New compounds have demonstrated effective scavenging of hydrogen sulfide with potential for preventing deposition of metal sulfides. These compounds come from a variety of functional families and compete against typical scavenging technology well with respect to molar efficiency, reaction rate, and stability. These inhibitors not only work on existing sulfide but some can also be modified to change the oxidation state of the system to provide a non-scaling scenario.

The presence of hydrogen sulfide is an ever increasing problem in the oilfield, whether the origin is biological or formation dependant. The presence of extremely toxic hydrogen sulfide increases the corrosion rates of many metals and makes necessary the sweetening of produced hydrocarbon. If solubilized metals such as iron, lead or zinc are present in the fluid, the deposition of sulfides may occur as flow restrictive scale on the tubulars, leading to corrosion and/or biofilm augmentation or formation damaging fine particulate in the pay zone.

These single component inhibitors were tested in standard synthetic formation waters which were either sulfide laden and/or metal or sulfide laden. Waters derived were standard unadulterated species at various pHs or were acidified and then spent on carbonate. The rate of sulfide uptake was monitored and the soluble metal ions were determined. Response surfaces were generated for a few key inhibitors and the performance of the inhibitors was compared to standard inhibitors. Stability was also checked to ensure insoluble or reversible scavenging species were measured.

The use of these scavengers for drilling, stimulation, completion, and produced fluids provides the service company and/or operator with a viable treatment for problems incurred when treating sour reservoirs.

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