A composition for inhibiting corrosion in gas wells includes a pyrazolopyridine derivative. The pyrazolopyridine derivative includes a pyridyl moiety, a first pyrazole moiety, a second pyrazole moiety, and a phenyl moiety. The first pyrazole moiety is bound to the pyridyl moiety. The second pyrazole moiety is bound to the pyridyl moiety. The phenyl moiety is bound to the pyridyl moiety. The composition can be flowed into a wellbore formed in a subterranean formation, thereby inhibiting corrosion in the wellbore.

A method is described for treating a subterranean formation penetrated by a wellbore including injecting into the formation a treatment fluid including a rheological modifier; at least one viscoelastic surfactant (VES) at a concentration of between about 0.1 and about 10 percent by weight; and a formation-dissolving agent selected from the group consisting of hydrochloric acid, formic acid, acetic acid, lactic acid, glycolic acid, sulfamic acid, malic acid, citric acid, tartaric acid, maleic acid, methylsulfamic acid, chloroacetic acid, aminopolycarboxylic acids, 3-hydroxypropionic acid, polyaminopolycarboxylic acids, salts thereof and mixtures of said acids and salts.

Disclosed are methods of preparing drilling fluid compositions containing treated calcium bentonite. One such method includes mixing calcium bentonite with an aqueous mixture containing soda ash, followed by adding starch to form the treated bentonite mixture that is used to prepare a drilling fluid composition. Another method includes mixing the calcium bentonite with an aqueous mixture containing soda ash and magnesium oxide, followed by adding starch to form the treated bentonite mixture that is used to prepare a drilling fluid composition.

An ecofriendly corrosion inhibitor composition and a method for inhibiting corrosion on a metal surface with the ecofriendly corrosion inhibitor composition are provided. The ecofriendly corrosion inhibitor composition includes 10-30 weight % of fatty acids derived from waste vegetable oils and 70-90 weight % of heavy aromatic naphtha. The fatty acids derived from waste vegetable oils include oleic acid, linoleic acid, and palmitic acid. In the method, the ecofriendly corrosion inhibitor composition is added to a hydrocarbon fluid exposed to the metal surface and the corrosion inhibitor composition inhibits corrosion on the metal surfaces.

Relatively low molecular weight, branched polyethyleneimine (B-PE), a specific class of polyamine, has been shown to be effective at inhibiting the formation metal naphthenate precipitate (MNP) in systems and fluids that include an organic phase and an aqueous phase where the system or fluid further contains metal ions and tetra acid, and in particular the addition of low molecular weight, B-PE molecules prevents the formation of metal naphthenate precipitates/deposits in the fluids. Inhibition of alkali earth metal naphthenates (e.g. calcium naphthenate) and alkali metal naphthenates (e.g. sodium naphthenate) are particular non-limiting embodiments.

A method of inhibiting corrosion of a metal surface in contact with geothermal system is provided. The method may include contacting the metal surface with a corrosion inhibitor composition by adding the composition to geothermal process water. The corrosion inhibitor composition may include an organic phosphonate, an ortho phosphate, and zinc or a salt thereof.

A method of inhibiting corrosion of metal during acid stimulation of an oil and gas well that involves treating the oil and gas well with an acidic treatment fluid that includes 10 to 28 wt. % of an acid, based on a total weight of the acidic treatment fluid, and a corrosion inhibitor composition containing gelatin, wherein the gelatin is present in the acidic treatment fluid in a concentration of 0.1 to 10% by weight per total volume of the acidic treatment fluid.

An inhibited hydrofluoric acid aqueous composition, said composition comprising: hydrofluoric acid in solution; and a weak base selected from the group consisting of: lysine, arginine, histidine, glutamine, asparagine, tryptophan, and tyrosine; wherein said weak base and hydrofluoric acid are present in a molar ratio of at least 1:1. Also disclosed is a mud acid using this inhibited acid composition.

A method of inhibiting corrosion of metal surfaces of piping, tubing, heat exchangers and other metal equipment during acid stimulation of an oil and gas well is provided. The method includes introduction of an acidic treatment fluid containing an inorganic acid and a corrosion inhibitor of formula I into the oil and gas well.

A completion/stimulation/production fluid and injection mixture blend is disclosed. The blend may include an aqueous fluid, a polymer system and an injection mixture that includes a polyol, a natural sugar, an artificial sugar, or a combination thereof.