API 14E sand free erosion velocity

[MortenA]

Gents,

The formula for calculating erosional velocity in API 14E is for "sand free fluids". What is the threshold value for "sand free"? I have heard a number like <1 lb per 1000 BBL i dont know where it comes from and i cant seem to find it in API 14E.

Best regards, Morten

 

[EmmanuelTop]

"Sand-free", like "free of sand". Theoretical case.

Dejan IVANOVIC
Process Engineer, MSChE

 

[EdStainless]

It depends on the sand. In general less than 1 lb/1000bbl is considered sand free, at this level you do not have to separate it or do anything special.
In wells that are free from; corrosion (or well inhibited), sand, and propant many people use c = 125, 150, or even 200.
The harder and more angular the sand is then the more conservative you need to be.
At the same time you need to think about restrictions (choke, valve, elbows) where conditions will be worse.


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P.E. Metallurgy, Plymouth Tube

 

[MortenA]

@Ed, have your seen a reference ever?

 

[LittleInch]

The attached is a freely available document and is the best reference material I've ever come across when it comes to erosion and its issues.

There are simply too many issues to be able to state 1 lb/ 1000 bbls is OK, but 2 isn't.

Composition of the "sand", velocity, turbulence, material all play a part.


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

 

[EdStainless]

When 14E was re-written in the 90's there were a lot of papers published by various oil companies talking about their experiences.
Get a bunch and read them.
My experience is mostly with pumps, and our velocities were a lot higher.
Given that 1 bbl of oil is roughly 300lbs, then we are talking about 3ppm sand.
We always saw issues at 15ppm (5 lb/1000 bbl), and depending on the sand we would see issues at 5ppm.

One thing to keep in mind is that a lot of modern propants have ceramics is them and they can be much more abrasive than sand.

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P.E. Metallurgy, Plymouth Tube

 

[MortenA]

@Ed, on say onepetro?

@littleinch, i know this and also use DNV-RP-501 that actually takes this into account but "everybody" wants me to do API14E also and then tell them how little is "free" So unless my production is below 10,000 bopd then 1 lb/1000 bbl is in the high end. I think i will try to discuss this with the sub surface guys

Best regards, Morten

 

[LittleInch]

OK,

Then tell them sand free means sand free - like none. 14E is used too broadly IMHO

Or tell them that if solids are present in any shape or form then the c factor is 50. However when you use xxx the velocity can be much higher.

As I'm sure you have, when I read API 14E I don't see the hard numbers everyone quotes and it's all rather vague and woolly, which of course Flow Assurance doesn't like...

The one I hate is when people quote section 2.3a as an ultimate fluid velocity (15ft/sec) without reading the entire para which is all about flow from one pressure vessel to another....


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