Whether expanding, upgrading, or constructing a new facility, Schlumberger advanced process technology is the solution to your difficult treating needs. The NATCO DUAL FREQUENCY electrostatic treater, used as a dehydrator and desalter in upstream crude oil processes, employs both AC and DC power to. Abstract Electrostatic treaters have been used at various Shell fields to dehydrate light, medium, and heavy crudes. The performance and operating envelope of.
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If they fail to function properly, the burners could remain off or on all the time.
Electrostatic Treater Operation | SCIENCE PARK
Help to improve this page What’s this? This arrangement utilizes one dump valve and level controller to maintain water ievels in the treater. The electrostatic grid polarizes the conductive water molecules treatef forcing them to coalesce into larger particles and settle out of the crude. Several things happen as emulsion moves upward across the firetubes. Generally, dispersed droplets approximately 2 to 3 drop diameters apart tend to coalesce. The inlet and surge sections are treatter at a slightly higher pressure than the treating section.
Usually less chemical is required to treat teeater warm emulsion. The produced fluids enter the treater and any gas is vented. However, the savings in chemical with higher temperatures may be offset by the loss of revenue caused by gravity and volume losses in the oil and increased fuel costs.
treaer From the spreader emulsion rises upward toward the high-voltage, alternating-current, electrical grids. An oil-water emulsion enters the treater flowing through an integral inlet heat exchan- ger where it is preheated thereby reducing the thermal load on the firetube and reducing fuel gas consumption.
Recommended steps for safely lighting a gas-fired electrostatic treater.
The operational success is not fully realized since in most cases the electric grids have been either switched off or short circuited. The performance and operating envelope of electrostatic dehydration have been demonstrated through pilot tests and field demonstrations.
NATCO DUAL POLARITY Electrostatic Treater
The firetube is protected by a heat shroud to ensure that no free-water comes into contact with it, thereby reducing fouling and ex- tending the firetube life. For smooth operation, the following maintenance checks should be performed as indicated:.
If used, incoming emulsion is preheated by the heat of outgoing oil. Therefore, the firetubes need to provide less heat. The two grids are suspended one above the other in the treating section. If the electrical forces are higher than gravitational forces, settling of the water drops will be hindered.
Both water dump valves operate by means of Interface level controllers which use gas or compressed air to open and close eelctrostatic dump valves. Both grids are suspended from the top of the vessel shell by insulated hanger rods.
Some treaters use an electrode section.
Most elechrostatic treaters have a reac-tance type transformer which has a reactor to protect the transformer from power surges and high voltage dispersion. By trial and error after installation, the electric grids may be able to allow treating to occur at lower temperatures.
Electrostatic treater – OilfieldWiki
Contact Us Subscribe to newsletter How to contribute? This makes them particularly attractive for desalting applications. Gas leaving at the top eelectrostatic the treater is controlled by a gas back-pressure valve which controls the pressure in the treater.
Free gas is released as emulsion strikes the hood or down-comer and rises to the top of the inlet section. A yellow flame with just enough air to keep from forming soot is best. Since coalescence of droplets in an electric field is so dependent on the characteristics of the particular emulsion to be treated, it is unlikely that a general relationship of water droplet size to use in the settling equations can be developed.
Dehydration of Crude Using Electrostatic Treaters: If they remain off, the emulsion may cool electrosttatic that it does not completely break up.
Generally, the voltage limits lie between 12 and 23 kV with elecrtostatic being inversely proportional to crude gravity and conductivity of the treated emulsion. The operating temperature of the electrostatic treater is normally lower than that of the heater treater. When heating is required, lower temperatures can be used in electrostatic treaters than in conventional heater treaters.
Electrostatic Treaters Process
elextrostatic Development of Design and Operating Guidelines. Electrostatic treating begins below the lower grid and is completed between the upper and lower grids where water droplets coalesce and settle out. The lower grid is charged with 15, 20, volts of electricity while the upper grid is grounded. Alternating current on the lower electrical grid GRIDS causes it to reverse polarity change from positive to negative times per second or 60 cycles per second.
When there is not enough entrained gas in the incoming fluid to maintain necessary pressure, a make-up gas line is usually connected to the gas equalizer. Electrostatic dehydration occurs due to the stretching and oscillation of the water droplets induced by the dipole state in electrical field.
When the interface returns to its pre-set level, the level controller vents the gas or compressed air and allows the diaphragm to seat, closing the dump valve.