text.