Oil Treating Equipment

How it works

The wellstream mixture of oil, emulsion, water, and gas enter the gas separation section at the top of the treater. The inlet diverter deflects the liquid outward against the treater shell and causes it to spread in a thin film so both free gas and solution gas are released quickly. The oil, water, and emulsion are collected on the diaphragm plate and they then flow through the downcomer pipe to the spreader underneath the firebox. The free-water immediately separates from the oil and is discharged from the treater bottom section through the outside adjustable siphon.

The oil and emulsion is broken into small streamlets by the perforated tray spreader and moves up through the hot water section surrounding the firebox. This action breaks the larger part of the emulsion. The water released settles to the bottom of the treater where it is discharged with the free water. The final traces of water are separated by gravity in the quiet settling section. The treated oil exits the treater through the oil outlet at the top of the settling section and passes through the oil valve to the storage tank.

Warm vapors from the settling section enter the gas separation section through the equalizer pipe and mix with the cool inlet wellstream gas. This causes condensation of valuable heavier fractions in the gas which are recovered in the oil. The gas also passes through a vaned demister where entrained large liquid droplets are removed and returned to the oil.

Features

• Gas separation section designed to “thin film” entering emulsion for quick gas break out.
• Immersed downcomer piping from gas separation section to emulsion spreader serves as an effective heat exchanger to preheat incoming emulsion and cool the clean oil.
• Deep Freewater Knockout sections below the firebox provides isolation and draw off of free water, thereby avoiding unnecessary heating of water and conserving fuel.
• Emulsion spreader rapidly breaks the emulsion and oil into small streamlets for rapid heat transfer by the hot water washing method and assuring minimum fuel consumption.
• Hot water wash heating method reduces foaming tendencies and prolongs firebox life.
• High capacity firebox furnishes abundant heat and quick response to thermostatically controlled demand.
• Quick adjustable outside water siphon provides easy interface control over a wide range of water and oil specific gravities.
• Adequate surge volume in the clean oil section relieves heading overload in gas separation section eliminating the possibility of liquid carryover with the gas.
• Cool underside of the diaphragm plate between the gas separation section and the settling section condenses vapors released in the heating gas that can be recovered in the stock tank product.  Mixing of hot vapors with cool incoming gas in the gas separation section condenses additional recoverable vapors for additional product volume and gravity conservation.
• The coalescing properties, of a filter section are not required.

Operation 

1. The wellstream enters the gas separation section at the top of the treater. 
2. Inlet diverter deflects the liquid outward against the treater shell where it spreads to a thin film so both free gas and solution gas are released immediately.
3. Oil, water, and emulsion collect on the diaphragm plate and flow through the downcomer pipe to the spreader underneath the firebox.
4. Free water immediately separates from the oil and is discharged from the treater bottom section through an adjustable siphon.
5. The oil and emulsion is broken into small streamlets by the perforated tray spreader and moves up through the hot water section surrounding the firebox.  This action breaks the large part of the emulsion.
6. The water released settles to the bottom of the treater where it is discharged with the free water.
7. Final traces of water are settled in the quiet settling section.
8. The treated oil exits the treater through the oil inlet at the top of the settling section and passes through the oil valve to the storage tank.
9. Warm vapors from the settling section enter the gas separation section through the equalizer pipe and mix with the cool inlet wellstream gas. This causes condensation of the valuable heavier fractions in the gas, which are recovered in the oil.
10. The gas also passes through a vaned demister where entrained large liquid droplets are removed and returned to the oil.

Horizontal Heater Treater

Freewater Knockouts

KW International manufactures a line of special vessels, which are called Freewater Knockouts. A Freewater Knockout is either a vertical or horizontal vessel, which removes a dispersed phase from a continuous phase. The degree of separation depends upon:  

1. The available retention time.
2. The density differential between the two fluids (larger differential means better separation) .
3. The operating temperature of the flowing fluids.
4. The presence or absence of slugging flow.
5. Interfacial area available for separation.

Freewater Knockouts are total liquid knockouts and generally do not have mist extractors. They can be used only on streams where water and oil exist separately and not as an emulsion. The gas phase is re-combined with the oil phase and the water phase is dumped to a wastewater disposal unit. These units are always used in conjunction with other equipment. If the oil phase is not re-combined with the gas and thereby discharged separately the vessel is not a freewater knockout but a three-phase separator.

Both high- and low-pressure Freewater Knockouts are offered. Vessels having working pressures of 150 psig or less are considered low-pressure units. Those with working pressures above 150 psig are considered high-pressure units. Units are available at pressures in excess of 3000 psig.