Scavenging chemicals used in mitigation treatments of hydrogen sulfide in hydrocarbon streams often continue to react and form polymers that foul the processing system. Disclosed herein are methods for determining if a scavenging chemical mitigator, or its reaction or degradation product, will polymerized during or after mitigation treatments. This information allows for the optimization of mitigation treatments that pre-emptively control or prevent polymer formation. Such pre-emption measures reduce the cost and time related to remedial actions to treat polymer-fouled equipment.

A method of demulsifying an emulsion with an ionic liquid having a nitrogen or phosphorus cation.

A method of demulsifying an emulsion with an ionic liquid having a nitrogen or phosphorus cation.

Metals, such as mercury, may be removed from glycol fluids by applying a sulfur compound having the general formula HS—X, wherein X is a heteroatom-substituted alkyl, cycloalkyl, aryl, and/or alkylaryl group either alone or in combination with or as a blend with at least one antifoam additive, at least one demulsifier and/or a buffering agent, to chelate the at least one metal and form a chelate complex of the sulfur compound with the at least one metal and then separating the chelate complex from the fluid.

Metals, such as mercury, may be removed from glycol fluids by applying a sulfur compound having the general formula HS—X, wherein X is a heteroatom-substituted alkyl, cycloalkyl, aryl, and/or alkylaryl group either alone or in combination with or as a blend with at least one antifoam additive, at least one demulsifier and/or a buffering agent, to chelate the at least one metal and form a chelate complex of the sulfur compound with the at least one metal and then separating the chelate complex from the fluid.

A scavenger comprising a formaldehyde sulfoxylate may be used to scavenge hydrogen sulfide (H.sub.2S) from systems that are brine or mixed production. Suitable formaldehyde sulfoxylates include, but are not necessarily limited to, sodium formaldehyde sulfoxylate, zinc formaldehyde sulfoxylate, and calcium formaldehyde sulfoxylate, potassium formaldehyde sulfoxylate, magnesium formaldehyde sulfoxylate, iron formaldehyde sulfoxylate, copper formaldehyde sulfoxylate, alkene aldehyde sulfoxylates, and combinations thereof.

A scavenger comprising a formaldehyde sulfoxylate may be used to scavenge hydrogen sulfide (H.sub.2S) from systems that are brine or mixed production. Suitable formaldehyde sulfoxylates include, but are not necessarily limited to, sodium formaldehyde sulfoxylate, zinc formaldehyde sulfoxylate, and calcium formaldehyde sulfoxylate, potassium formaldehyde sulfoxylate, magnesium formaldehyde sulfoxylate, iron formaldehyde sulfoxylate, copper formaldehyde sulfoxylate, alkene aldehyde sulfoxylates, and combinations thereof.

Metals, such as mercury, may be removed from aqueous, hydrocarbon, or mixed oilfield or refinery fluids by: applying a sulfur compound having the general formula HS—X, where X is a heteroatom substituted alkyl, cycloalkyl, aryl, and/or alkylaryl group either alone or in combination with or as a blend with at least one demulsifier, a buffering agent, a pour point depressant, and/or a water clarifier to chelate the at least one metal and form a chelate complex of the sulfur compound with the at least one metal and then separating the chelate complex from the fluid.

Metals, such as mercury, may be removed from aqueous, hydrocarbon, or mixed oilfield or refinery fluids by: applying a sulfur compound having the general formula HS—X, where X is a heteroatom substituted alkyl, cycloalkyl, aryl, and/or alkylaryl group either alone or in combination with or as a blend with at least one demulsifier, a buffering agent, a pour point depressant, and/or a water clarifier to chelate the at least one metal and form a chelate complex of the sulfur compound with the at least one metal and then separating the chelate complex from the fluid.

Methods for preventing elemental sulfur deposition from a hydrocarbon fluid is disclosed. A mercaptan is added to a hydrocarbon fluid that has elemental sulfur and reacted with the elemental sulfur to produce a disulfide and hydrogen sulfide. Amines and/or surfactants can assist with the process. Secondary reactions between the disulfide and the elemental sulfur result in a polysulfide and a solvated sulfur-disulfide complex. The disulfide, hydrogen sulfide, polysulfide and solvated sulfur-disulfide complex do not deposit, and can optionally be removed.