Abstract: A chemical distribution device includes mixing manifold that receives well treatment chemicals and solvent that are to be mixed. A siphon is positioned within the mixing manifold to control the fluid level. The mixture is not delivered from the chemical distribution device until the fluid level of the mixture is above a crest of the siphon. The mixture is delivered in a batch to the well via a flowline until the fluid level of the mixture is below the inlet of the siphon.

Abstract: The instant invention pertains to a composition which may be useful for enhancing oil recovery. The composition typically comprises the reaction mixture of at least (a) two or more compounds capable of generating at least about 20 kcal to about 150 kcal per mole when contacted; (b) one or more suitable surfactants or one or more suitable polymers or a mixture thereof; and (c) oil. The invention also pertains to a method for enhancing oil recovery wherein a suitable system is injected through a wellbore into a reservoir to enhance mobility of oil.

Abstract: A method for preventing scale formation during an alkaline hydrocarbon recovery process is disclosed. An aqueous solution (e.g., recovered sea water, water produced from the subterranean reservoir, or a combination thereof) having a concentration of metal cations (e.g., calcium, magnesium) is provided. A stoichiometric amount of an organic complexing agent relative to the concentration of metal cations is introduced into the aqueous solution such that the organic complexing agent forms aqueous soluble cation-ligand complexes with the metal cations. At least one alkaline is introduced into the aqueous solution to form an injection fluid having a pH value of at least 10. The cation-ligand complexes remain soluble in the injection fluid such that scale formation is prevented when the injection fluid is injected into a subterranean reservoir.

Abstract: The instant invention pertains to a composition which may be useful for enhancing oil recovery. The composition typically comprises the reaction mixture of at least (a) two or more compounds capable of generating at least about 20 kcal to about 150 kcal per mole when contacted; (b) one or more suitable surfactants or one or more suitable polymers or a mixture thereof; and (c) oil. The invention also pertains to a method for enhancing oil recovery wherein a suitable system is injected through a wellbore into a reservoir to enhance mobility of oil.

Abstract: An apparatus, system and method for delivering a mixture of well treatment chemicals into a well are disclosed. A chemical distribution device includes mixing manifold that receives well treatment chemicals and solvent that are to be mixed. A siphon is positioned within the mixing manifold to control the fluid level. The mixture is not delivered from the chemical distribution device until the fluid level of the mixture is above a crest of the siphon. The mixture is delivered in a batch to the well via a flowline until the fluid level of the mixture is below the inlet of the siphon.

Abstract: The present invention is directed to an enhanced oil recovery formulation which comprises: (a) an alkylaromatic sulfonate; (b) an isomerized olefin sulfonate (c) a solvent; (d) a passivator; and (e) a polymer.

Abstract: A method for enhancing oil recovery includes the step of providing a subsurface reservoir containing hydrocarbons therewithin. A wellbore is provided in fluid communication with the subsurface reservoir. A surfactant-polymer solution is formed for injection into the reservoir. The surfactant-polymer solution is formed by mixing a composition with at least one surfactant, at least one polymer, and at least one co-solvent or co-surfactant such that the surfactant-polymer solution is clear and aqueous stable. The surfactant-polymer solution is injected through the wellbore into the reservoir. A chaser solution is formed for injection into the reservoir. The chaser solution has an additional predetermined quantity of the co-solvent or co-surfactant. The chaser solution is injected through the injection wellbore into the reservoir to increase the production of hydrocarbons from the reservoir while maintaining the clear and aqueous stability of the surfactant-polymer solution.

Abstract: A method for enhancing oil recovery includes the step of providing a subsurface reservoir containing hydrocarbons therewithin. A wellbore is provided in fluid communication with the subsurface reservoir. A surfactant-polymer solution is formed for injection into the reservoir. The surfactant-polymer solution is formed by mixing a composition with at least one surfactant, at least one polymer, and at least one co-solvent or co-surfactant such that the surfactant-polymer solution is clear and aqueous stable. The surfactant-polymer solution is injected through the wellbore into the reservoir. A chaser solution is formed for injection into the reservoir. The chaser solution has an additional predetermined quantity of the co-solvent or co-surfactant. The chaser solution is injected through the injection wellbore into the reservoir to increase the production of hydrocarbons from the reservoir while maintaining the clear and aqueous stability of the surfactant-polymer solution.

Abstract: The present invention is directed to an enhanced oil recovery formulation which comprises: (a) an alkylaromatic sulfonate; (b) an isomerized olefin sulfonate (c) a solvent; (d) a passivator; and (e) a polymer.

