Low Pressure Mixing System for Desalting Hydrocarbons

A system for desalting hydrocarbons comprising:

• a crude oil stream;
• a water stream;
• a quill;
• a first, second, third and fourth mixing stage;
• a separator vessel located downstream of said fourth mixing stage;
• said separator vessel being selected from the group consisting of a dual frequency electrostatic separator vessel and a dual polarity electrostatic separator vessel;
• each said mixing stage being effective for increasing the homogeneity of a mixed oil/water stream;
• said first and third mixing stages including a static mixer and each being a lower pressure mixing stage relative to the second mixing stage;
• said second mixing stage providing a pressure increase effective for flowing the mixed oil/water stream through the third and fourth mixing stages;
• said fourth mixing stage including a mixing valve and being capable of providing increased mix energy relative to said third mixing stage.