Combinations of a nitroprusside, such as sodium nitroprusside (SNP; Na.sub.2[Fe(CN).sub.5NO].2H.sub.2O) and a nitrate, are provided, together with methods for the combined use of the nitroprusside and the nitrate as metabolic inhibitors of microbial cultures. The microbial cultures may include sulfate reducing bacteria (SRB) in aqueous culture. This metabolic inhibition may for example be implemented in the presence of a hydrocarbon, for example in an oil reservoir or in oil field systems and facilities. When applied to an SRB culture in the presence of a hydrocarbon, the combination of the nitroprusside and the nitrate may accordingly be used to ameliorate the biological formation of sulfides, particularly hydrogen sulfide.

A synthetic caustic composition for use in oil & gas industry activities, said composition comprising: metal hydroxides; an amino acid; urea; a sodium silicate and water.

A synthetic caustic composition for use in oil & gas industry activities, said composition comprising: metal hydroxides; an amino acid; urea; a sodium silicate and water.

Methods for the use of zinc ammonium carbonate as a scavenger of sulfur-containing species encountered in oilfield operations are provided. In one embodiment, the methods include introducing a sulfide scavenging additive including zinc ammonium carbonate into at least a portion of a conduit through which a potential sulfur-containing fluid is flowing.

Methods for the use of zinc ammonium carbonate as a scavenger of sulfur-containing species encountered in oilfield operations are provided. In one embodiment, the methods include introducing a sulfide scavenging additive including zinc ammonium carbonate into at least a portion of a conduit through which a potential sulfur-containing fluid is flowing.

Fouling and/or asphaltene agglomeration (or flocculation) in midstream processes and transportation and in upstream transportation of a hydrocarbon oil is reduced by providing in the oil an additive combination including; (A) a polyalkenyl-substituted carboxylic acid or anhydride, and (B) a metal detergent system comprising a hydrocarbyl-substituted hydroxybenzoate metal salt or a hydrocarbyl-substituted sulfonate metal salt or a mixure of both salts or a complex thereof,
where the mass:mass ratio of (A) to (B) is in the range of 20:1 to 1:20 and the treat rate of the additive is in the range of 5 to 10000 ppm by mass.

Fouling and/or asphaltene agglomeration (or flocculation) in midstream processes and transportation and in upstream transportation of a hydrocarbon oil is reduced by providing in the oil an additive combination including; (A) a polyalkenyl-substituted carboxylic acid or anhydride, and (B) a metal detergent system comprising a hydrocarbyl-substituted hydroxybenzoate metal salt or a hydrocarbyl-substituted sulfonate metal salt or a mixure of both salts or a complex thereof,
where the mass:mass ratio of (A) to (B) is in the range of 20:1 to 1:20 and the treat rate of the additive is in the range of 5 to 10000 ppm by mass.

A method of correcting measurements of a chemical sensor used in an industrial facility. The method involves correcting for errors known to occur in the steady state and the dynamic state for specifically recognized situations. This method allows for correcting errors that occur due to deadtime, false zero measurements, and non-linear disturbances. The method combines automated measurement techniques and human know how to progressively learn and refine the accuracy of the corrections.

A method of correcting measurements of a chemical sensor used in an industrial facility. The method involves correcting for errors known to occur in the steady state and the dynamic state for specifically recognized situations. This method allows for correcting errors that occur due to deadtime, false zero measurements, and non-linear disturbances. The method combines automated measurement techniques and human know how to progressively learn and refine the accuracy of the corrections.

Methods and systems for converting inactive chemicals into active chemicals in-situ for treating oil and gas pipelines, other industrial systems, or sanitizing surfaces. Also, methods of treating an oil and gas pipeline including feeding an inactive additive through a first conduit and into a second conduit, the second conduit is in fluid communication with the first conduit and the oil and gas pipeline. The inactive additive is converted into an active additive within the second conduit and introduced into the oil and gas pipeline.