Abstract: A method for retaining a treatment chemical in a subterranean formation containing hydrocarbons is disclosed. The method includes first preparing an emulsion. The emulsion contains an oil continuous phase and first and second aqueous phases. The first aqueous phase includes a treatment chemical, such as a scale inhibitor. The second aqueous phase comprises a retention enhancing chemical which is to be reacted with the treatment chemical in the subterranean formation. Preferably, the first and second aqueous phases remain generally separately dispersed and stable within the oil continuous phase prior to being introduced into the subterranean formation. The emulsion is then placed down a well bore and into the subterranean formation.

Abstract: A method for retaining a treatment chemical in a subterranean formation containing hydrocarbons is disclosed. The method includes first preparing an emulsion. The emulsion contains an oil continuous phase and first and second aqueous phases. The first aqueous phase includes a treatment chemical, such as a scale inhibitor. The second aqueous phase comprises a retention enhancing chemical which is to be reacted with the treatment chemical in the subterranean formation. Preferably, the first and second aqueous phases remain generally separately dispersed and stable within the oil continuous phase prior to being introduced into the subterranean formation. The emulsion is then placed down a well bore and into the subterranean formation.

Abstract: A method for recovering surfactants from produced fluids by mixing with produced fluids about 0.1% to about 5% of a nonionic surfactant having a phase inversion temperature above the temperature of the produced fluids, heating the mixture above the phase inversion temperature, mixing the phase containing oil and the surfactants with water, and cooling the mixture below the phase inversion temperature to extract the surfactants into an aqueous phase, provided that if a sufficient concentration of the nonionic surfactant is already in the produced fluids, it need not be added.

Abstract: A method for improving the injectivity of an injection well for water or gas injection into an underground hydrocarbon formation which comprises injecting into the formation through an injection well a sufficient amount of a solvent-in-water microemulsion comprising about 0.5% to about 5% by weight of an alkoxylated linear alcohol having about 10 to about 16 carbon atoms in the linear alcohol moiety and an average of about 5 to about 12 alkoxylate groups, about 0.5% to about 5% by weight of an alkylbenzene sulfonate having an alkyl chain of about 8 to about 20 carbon atoms, about 1% to about 10% by weight of an ethylene glycol alkylether solvent, and water.

Abstract: The invention is a method of recovering heavy oil from an underground reservoir by surfactant flooding which comprises injecting an aqueous surfactant solution comprising about 0.1% to about 5% by weight of an alkoxylated nonionic or ionic surfactant through an injection well into an underground reservoir containing a heavy oil having an average API gravity below about 20.degree. and a reservoir temperature above about 150.degree. F., where the alkoxylated surfactant must have sufficient alkylene oxide groups comprised of ethylene oxide or propylene oxide to have a cloud point above about 100.degree. F. and below reservoir temperature, and to be water-soluble in the surfactant solution to be injected at a temperature below its cloud point, and have a sufficiently large hydrophobe to be soluble in the reservoir's heavy oil at a temperature equal to or greater than reservoir temperature.

Abstract: The disclosed invention is a method of injecting a solution or emulsion containing about 0.05% to about 10% by weight of urea as a sacrificial agent for surfactants into an underground formation in enhanced oil recovery operations, said underground formation having a temperature greater than about 130.degree. F.

Abstract: A method is disclosed for increasing the recovery of oil in enhanced oil recovery operations employing anionic surfactant by blending a taurine with said anionic surfactant. The taurine may also increase the salt and divalent ion tolerance of the anionic surfactant.

Abstract: The invention is a method for recovering hydrocarbons from an underground hydrocarbon reservoir penetrated by at least one injection well and at least one production well, which comprises injecting into the reservoir through an injection well an aqueous caustic solution comprising greater than 0.1% and less than 1.0% lignosulfonate by weight to shift the optimal salinity for enhanced oil recovery of the caustic solution to a relatively higher salinity, and producing hydrocarbons and other fluids through a production well.

Abstract: The invention extracts surfactants from produced emulsions of oil, water and surfactants from enhanced oil recovery operations and concentrates the surfactants into an aqueous solution. The produced emulsion is mixed with an alkali metal chloride salt, and butanol or pentanol, and allowed to separate into two phases, an oleic phase and an aqueous phase. The oleic phase is then mixed with fresh water containing about 1% to about 10% by weight of isopropanol, ethanol or methanol, and the mixture is allowed to separate into at least two phases, a substantially water-free and surfactant-free crude oil phase and an aqueous phase containing virtually all of the enhanced oil recovery surfactants originally within the produced emulsion. The surfactants in the aqueous phase may be reutilized for further enhanced oil recovery operations.