Trunkline Material Selection

[EmmanuelTop]

Design of production gathering system is in progress. There is an issue of material selection for the trunklines, handling 2-phase production stream consisting of gas (0.25% mol CO2 and the rest is Methane) and produced water, having very high Chloride content (over 100 g/L). Operating pressure is 3 barg, operating temperature is 20 degC.

What options do we have? Carbon steel is rejected as there is no redundancy of trunklines, and any failure of material would cause very long production shutdowns.

There are expensive alloys considered (e.g. Alloy 625) but we would like to see if there is something like optimized solution, where less exotic material is used in combination with a sound corrosion protection and management. Can we consider organic coating of Carbon steel, or anything else instead of fabricating trunklines of solid CRA's?

Many thanks in advance.

http://antwrp.gsfc.nasa.gov/apod/astropix.html

 

[EdStainless]

Is this production system truly closed? No oxygen at all?
There are many lower alloy CRAs that have been used for this.
For reliability though I might suggest fiberglass pipe.

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Plymouth Tube

 

[EmmanuelTop]

Internal standards do not allow use of FRP and GRP in production systems containing gas.
The system is Oxygen free, but it containts significant amount of sand resulting in the need for abrasive-resistant material.

Any hint would be appreciated.

http://antwrp.gsfc.nasa.gov/apod/astropix.html