×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

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!
  • Students Click Here

*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

Jobs

Test Separator performance?

Test Separator performance?

Test Separator performance?

(OP)
Could any one advices a best way of Operating a Test Separator in an Oil field with 5 wells producing 20000bopd with much Sand(5lb/bbl)?

RE: Test Separator performance?

Koka11, could you be a bit more specific?

Do you want to avoid filling the test separator with sand?  If so, one solution might be to test the well on a reduced choke, so that the rate is below the sanding rate and then use a programme like Prosper or Wellflo to calculate what the production would be on a larger choke (you will have to calibrate the Propser model with an accurate PI and with tubing pressure loss information - a spinner survery, that kind of thing).  Or just clean out the sand in the separator periodically- it's a test separator, so you could do it without interupting production.

RE: Test Separator performance?

(OP)
Great DrillerNic, we are going to clean it and then come back on production. The thing is the BHP of all wells are monitor by Gas lift and we do believe that a correct Gas lift optimisation must be performed to check the efficiency of wells management. thsi may reduced the incoming sand.

RE: Test Separator performance?

Koka11, I'd suggest you do the follwoing:

1. Clean the test separator
2. Get a static and a flowing pressure survey done on all your wells as a minimum (to make sure you know where you're lifting from).  You should be doing these regularly anyway!
3.  Ideally, get information about the PI and reservoir pressure from each well- a build up test, for example.  Don't assume that the measured PI when the well was originally drilled is OK: scale, tubing fill etc can all alter a well's PI.

This should then let you build your Prosper/ Wellflo model accurately.  Then you test on a reduced choke, match the test production numbers to the Propser or Wellflo model with the test Flowing Tubing Head Pressure and then re-run the model forward on the producing FTHP for allocation purposes.

The main sources of error in this method are:
1. friction losses in the tubing may not be modelled correctly; one way around this is to get a plt log done and then tune the tubing loss correlations with the plt data.

2. the match to the test results: with a gas lift completion, assuming you know things like water cut, flow rate, gas lift rate and gas lift gas composition accurately, you can alter many unknown parameters to get a match (reservoir PI, reservoir pressure, gas lift entry point etc), giving you lots of different solutions.  Knowing some of these parameters accurately (reservoir PI, gas lift entry point for example), means you reduce the number of variables you can alter to get a match.  

This is the main problem with this method: I once spent ages matching every monthly production test done of a well over the previous  2 years, getting a nice consistent story of declining reservoir pressure.  I proposed a GLV changeout to change the lift point to get more production, only to find after the GLV changeout that all my matches had been wrong due to a  shallow hole in the tubing that had been gradually growing so that the lift point had gradually become shallower, and changing the GLVs didn't alter this....

RE: Test Separator performance?

Are you eroding your fittings?

RE: Test Separator performance?

Why don't you use a sand detector like the ones manufactured by Roxar ?(www.roxar.com)
You can then real time optimise your sand free production rate. This is a clamp on device which is quite handy.

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!


Resources