Contact US

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Finger Type Slug Catcher Design

Finger Type Slug Catcher Design

Finger Type Slug Catcher Design


Can anyone point to a reference which details how to design a finger type slug catcher

RE: Finger Type Slug Catcher Design

The trick is not so much the design of the catcher as it is estimating the volume it should contain and how often it can be disposed of.

Several ref here.

--Einstein gave the same test to students every year. When asked why he would do something like that, "Because the answers had changed."

RE: Finger Type Slug Catcher Design

It seems like this post is referenced to petroleum engineering. You should move it to a relevant forum.

RE: Finger Type Slug Catcher Design

There are some guidelines written by companies like Shell and ExxonMobil, but no generic guide that I know of.

A finger type slug catcher is really a series of first stage separators so the art is to first equally distribute the incoming three phase fluid, often by dividing equally one to two to four or a header.

Then allow the gas to go off the top. Hence gas velocity at that point should be <5m/sec to avoid taking all the liquid with the gas...

Storage volume is an estimate. Basing it on worst case (usually the pigging case) would lead to a massive set of pipes so it's usually a compromise, but always leave room and flanges so that you can add pipes. Fluid composition changes over a field life so you can have more liquid later on so might need more fingers. Also if you have some surge capacity for dealing with the liquid that would help a lot.

The bottom will end up with water so have a water line and a HC line to your process plant. The interface between the two can be corrosive so make sure you internally coat the fingers and also allow flanges on the bottom header to clear out all the dirt and dead rates etc which somehow end up there.

Angle is up to you but 10 degrees rings a bell. too steep and the inlet ends up miles in the air.

These type of slug catchers are interesting to design as there is no one answer and in reality the input data is usually a bit conservative from the analysis software so don't sweat the last degree of accuracy. In the end if its too small they just add a few more fingers or have to slow the start ramp rate or flow down a bit.

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

RE: Finger Type Slug Catcher Design

That's quite a neat design alright - A lot depends on how much space you have and the particular gas and liquid flows.

Slug catchers are never intended to be super effective at gas liquid separation, the intent is just to stop the first stage separators from getting overwhelmed with liquid flow from either start up, ramp up or pigging. Given that the flow of liquid can vary hugely for the same gas rate, sometimes up to 100 times the instantaneous flow over a 5 second period, then it is just a bit of judgement as to how to design these things, but always leave room to add another couple of fingers in case reality doesn't turn out the same as the theoretical calculation.

At the end of the day, if the slug catcher doesn't work as well as you want then the first stage separator just trips on HH level and the plant stops for a little while. The designer then just says that the composition and flowrate of the fluid coming in is different to what the design basis said....

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

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members! Already a Member? Login


Close Box

Join Eng-Tips® Today!

Join your peers on the Internet's largest technical engineering professional community.
It's easy to join and it's free.

Here's Why Members Love Eng-Tips Forums:

Register now while it's still free!

Already a member? Close this window and log in.

Join Us             Close