3 replies to this topic

[kasri]

dear all,
i had seen a three phase separator in which gas blaketting was given.They mentioned blanketting is due to Low GOR in later years.
I dont understand, if gas not available what will happen ,why we need to pressurize that means maintain some pressure in the separator.
if i locate the separator at height to give static pressure to d/s equipments means whts the need to maintain pressure in the system by blanketting eventhough blanketting doesnt aid any separation, because Liquid/liq. separation is mainly based on retention time.
please clarify my understandings.
regards,
kasri

[latexman]

What does GOR mean?

[ankur2061]

GOR stands for Gas-Oil-Ratio of the incoming stream to the 3-phase separator.

Kasri,

I have never seen a 3-phase separator being provided with a continuous gas blanketing. When the 3-phase (gas-oil-water) mixture enters the separator it flashes at the pressure being controlled in the separator. The gas and a small amount of entrained liquid droplets are then sent for further separation / treatment. The oil and water separate out based on gravity separation (Stokes Law) and retention time of the separator.

I have seen start-up purge gas connections to separators which serve the purpose of purging the separator to purge air from the system but not a continuous gas blanket. Is there an operating manual for your separator? It might mention the purpose and the operational steps for the gas blanket.

In the upstream oil and gas field gas blanketing is mainly provided for large tanks such as FWKO (Free Water Knockout), Skim tanks and produced water tanks with very low gas blanket pressures of the order of 50-100 mmWCg to preclude air from the system.

Regards,
Ankur.

[kasri]

Dear Ankur,
In this separator they provided pressure transmitter from which signals goes to pressure control valves( one valve in flare line & one valve in gas blanaketting line).
If the pressure exceeds the set point the valve at flare line opens , if the pressure in the system lower than the set point the blanketting valve opens to maintain the pressure and they mentioned blanketting is due to later stage there is no gas in the field and to maintain the pressure in the system.
My doubt is if there is no gas in the production and only oil in future means whts the need to provide blanketting, blanketting not going to aid separation.If I locate the separator at height to give postive pressure to the downstream equipments means whats the necessity to provide the blanketting in the system.
Please clear my doubts.
Regards,
Kasri