Some naphthenic acids will not partition into the water phase and normally do not create a wastewater issue. In case of washwater and brine pH’s above 8.5 the naphthenic acids can form a soap, and this can cause severe emulsion formation and oil carry-under to the WTP.

The main influence is on level controllers, the most sensitive are the float type controllers but other instruments are also somewhat influenced by the crude Sulphur content.

The advantage is a reduction of freshwater use and sometimes a reduction in the load of contaminants(phenols) to the WTP. We have developed desalter washwater specs to prevent negative effects on desalter performance, fouling and corrosion. Oxygen, Ammonia, Hardness, TDS and Filterable are solids, the most obvious ones.

The main source seems to be crystalline salt. A relatively new method to determine total chlorides is the Chlora instrument, desaltable chlorides can be determined by the extraction method, and the difference is taken as un-desaltable chlorides.

For the operating company, what are your crude unit typical run lengths between shutdowns? What factors do you consider when setting this run cycle?

What are the advantages and disadvantages to constructing “modular" refining process units versus traditional "stick built" units? What are the issues with each construction approach?

Various methods exist to determine blend compatibility; one method would be a comparative asphaltene instability point determination via an anti-solvent titration, or another method used is the Wiehe insolubility number to solubility blend number method.

How does the mercury in crude distribute in your refinery (e.g., what units are affected)? What operating procedures or technology are you using to mitigate this issue?

Some laboratory simulation experience has demonstrated that there were no adverse impacts to processing crude oil treated with a certain pour point depressant relative to oil-water separation for desalting.

If Condensate or BFW is used as velocity media or to clear the heater tubes during a heater trip, precautions must be taken as excess free water has the potential to overpressure the heater during a shut-in condition.