Ferrous sulfide deposition is a significant oilfield problem that has not been studied extensively, partly because of the difficulty in studying it under the reducing conditions found in the oilfield, partly because of a perception that its formation can not be controlled using current technology, and partly because of a perception that it is easy to remove when it does form. The difficulties in studying it may be overcome with careful work, and the perceptions are not entirely accurate.

Ferrous sulfide is not a single entity; it exists in numerous solid forms. One of the determinants of the form taken by the solid is the oxidation-reduction potential of the system. This paper discusses precautions that need to be taken when conducting studies under reducing conditions.

The paper presents laboratory data obtained at defined oxidation-reduction potential and pH. It shows how the deposition of ferrous sulfides may be reduced significantly using chemicals at mg/L levels.

Keywords:
asphaltene remediation, ppm oxy2 200, ferrous sulfide solid formation, wax remediation, oxidation potential, ppm oxy 100, compound, spe 80260, iron sulfide, asphaltene inhibition
Subjects:
Production Chemistry, Metallurgy and Biology, Pipelines, Flowlines and Risers, Inhibition and remediation of hydrates, scale, paraffin / wax and asphaltene, Materials and corrosion, Well Integrity, Subsurface corrosion (tubing, casing, completion equipment, conductor)
Copyright 2003, Society of Petroleum Engineers
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