Leakproof Pipeline 5

[dik]

Is it possible to construct a pipeline that is reasonably leakproof. Does it have to be exposed, buried, or whatever? The actual construction? materials? single or double wall? monitors for leakage? inspection both during construction and in service? cost? any other issues?


Dik

 

[dik]

Thanks, BigInch...

Dik

 

[BigInch]

Pipe-In-Pipe has only been used for short, smaller diameter flowlines (gathering), carrying hot oil, insulated in the annulus, offshore, cool waters .. that I am aware of.

"He's declaring war on the planet itself."- Vicente Fox

 

[dik]

Came across a really neat document on pigging... Delete the attached file link (I don't know how to, but it doesn't load), URL is OK.

https://www.aucsc.com/_aucsc speake... Period 9 & 10 Difficult to Pig Pipelines.pdf

Dik

 

[BigInch]

Watch it. Reading that kind of stuff is the first step in turning yourself into oilfield trash.

"He's declaring war on the planet itself."- Vicente Fox

 

[DerbyLoco]

This is all very interesting. What is the normal life of a pipeline? In my area there is part of the UK natural gas distribution network which I remember being laid in 1968. The pipe is underground and around 24" diameter and judging by the absence of a smell or a big hole has remained safe for all that time. I know it is examined by helicopter on a fairly regular basis for nearby activity as I have heard of farmers being challenged.
The water mains seem much more prone to failure and there have been some major bursts causing serious damage to houses.

 

[BigInch]

Many pipelines (outside the oil field gathering systems) that transport realtively pure, clean, dry corrosion free products, do not have a defined operating life based on their design specification. In my opinion you can assume that othey will last 50 years, and with care, that can be extended to 75 years. Up to and ver 75 years becomes increasingly problematic and I assume only with good care, internal and external coorosion inspection, coating removal and repair as necessary.



"He's declaring war on the planet itself."- Vicente Fox

 

[LittleInch]

Pretty good. One or two things I would change, but pretty minor.

I find it astonishing it took until 1994 for new pipelines to be piggable as part of the regulations and that gas pipelines has liquid in them(!!)

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Also: If you get a response it's polite to respond to it.

 

[BigInch]

I don't think You ever really get all the liquids out, especially if your pipeline goes from Texas to Minnesota, warmer to colder and colder. The water and condensates keep on dropping out little by little as the temperature of the pipe and gas inside decrease.

"He's declaring war on the planet itself."- Vicente Fox

 

[LittleInch]

Derby loco,

Agree with BI - can be a very long time. Gas pipelines can end up being restricted by fatigue and the daily pressure variations causing stress fluctuations, but in most pipelines this is 50 years plus.

The coating has a finite life and is often the first thing to start causing issues and increased number of external corrosion holes which need repair.

One thing though - the high pressure network in the UK is no longer odourised. The odour is now put in at the pressure let down stations before it goes to domestic customers but things like high pressure transmisison lines and pipelines to power stations have no odour.

The helicopter is for spotting infringements on the pipeline easement and any construction work on or close to the pipeline which was not previously notified. Sometimes they use infrared cameras to spot any area of lower temperature which can indicate a small leak as the gas cools a lot from high pressure to ambient air pressure and shows up as a cold spot.

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

 

[dik]

BigInch:

I'm approaching my 70th with 45+ years of experience, and, have never lost my childhood curiosity. I'm a bit of a techno packrat. When I come across interesting 'stuff' I pass it on... always done that. I'm at the end of my career and my main purpose is to act as a mentor for younger engineers. We have a senior engineer in the office and I went to school with his dad.

No fear of becoming oilfield trash; I know my limitations. Last time I did any indepth review was for thermal siphon piles, a suggestion on how to fix a pipeline that suffered from premafrost thaw. Other than that, I've never worked with pipelines... prior to this posting, I had no idea of what a pig was '(sheltered life); I'd never heard the term.

Dik

 

[LittleInch]

"I had no idea of what a pig was '(sheltered life); I'd never heard the term."

That's ok, not many do. Just remember it's a name. If anyone EVER tries to tell you it stands for Pipeline Inspection Guage then immediately discount any other pipeline related material to come out of them.

Some environmental engineer somewhere decided to include it in an ESIA or non technical summary and it's just grown a life of its own since then. It doesn't, it never has and it never will.

/rant over

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

 

[Gator]

I like the pipeline carrot - bunnies are subterranean critters, aren't they?

 

[dik]

Gator.... came across that, just recently... wascally wabbit... just added... carrots interfere with pigs... only wabbits appreciate them...

Dik

 

[BigInch]

Pig comes from the tangled ball of chickenwire that they used back in the day. It would squeel it's way down the pipeline.

"He's declaring war on the planet itself."- Vicente Fox

 

[dik]

just grease it a bit so it slides down easier...

Dik

 

[BigInch]

It was running in a crude oil pipeline. It don't get more slippy than that.

"He's declaring war on the planet itself."- Vicente Fox

 

[dik]

I guessed that much for the grease... didn't know why it was called a pig... other than the "Pipeline Inspection Gauge" meaning. I'll be aware of those guys...

Dik

 

[LittleInch]

The origin is not clear - some say it was when they sent actual pigs to eat their way out of medieval sewers, most refer to the squalling of rubber or leather cups and similar "back in the day".

You need to call them "scrapers" in the Middle East just in case anyone takes offence....



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

 

[IRstuff]

Pipeline Inspection Gadget or Gizmo would sound more apropos.

TTFN (ta ta for now)
I can do absolutely anything. I'm an expert!

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[dik]

IR: Not given the time period... even early in the just passed century.

Just finished that article on pigz and had no idea there were so many different types...

Dik