The subject invention provides multi-functional biochemical compositions, as well as their use in enhancing oil recovery from an oil-bearing subterranean formation. Advantageously, the compositions and methods of the subject invention are operationally-friendly, cost-effective, and environmentally-friendly. More specifically, in preferred embodiments, the subject invention provides a multi-functional composition for enhanced oil recovery (EOR) comprising one or more surfactants, one or more chelating agents, and one or more solvents.

The subject invention provides multi-functional biochemical compositions, as well as their use in enhancing oil recovery from an oil-bearing subterranean formation. Advantageously, the compositions and methods of the subject invention are operationally-friendly, cost-effective, and environmentally-friendly. More specifically, in preferred embodiments, the subject invention provides a multi-functional composition for enhanced oil recovery (EOR) comprising one or more surfactants, one or more chelating agents, and one or more solvents.

A polymeric surfactant for use in chemical enhanced oil recovery, including a terpolymer of a first non-ionic monomer, a second non-ionic monomer, and an ionic monomer, the first non-ionic monomer being a hydrophilic monomer and the second non-ionic monomer being a hydrophobic monomer, the ionic monomer being in a lower proportion than the first and second non-ionic monomers. A method of preparation of polymeric surfactants.

A polymeric surfactant for use in chemical enhanced oil recovery, including a terpolymer of a first non-ionic monomer, a second non-ionic monomer, and an ionic monomer, the first non-ionic monomer being a hydrophilic monomer and the second non-ionic monomer being a hydrophobic monomer, the ionic monomer being in a lower proportion than the first and second non-ionic monomers. A method of preparation of polymeric surfactants.

The subject invention provides compositions and methods for simultaneously enhancing oil recovery, improving the quality of oil and gas through reduction in sulfur-containing compounds, and preventing and/or reducing corrosion of oil and gas production equipment. A multi-functional composition is provided comprising an antimicrobial biosurfactant component, a first ammonium salt, and ammonium hydroxide. In some embodiments, the efficiency of the composition is further enhanced by the addition of a chelating agent, a phenol (e.g., carbolic acid or phenolic acid), and/or an H.sub.2S scavenger. In some embodiments, the composition is further enhanced for use in cold climates by the addition of an antifreeze mixture comprising one or more of a second ammonium salt, sodium chloride and glycerol.

The subject invention provides compositions and methods for simultaneously enhancing oil recovery, improving the quality of oil and gas through reduction in sulfur-containing compounds, and preventing and/or reducing corrosion of oil and gas production equipment. A multi-functional composition is provided comprising an antimicrobial biosurfactant component, a first ammonium salt, and ammonium hydroxide. In some embodiments, the efficiency of the composition is further enhanced by the addition of a chelating agent, a phenol (e.g., carbolic acid or phenolic acid), and/or an H.sub.2S scavenger. In some embodiments, the composition is further enhanced for use in cold climates by the addition of an antifreeze mixture comprising one or more of a second ammonium salt, sodium chloride and glycerol.

The present invention provides compositions and methods for enhancing oil recovery from low permeability subterranean formation using three mechanisms: repressurization; reduction of interfacial tension; and increased permeability. The subject compositions comprise a chelating agent, a biosurfactant, a carbonate or bicarbonate salt, water, and a pH adjusting substance, which when applied to an oil-bearing formation according to the methods of the subject invention, allow for controlled release of carbon dioxide within the formation without complicated machinery or gas-producing microorganisms.

The present invention provides compositions and methods for enhancing oil recovery from low permeability subterranean formation using three mechanisms: repressurization; reduction of interfacial tension; and increased permeability. The subject compositions comprise a chelating agent, a biosurfactant, a carbonate or bicarbonate salt, water, and a pH adjusting substance, which when applied to an oil-bearing formation according to the methods of the subject invention, allow for controlled release of carbon dioxide within the formation without complicated machinery or gas-producing microorganisms.

Compositions suitable for enhanced oil recovery comprising a) a mixture of α-sulfocarbonyl compounds of formulae (1) and (2) in a mixture ratio (1) to (2) of from 1:99 to 99:1 ##STR00001## wherein R.sub.1, R.sub.3 and R.sub.5, which may be the same or different at each occurrence, are hydrogen or a linear or branched alkyl chain having 1 to 20 carbon atoms, R.sub.2 and R.sub.4, which may be the same or different at each occurrence, may be a linear or branched alkyl group having 4 to 24 carbon atoms and in which the alkyl chain may comprise one or more cycloaliphatic groups, and X is H or a metal forming a salt with the sulfonate group, and b) a salt containing aqueous solution.

Compositions suitable for enhanced oil recovery comprising a) a mixture of α-sulfocarbonyl compounds of formulae (1) and (2) in a mixture ratio (1) to (2) of from 1:99 to 99:1 ##STR00001## wherein R.sub.1, R.sub.3 and R.sub.5, which may be the same or different at each occurrence, are hydrogen or a linear or branched alkyl chain having 1 to 20 carbon atoms, R.sub.2 and R.sub.4, which may be the same or different at each occurrence, may be a linear or branched alkyl group having 4 to 24 carbon atoms and in which the alkyl chain may comprise one or more cycloaliphatic groups, and X is H or a metal forming a salt with the sulfonate group, and b) a salt containing aqueous solution.