Statoil... the old Norwegian state oil company. Rebranded as 'Equinor' now.
It doesn't matter what your business is, shareholders demand that you 'sound' green. Having 'oil' in your name is a big no no these days, despite the fact that you make all your money from extracting oil and gas and exporting it around Europe.
The suction anchors above are a simple yet effective anchorage system, so long as you have the correct type of seabed.
I posted this before somewhere, but nice to get it all together.
The suction anchor is just a hollow metal cylinder, open at the bottom, closed at the top. Maybe 4m diameter, 10m tall.
The anchor is lowered to the seabed and gravity will help initial settlement. Then an ROV pumps out water to create negative pressure within the anchor, and the weight of a few hundred metres of seawater does the rest. So long as you have thick clay it's as simple as that. If you ever need to retrieve an anchor, just break the seal at the top and it can be dragged out of the seabed.
The majority of FPSOs and semi submersibles will have an anchorage system using suction anchors. Chains attach the floating structure to the anchors.
Hey wedgie...someday I may talk. Given time and all.
Great thread BTW. Opens the eyes of those that knew not and all.
Cool,best of luck and stay safe.
The CLOV project off Angola. Product from two oil fields collected at one central FPSO.
A lot of work remained to be done on the FPSO, even when in position. It's all about saving time. The barge to the right was an accommodation barge, or 'flotel' to house the workers when off shift. There were too many workers for the FPSO to accommodate. Drilling is ongoing in the distance, to the left.
The flotel alongside the FPSO to transfer workers at a shift change. The Rockwater 1 directly in front of the FPSO was an old diving vessel. The divers were working on a buoyant 'midwater arch' structure designed to provide support for flexible risers. The arch was about 200m down, in approximately 1200m of water. Personally, I can't think of anything more terrifying than working 200m below the sea surface, with another kilometre of water below... rather them than me.
The Eagle laying flexible risers - to connect flowlines on the seabed with the FPSO. The product ascends the risers for processing onboard the FPSO, prior to offloading.
And a couple more of the Eagle, in lay mode...
Crew change for some guys on the FPSO. Occasionally we had to crew change via the FPSO depending on operations and availability of space on the surfers (crew change boats).
These projects get busy towards the end, with all the vessels fighting for access to get their work finished on time. A drill ship next to the FPSO, and the ship on the left with the tower on the back deck would have been commissioning wellheads.
And a very welcome sight... a food container coming aboard! It was always much better if the containers were delivered directly from the supply vessel. Occasionally the containers came to us via another construction boat, in which case all the half decent food would have been nicked. Even when the containers came aboard intact, they guys on the back deck would steal all the biscuits and boxes of chocolate.
This is sort of related and and interesting read/look.
Maybe 3 mins to get through it.
They scale ships the size of buildings to keep $30 billion in goods flowing through one of Australia's biggest shipping hubs each year.
Meet the men and women of Fremantle Port.
https://tinyurl.com/yxxp637c
Thanks to Mendip and all the contributors in this thread. Very interesting info for land-based mammals. Cheers!
The Borealis, a state of the art, DP (dynamically positioned) pipelay vessel. Working on the CLOV project, Angola.
Here preparing to install a manifold (a structure used to connect wellheads to export or injection pipelines and to control product flow). The manifold awaits installation on a barge tied up alongside the Borealis.
Steady as she goes...
And about to start the long descent to seabed in around a kilometre of water...
A video from the Nord Stream 2 pipe laying vessel. Illustrating the processes from the delivery of pipes to the ship, to them disappearing into the sea.
^^
As requested, "posting a video".
Follow the P T Q Instructions
Preparation
Find the video you want to post.
Copy the internet video ID link. Only one video is allowed per post.
TD Site Procedures
Click in the "Quick reply" box, under the last post, the flashing DOS symbol , "awaiting input", appears.
On the line of icons at the top of "quick replly box", At the right hand end, the last but one is clicked on, to "insert a video".
Hover over the icons and there function/usage, for example "insert video", is displayed.
Click on that icon and another dialogue box opens.
In the top line, paste the video internet link, and then the "OK" box.
The video link appears as text, wrapped on code.
Post your reply and the video appears, as in the original source page.
QC
Click to ensure it works.
Voila, you are now a Video Insert Expert.
Note, I always try and use the original youtube page link, some others don't work so well.
Two bottles of Argentinian Merlot, will be appreciated.
Last edited by OhOh; 16-12-2019 at 11:37 AM.
A tray full of GOLD is not worth a moment in time.
^ Thanks. Is there something about deleting an 's' as well?
How about to post an MP4 from a computer? Same as for a picture?
