3 replies to this topic

[roshimessi]

FREINDS

1-for sizing the slug catcher can we use both pipisim and olga or one of them can cover another

it means that do we need to do both steady sate  and transien study ?

2- aft impulse can cover the surge analysis in the system for liquid ,can we do this surge analysis with olga 

which one is better for surge analysis study?

3-how we ca determine the  rate of the chemicals like  wax/asphalt inhibitor and,

anti scale in the system  (inject it in the wellhead)

4- what is the ramp down and well warm up  scenario in olga and when we use this scenario

[ankur2061]

roshimessi,

 

1. PIPESIM can be utilized to size slug catcher based on steady state conditions of flow which is not adequate for transient conditions.

 

2. OLGA can size your slug catcher based on unsteady state scenarios such as "start-up" "shutdown", "ramp-up", "rampdown". The slug catcher needs to be sized for the maximum slug size that can be generated during any of these unsteady state or transient conditions in the flowline / trunkline.

 

3. I have no idea of the capabilities of "AFT Impulse" as far as surge analysis is concerned. OLGA, TLNET, Flowmaster are the software used by many companies to perform surge analysis.

 

4. Normally laboratory analytical tests will provide information such as wax content, asphalt content, suspended and dissolved solids etc. Based on this crude oil analysis, a chemical treatment program should be decided in consultation with the chemical manufacturer. This treatment program will include storage, handling, injection and safety related to the chemicals that are required for treatment.  There are many oilfield chemicals manufacturers worldwide which a google search will reveal. One famous name is NALCO. A link is provided below for NALCO:

 

http://www.nalco.com...d-chemicals.htm

 

5. If you have OLGA, read their tutorials and HELP. If you are still not able to manage, get in touch with the technical representative of OLGA to solve your issues. OLGA is not the simplest of software to use.

 

Hope this helps.

 

Regards,

Ankur.

[paulhorth]

Roshimessi,

 

As well as the scenarios mentioned by Ankur, you need to consider what happens when the pipeline is pigged, which can deliver a large slug of liquid. You also need to consider variation in fluid composition and pressure over the life of the pipeline.

 

Running OLGA and interpreting the results takes a great deal of experience. I have defined and reviewed a number of pipeline transient flow studies, including slug catcher sizing, but have not run OLGA myself, leaving this to the specialists.

 

Paul

[Uguru]

 In addition, if you are working for client like Shell, the Shell Global Solution has developed a spreadsheet in which you input PIPESIM steady state results and you are able to have a good estimate of the surge volume as a  result of ONLY production ramp up. I have personally used it and results compare well with OLGA ramp up studies.

 

In case you want to do detailed analysis for slug catcher sizing, please use OLGA. This will entail detailed analysis including establishing the minimum turndown, ramp up from minimum turndown, slugging analysis, shutdown and start up and pigging analysis. Slug catcher sizing surge volume is selected from the worst case of all analysis.

 

 

 

Hope this is helpful