Multi-Phase (AC/DC) Electrostatic Treaters
Unmatched Oil Dehydration
OTSO Multi-Phase (AC/DC) Electrostatic Treaters are without question the most efficient option available for large scale crude oil dehydration. Our electrostatic treaters easily outperform all other methods available for both mechanical and conventional large scale oil dehydration. The effectiveness of these treaters allow smaller vessels to process large quantities of oil per day at lower operating temperatures with lower BS&W contaminant content.

Extreme Efficiency Through Rapid Coalescing
Our Multi-Phase Electrostatic Treaters are innovatively designed pressure vessels incorporating AC and DC electrical fields to enact rapid separation. These vessels are internally configured with electrical grids, firetubes and degassing section, a spillover box and coalescing section containing metered orifice distributors.
As crude oil emulsion enters the vessel, it flows down over the hood baffle where water immediately separates. This occurs without heating the water, thereby increasing overall heating efficiency and fuel consumption. In addition, the hood baffle also prevents firetube scaling by inhibiting free water from directly contacting the firetube.
As oil and emulsion flow past the fire tube for heating, large water droplets coalesce and separate, whereas the small water droplets flow past the firetube with the oil ultimately making their way to the coalescing section of the vessel. At this point, all remaining water is separated from the oil via the AC/DC electrostatic section of the vessel.
Split VOltage with Reliable AC Power Supply
Design Benefits
- Multi-Phase (AC/DC) Treaters use reliable AC Power Supply / Transformer to distribute twice the AC field voltage.
- The DC field’s polarity allows water droplet response time as they travel between electrodes.
- Upon electrode plate contact, water droplets are equally charged with the same high voltage static charge as the electrode plate.
- The DC field forces water droplets to collide and become large enough for gravity to overcome the DC field. When this happens, the water suspended between the plates and water simply falls into the water section of the vessel.
Operating Advantages
Multi-Phase for High Viscosities & Low Operating Temp for Reduced Fuel Consumption
OTSO’s Multi-Phase (AC/DC) Electrostatic Treater is designed for efficiency, operating at temperatures of 15+ºF lower than standard designed electrostatic treaters and operating approximately 60+ºF cooler than conventional heater treaters.
Our Multi-Phase Electrostatic design allows for the processing of high viscosities at lower temperatures while providing superior dehydration that traditional units. This unique combination offers our clients considerable fuel cost savings, regardless of the crude oil’ gravity.
For example, API gravity crude at 32.5ºF at 10,000 bopd and 1,000 bwpd, the OTSO Multi-Phase Electrostatic Treater (MPET) is designed to treat crude oil emulsion at 15°F reduction in temperature. This provides an optimum return from reduced fuel as well as minimum chemical use, while at the same time ensuring minimum gravity volume losses through the process. This yields a saving of 1.1MM / btu/hr, at 60% heat transfer, resulting in a fuel consumption saving of over 46,000 scf/day.
Additional advantages of Multi-Phase and low operating temperatures are seen through less vaporization which equates to increased hydrocarbon capture. OTSO’s Multi-Phase Electrostatic Treater will decrease vapor loss by 0.25%, at 10,000 bpd, that’s an additional 25 bpd.
High Throughput Rates = Smaller Footprint
Operating Benefits
- Increased Crude Sales
- Lower Fuel Consumption
- Process Higher Gravity Crude
- Lowers Chemical Usage
- Increased Gas Btu Content Control
- Lower BS&W Cuts
- Products sold, not stored
- Reduces Crude Inventory within Treater
- Rapid Upset Recover