Application Description - Genesis ED1 Installation And Operating Manual

Signals are transmitted
from both ends of the
probe:
The 'top-down' signal
provides a clear view of
the oil layer.
Air
Oil
Emulsion
Water
The 'botttom-up' signal
provides a clear view of
the water level.
Two Signals
One transmitting for the
top-down measurement.
One transmitting for the
bottom-up measurement.
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2.2.2 Application Description

Hydrocarbon/water (two-phase) interface measurement is
prevalent in the Oil & Gas and Chemical (and other)
industries. The ability to separate dry (water-free) hydrocar-
bon upper fluid in the top of a vessel and clean (hydrocar-
bon-free) water from the bottom is fundamental to this
measurement.
Developments in TDR/GWR measurement have shown to
measure both levels quite accurately when the interface is
relatively clean and distinct. However, when a mixture of
HC/water, i.e. an emulsion (or rag layer) is present (thereby
no distinct impedance change), TDR/GWR based measure-
ments become less effective.
In that case, the application could actually become a four-
phase measurement:
• Total Level (top of hydrocarbon)
• Top of Emulsion (water in oil)
• Bottom of Emulsion (oil in water or water level)
• Sand (sediment)
Two common applications where multiphase detection is
very beneficial to customers are in Separators/Treaters and
Desalters. 3-Phase Separators are typically large horizontal
drums designed to separate raw hydrocarbon streams into
their individual components. The challenge is that interface
level measurement is a critical measurement which is often
relied upon to actuate a water "dump" valve to eliminate
unwanted water-bottoms from the vessel. Inaccurate mea-
surement of the oil, emulsion, or water levels can increase
settling times, can increase the use of Demulsifying chemi-
cals, reduce vessel throughput (capacity). All of which
adversely impact profitability as the emulsion layer along
the hydrocarbon/water interface can contaminate the hydro-
carbon with water (and vice versa). Accurate level control
ensures the hydrocarbon is "water-free"; and, the disposal
water doesn't carry much hydrocarbon requiring treatment
to be re-processed or disposed of. Furthermore, companies
spend millions of dollars each year to treat their waste water
to be hydrocarbon-free. This spending can be reduced with
more accurate separation/interface level control, reducing
the amount of processing and chemical use to ensure no
hydrocarbon and other materials remain in the water. All
said, the goal is to ensure that the oil goes where it needs to
without containing water, and that water goes where it
needs to without containing oil...all the while reducing the
use and cost of chemicals while maximizing throughput.
63-601 Genesis Models ED1 & ED2 Multiphase Detector