Wole Olowu and Tim Oubre, Athlon, a Halliburton Service, USA, offer solutions to some unique desalter challenges that the company has helped refiners to overcome.
F
or many desalter challenges, there is a proven solution to mitigate the impact on a refinery’s performance and economics. Whilst troubleshooting, companies’ operations teams are often taught the following: when you hear hoofbeats, think horses not zebras. However, once in a while there are zebras. This article details some of the most difficult situations that Athlon team members have encountered over the years, which may offer a solution to the reader’s unusual desalter challenges.
emulsion between the two phases. In Figure 1, clean water is seen at the 3 ft and 2 ft, 6 in. try-lines, but the desalter effluent from the bottom of the vessel shows 10% oil. In this example, the plant assumed (and had been told by the chemical supplier) that there was heavy oil and/or asphaltenes in the brine. A sample and extraction of the oil in the effluent with heptane revealed that the oil was heptane soluble, which eliminated asphaltenes as the culprit. Somehow, oil was transferring through the water phase to the effluent.
Case one: three phases in a desalter
A skin temperature profile was conducted on the vessel, using corrosion inspection ports on the insulation. Skin temperature vs desalter oil temperature suggested significant mud buildup. A continuous bleed of the two bottom try-lines for approximately 30 minutes eventually
Challenge
It is very unusual for a desalter to have three phases. Usually, there are only two – oil and water, with an
Solution
HYDROCARBON 37
ENGINEERING
March 2022
