FPSO - Key Loads Basics 2

[NickParker]

Im an Electrical Engineer and new to Oil and gas. The below listed are some of the main loads of the FPSO which I got to know from the Key One line diagram. I would like to know some basics of the below loads like what does it do? when does it operate? sequence of operation? which of the load operate during normal production? which of the load must run during non production? etc?
Can any one help me out or point out to the correct document on the internet to refer to..

1. Sea Water Lift Pump
2. Produced Water Recycle Pump
3. Cooling Medium Pump
4. Water Injection Pump
5. Water Injection Booster Pump
6. HP Feed Pump
7. Produced Water Re-injection Pump
8. Injection Gas Compressor
9. Main Gas Compressor
10. CO2 Gas Compressor
11. VRU Compressor
12. LP Service Pump
13. Heating Medium Pump
14. Crude Oil Pump
15. Electro Static Treaters
16. TEG Reboiler Electrical Heaters
17. TEG Lean Circulation Pump

Thank you!

 

[LittleInch]

I'm making a few assumptions here, but basically everything you list is needed when you have flow coming up the well bore into the FPSO and not needed when the wells are shut in.

It all operates together as a combined process.

The only "optional" thing might be what looks like the seawater injection system and water injection.

In a crisis I guess they might be able to flare the gas instead of reinjecting it, but that's not normally permitted nowadays and is bad economics.

In very simple terms.
As the Crude oil / gas / water mix comes up from the reservoir, the components are separated in one or more separators.
Then you end up with produced water ("produced" from the reservoir), Crude Oil and gas (methane plus other gases)
The produced water is then re injected into the reservoir with reinjection pumps
In this case it looks like there is also seawater injection on top to maintain reservoir pressure to replace the Crude oil removed.
The Crude oil stream goes through your electrostatic treaters to help remove even more water and is then dumped into the tanks on the vessel ready for export via pipeline or tanker (so your crude oil pump might be intermittent - depends on the field)
The gas looks like it is then dehydrated in the TEG system which strips the water out of the gas so that you can either burn it in the gas turbines or reinject it back into the reservoir. The TEG system then heats up the water laden TEG, boils off the water then returns the now "lean" (i.e. not much water) TEG back in a continuous loop.

Try getting a process schematic or PFD and follow each line through.

Does that help?

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[TiCl4]

I'm not in the O&G industry, but shouldn't your question be directed internally? Most companies have basic data reports or process narratives that describe the general process addressed. More specific knowledge of process control sequences, startup/shutdown, standby, etc will only be found either in company-specific documentation or by questioning knowledgeable individuals who work with that process.

Can any one help me out or point out to the correct document on the internet to refer to..

LI provided a (from my outsider's view) fantastic description of the general process, but I would be very surprised if these setups were so modular as to be able to find all your required information online.

 

[LittleInch]

A nice conversation with the Process engineer will be worth it for sure, but try finding the PFD and the process description to get you the specifics of your FPSO.

One thing to watch on FPSOs is that they often get designed for one filed, that field dries up and then they get moved to another one where the oil and gas properties are different and hence the equipment gets over loaded or not used.

Or the field changes over time so you end up with more water than you can cope with and not enough gas to run things properly.

On the electrical side they often still use the ships electrical system which is old and knackered and often a strange voltage.

I don't FPSOs much to be honest. Sounds great, but difficult to design and operate.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[EdStainless]

LI is correct, while a few of these services may intermittent if the field is producing you need to be able to run all of them at once.
Is this being done using an old tanker? This is common and real PIA.
Shipboard service isn't enough to support all FPSO services, so you end up with multiple systems.
You need a lot more detail.
Most companies that do this have standard descriptions and methods.

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P.E. Metallurgy, consulting work welcomed

 

[georgeverghese]

All will be running during normal ops, but #12 doesnt ring a bell with me - what LP service is this ? LP Flare service pump?
Many of these would have standby inline units. Typically N+1. Some of the larger units may not have standby, like 8,9,10, 11,4,5. Ask the plant process engineer for details.