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Salt Water Disposal Piping Material?

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Riley15

Mechanical
Apr 17, 2017
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The service of this pipeline is salt water with a small percentage of hydrocarbons. We are running piping to a salt water disposal well and there is a situation where we need to have a section of metallic piping and the design pressure is 3,500 [psig]. Temperature is ambient 0°F < t < 100°F. What kind of pipe material should be utilized?
 
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The key is the amount of oxygen in the water.

Very low (100 ppb) and you can use Carbon Steel with a reasonable corrosion allowance,

Normal aerated levels and you will need Duplex or possibly even Super Duplex.

Or a lined pipe, either PE or Inconel.

Size and length will make a big difference.

What is the internal well tubing going to be made of??

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Also: If you get a response it's polite to respond to it.
 
Thank you LittleInch.
I am not sure what the internal well tubing is made of. I know that in other areas they are utilizing something called Fiberspar.
 
Fibrespar is a form of plastic or epoxy pipe. Implies you've got a serious corrosion issue with a carbon steel pipe

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.
 
Riley15,
It sounds like this might be a touch outside of LittleInch's wheelhouse. I've designed produced water systems--the pipe that they used to call "Spoolable Composite" (now called "Reinforced Thermoplastic Pipe" or RTP) is an excellent choice. Far better than HDPE (which I find to be a terrible choice because of the limited pressure rating) or carbon steel. In my experience (proposing 24 different gathering systems and designing and building 10 for 8 different companies), no company is going to pay for high-end stainless steel and their reasoning is very good.

Go with RTP wherever your system design calls for 8-inch or smaller. Fiberspar is good, but so are Soluforce and Flexsteel. Look at all 3. I like Soluforce a lot because the arimid fiber strength layer is extremely light weight for the same pressure rating and is pretty inexpensive to handle and put in the ground.

If your system design calls for bigger than 8-inch I would pull an HDPE liner through the pipe while you build it (i.e., build a drag section of 30-40 joints, put flanges on both ends and pull the liner before lowering in)

[bold]David Simpson, PE[/bold]
MuleShoe Engineering

In questions of science, the authority of a thousand is not worth the humble reasoning of a single individual. Galileo Galilei, Italian Physicist
 
Zdas04,

I was just keeping it simple, but I've designed a number of similar systems and agree, Duplex is pretty rare, but the OP specifically stated he or she needs "a section of metallic piping" at a design pressure of around 240 bar.

How long or what diameter is unknown as is the amount of hydrocarbon - could be 5 %.

The RTPs around now are pretty good and the market seems to have consolidated to a couple of suppliers?

I was just asking about the well tubing for information.

Riley15 - You really need to find a materials engineer to give you an answer you can use to go and design and buy something and know what your fluid is and how much dissolved Oxygen and chlorides there are in it.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.
 
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