Construction in various pipeline corridors

[alchemon]

Hello all,

I am looking for opinions on the viability of laying pipeline in various corridor widths. For example, say that the client only wants to purchase a 20' easement without additional work space, that the line is 10", 3' average depth, mostly cross country, and we have roughly 5000 LF to lay. It seems like a tight corridor and may increase construction costs more than the cost to just acquire more temporary (but everyone knows how land is these days). I would assume that to make this work they would have to do something like 1. Excavate trench with equipment wheels/tracks straddling the trench 2. Weld up line 3. Equipment 2 comes straddling the trench and then lifts line and lays into trench and then begins backfilling.

What is everyone's opinion on the increase of production if it were increase to 30' or 40'.

 

[HTURKAK]

For the base case , 20' ROW ( or permanent corridor) seems O.K. But, for ‘construction corridor’ , should be minimum 60' or more..
I will suggest you to conduct constructability study to fix the width.

The following doc. is useful for constructability study ..

https://vebuka.com/print/1401211939...7/Onshore_Pipelines_The_Road_to_Success_Vol_1

 

[LittleInch]

At little more than 6m this is "Street works".

Productivity for 20m would probably be 70 to 100% better.

Lots of double handling of back fill and barely any room to work or get access.

Might need to weld up then pull in long lengths in a leap frog fashion.

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

 

[1503-44]

Only 2X faster?

Statements above are the result of works performed solely by my AI providers.
I take no responsibility for any damages or injuries of any kind that may result.

 

[LittleInch]

It's only 1500m of pipe,... Maybe three times?

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

 

[1503-44]

Good point. The cross country aspect he mentioned stuck in my head. Only 5000ft makes it much worse.

In the case of only 1 mile long with in and out access only at each end, 20ft would necessitate that you do the construction sequence one by one. If you excavate the trench and stockpile on one side, you've only got 10 feet to move around in at most. That probably means welding in the ditch, because you can't weld it alongside with enough room for some trench edge distance and still have curvature space and room for sidebooms to come in and lower it afterwards. Alternative is removal and temporary storage of ditch spoils elsewhere and then hauling it back in for backfilling later. Not great. Probably hand welding. Radiography. All in the ditch. Or weld up at one end and pulling in the string from there.

I could go with minimum 3. But up to 4 or 5x just because its a short length, yet you have to recover the same mobilisation expenses for 5000 ft as you do for a much longer pipeline. Instead of being able to spread those costs over say a more typical length of 10 to 20 miles minimum, you only have 5000 ft and that makes for a pretty high price per foot. As I always say, the biggest cost of a pipeline is that FIRST ONE FOOT. All the rest only make it cheaper by the mile.

Statements above are the result of works performed solely by my AI providers.
I take no responsibility for any damages or injuries of any kind that may result.

 

[alchemon]

Hello all,

Thanks for the responses. To give some additional details, yes we are talking about a 20' corridor to construct the pipeline (aka permanent and temporary workspace).

It may seem confusing, but the 20' was acquired many years ago but pipeline never installed. Client is ready to install in 20', however, the landowner is a public agency that is not known for quickly granting additional easements (for workspace). We will have access to the corridor off a public road so that is not a concern, but the entire corridor will be roughly 20' wide by 5000' long. Slow moving and expensive to install, but potentially advantageous from a schedule prospective (time is money after all).

 

[LittleInch]

The best way I've done it for such a limited width corroder is to string the pipe, weld on the surface, test, field joint coat etc then lift it onto a set of rollers. At the end of your section excavate the trench casting the dirt to one side. If there's too much then you might need to excavate, turn 180 degrees and trailer it away as you move down the trench. then put a few rollers in the trench and pull you section in. Then start backfilling leaving a bell hole at both ends for tie in of the next section.

Then do the same over the section you've just installed. You should be able to do at least 100m and possibly more if its a straight line dig.

And have a one way system.

But yes probably 2-3 times longer / costlier in terms of installation

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

 

[1503-44]

I would agree. "Or weld up at one end and pulling in the string from there."
However long you can fabricate in the space available, or however long a segment you can pull.

Statements above are the result of works performed solely by my AI providers.
I take no responsibility for any damages or injuries of any kind that may result.