Pipeline River Crossing
Pipeline River Crossing
(OP)
How is the required boring depth below river bottom determined for a petroleum pipeline?
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Pipeline River Crossing
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Pipeline River CrossingPipeline River Crossing(OP)
How is the required boring depth below river bottom determined for a petroleum pipeline?
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RE: Pipeline River Crossing
RE: Pipeline River Crossing
Soil bores are taken to determine soil type/water and how deep you need to go inorder to get to a stable enough area in order control bouyant forces.
RE: Pipeline River Crossing
RE: Pipeline River Crossing
RE: Pipeline River Crossing
Anyways i have to do a comparison between HDD and Pipeline subsea dredging (Excavation and Back Filling). The sea bed is shallow so client is asking for a comparison. Anyone having background knowledge?
RE: Pipeline River Crossing
If you are talking about direct burial, or thrust bore, then you are usually thinking more about scour depth considerations, because the geometry of the pipe bending radius does not enter into the formula.
Aside from those considerations, soil type may enter into the decision. Looser soils with rocks should be avoided in most cases which, if rocks and boulders are prevalent, they should force you to choose a different depth.
Don't forget to evaluate the potential for erosion of the setup location and banks while you are at it.
Let your acquaintances be many, but your advisors one in a thousand' ... Book of Ecclesiasticus
RE: Pipeline River Crossing
In a pipe going under a mud-deposited river regularly scouring even more tons of mud from the banks like the lower Mississippi or mid Missouri, where the river bed itself is "solid mud" and almost fluid, how do you get down under the dirt under the river bed? That's got be several hundred feet down in the lower Missip. Worse, the loops and meanders are eventually going to wash out the pipe embed's on both banks aren't they?
Will that problem be different for water (heavier than the river water) oil (lighter than river water) or natural gas (significantly lighter than river water) for the fluid carried? I can see a pipe being brought intact across ther iver and deposited into the bottom muck, but then it would appear you'd need to get the pipe into a "ditch" already dredged in the river bottom - then re-buried somehow.
RE: Pipeline River Crossing
With a horizontal drilling installation, (a bit of a misnomer in relation to thrust boring), you are installing with a drilling rig that has been backed off from the riverbank for what could be several hundred meters or more, and the drilling angle is much more horizontal than vertical, 20 deg from the horizon or something. When you initially curve down to the center of the river, then start curving the drilling path back upward to the surface on the other side. You thread that hole with a pull line. Then you redrill the pilot hole to your pipe diameter as you pull your pipe through.
The distance back off the bank will usually depend on your target depth at the river centerline and the curvature you can safely get with your pipe diameter.
The Mississippi can reach depths of 180 feet, thus you might have to back off a mile to curve down under somethign like that, but there are probably better places to cross as well.
For such major crossings, you will want to take a pretty good number of test cores to short list crossing points from a number of potential crossing points, study the results and take more borings from those shortlisted, until you can finally decide on the final location. The river is probably navigable, so ask the COE for advice at an early stage. You'll need their permit to do it anyway.
Let your acquaintances be many, but your advisors one in a thousand' ... Book of Ecclesiasticus
RE: Pipeline River Crossing
Need a pipeline engineer yet?
Let your acquaintances be many, but your advisors one in a thousand' ... Book of Ecclesiasticus
RE: Pipeline River Crossing
RE: Pipeline River Crossing
Let your acquaintances be many, but your advisors one in a thousand' ... Book of Ecclesiasticus
RE: Pipeline River Crossing
8<)
Nah. The power plant owners tend to get nervous when their steam, oil, and condensate flow distances get longer than 400 feet. Much less 400 yards. Or 400 meters. 400 cubits even.
RE: Pipeline River Crossing
The gas turbine operators don't mind having 1000 mile long natural gas lines though.
Let your acquaintances be many, but your advisors one in a thousand' ... Book of Ecclesiasticus