Abstract:
A surfactant composition usable in the presence of from about 500 to about 5,000 parts per million polyvalent ion concentrations, such as calcium and/or magnesium, comprising a sulfated aliphatic anionic surfactant such as sodium tridecyl sulfate, a water soluble guanidine salt such as guanidine hydrochloride, and a nonionic surfactant such as polyethoxylated aliphatic alcohol.
Abstract:
Bitumen may be efficiently and economically extracted from tar sand deposits in situ by imbibition flooding. The imbibition flooding is performed in two general steps. First, the tar sand deposits are contacted with a bitumen solvent followed by a soak period to allow imbibition of the solvent. Next, the tar sands are contacted with an aqueous fluid followed by a soak period to allow imbibition. The freed bitumen is then produced by conventional means.
Abstract:
A method for recovering heavy oils and tar sand oils which involves first improving the reservoir permeability without fracturing the reservoir and subsequently flooding the reservoir with hot water or steam. The permeability is improved by establishing some permeability using water injection followed by flooding with an aqueous fluid containing chemical additives which will spontaneously emulsify the oil.
Abstract:
At the conclusion of a secondary recovery operation after breakthrough of the driving fluid at the production wells, additional injection wells are located between the original injection well and the production well(s), this region usually having a high oil saturation after the drive.
Abstract:
An aqueous solution comprising an alkalinity agent such as sodium hydroxide, a water soluble guanidine salt such as guanidine hydrochloride and an anionic surfactant such as an aliphatic sulfate, specifically dodecyl sulfate or cetyl sulfate, or a water soluble salt of an unsaturated aliphatic monobasic carboxylic acid, such as sodium oleate, is injected into a subterranean petroleum containing formation, followed by the injection of water to displace a surfactant-guanidine solution through the formation. A plurality of benefits result from the use of this combination, including increased injection solution viscosity for mobility ratio improvement, inhibition of clay swelling which causes formation permeability damage, and improved salt tolerance of the surfactant solution so that surfactantemulsion flooding may be carried out in subterranean petroleum containing formations whose formation water salinity is as high as 4 percent.
Abstract:
A method of recovering hydrocarbons from a subterranean hydrocarbon-bearing formation wherein a mixture of steam and a minor amount of an interfacial tension reducer, such as quinoline, etc. is introduced into the formation and oil displaced through the formation is recovered through a production well. Preferably, the formation is heated prior to the introduction of the steam-interfacial tension reducer mixture.