Wellhead Shutdown Valve for Oil Well

[normf]

Can anyone please advise whether any codes or standards prohibit the use of an API 6D ANSI600#RFF ball valve as a wellhead wing shutdown valve. There is an upstream gate type manual wing valve rated the same as the Xmas tree at 5000psi. A transition piece will be used to get from 2 1/16" RTJ to 2" RFF.

The well is gas lifted but without the gas lift, the well will not flow on its own (it used to - but now watered out). Maximum gas lift pressure is 80barg.

Proposed shutdown system will shut gas lift valve as well as wing valve.

All comments appreciated.

 

[mgp]

Did you look in

API 6A
Specification for Wellhead and Christmas Tree Equipment

See more on page 75 of this link

http://api-ep.api.org/filelibrary/ACF1B8.pdf

regards
Mogens

 

[normf]

Thanks Mogens

I have looked in API 6A. It has specifications for wellhead equipment including the SSV, but it does not provide recommendations on what can be used as the SSV wing valve (termed "secondary wellhead equipment&quot.

I guess what I am looking for is a code of practice or recommended practice that gives guidelines on where the pipeline pressure specification break can be, ie, before the shutdown valve or after the shutdown valve. Keeping in mind that there is an API 6A manual wing valve just upstream.

Cheers Normf

 

[SooCS]

I would look at it in a different aspect rather than the exact words from the cook book.

What is the SSV is to be design for? In this case it is to protect the flowline and the downstream equipment by withholding the pressure from the reservoir like any of the other wellhead equipment. Therefore, it should be subject with the characteristics, quality control and testing requirements such as PSL1, PSL2, or PSL3 as required by the other wellhead equipment.

The ANSI 600# valve inlieu of the 5000# wellhead valve is questionable. What if the master valve or the downhole valve leak? Dont forget the valve cook book allows certain leakage.

If you chose to use the 600# valve, I hope the reservior pressure does not exceed the ANSI 600# MAWP.

 

[Hush]

Usually this is loosely specified or recommended by the jurisdiction you're in. Beyond that its 'best engineering practise'. For Alberta and most of Canada the following guidelines apply:

http://www.psc.ca/arpirponline.html

They might be useful to you as a guideline.

 

[normf]

Thanks, I'll check it out.

 

[SooCS]

never mind my comment. I guest I didnt read your question in full.