Page 162 - Petroleum and Gas Field Processing

Figure 9 Three-phase free-water knockouts.

This is a destabilization process and is affected by using what is
called an ‘‘aid,’’ such chemicals and heat.
2. Coalescence: This involves the combination of water particles
that became free after breaking the emulsion, forming larger
drops. Coalescence is a strong function of time and is enhanced
by applying an electrostatic field, impingement on a solid surface
area, and water washing.
3. Gravitational settling and separation of water drops: The larger
water droplets resulting from the coalescence step will settle out
of the oil by gravity and be collected and removed.
Because these steps are in series, the slowest one is the most
controlling. Out of these, coalescence is the slowest step. In other words,

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