2 replies to this topic

[vnpetroleum]

Hi all,

I am working on the gas brown field relating to topside piping adequacy asssessment. The topside piping was designed to handle 15 MMSCMD gas continously, with the limit of topside pressure not lower than 85 barg (due to erosion limit and noisy limit). For 16MMSCMD intermittently, topside pressure not lower than 88 barg

The engineering calculation used C = 135 (API-14E) (empirical unit) to verify the topside adequacy. This piping is Duplex SS, employing corrosion resistant (cladding).

However, the reservoir pressure delines until now, we are facing to the pressure limit. A request is to re-verify the minimum topsides pressure limit.

I tried to find some other standards applied for multiphase piping sizing,
- Technip: v <= 23 m/s
- Norsok: C = 150 (empirical unit)
- Shell: v <=20 m/s

Please let me know your experience in piping adequacy assessment. Which standards do you use? Which methods do you use to monitor the piping integrity (thickness, erosion...)?

Many thanks - vnpetroleum

[ankur2061]

vnpetroleum,

Refer my blog on erosion and the link provided in that for "C" values for 2-phase flow erosional velocity calculation based on the MOC of the pipe.

http://www.cheresour...on-due-to-flow/

Also refer the attached article. This is an SPE article about erosional velocity on offtake from gas wells. Although I would not recommend using the erosional velocities or "C" values provided in this paper you still can consider a "C" value of 350 for Duplex Stainless Steel if your gas is solids free.

Regards,
Ankur.

Attached Files

•  SPE_Paper_Erosional_Rates_Velocities.pdf   279.69KB   440 downloads

[vnpetroleum]

Dear Ankur,

Your article is so interesting.

Yup. Gas from our wells is solid free for Duplex SS. You recommend C = 350; it is so very high compared with the existing engineering calculation. I am trying to find a good justification to convince the partner with using C = 350. This C value will affect the limit of gas production. Now, we cannot produce gas higher than 15 MMSCMD if the topside pressure is lower than 85 barg (using C = 135). With new C factor, we can do it without the erosion limit.

Many thansk for your response - vnpetroleum