Innovative Engineering Vessel Internal Electrostatic Coalescer ( VIEC ) Novel oil-water separation technology (original) (raw)

In offshore oil production, the well output is a mixture of oil, gas and water. Gas is released as pressure decreases along process stages but water-oil separation, especially in high viscosity crude oils is much more difficult. Water droplets are dispersed forming water-oil emulsions which can be extremely stable due to surface-active molecules and particles attaching themselves to the water-oil interface. Typically, a multi-stage separation process is employed and the first stage separation vessel is one of the largest pieces of equipment on the platform. In many cases, to achieve a separator output with 5-10 % water is time consuming and requires an injection of chemical demulsifiers. ABB has significantly improved this process by successfully employing what is known as the electrocoalescence technique to the first stage of the separation process. This has led to the development of a modular device known as a Vessel Internal Electrostatic Coalescer (VIEC). The VIEC has reduced the troublesome emulsion layer in the first stage separator and has also reduced the required injection of demulsifier from 10 to 2 ppmv.