^^^ I worked on Nord Stream 1 a few years ago, but not Nord Stream 2. Each project comprises two gas pipelines around 1200 km long between Russia and Germany, so now around 5000 km of pipeline in total. 48" diameter pipe as well to memory, so Russia is exporting an awful lot of gas.
The view across the back deck of a reel lay vessel towards the end of a pipe lay.
This was a 12inch diameter rigid carbon steel water injection pipeline. I have no idea how they can spool rigid steel pipe onto a spool without it buckling... maybe any metallurgists are on Teakdoor?
For an idea of scale, the yellow wrapped field joints are 12 metres (40ft) apart. The reel would probably carry a batch of around 12 to 15km of pipeline in one go.
The green 'chase' boat behind the lay vessel is to see off any fishing boats to prevent nets getting tangled with the suspended pipeline as it's being laid.
Between the holding reel and departing the vessel, the pipeline goes through a series of work stations for welding on anodes, checking for ovality, etc. Other smaller spools are used to debend the pipeline.
A close-up of a field joint, where lengths of 12m pipe have been welded together onshore. Each joint is numbered, catalogued and documented in case of any future problems or failures. Each weld has been X-rayed and subjected to any number of NDT.
And a few months later... one of the field joints on the seabed during the As-built survey.
Mendip
I think you answered your own question re bending the pipe onto a roll.
They must use a pipe bender to bend it into the right curvature to go onto the roll and then as you said it goes back through smaller rollers/spools to straighten/debend it.
I am sure you have seen a pipe bender that is used for steel 1inch pipe.
they would just need a much bigger version for this 12inch pipe.
^ Not quite, coiled tubing is used daily in the oilfields, CT is ~1" and up to 20,000' long, it is run into wells without any straightening, same as when it is pulled out it will go back onto the reel tightly, the weight below it keeps it in tension. It's all in the composition of the steel, generally HSLA, with a high ksi, not something you would pick up of the shelf, all the steels will be made for the task based on minimum and maximum bend radius, Psi etc. It's all down to the composition of the steel.
Last edited by Airportwo; 25-01-2020 at 01:54 PM.
An example:- As a Rock Doc you have possibly been around when horizontal sections of hole are drilled, when the pipe is pulled out it is still perfectly straight as it's "design" limitations have never been exceeded, the molecular structure returns to its previous state - something like that!
Yes you are correct I have seen some surveys of holes that have very big bends in them but they were drilled with straight drill rods that I would have thought could not possibly bend.
I always thought the bending was made possible due to some slight flew at the joints of rods rather than the rod itself.
I just find it amazing that the pipe that size and wall thickness can bend at all.
Is the pipeline filled in with sea-water when is being laid under the sea level away from the ship? Otherwise, I assume it would float?
The pipeline is laid filled with air... it's made of steel, half inch wall thickness so will never float. Once laid, it will be flooded with inert water (seawater is extremely corrosive) which causes the pipeline to settle down into the seabed.
I dusted off an old excel sheet that I used to use for onshore horizontal directional drilling. If we assume that the pipe is exactly 12" OD and the wall thickness of the pipe is 0.5", no external or internal coating and that sea water has an SG of about 1, then the pipe would sit on the ocean floor with a downward force of 16.4 kg/m.
If the pipe was positively buoyant, I imagine that the engineers would look at either increasing the wall thickness or the pipe or look at concrete coating the pipe before using water. But to be fair I am (was) involved in onshore pipelines and we looked at things a bit different.
Concrete coatings are used for a lot of subsea pipelines, both for anchorage (I assume) and protection against trawling. These tend to be large diameter trunk export pipelines, that are laid by welding sections together onboard a barge/vessel, and usually carry gas. A concrete coating would just crack off if using the reel lay method above.
The reel lay, smaller diameter pipelines have poplypropylene (ppe) coatings which may be several inches thick... I think mainly to provide thermal insulation to keep a viscous product moving.
Pipelines may carry oil, gas or anything in between, or also water. The intended product must play a huge part in design... but this is way outside my area. Pipeline engineering is a whole new sector.
Excellent insight to the many factors of unrolling the pipe, placement and readying it for the oil/gas.
Thanks.
Beside the visual check of each connection is there any other testing (X-ray) before it's laid away?
Can a breakage of the pipeline be repaired under sea? e.g. earthquake, impact of a sunk vessel, a torpedo...
Onshore, every welded joint is x-rayed by a third party sub contractor and the x-rays are then signed off by the project owners consultant. This keeps the inspection and approval out of the main contractors hands. I assume that off shore would be a similar process.
Repairs can be made to damaged pipelines. From a simple clamp that fits over the damaged portion of the pipe to having a full hot tap bypass where long sections of pipe can be replaced.
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