A chelating agent can be used to enhance secondary hydrocarbon-fluid recovery during waterflooding operations. A composition can include a fluid and a chelating agent. The chelating agent can increase the viscosity of the fluid, which can enhance the efficacy of the waterflooding operations. The chelating agent can also form complexes with divalent cations in precipitates and solids formed by the divalent cations. The complexes can keep the cations in a soluble form until the composition exits the production well, which can prevent precipitates from forming in the production well and blocking pore throats in the production well.

The present invention relates to a composition comprising: at least one copolymer of which at least one of the repeating units comprises at least one amide function; and at least one polyether having a molecular weight (Mw) greater than 60 g.mol.sup.-1. The invention also relates to the use of said composition for delaying, or even preventing, the formation of gas hydrates, in particular in a method for extracting oil and/or gas and/or condensates, as well as to the method for delaying, or even preventing, the formation and/or agglomeration of gas hydrates, using a composition as defined above.

The present invention relates to a composition comprising: at least one copolymer of which at least one of the repeating units comprises at least one amide function; and at least one polyether having a molecular weight (Mw) greater than 60 g.mol.sup.-1. The invention also relates to the use of said composition for delaying, or even preventing, the formation of gas hydrates, in particular in a method for extracting oil and/or gas and/or condensates, as well as to the method for delaying, or even preventing, the formation and/or agglomeration of gas hydrates, using a composition as defined above.

A method is provided for inhibiting formation of a gas hydrate in a pipeline or removing a gas hydrate existing in a pipeline. The method can comprise injecting a foam composition into a fluid in the pipeline to inhibit formation of the gas hydrate in the pipeline, prevent gas hydrate formation in the pipeline, or remove the gas hydrate from the pipeline.

Disclosed are molybdenum-containing complexes used in compositions and methods for inhibiting or reducing the deposition of foulant on equipment.

Disclosed are molybdenum-containing complexes used in compositions and methods for inhibiting or reducing the deposition of foulant on equipment.

The disclosure is directed to a process for treating a subterranean earth formation by introducing a buffered acidizing treatment fluid comprising a monovalent salt of monochloroacetic acid and at least one acid into said subterranean earth formation, wherein the pH of the buffered acidizing treatment fluid is from about 1.2 to about 5. It also pertains to a buffered acidizing treatment fluid comprising a monovalent salt of monochloroacetic acid, at least one acid and optionally an element to suppress salt precipitation.

A composition for inhibiting corrosion in hydrocarbon wells includes a pyranopyrazole derivative. The pyranopyrazole derivative includes a pyrazole moiety, a dihydropyran moiety, and a phenyl moiety. The dihydropyran moiety is bound to the pyrazole moiety. The phenyl moiety is bound to the dihydropyran moiety. The composition can be flowed into a wellbore formed in a subterranean formation, thereby inhibiting corrosion in the wellbore.

A composition for inhibiting corrosion in hydrocarbon wells includes a pyranopyrazole derivative. The pyranopyrazole derivative includes a pyrazole moiety, a dihydropyran moiety, and a phenyl moiety. The dihydropyran moiety is bound to the pyrazole moiety. The phenyl moiety is bound to the dihydropyran moiety. The composition can be flowed into a wellbore formed in a subterranean formation, thereby inhibiting corrosion in the wellbore.

A corrosion inhibition package for use with an aqueous acid composition, said package comprising: a terpene; a cinnamaldehyde or a derivative thereof; at least one amphoteric surfactant; and a solvent. Also disclosed are compositions comprising said corrosion inhibitor package. Preferably, the corrosion inhibition package meets the environmental requirements for classification as yellow according to the Norwegian North Sea offshore drilling regulatory requirements.