Lateral piping design downstream of Choke plate 1

[lgq]

Is there a paper or research out there to determine the best design for lateral piping out of a natural gas storage field well? Downstream of the choke (basically an orifice plate), at high inventories, the downstream face and flange are being eaten up, apparently from eddies forming or turbulence. How can the piping be optimized to prevent this from happening?
The upstream face looks ok. Should we step the pressure drop, increase pipe size, decrease pipe size, change choke design, ? Seems like we need to achieve laminar flow directly out of the orifice. Also, will the action of the gas turbulence cause this or does there have to be sand present to cause damage?

 

[dhayes]

One solution might be some sort of surface hardening, such as nitriding. This is done with downhole tubular equipment to prevent erosion during frac stimulation. What are the velocities downstream of the choke? You might consider larger piping to reduce the velocities, or take the pressure drop immediately upstream of a separator, so that any liquids that are condensing can be separated out of the stream.

 

[Chazadd]

I argee with dhayes you need to consider a velocities and pressure drops.
Refer to API14E for info on errosion velocities Ve=constant/root(mean fluid density). The constant ranges from 100 to 250 depending on the strength of materials involved and if it is continuous or intermittent service . However the limitations are the fact that this does not consider the effects of sand on the system.

Why not monitor the sand content?
If sand is more than say 10lb/1000bbl oil (yes i do know you said a gas well). Then the flow should be limited to approximately 14m/s.

I advise you to speak to CCI Severe Service control valve manufacturer. There valves step the pressure down so as not to enter into the cavitation region, hence not damaging the
valve body and flange. They came to my company and did a good days seminar, which impressed me. Always worth a look. Think the guy even said that for some valves they will give you it for free if it doesn't last as long as they say it will.

Regard
Chaz