Abstract: A post-primary oil recovery process wherein the subterranean oil-bearing formation is treated by the sequential injection of (1) optional aqueous preflush to adjust connate water salinity, (2) aqueous saline surfactant system containing at least one acylated polypeptide salt surfactant, (3) optional thickened aqueous mobility buffer and (4) an aqueous drive, for the recovery of oil driven from the formation thereby.

Abstract: Polymerization in-situ to effect permeability contrast correction in oil-bearing subterranean formations comprising the injection of at least one water-soluble monomer comprising N-3-oxohydrocarbon-substituted acrylamides, such as diacetone acrylamide, and optionally at least one water-soluble comonomer, such as alpha,beta-unsaturated amides, alpha,beta-unsaturated nitriles, vinyl-containing sulfonates and N-vinyl amides and polymerization initiator to cause polymerization and formation of water-insoluble polymers in high permeability zones.

Abstract: A post-primary oil recovery process wherein the subterranean oil-bearing formation is treated by the sequential injection of (1) optional aqueous preflush to adjust connate water salinity, (2) aqueous saline surfactant system containing at least one acylated polypeptide salt surfactant, (3) optional thickened aqueous mobility buffer and (4) an aqueous drive, for the recovery of oil driven from the formation thereby.

Abstract: A polymerflood oil recovery process comprising the use of low molecular weight polymers of alpha,beta-unsaturated mono- and dicarboxylic acids and alkali metal salts thereof in aqueous polymer slugs to stabilize the solution viscosity of said slugs throughout a polymerflooding process in which adverse subterranean conditions are encountered, such as high temperature, high salinity and/or high concentrations of "hardness" ions.

Abstract: In accordance with the present invention, oil is recovered from a subsurface earth formation by injecting into the subsurface formation an aqueous surfactant system containing a polyvalent metal carboxylate, as a surfactant, a cosurfactant and an electrolyte in concentrations and proportions to form multiphase system with the reservoir oil, thereafter, injecting into the earth formation a drive fluid to drive the multiphase system through the reservoir and displace a significant amount of the reservoir oil and withdrawing the thus displaced oil from the subsurface earth formation. A novel aqueous surfactant system, adapted to thus recover oil from a subsurface formation, comprises a polyvalent metal carboxylate, such as calcium isosteareate, as a surfactant, and an alcohol having at least five carbon atoms, as a cosurfactant, and an electrolyte, such as sodium chloride, in proportions which form a multiphase system with the reservoir oil.

Abstract: In accordance with the present invention it has been found that improved recovery of oil from a subsurface earth formation can be attained by injecting into the formation a surfactant system comprising a carboxylate surfactant, a cosurfactant and an electrolyte in concentrations and proportions to form an immiscible three-phase system with the reservoir oil comprising a predominantly oil phase, a microemulsion phase and an aqueous phase. The carboxylate surfactant is preferably selected from the group consisting of branched aliphatic carboxylates and mononuclear aromatic carboxylates. Where aliphatic carboxylates are utilized as a surfactant, it is preferred that the polar organic material utilized as a cosurfactant have a solubility in water less than about ten grams per hundred grams of water at about 20.degree. C.

Abstract: Enhanced oil recovery process comprising the injection of aqueous alkaline hypochlorite solution and aqueous alkaline alcohol solution into a subterranean formation to react with crude oil and form carboxylate surfactants in-situ. In a preferred embodiment, aqueous alkaline hypochlorite solution is followed by injection of an aqueous alcohol solution to form a carboxylate-alcohol surfactant system and then an aqueous mobility buffer.

Abstract: Enhanced oil recovery process comprising the injection of an aqueous solution of an aldehyde and a sulfite into a subterranean formation to react with crude oil and form a surfactant in situ. In a preferred embodiment, an aldehyde/sulfite solution is followed by injection of an aqueous alcohol solution and then an aqueous mobility buffer.

Abstract: In accordance with the present invention acidic materials, preferably naturally-occurring carboxylic acids from crude oils and acids formed by the oxidation of components of crude oils, are extracted from organic liquids containing the same by contacting the organic liquid with an aqueous polar organic solvent solution of potassium hydroxide. The polar organic solvents are preferably solvents selected from the group consisting of OH substituted hydrocarbons, SO substituted hydrocarbons, SO.sub.2 substituted hydrocarbons, NH.sub.2, NHR and NR.sub.2 substituted hydrocarbons, CONH.sub.2, CONHR and CONR.sub.2 substituted hydrocarbons and CN substituted hydrocarbons. The thus extracted acidic materials may be neutralized with an appropriate alkaline material to produce the corresponding salts thereof.

Abstract: This invention relates to a shelter construction including a roof section and vertically disposed legs for supporting the roof section. A vertical wall extends between the legs and advertising material or the like is retained by the wall. The legs combined with horizontal supports provide a border for the wall, and transparent panels are utilized for retaining advertising material between the panels and the wall. The roof is provided by means of sheets which extend substantially horizontally and then downwardly and inwardly to provide enclosures along the roof edges. These enclosures house additional advertising material, and lighting is utilized within the enclosure for enhancing the display.