These simplest 2 phase cold FWKO’s can operate using the treater’s back pressure control valve. Emulsion and gas are drawn using a “stinger” located in the top of the vessel to provide gas disengaging space.
A free water knockout (FWKO) is commonly used in the oil & gas industry to separate gas, oil and free water, hence the name. FWKO’s can be built as either a 2phase, or as a three-phase separator with its own gas metering.
Free water knockouts, for the removal of free water from emulsion, typically upstream of a treater, are built in heated and cold versions. Both are available in 2 phase (emulsion/gas out the top & disposal quality water out the bottom ) or 3-phase (water, emulsion and gas).
At OilPro, our inventory includes both heated and cold designs. Sweet and sour units are available in 4′, 6′,8′ and 10′ diameters.
As you’ll see on our dedicated FWKO page, we offer a wide variety of options including free water knockouts from Sivalls and can tailor one that meets what you need including skid-mounted and fully houses options.
Why choose a FWKO and why do I need one?
Where large amounts of free water are produced with crude oil such as in secondary recovery or later in life cylce installations, it may be desirable to install free water knockouts ahead of the treating system. Free water knockouts which separate large amounts of free water from the crude oil emulsion offer advantages in reducing the size of treating equipment and the amount of heat and fuel required for the facility. Such measures will have significant advantages in reducing the facility’s overall carbon footprint as less fuel gas is consumed. For cold weather applications, a firetube, located higher up in the system to preferentially heat emulsion over water can help reduce the firetube requirement of the treater, allowing more settling volume for emulsion cleaning.
Free water knockouts are often recommended where the incoming emulsion water cut exceeds 30% of the total volume. Sivalls has pioneered combination units with a built-in free water knockout section, with or without coalescing sections, flowing into a treating section in a single shell.
Free water knockouts from OilPro
Here are several examples of FWKOs from OilPro to give you an idea of our capabilities and what we’ve produced for other customers.
8×30 sour service Free Water Knockout
SKUD- IFWKO – Used 36 x 55 – 320 psi -Sour Service
Sour 8 x 30psi 2.5 mm
A properly designed heated FWKO features a firetube placed high up in the vessel so that no heat is wasted on free water. This improves efficiency and ensures only the cleanest emulsion carries over to the treater.
A heated 3phase FWKO delivered with the firetube installed for future use. Note the optional gas dome, designed to provide additional gas disengaging space.
End-controls systems provide a greater horizontal interface area, and allow for greater interface level control variation which means they can be adjusted to emulsion mixtures throughout the facility’s lifespan as water volumes increase.
Visit our free water knockouts page to learn more. You can also call us directly at +1 403 215 3373 or contact us by email at [email protected] for more details.
Interested to learn about flare knockout? Check out our article How To Choose A Flare Knockout.