Abstract: Waste water streams from an oil or gas recovery or refinery operation contaminated with a metal such as a heavy metal (e.g. mercury) can be treated with a protein including chordin and chordin-like proteins so that ion bonding the protein with the metal occurs to give a metal protein complex. The metal protein complex is then removed from the aqueous stream by a process such as flocculation and/or filtration.

Abstract: An additive comprising tris (2-carboxyethyl) phosphine (“TCEP”) and/or tris (3-hyroxypropyl) phosphine (“THPP”) may be added to an aqueous system in an effective amount to inhibit corrosion of the metallurgy within the aqueous system, wherein the additive may be in the form of a solution and maintains its stability and effectiveness in inhibiting corrosion in a wide range of temperature, pressure, and pH conditions of the aqueous system.

Abstract: This disclosure provides a method for scavenging hydrogen sulfide (H2S) from a fluid containing H2S and metal ions by introducing into the fluid at least one metal chelant in an amount effective to chelate metal ions in the fluid to form at least one metal-chelate complex; and removing at least a portion of the H2S from the fluid with an effective amount of the at least one metal-chelate complex. The method may further comprise the step of introducing at least one enzyme having an ability to scavenge H2S into the fluid in an amount effective to scavenge H2S from the fluid, where the amount of the at least one metal-chelate complex is effective to influence the ability of the at least one enzyme to scavenge H2S.

Abstract: A method of reducing an amount of a sulfur-containing compound in a reservoir fluid includes contacting a treatment fluid comprising an aqueous medium and an enzymatic scavenger with a precipitating fluid to precipitate the enzymatic scavenger; contacting the precipitated enzymatic scavenger with the reservoir fluid comprising the sulfur-containing compound; and reducing a number of the sulfur-containing compound in the reservoir fluid.

Abstract: A method of reducing an amount of a sulfur-containing compound in a reservoir fluid includes contacting a treatment fluid comprising an aqueous medium and an enzymatic scavenger with a precipitating fluid to precipitate the enzymatic scavenger; contacting the precipitated enzymatic scavenger with the reservoir fluid comprising the sulfur-containing compound; and reducing a number of the sulfur-containing compound in the reservoir fluid.

Abstract: A method of reducing an amount of a sulfur-containing compound in a base fluid comprises contacting the base fluid comprising the sulfur-containing compound with a treatment composite, the treatment composite comprising an enzymatic scavenger which is encapsulated by a encapsulating material, or disposed in a matrix, a container, or a combination thereof; releasing the enzymatic scavenger from the treatment composite; and reducing a number of the sulfur-containing compound in the fluid.

Abstract: Cysteine synthase enzymes (e.g. O-Acetyl-L-Serine Sulfhydrylase enzymes) may be used in combination with sulfide quinone reductase enzymes in additive compositions, fluid compositions, and methods for decreasing or removing hydrogen sulfide from recovered downhole fluids and/or the subterranean reservoir wellbore from which the downhole fluid was recovered. The fluid composition may include at least one cysteine synthase enzyme with at least one sulfide quinone reductase, and a base fluid, such as a water-based fluid, an organic-based fluid, and combinations thereof.