An acid treatment composition includes a nonionic surfactant, including nonyl phenol ethoxylate. The acid treatment composition also includes a retarding agent comprising magnesium, an acid, and water. The nonionic surfactant and retarding agent of the acid treatment composition are reactive with carbonate.

New formulation for pyrite scale removal from oil and gas wells and a method of pyrite scale removal are disclosed. The chemical formulation is composed of K.sub.2B.sub.4O.sub.7-4H.sub.2O, in a concentration of about 9-20 wt. % of the composition, preferably about 14 wt. % of the composition. The new formulation has the ability to dissolve pyrite without generation of the toxic H.sub.2S. Furthermore, the new formulation is cheaper and has very low corrosion rate compare to 15 wt. % HCl with corrosion inhibitor. The disclose method uses the disclosed new formulation to dissolve iron sulphide scale, performed at about 100-150° C. and about 500-2000 psi.

A method of drilling a subterranean geological formation is described. The method includes driving a drill bit to form a wellbore in the subterranean geological formation thereby producing a formation fluid including hydrogen sulfide. The method further includes injecting a drilling fluid into the subterranean geological formation through the wellbore. The drilling fluid includes an aqueous solvent, a hydrogen sulfide scavenger including particles of a manganese oxide supported on a porous support. The particles are suspended in the aqueous solvent. The method further includes reacting the hydrogen sulfide scavenger with the hydrogen sulfide present in the formation fluid to form a manganese sulfide.

Methods of acidizing a subterranean formation penetrated by a wellbore that include the steps of (a) injecting into the wellbore at a pressure below subterranean formation fracturing pressure a treatment fluid having a first viscosity and including an aqueous acid and a gelling agent selected from the group consisting of Formulas I-XI and combinations thereof; (b) forming at least one void in the subterranean formation with the treatment fluid; and (c) allowing the treatment fluid to attain a second viscosity that is greater than the first viscosity.

A method of reducing the viscosity of a crude oil, the method comprising adding to the crude oil (i) a surfactant compound including at least two hydrophobic groups wherein the resultant mixture has a water content of less than 10 vol %.

A biocide blend can be used in an oil or gas operation. The biocide blend can include a first biocide of a formaldehyde-releasing biocide and a second biocide of a quaternary ammonium compound. The formaldehyde-releasing biocide can release formaldehyde after introduction into a wellbore. The first and second biocide can possess at least one property that is the same. The first biocide and/or the second biocide can maintain biocidal activity for extended periods of time in high salinity wellbore fluids, be thermally stable, and less expensive than other biocides.

Methods for treating fluids used in the production and/or transport of petroleum products and natural gas, and methods for the removal of acidic gases encountered in fluids used and encountered in such operations are provided. In one embodiment, the methods include introducing a treatment fluid including a polymeric swellable acid scavenger that includes at least one polymeric composition into a wellbore penetrating at least a portion of a subterranean formation in which an acidic gas, an acid-containing fluid, or both, are present.

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.

Provided herein are compositions and methods for the controlled delivery of acid to a subterranean formation.

An additive composition for a well fluid and method of use. The additive composition is formulated to remove contaminates, such as hydrogen sulfide, asphaltenes, and paraffins from well fluids and improve well yield during oil and gas recovery and production operations. The additive composition is also used to clean and lubricate oil production equipment associated with the oil and gas recovery and production operations. A drip system may be used to introduce the additive composition into an oil well, tank, or pipe. Alternatively, a processing tool may be used to inject and circulate the additive composition into a tank to precipitate solid waste, heavy metals, and oil out of the well fluid